Pressure vessel for compressed air operations

Abstract

Systems, methods, and apparatuses related to localized excavation using compressed air are disclosed. A pressure vessel may include a working chamber having an inner space for personnel and equipment, and an opening on the working chamber that surrounds an area for excavation of a second passageway. The main passageway may be a first excavation path and the second passageway may be a second excavation path in a direction different than the first excavation path. A sealing frame, secured to the pressure vessel, forms an airtight seal with the main passageway when positioned around the area for excavation. A load reaction structure stabilizes a position of the pressure vessel in the main passageway and maintains the airtight seal during pressurization. A controller may manage pressure within the pressure vessel during excavation operations.

Description

Docket No. 131682.010005PRESSURE VESSEL FOR COMPRESSED AIR OPERATIONSTECHNICAL FIELD

[0001] The present disclosure generally relates to tunneling, and more particularly, to ground excavation systems, apparatuses, and methods for using the same.BACKGROUND

[0002] Tunneling methods and boring machines enable the construction of underground passageways for purposes such as transportation, utilities, and mining. Traditional tunneling techniques are often labor-intensive, dangerous, and expensive. Manual excavation, for example, often requires the use of explosives and other techniques that present inherent safety risks for tunnel workers. Tunnel Boring Machines (TBMs) are specialized and typically custom-built for mechanized tunneling. Many tunneling techniques also require ground treatments to an area above the excavation site to stabilize the ground and prevent water inflow control. However, ground treatment is costly, poses environmental risks, and often requires compliance with extensive permitting and regulatory requirements.

[0003] Cross passage excavation relates to the construction of passageways between two or more tunnels. Many tunnel construction projects, especially rail tunnel and road tunnel projects, require a cross passage at certain locations or distances throughout a main passageway to provide a safe means of escape from one tunnel to the other. The spacing of cross passages varies from country to country and is usually dictated by a combination of risk analysis, a review of best-practices, and fire regulations. In North America and Australia, for example, the spacing of cross passages for twin rail tunnels is 800 ft (244m). In the United Kingdom and Europe, spacing may vary from 1000ft to 1600ft (300m to 500m). For twin road tunnels, the cross passage spacing may be less. In the USA, the spacing may range from 500ft to 650ft (150m to 200m), and Australia the spacing is 394ft (120m).

[0004] Cross passage excavation presents additional challenges since cross tunnels often require different techniques and considerations compared to main passageways. For example, a tunnel boring machine used to form a main passageway may not be applicable for cross passages, due the smaller size and orientation of the cross passage. Such tunnel boring machines, w hich excavate in a forward direction, may be longer than a w idth of the tunnel and w ould not fit within the main passageway w hen oriented in the direction of the crossDocket No. 131682.010005 passage, especially if the tunnels are less than 7m in diameter. If a main passageway tunnel boring machine could be used for cross passages, the main passageway excavation would need to be stopped for the duration of each cross passage excavation, likely leading to delays.

[0005] Construction of soft ground tunnels can be challenging, as the ground is usually unstable and often not self-supporting, thus requiring specialty7techniques in many circumstances. Some soil types, such as clay, can be stiff and cohesive and require little primary support. Such soils may also have low permeability7and therefore possess less ground water challenges. When tunnels are constructed in soft ground, for example, silts, sands, less cohesive, or non-cohesive materials, combined with an alignment that is under the water table, the construction technique is very complex. Such soils are often extremely unstable when saturated, so collapse is very likely, and since permeability is very high, ground water control is very difficult.

[0006] In 1818, Brunel patented the first tunneling shield, which assisted in constructing tunnels in soft ground. The shield was rectangular. Variants of the soft ground shield evolved, and the circular shield was recognized as having advantages with fabrication structural properties and allowing a more efficient tunnel support lining system. It wasn't until 1869, however, when Greathead patented and constructed a circular shield and used Compressed Air to pressurize the soft ground, to prevent ground water ingress and also helped stabilize the soils.

[0007] In the 1970s, most subaqueous soft ground tunnels in non-cohesive soils continued to be constructed using shields and compressed air. In the meantime, rock tunnel boring machine designs made some advancements, and rotating cutterhead wheels at the front of the boring machines replaced the manual compartmentalized digging portions in the shield. Cutterheads were also added to soft ground shields.

[0008] In the 1970s, a major shift in soft ground tunneling occurred, where pressurized TBMs were developed, and two techniques are now used to construct most subaqueous soft ground tunnels. Thus, the method of constructing tunnels using compressed air became obsolete. The two techniques used in pressurized TBMs are Earth Pressure Balance (EPB). or Slurry. With the advent of pressurized TBMs, came the need to install gaskets on the segment tunnel liners to seal the environment within the tunnel from the pressurization formed by the TBM, and the need to seal the rear part of the TBM at the Tail Shield where the segmental tunneling is constructed. Both pressurized TBMs maintain a pressure in front of the TBM in the excavation chamber where the rotating cutterhead operates and contain sealing systems at the main bearing of the cutterhead and in the Tail Shield, to isolate theDocket No. 131682.010005 tunnel which remains in “free-air."’ The pressurized mode is commonly referred to as “Closed Mode.” The EPB technique injects soil conditioners, such as foam, into the excavation chamber, and through machine operation, the pressure is maintained to "balance’ the pressure from ground water and soil. The Slurry technique uses a pressurized slurry circuit which maintains a set pressure to balance the pressure from ground water and soil, whilst the slurry circuit carries the excavated spoil. The slurry usually contains bentonite, which has advantageous rheological properties and can help stabilize the excavated face of the tunnel in front of the TBM. On the surface, in a Slurry Treatment Plant, the spoil is separated from the slurry', and slurry' is treated to ensure the bentonite content is sufficient to maintain the special rheological properties. The density and viscosity of soil with an EPB technique is high and resembles stiff concrete, whereas with the Slurry technique the density is quite low, and soil is transported in liquid form. A variable density shield is able to operate in both EPB and Slurry' mode, where it can vary' the density7and viscosity7from an EPB state to a Slurry state, or somewhere in between. Other TBM configurations exist which can operate in a non-pressurized mode (e.g., an Open Mode) and then be converted to operate in either of the pressurized modes it is designed for. All closed mode TBMs have gasketed segmental tunnel linings, usually made of precast concrete, but some tunnels have fabricated steel segments.

[0009] The compressed air technology was not totally lost when the soft ground TBMs changed. Most pressurized TBMs have a compressed air system, similar to what was used in the olden days, but configured differently. When the TBM cutting tools require maintenance, compressed air is used, but instead of pressuring the complete tunnel, like the olden days, compressed air is piped in the tunnel and fed into the excavation chamber at the front of the TBM and is used to create a safe pressurized working environment in front of the TBM cutterhead to allow maintenance works to occur. Most projects which utilize pressurized TBMs, have a compressed air supply system in place, compressed air controls and have a team of doctors, medics and trained staff able to perform the Hyperbaric work. To note, there are a small number of very large TBMs (16m diameter + / -) which are fitted with “accessible” cutterheads where the cutterhead is so big that maintenance workers can w alk thru the cavities in the structure of the cutterhead and change cutterhead tools in “free air” via individual cutter tool isolation gates / locks. Nonetheless, most of these projects with accessible cutterheads will have a compressed air system, and hyperbaric plans in place so that compressed air work can be conducted. Accessible cutterheads are difficult to make for smaller diameter TBMs.Docket No. 131682.010005

[0010] Most tunnels constructed for rail or road require cross passages interconnecting the tunnels mainly for fire safety, where people can escape to the other tunnel, when a fire occurs. The quantity and spacing varies for both road and rail tunnels, and are not consistent from country to country, but there is some consistency. An example is that for metro train tunnels constructed in cities, the cross-passage spacing must be no more 244m apart (800ft) in Australia and USA, and for road tunnels in Australia, the cross-passage spacing must be no more than 120m apart.

[0011] Additionally, many traditional cross-passage excavation techniques require ground treatment in the zone of excavation. Ground treatment, as noted above, is expensive and poses environmental risks and regulatory hurdles. Each cross passage will also have unique challenges and various ground material, pressure, passage size, and direction considerations. As a result, cross passage construction costs tend to increase as both the length of the main passageway and the number of required cross passages increase.

[0012] In various examples, when the tunnels are in sub-aqueous soft ground, the construction of the cross passages is difficult. Since the soil is unstable, some kind of ground treatment must be performed at each cross-passage location to ensure the treated ground is stable when a portion of the tunnel liner is removed in the location of cross passage. An example of ground treatment is jet grouting, chemical grouting, deep soil mixing and ground freeze. In most cases, the ground treatment is a costly and time-consuming exercise, so projects usually expedite the ground treatment ahead of the tunneling and perform the ground treatment works from the surface. Performance of some ground treatment from within the tunnel is possible, but usually this method is not chosen as it adds the ground treatment duration to the critical path of the tunnel operations.

[0013] Since the spacing of the cross passages is quite close, some projects may have 30+ cross passages to treat, and this work can be problematic if the tunnel is under an urban environment, where houses, buildings, lakes, rivers, ocean or bridges are present, where land access is sensitive, or access to the site is difficult or head room for drilling rigs is not favorable.

[0014] Ground treatment is also quite expensive, and it is common for approximately 50% of the cement injected into the soils for jet grouting to be wasted. Jet grouting is one of most commonly used ground treatment methods for soft ground tunnels and consists of injecting cement into the soil to form a series of overlapping ground treated columns. Successful jet grouting relies on a design, column spacing and good soil properties, where the soil must be fairly weak, so it can be eroded by the high-pressure jet of groutDocket No. 131682.010005 spinning from the drill rig. If the soils change or there are layers of “non-erodable"’ soils (such as stiff clays), then the desired diameter of a column of treated ground is not achieved. Boulders and buried foreign objects can also prevent the column from being formed adequately.

[0015] Ground freeze is often used as a last resort, when other ground treatment techniques are not possible, or not feasible. Ground freeze can be conducted from the surface or from within the tunnel. Ground freezing is probably the most expensive ground treatment process, but when tunnels are under vast stretches of water, or access from the surface is problematic, then it may be the only choice. The other issue with ground freeze, is that it is a time-based treatment. It may take many weeks to drill and establish the freeze pipes and then take 6-8 weeks for the ground freeze to form. If the ground freeze if formed prior to tunneling from the surface, it may be necessary to remove some freeze pipes which are in the way of the TBM. With some freeze pipes removed, the ground will still remain frozen, but over time, the complete integrity of the ground freeze may be affected. If the ground freeze is conducted in the tunnel, then the drilling operations may be difficult to complete in the tunnel whilst tunnel supply transport vehicles are travelling in and out of the tunnel. For metro train tunnels, it is quite common to begin the cross-passage construction works once the TBMs have arrived at one of the metro stations, whereby the tunnel supply equipment for both tunnels can be fed through one tunnel, and the other tunnel can have minimal traffic and be dedicated to cross-passage construction works.

[0016] As explained, the use of ground treatment for cross passages has many challenges, and sometimes, the ground treatment does not work, and / or ground collapse occurs when the cross passage is constructed, leading to injury' or death, and damage and delays to the tunnel.

[0017] For large tunnels, in the order of 14m internal diameter, which are usually road tunnels, the cross-passage size and location in the main tunnel, can often allow for a micro-TBM to be used. The capital expense and complexity7of the method is high, but the risks of ground collapse are avoided, and this method can also be completed with no ground treatment, so there can be significant savings which can offset the high capital expense of the equipment. In most cases, the micro-TBM uses a slurry7system to excavate the tunnel, and the micro-TBM is jacked forward by a tunnel lining. A reinforced structural collar (and seal) is required at the junction of the main tunnel and cross passage, on both tunnels. When a cross passage is excavated in treated ground, in free-air, the excavation is enlarged at the junction to form the collar, on the outside of the tunnel lining (an external collar) but with aDocket No. 131682.010005 micro-TBM, there is no way to do this, so an internal collar must be installed. This internal collar may interfere with the dynamic envelope of the road traffic, and it may be necessary to increase the diameter of the tunnel to compensate for this internal collar. It should be noted that the apparatus located in a large diameter tunnel does not prevent the tunnel supply transport vehicles from passing.

[0018] When the tunnels are smaller in diameter, the geometry and alignment of the cross passages with the main tunnel makes the micro-TBM concept difficult or not possible. For example, it would be difficult to configure a micro-TBM concept for a metro tunnel, of diameter 7m + / -. In some cases, the invert of cross passage is aligned with the top of rail in the tunnel, and a portion of the excavation of the cross passage is below the tunnel. In addition, a lot of tunnels have low points, and require sump structures in the cross passages to capture the water drainage. The micro-TBM concept cannot construct all of the sump crosspassage structure.SUMMARY

[0019] Systems, methods, and apparatuses for localized excavation are disclosed. In an example, a pressure vessel may be positioned in a portion of a main passageway, the pressure vessel may include (i) a working chamber comprising an inner space for personnel and equipment, and (ii) an opening on the working chamber that surrounds an area for excavation of a second passageway. The main passageway may include a first excavation path and the second passageway may include a second excavation path in a direction different than the first excavation path. A sealing frame, secured to the pressure vessel, may form an airtight seal with the main passageway, when positioned against or around the area for excavation. A load reaction structure may stabilize a position of the pressure vessel in the main passageway and maintain the airtight seal during pressurization.

[0020] In an example, the load reaction structure may include at least two ring beam frames surrounding a perimeter of the pressure vessel, and a set of supports connecting the at least two ring beam frames. The load reaction structure may also be secured to an exterior of the pressure vessel.

[0021] In additional examples, the systems, methods, and apparatuses may include at least one airlock extending longitudinally from an end of the pressure vessel. A first airlock may be a personnel lock and a second airlock may be a material lock. A safety door may be provided between the pressure vessel and the at least one airlock. In examples, the safety'Docket No. 131682.010005 door opens inwardly towards the pressure vessel. According to various examples, the localized excavation apparatus may have a rounded cross-section, such as an ovoid crosssection. The at least one airlock may have a rounded shape, such as a cylindrical shape with a circular cross-section. The pressure vessel may also have a cross-section having less area than a cross-section of the main passageway.

[0022] In examples, the position of the pressure vessel in the main passageway maintains a space in the main passageway for at least one of personnel, ventilation, utilities, drainage, service pipes, and equipment. Additionally, the position of the pressure vessel in the main passageway does not prevent transport past the pressure vessel, in the main passageway, of at least one of personnel, ventilation, utilities, drainage, service pipes, and equipment.

[0023] Embodiments may further include a mobility system to propel the pressure vessel along a pathway in the main passageway. The mobility system may include at least one of a set of wheels, treads, a jacking system, a rail, and a track. For example, the mobility system may be a self-propelling system. In examples, a controller may manage pressure within the pressure vessel during excavation.

[0024] At least one platform positioned on or secured to an exterior portion of the pressure vessel. The sealing frame may form an airtight seal by attaching to a corresponding frame on a perimeter of the area for excavation. In various embodiments, the area for excavation comprises at least one of: a tunnel lining, a shaft lining, and a station lining. The main passageway is at least one of: a tunnel, a shaft, and a station. The second passageway may be at least one of a cross passage, an adit, a connection to a riser, and a shaft.

[0025] Methods and processes for compressed air excavation are also provided herein. In an example, a method for compressed air excavation may include positioning a w orking chamber of a pressure vessel in a portion of a main passageway, aligning an opening on the working chamber to surround an area for excavation of a second passageway, forming an airtight seal between the opening on the w orking chamber and a frame secured to the main passageway, and excavating the second passageway using a compressed air operation. The working chamber may include an inner space for personnel and equipment, and the main passagew ay may include a first excavation path. The second passageway may be a second excavation path in a direction different than the first excavation path.

[0026] These and other features will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings and claims. This Summary is provided to introduce a selection of concepts in a simplified form that are furtherDocket No. 131682.010005 described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG. 1 is a front perspective view of a localized excavation apparatus, in accordance with an embodiment.

[0028] FIG. 2 is a rear perspective view of the localized excavation apparatus in accordance with an embodiment.

[0029] FIG. 3 is a cross-sectional view of a cross tunnel in accordance with an embodiment.

[0030] FIG. 4 is an example ring beam support in an open position, in accordance with an embodiment.

[0031] FIG. 5 A is another example view' of a ring beam support in the open position, in accordance with an embodiment.

[0032] FIG. 5B is another example view of a ring beam support in the closed position, in accordance with an embodiment.

[0033] FIG. 6 is an example view of localized excavation apparatus features in accordance with an embodiment.

[0034] FIGs. 7A-F illustrate an example wall frame and sealing system in accordance w ith an embodiment.

[0035] FIG. 8 illustrates a cross-sectional side view of a localized excavation apparatus in a primary tunnel accordance with an embodiment.

[0036] FIG. 9A illustrates a cross-sectional view' of an example seal frame in accordance with an embodiment.

[0037] FIG. 9B illustrates a cross-sectional view of another example seal frame in accordance with an embodiment.

[0038] FIG. 10A-10E illustrate another example of a seal configuration in accordance with an embodiment.

[0039] FIG. 11 A illustrates a sealing bracket in accordance with an embodiment.

[0040] FIG. 1 IB illustrates a sealing frame in accordance with an embodiment.

[0041] FIG. 11C illustrates a sealing attachment in accordance with an embodiment.Docket No. 131682.010005

[0042] FIG. 12A illustrates a retracted view of a sealing system in accordance with an embodiment.

[0043] FIG. 12B illustrates an extended view of a sealing system in accordance with an embodiment.

[0044] FIG. 12C illustrates sealing system clamps in accordance with an embodiment.

[0045] FIG. 13 A illustrates an example seal in accordance with an embodiment.

[0046] FIG. 13B illustrates another example seal in accordance with an embodiment.

[0047] FIG. 13C illustrates another example seal in accordance with an embodiment.

[0048] FIG. 13D illustrates another example seal in accordance with an embodiment.

[0049] FIG 13E illustrates another example seal in accordance with an embodiment.

[0050] FIG. 14A illustrates a method for in a cross passage excavation accordance with an embodiment.

[0051] FIG. 14B illustrates additional aspects of a cross passage excavation method in accordance with an embodiment.

[0052] FIG. 14C illustrates additional aspects of a cross passage excavation method in accordance with an embodiment.

[0053] FIG. 14D illustrates additional aspects of a cross passage excavation method in accordance with an embodiment.

[0054] FIG. 14E illustrates additional aspects of a cross passage excavation method in accordance with an embodiment.

[0055] FIG. 14F illustrates additional aspects of a cross passage excavation method in accordance with an embodiment.

[0056] FIG. 15 illustrates a flow chart for a compressed air excavation method, in accordance with an embodiment.

[0057] FIGs. 16A-B illustrate a side view for excavation of a riser, in accordance with an embodiment.

[0058] FIGs. 16C-D illustrate a side view for excavation of a cross passage collar, in accordance with an embodiment.

[0059] FIGs. 17A-B illustrate a top view of an arrangement to construct a riser, in accordance with an embodiment.Docket No. 131682.010005

[0060] FIGs. 18A-B illustrate a top view of another arrangement to construct a riser, in accordance with an embodiment.

[0061] FIGs. 19A-B illustrate additional view of riser construction, in accordance with an embodiment.

[0062] FIG. 20 is a block diagram of an embodiment of a computer system in accordance with an embodiment.DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0063] The present disclosure describes particular embodiments and their detailed construction and operation. The embodiments described herein are set forth by w ay of illustration only and not limitation. Those skilled in the art will recognize, in light of the teachings herein, that there may be a range of equivalents to the exemplary embodiments described herein. Most notably, other embodiments are possible, variations can be made to the embodiments described herein, and there may be equivalents to the components, parts, or steps that make up the described embodiments. For the sake of clarity and conciseness, certain aspects of components or steps of certain embodiments are presented without undue detail where such detail would be apparent to those skilled in the art in light of the teachings herein and / or where such detail would obfuscate an understanding of more pertinent aspects of the embodiments.

[0064] Disclosed herein are systems, methods, and apparatuses for localized excavation for passageways, including shafts, tunnels, stations, adits, connections, and cross passages. Passageway is not limited to the use of connect for the passage of persons or material but is intended to encompass any three-dimensional space that may also be used for other identified purposes of an underground space such as storage of materials, chemicals, gases, etc. Aspects of the present disclosure include a mobile, self-contained, multiple-use hyperbaric apparatus to enable localized excavation of inter-connecting passageways without the use of ground treatment techniques, such as grouting, soil replacement, ground freezing, etc. The elimination of ground treatment requirements may significantly reduce cost and environmental impact. Compressed air may be applied via a hyperbaric pressure vessel to a localized area and enable excavation while allowing the surrounding environment (e.g., a main tunnel, inter-connecting passageways, etc.) to remain in atmospheric (i.e. , free air) conditions. As used herein, compressed air means that a gas is supplied to a confined spaceDocket No. 131682.010005 that pressurizes the pressure of gases in the space as the pressure increases from the supplied gas. It is not limited to a supply of compressed air.

[0065] In some examples, aspects may include a mobile, underground, hyperbaric, excavation lock. Such aspects enable tunnel cross passages to be constructed in unstable subaqueous ground conditions. In various examples, the systems, methods, and apparatuses discussed herein are mobile and may be used multiple times, e.g.. to excavate multiple cross passages. Aspects of the present disclosure may be modifiable for application and use in various tunnel types and sizes, such as tunnels around 19ft to 26ft (6m to 8m) diameter, and larger tunnels, greater than 30ft (9m). While cross passages and tunnels are commonly referenced herein regarding localized excavation, such techniques may be applicable to other environments, construction sites, and excavation projects.

[0066] Various systems, methods, and apparatuses allow the construction of a cross passage to be performed in compressed air whilst maintaining the main tunnel in “free-air,” and allows the tunnel services, ventilation, personnel egress, drainage, mobility, and rail track (if used) to remain active. In the past, to perform the compressed air works in a tunnel, the complete tunnel required compressed air supply, and large full tunnel bulkhead would be installed. For inter-connecting passageways in the main line tunnel, such as cross passages, these would be constructed when the main tunnel was still pressurized with compressed air.

[0067] The apparatus may have many configurations and may comprise a working chamber for the compressed air works to commence from, airlocks that join to the working chamber to allow personnel, materials and equipment to safely transfer in and out of the compressed air working environment without changing the pressure of the compressed air working environment. The working chamber has a sealing system to isolate the crosspassage working zone so only the cross passage and small portion of the tunnel is pressurized. The working chamber also has a load transferring structure to account for the forces developed on the working chamber from the compressed air pressure. In examples, the working chamber is a pressure vessel with one or more adjoining airlocks. The apparatus is self-contained and mobile and can be used multiple times at each cross-passage location. The apparatus can be towed, or it can have a self-propelled system that jacks itself or uses driven wheels which may run directly on a tunnel liner or on a rail track system. Features that are optional for the apparatus are the inclusion of a temporary tunnel liner support frame, and an emergency isolation gate. The project may choose to use steel tunnel liner segments to eliminate the requirement for the temporary tunnel liner support frame and may not deem the works risky enough to warrant the inclusion of an emergency isolation gate.Docket No. 131682.010005

[0068] With the use of the apparatus, ground treatment can be eliminated saving the project considerable cost, eliminate considerable energy- consumption, eliminate waste, eliminate troublesome and intrusive surface works, and eliminate unknown risks where ground treatment is not conducted properly.

[0069] In a rock tunnel, the apparatus can be used in sub-aqueous alignment, where the ground may be stable, but ground water ingress could make the construction works difficult, especially when it comes to installing waterproofing membranes and final concrete lining. The apparatus, when operated at the appropriate pressure, would repel the ground water.

[0070] The apparatus can be used in other applications where dead-end side adits are required or can be configured to seal the top portion of the tunnel to allow a safe construction of the connection to riser shafts. As discussed herein, a riser may be a vertical shaft constructed in a sea bed, or the base of a lake, river or ocean, and connected to a pipe line or a tunnel.

[0071] The apparatus can be used in shafts where multiple adits are required to connect to the mam tunnel. The apparatus can also be used as an alternative to the micro- TBM, to allow an external collar to be constructed and minimize / optimize the tunnel diameter. On the other hand, the apparatus can be used in conjunction with a micro-TBM and allow more simplified shields and jacking systems to be used, as the ground conditions are stable, and the jacking forces are less, as there is no ground water pressures to balance.

[0072] It is envisaged that the apparatus be used to allow for the excavation and installation of a primary support structure that can support and seal the ground once the compressed air pressure is removed. If conditions and schedule warrant it, it may be worthwhile maintaining the compressed air pressure until the waterproofing membrane and secondary concrete lining is complete. In any case, the stability and waterproofness of the primary lining can be carefully tested by reducing the compressed air pressure, once the work is complete, and if issues arise, the pressure can be increased again, and rectifications made.

[0073] In case of high working pressures, the apparatus can be set up for saturation diving, whereby one of the personnel locks can be docked with a shuttle, to allow workers to remain in compressed air, and be transported to a compressed air living habitat, or the compressed air living habitat could be located next to the apparatus and be permanently connected. In examples, the apparatus may have at least one set of personnel airlocks and at least one set of material airlocks. The personnel airlocks allow workers to transfer in and out of the compressed air work environment, and there is usually a primary lock for the crews,Docket No. 131682.010005 and a smaller auxiliary lock for emergency use. A primary lock may include a primary chamber for compression and decompression. An auxiliary chamber may provide an area to allow, for example, extra crew members to enter within a work shift, doctors or medical personnel to attend to a sick or injured worker and enable a space to remove an individual from a pressurized environment. The material airlocks allow cutter tools, materials and small equipment to transfer in and out.

[0074] With a tunneling project already set up for hyperbaric works, to allow for TBM cutterhead interv entions, the proj ect is already trained up and procedures for compressed air work are established. The addition of the apparatus may warrant an independent compressed air system dedicated to cross-passage works, or the project can share the compressed air system that is used for cutterhead interventions, if cutterhead interventions are not very frequent. The project would be responsible for ensuring the compressed air supply system meets all appropriate safety standards. For tunnels around 7m diameter, which encompasses metro tunnels, the apparatus will consume most of the space of one tunnel, but during the operation of the apparatus, the other tunnel will remain open, and able to maintain tunnel supply transport to both TBMs. assuming there is a station or shaft in between the apparatus and the tunnels the TBMs are operating in.

[0075] FIG. 1 illustrates a front perspective view of a local excavation apparatus 100, and FIG. 2 illustrates a rear perspective view of the local excavation apparatus 100. The apparatus 100 may be a hyperbaric pressure vessel including one or more independent sections, which may be separately pressurized. The separate pressurization allows the independent sections to be separate airlock chambers to enhance safety and facilitate efficient movement of equipment and personnel.

[0076] In examples, a first chamber 110 serves as main working chamber for performing localized excavation. The apparatus 100 may align opening 140 with an excavation site, such as a tunnel wall and / or a cross passage location and form an airtight seal via a sealing system discussed in more detail below with respect to FIGs. 7-9. The interior of apparatus 100 can be pressurized and depressurized to enable excavation techniques, such as compressed air excavation, at the excavation site.

[0077] A second chamber 120 provides an airlock for personnel to transit between the exterior atmosphere of the apparatus (i.e. atmospheric pressure) and the pressurized first chamber 110. In examples, the second chamber 120 includes one or more sections and doors (e.g., safety door(s)) to facilitate entry into and out of the first chamber 110, and provides a decompression environment for personnel leaving the first chamber 110 to acclimate toDocket No. 131682.010005 atmospheric pressure before exiting the apparatus 100. One or more sections of the second chamber 120 may be independently pressurized and depressurize to facilitate compression and decompression. In examples, the second chamber 120 includes seating areas and provides space for multiple individuals to comfortably walk through and around the chamber. Other features may be included, as desired to promote comfort and safety of personnel.

[0078] A third chamber 130 provides a separate airlock for materials and equipment. In examples, the third chamber 130 provides space for common excavation and other equipment to easily pass through to the first chamber 110. Since equipment and machinery do not have decompression requirements like humans, the third chamber 130 may be sized differently and pressurized and depressurized differently than the second chamber 120.

[0079] In some examples, the third chamber 130 contains a single, open interior section for storing and transferring excavation and other equipment. While multiple sections may still be included in the third chamber, they are not necessary. In examples, the third chamber 130 may be sized and equipped for rapid pressurization and depressurization when not occupied by humans, thus enabling a faster transfer of equipment from an area exterior to the apparatus 100 and into the first chamber 1 10. Doors and entry ways 159, 161 of the third chamber 130 may also be sized differently, e.g., larger, than doors and entryways 150, 155, 157 of the second chamber 120, as the third chamber is sized to accept equipment whereas the second chamber is sized to facilitate human entry and exit.

[0080] Doors, e g., 150, 155, 157, 159, 161 within the apparatus 100 (also referred to herein as safety doors) preferably open inwardly, e.g., towards the first chamber 110, to provide a safety feature in the event of a pressure malfunction. For example, pressurization of the first chamber 110 may cause significant outward force on interior surfaces. Openings, doorways, and seals (e.g., seals 152a-e) between door and entryways are potential areas of leakage and failure. However, the inward orientation and positioning of doors (e.g., doors 150, 155, 157, 159, 161) causes the pressurization to ensure that the doors remain closedby naturally pushing the doors against the seals and entry ways, decreasing the risk of mechanical failure, malfunction, or rapid decompression. In contrast, if the doors opened outwardly, the pressurization would naturally push the doors away from seals and entryway requiring physical mechanisms to hold the doors shut during a first chamber pressurization. That could cause the seals and physical mechanisms to weaken over time and risks failure.

[0081] Doors, e.g., 150, 155. 157, 159, 161 also isolate the apparatus and excavation site from the rest of the tunnel in emergency, such as a ground collapse, e.g.,Docket No. 131682.010005 within the cross passage, during construction, or excavation. While additional systems may be implemented for different emergency isolation scenarios, the doors will at least create a sealed barrier and may help to contain debris from a ground collapse within only one chamber. In addition to doorw ays opening inwardly, into the pressurized compartment of the compressed air chambers (e.g., first chamber 110), one or more doors may also include a smaller access hatch 163 that can be opened into a non-pressurized area compartment. Therefore in the case of a ground collapse forcing closure of an inwardly opening door (e.g.. door 150), the hatch 163 provides an exit pathway for any personnel stuck in the compartment.

[0082] Such airlocks and chamber discussed above, along with plumbing and valving, and hyperbaric controls allow personnel, materials and equipment to safely pass between a pressurized working zone (e.g., first chamber 110) to the atmospheric pressure (e.g., “free air”) in the rest of the tunnel, external to the apparatus 100. In examples, the apparatus is completely equipped with hyperbaric valving, plumbing, and controls in compliance with regulations. One or more controllers may be locally and / or remotely operated to, e.g.. provide pressurization controls, monitor conditions interior and exterior to the apparatus 100. In examples, all chambers of the apparatus are designed and manufactured in accordance to relevant codes and regulations.

[0083] A support sy stem 160 may surround the apparatus 100, and in examples, primarily surround the first chamber 1 10, to stabilize the apparatus’s position during sealing, pressurization, and excavation. As discussed herein in more detail with respect to FIGs. 4-6, the support system 160 may include a ring-shaped frame with supports to secure the apparatus against a wall, e.g., a tunnel wall, or other stable structure. The support system may securely attach to an exterior portion of the apparatus to ensure minimal or no movement during operations of the apparatus 100. The support system 160 may also be movable, e.g., manually moved, along a track system, etc., and reusable at various excavation sites. During cross passage excavations, for example, the support system 160 may be set up at a first excavation site, secure apparatus 100 during excavation of a first cross passage, then detach and move to a second excavation site, to secure and stabilize the apparatus during a second cross passage excavation.

[0084] The support system 1 0 may also be shaped to enable stability' and support to the apparatus, while still providing space for personnel and equipment outside the apparatus 100 to pass by. In a tunnel, for example, space is limited by the size of the tunnel,Docket No. 131682.010005 e.g., the tunnel diameter, and most tunnel sites will have electricity, piping, boring machinery, and many personnel operating at various positions along the length of the tunnel.

[0085] As noted above, cross passages are challenging to construct as tunnel projects typically require multiple cross passage excavations and the large size of traditional excavation and boring machinery (e.g., nearly the entire tunnel diameter) would make it difficult, or even impossible, to orient the machinery for cross passage excavation and / or allow equipment and personnel to pass by during operations. The apparatus 100 and support system 160, however, enables localized excavation, e.g., for cross passages, while leaving space for equipment to pass (i.e., in free air) and for existing systems, such as rail systems, conveyors, piping, electrical equipment, booster systems, and slurry systems, among others, to remain in place. Such orientations further enable equipment, e.g., existing compressed air supply pipes within the tunnel, to be remain in place, and even be utilized, by the apparatus and its pressurization and excavation operations. This may help reduce operational costs and disruptions to a main tunnel excavation, since equipment need not be moved, re-located, or newly installed in order for the apparatus 100 to work.

[0086] In twin tunnel systems (e.g., tunnels systems having a first main passageway and a second main passageway), for example, the apparatus may consume space in only one tunnel, to allow the interconnecting cross passage to be constructed. The unobstructed tunnel may be used for access for tunnel supplies to the two Tunnel Boring Machines. In some examples, the unobstructed tunnel may rely on the notion that there is a shaft or station between the Tunnel Boring Machines and the twin tunnels where the apparatus 100 is being used. This allows for tunnel supplies to enter each tunnel for each Tunnel Boring Machine, at the shaft or station. In other examples, tunnel supplies may be fed directly to the shaft or station between the twin tunnels.

[0087] In FIG. 2, pathway 170 positioned on a side of the apparatus 100 illustrates one example for the spacing created to enable personnel and equipment to pass by during the apparatus’s excavation operations. In some examples, the support system 160 has at least one adjustable arm 180 (also shown in Fig. 4) to create additional space for equipment and personnel. The adjustable arm 180 may be a movable arm forming part of a ring of the support system. The adjustable arm 180 may be rotated into an open position, as seen in FIG. 2, to create additional space for equipment and personnel. The adjustable arm 180 may also be secured in a closed position, e.g., creating a ring-shaped support frame, and assist in providing additional security and stability to the apparatus during operation.Docket No. 131682.010005

[0088] In some examples, the apparatus 100 may include one or more platforms, e.g., platform 165 for personnel and / or equipment. The platform 165 may be in an elevated position, such as above one or more of the chambers. The platform 165 may provide additional space for personnel and equipment and / or serve as a viewpoint from which personnel may monitor movement and excavation operations of the apparatus. The one or more platforms may also provide access to various parts of the apparatus which may enhance safety and security during apparatus operations and movement.

[0089] FIG. 3 illustrates a cross-sectional view of apparatus 100 and a cross passage 300. In an example operation, the apparatus 100 first aligns with an excavation site 310 at a first tunnel (e.g., tunnel 320) and seals against the tunnel wall as explained in more detail with respect to FIGs. 7-9. The support system 160 stabilizes the apparatus in the desired position against the tunnel wall. The main working chamber (e.g., first chamber 110) is pressurized to the necessary conditions for excavation of the cross tunnel, and an excavation technique, e.g., compressed air excavation, may be performed until a second tunnel (e.g., tunnel 330) is reached. During the excavation, the walls of the second tunnel may be supported via a second support system 340. In some examples the second support system 340 is a ring support system (see, e.g., FIGs. 4-6) and / or the same type of support system as the support system surrounding the apparatus 100 (e.g., support system 160). These techniques therefore enable excavation, such as cross passage excavation, without the need for ground treatment (e.g.. cement treatment, freezing, chemical, etc.).

[0090] As seen in FIG. 3, the apparatus 1 0 may have an oblong, rounded cross- sectional shape. The rounded shape supports even force distribution for pressurization operations. The oblong shape, along with the articulated orientation against the excavation site 310, may assist with creating allowance or a space 350 within the tunnel for personnel and equipment to pass by. The shape of the apparatus 100 further enables movement, use, and alignment within curved tunnels. Since tunnel walls, including various excavation sites, are not uniform, the oblong, rounded shape enables the apparatus to better adapt to various shapes and tunnel conformations.

[0091] The shape additionally enables irregularly-shaped and differently-sized cross passages to be excavated. For example, the excavation site does not need to be circular and the excavation area may be larger than the apparatus’s interface (e.g., opening 140) with the tunnel lining.

[0092] In examples, an articulated joint 360or spherical bearings may be used to connect a main chamber (e.g., first chamber 1 10) to one or more airlocks (e.g., secondDocket No. 131682.010005 chamber 120, third chamber 130). In such examples, as seen in FIG. 3, the cross-sectional shape of the airlocks may be circular. The rounded shape, similar to the first chamber’s shape, helps supports force distribution during pressurization operations. Other cross- sectional shapes may also be applied to the apparatus and its various sections, depending on its application, space requirements, and other considerations.

[0093] FIG. 4 illustrates in more detail an example tunnel support system 160 usable, for example, to brace tunnel lining during cross passage excavations. The tunnel support system 1 0 may include at least one ring support section 420 and a set of lateral supports 430, e.g., cross beams, extending from the at least one ring support section 420. The ring support may have at least one adjustable arm 180 that may articulate around a joint. The open position, as illustrated in FIG. 4, may create additional space, e.g., for movement past tunnel pipes, or conveyors, mounted to the side of the tunnel wall, when placed in a tunnel environment. The ring support and lateral supports may include one or more support beams 410, 415 which may be retractable beams, to brace the tunnel support system 160 against a tunnel wall, for example. In examples, the support beams 410, 415 are individually adjustable and may be extended or retracted. Support beams 410 may be positioned on an exterior section of the ring support to brace against a tunnel wall. Support beams 415 may be positioned on an interior section of the ring support to brace against the apparatus 100, such as against an exterior section of the apparatus. The flexibility enables the support system 160 to be adaptable to range of tunnel shapes and sizes, including uneven tunnel walls. The support system may include a base section 440, which in some examples, may be adapted to travel on a track (as shown, for example, in FIGs. 5-6), to aid in movement of the apparatus 100 and / or other equipment.

[0094] The tunnel support system 160 creates stability against tunnel walls and prevents movement of the apparatus 100 when the chambers are pressurized. To provide an example, when a tunnel liner on the tunnel wall is opened, and compressed air is applied to the cross passage work zone (e.g., an excavation site), there will be a shift in the tunnel liner forces. The tunnel support system 160 distributes those forces via the at least one ring support 420. In examples, tunnel support system 160 provides a ring support 420 on each side of the cross passage site, and the set of lateral supports 430 connect to each ring support. In examples, the set of lateral supports 430 are cross beams. Upon positioning and mobilization of the apparatus 100 at the cross passage location, the apparatus 100 may connect with the support system 160 and lock into a secure position. In examples, the support beam(s) 410 are screwjacks extending from at least one of the ring support 420 and a lateral support 430.Docket No. 131682.010005Support beams 410 may be positioned around a circumference of the ring support 420 and along a length of the lateral support 430, thus providing 360-degree support of the tunnel liner. In some examples, if additional support is desired or required, an additional support frame may be provided.

[0095] In some examples, the at least one adjustable arm 180 may be positioned on a site of the tunnel opposite the excavation site. These segments, e.g.. of ring support 420, may be folded inward and upward when the tunnel support system 160 is not in use and / or when the apparatus is ready for travel along the tunnel (see, e g., FIG. 5A). The adjustable arm(s) 180 provide space and clearance between the apparatus from tunnel utilities, including but not limited to tunnel conveyors, slurry pipes, boosters, and other equipment. The tunnel support system 160 may also be moved into a new position, such as a new excavation site for a cross passage. When the tunnel support system 160 and the apparatus 100 are positioned at the excavation site, the adjustable arm(s) may be moved back into place to create the full ring support 420 (see, e.g., FIG. 5B).

[0096] In examples, an interface between the tunnel liner, cross passage, and apparatus opening 140 ensures adequate sealing and support of apparatus 100 to the excavation site, e.g., site 310. In some examples, custom interfaces may be required to adapt to various tunnel liner shapes and designs. Alternatively, a common or standard tunnel liner may be used to ensure connection with the apparatus 100.

[0097] In an opposite tunnel (e.g., tunnel 330, opposite the apparatus 100), there may also be a tunnel support system and ring beam to support the tunnel liner, providing an anchor and support for the receiving seal 370 on the opposite tunnel.

[0098] In an illustrative example, the apparatus 100 may utilize the tunnel support system 160 to brace the tunnel lining during the opening of the tunnel lining and cross passage excavation. The second tunnel support system 340 may be provided in the opposite tunnel. This configuration enables an additional temporary support frame, if warranted. When the cross passage excavation is complete, the cross passage may be depressurized, and the tunnel support systems on both sides may be disassembled and relocated to a next cross passage site. In some examples, the tunnel support system 160 may remain in place until a permanent lining, e.g., final concrete lining is installed. Once the lining is complete, the tunnel support system 160 may then be relocated to another cross passage.

[0099] FIGs. 5A-5B and 6 further illustrate the tunnel support system, along with applicable mobility features and mobility systems 500. In various examples, a mobility system may be at least one of: a self-propelled jacking system, wheels, wheels movable on aDocket No. 131682.010005 tunnel lining, wheels that run on a rail track, a tow hitch 517 connected to the apparatus or equipment that can tow the apparatus 100.

[0100] FIG. 5 A illustrates an example wherein the adjustable arm(s) 180 are folded inward, in an open position, to create additional space in the tunnel. As discussed above, the open position may be implemented when the support system 160 is being moved between locations and / or when the support is not needed at the moment. FIG. 5B illustrates an examples wherein the adjustable arm(s) 180 are rotated into the closed position, to complete the ring support. As discussed above, the closed position may be implemented when the support system is or will be used to secure the apparatus during pressurization and excavation operations. FIG. 6 illustrates how the tunnel support system may be applied despite existing piping and still provide pathways for equipment and personnel. In the illustrated example, adjustable arms’ 180 open position enable the tunnel support system to reach its intended position within the tunnel, and pass pipes that could not be crossed in the closed position. Once positioned, the adjustable arms 180 may return to the closed position and brace against the tunnel wall, as seen, for example, in FIG. 6. FIG. 6 shows the adjustable arms 180 in the closed position and support beams 410 bracing against the tunnel wall.

[0101] A track 510 may be positioned beneath the apparatus 100 to enable mobilization. In some examples, the apparatus may be a self-propelling system, movable along the track. The self-propelling system may include one or more motors 515 and be controllable, e.g., remotely and / or locally at the apparatus itself. In some examples, a controller may be managed by an operator, to control movement of the apparatus along the track 510. The apparatus may include one or more treads, a jacking system, wheels (not shown, positioned beneath the apparatus in FIGs. 5A, 5B), or other mobility features that may be usable for movement with or without a track.

[0102] In an example, a shuffle-shoe travelling system may enable movement of the apparatus. The travelling system may be located on the first chamber 110. The shuffleshoe travelling system, rail-less variations may be implemented to enable movement without the use of a rail. If there is no rail, one or more chambers may have wheels. In an example where the tunnel includes a rail (e.g., track 510), one or more chambers (e g., second chamber 120 and third chamber 130, or first chamber 110) may include wheels that ride on the rails (see e.g., track 510). An analysis of the terrain, such as tunnel grades, may determine whether some wheels should be replaced with skids, or vice versa, to ensure the apparatus does notDocket No. 131682.010005 roll unintentionally or uncontrollably along the tunnel. Other mobility systems and movement methods may also be utilized to position the apparatus to a desired location.

[0103] FIGs. 7A-7E illustrate a sealing system and implementation method. The sealing system serves to isolate an excavation area, such as a cross passage area or an excavation area under pressure, from the rest of the atmosphere, i.e., free air environment. The sealing system may be applied to the tunnel wall on both ends of the cross passage location, e.g., site 310.

[0104] In an example, the complete circumference of the tunnel can be sealed either at each side of the cross passage, or the perimeter of the cross passage opening 715. Although either can be done, the latter may be preferred as this would allow for existing tunnel utilities, tunnel conveyors, or slurry’ pipes to remain in place, and provide a space for personnel to pass by apparatus 100 during cross passage excavation operations.

[0105] The cross passage seal may be achieved in multiple ways. For example, if a temporary' support frame is used (e.g., support system 160), a sealing frame secured to the pressure vessel, e.g., apparatus 100, may be pre-installed and sealed against the tunnel liner, and then the apparatus 100, can be sealed against the temporary support frame. Alternatively, a sealing system may directly seal against the tunnel liner.

[0106] In an example utilizing a support frame (e.g., support system 160), the support frame must be anchored to the tunnel liner to adequately carry the loads imparted when the tunnel liner is removed and the cross passage opening is formed. FIGs. 7A-7B illustrate anchor holes 710 and anchors 720 on the tunnel liner 705.

[0107] FIG. 7C illustrates installation of plates 730 around the anchors 720 for further stability' and as a base for a mount 750a, 750b, containing one or more adjustment hubs 755 as seen in FIGs. 7D-E. A static seal frame 740 provides a mounting structure for stability of the tunnel liner. FIG. 7E illustrates an example of an adjustment hub 755 applicable to install on a tunnel liner support frame. The adjustment hub 755 may include a one or more fasteners (e.g., screws) to hold the base mount 750a, 750b in place. The adjustment hub 755 may help to secure a tunnel support frame 815 without requiring installation, drilling, and applying epoxy’ to a plurality of anchors. FIG. 7F illustrates an addition of the tunnel support frame 815 provided on the tunnel liner 705 to surround the tunnel liner opening, and an emergency isolation gate 805, as discussed herein. The static seal frame 740 may be positioned between the tunnel support frame and the emergency isolation gate. FIG. 7F further illustrates a sealing system 700 installed on a tunnel wall.Docket No. 131682.010005

[0108] In examples, the working chamber (e.g., working chamber 880, first chamber 110, etc.) may have a telescoping sealing system 1100 (as further described in FIGs. 11A-C and 12A-C) which maintains seal if the working chamber deflects or moves when loaded. The loads imparted on the apparatus from compressed air pressure are supported by the working chamber support system (e.g., support system 160) and not transferred through the sealing system (e.g., sealing system 700). The telescoping sealing frame 1100 seals the junction between the working chamber 880 and the entrance to the secondary passageway (e.g., the cross passage) and comprises a static seal frame 740 rigidly connected to the working chamber, and a telescoping sealing frame 1100 which engages and seals against the surface around the periphery of the opening to the secondary passageway. There may be one or more seals in between the sliding joint of the static seal frame 740 and the telescoping sealing frame 1100 to make this junction airtight.

[0109] In additional examples, installing a temporary tunnel liner support frame, e.g., support frame 815 helps secure a working chamber to an excavation site. The installation method may include casting a plurality’ of pin inserts (e.g., anchors 720) into a tunnel liner (e.g.. tunnel liner 820). The plurality of pin inserts (e.g.. anchors 720) may be shear pins. As described herein, the tunnel liner may be non-planar, e.g., a curved tunnel liner shape. In addition to shear pins, packers and seals may also be installed. An upper bracket (e.g., base mount 750a) may be mounted and installed along a first section of an excavation site, and a lower bracket (e.g., base mount 750b) may be mounted and installed along a second section of an excavation site. The upper bracket and lower bracket may be horizontal brackets. At least two interconnecting vertical members (see, e.g., vertical members 752a, 752b in FIG. 7D) may be mounted and installed to connect the upper bracket and the lower bracket, thus forming a frame (e.g., static seal frame 740, tunnel support frame 815). A junction may be sealed along the support frame. For example, junctions between the upper bracket, the lower bracket, the at least two interconnecting vertical members, and the tunnel lining may be sealed. In some examples, a first adjustment hub (e.g., adjustment hub 755a) may be provided in the upper bracket (e.g., base mount 750a), and a second adjustment hub (e.g., adjustment hub 755b) in the lower bracket (e.g.. base mount 750b) to allow load from the plurality of pin inserts (e.g., anchors 720) to transfer load to the upper bracket and the lower bracket.

[0110] Since many tunnel liners have steps in between circumferential rings, and the rings may be tapered to follow a curved tunnel alignment, consecutive rings in a cross passage region are not necessarily co-planar or aligned in a straight line. As such, the support system (e.g., support system 160) would not be completely flush on the in all places on theDocket No. 131682.010005 face of the liner in all places. In such cases, shims and / or an adjustable anchoring system may be used. According to examples, anchors 720 may be installed in situ when the support system is positioned in place. The sealing system and anchoring method illustrated in FIGs. 7A-7D may be also pre-installed and make the installation and removal process quick and efficient.

[0111] To address potential leakage points that must be sealed, such as small gaps between the tunnel liner segments, anchor holes 710 may be drilled from an interior of the tunnel liner (e.g., tunnel liner 820) down to a tunnel liner gasket, and epoxy may be injected to fill the hole and seal the potential leakage point. The zone where the support system will be located (e.g., the cross passage opening) may be mapped out on the tunnel liner prior to installation of the frame, and the leakage gaps may be identified and sealed. This sealing preparatory works can occur far ahead of schedule.

[0112] When potential leakages points are sealed, the apparatus 100 and / or support system 160 may seal against the tunnel liner 820. The support system 160 may be sealed, as discussed herein. The sealing system and methods of Fig. 7A-7F may be completed separately, e.g., in advance of excavation operations, to improve project timeline and scheduling. The apparatus 100 sealing system (e.g., surrounding frame of opening 140) on the apparatus 100 can then be tailored to match the common receiving sealing surface of the support system 160, which can be made identical for all units. In examples, edges and gaps between the frame and tunnel liner may be sealed using epoxy. In another example, a rubber flap may be used to seal gap(s) betw een the frame of the apparatus and the tunnel liner. Such features may address minor deflections and movements occurring in the tunnel liner during the cross passage construction.

[0113] On an opposite tunnel such as the end point for the cross passage (e.g.. tunnel 330), the tunnel support ring beam may include have a receiving seal to ensure the tunnel is sealed and to ensure the compressed air work environment in the cross passage is maintained. In examples, a temporary support frame may be installed. Depending on the option chosen, the seal can be made with the support system 160 or directly to the tunnel liner.

[0114] FIG. 8 illustrates a cross-sectional view of a localized excavation apparatus (e.g., apparatus 100) secured to a tunnel liner 820 within a main passageway 810. As discussed herein, the localized excavation apparatus includes a working chamber 880 (e.g., first chamber 110) and at least one airlock 870 (see also, second chamber 120, third chamber 130). In various embodiments the localized excavation apparatus may be apparatus 100 ofDocket No. 131682.010005FIG. 1. The working chamber 880 may be sized to house personnel, pressurization equipment, and excavation equipment. In some examples, the working chamber may hold multiple personnel and excavation equipment. The airlock 870 may provide a passage to the working chamber from the main passageway 810.

[0115] A load support structure (e.g., support system 160) may include at least one ring beam (e.g., ring support 420) with struts 860 to support a position of localized excavation apparatus within the main passageway. The ring beam (e.g.. ring support 420) and struts 860 may be further supported with a brace 890 and support beams 410 for additional stability and security. In some examples, the ring beam and struts are secured to an outer portion 835 of the localized excavation apparatus and braces against the tunnel liner 820 of the main passageway.

[0116] The localized excavation apparatus may be positioned and sealed against the tunnel liner 820 so that a tunnel liner opening 825 and a cross passage 850 may be created. A tunnel support frame 815 may be provided on the tunnel liner to surround the tunnel liner opening 825. To create the seal, an outer seal frame 830 may be statically connected to the working chamber 880, and an inner seal frame 840 may be slidable to position the seal in a manner to create an airtight seal. The inner seal frame 840 and the outer seal frame 830 may be provided on the pressure vessel, such as around an opening to be aligned with an area for excavation. An emergency isolation gate 805 may be provided to slidably close and block the tunnel liner opening 825 in the event of an accident, such as a leak or a depressurization event. In examples, the sealing frame extends to and connects with the isolation gate.

[0117] FIGs. 9A-B and FIGs. 10A-E illustrate examples of seal configurations to create an airtight seal between the localized excavation apparatus 100 and the tunnel liner 820. FIG. 9A illustrates a flat seal arrangement and FIG. 9B illustrates an angled seal arrangement.

[0118] FIG. 9A illustrates a static outer seal frame 830 secured to the working chamber 880, and a slidable inner seal frame 840 that may extend to a sealed position and retract to the unsealed position. The inner seal frame 840 may include one or more frame seals 910 to form a seal against the outer seam frame 830. The inner seal frame 840 also braces against a plate 920, which may be secured to a frame of the emergency isolation gate 805. The emergency isolation gate is braced against the tunnel liner support frame 815, which surrounds the tunnel liner opening.Docket No. 131682.010005

[0119] In examples, the emergency isolation gate 805 may be installed, and configured to close, either manually or automatically, if conditions inside the interconnecting passageway become unstable, or there is concern of flooding or ground collapse. The emergency isolation gate 805 may have a fail-safe energy system so that it can operate if electrical power is lost. Examples of fail-safe energy' systems may include batteries and hydraulic accumulators. The operation of isolation gate 805 can be designed to meet safety standards, and be manually operated, e.g.. when strict procedures are followed. The energy system for activating the emergency isolation gate 805 may have a series of isolation valves (e.g., two) or controls, and have safety' covers over the controls when normal work is occurring. In various examples, at least one emergency isolation gate 805 may be installed on interconnecting passageway entries prior to the excavation apparatus (e.g., apparatus 100) arriving. If required, the emergency isolation gate 805 may remain in place when the apparatus is removed and moves to a new location and be kept in place until the final concrete lining is installed. The emergency isolation gate 805 may then be removed and relocated to a new location. In examples, numerous emergency isolation gates 805 may be procured and installed. In examples when the apparatus is moved to a new location, if an emergency isolation gate 805 is not present, the apparatus may travel past the work location, to allow the emergency isolation gate 805 to be installed, and then the apparatus can be positioned in the work zone and mobilized for use. Additionally, or alternatively, a removed emergency isolation gate 805 may be taken backwards through the tunnel and fed into the other end of the tunnel, forward of the apparatus and installed prior to the apparatus arriving at a next location.

[0120] FIG. 9B similarly illustrates a static outer seal frame 830 and a slidable inner seal frame 840 but includes an angle seal 940 braced by angle seal clamps 930a, 930b. The angle seal 940 creates an airtight seal between the localized excavation apparatus and the tunnel liner. In some examples, angle seal clamps 930a, 930b are slidable between and open and closed position to secure the angle seal 940 as desired.

[0121] It will be appreciated that the discussed sealing configurations in Figs. 7-10 are examples for creating an airtight seal between the working chamber of the localized excavation apparatus and the tunnel liner. Variations of the described examples may be provided based on particular design considerations to enable the creation of an airtight seal and to prevent leakage at the point of connection between the localized excavation apparatus and the tunnel liner.Docket No. 131682.010005

[0122] As discussed above, with respect to FIGs. 7-12, a first sealing system configuration may include a sealed working chamber supported by ring beams (e.g., ring support 420) which transfer loads to the tunnel liner, and a sealing system 700 which may include a telescoping seal frame 1100 to seal around the excavation of the interconnecting passageway. The telescoping sealing frame (see, e.g., telescoping sealing frame 1100, FIGs. 7-13 and 16) may attach to a static sealing frame (e.g., static seal frame 740). and seals against the main passageway lining. The static sealing frame may be a frame (e.g.. a rectangular frame) housing the telescoping sealing frame and connected solidly and sealed to the working chamber. Airlocks (e.g., second chamber 120, third chamber 130) connected to the working chamber (e.g., first chamber 110) allow personnel, equipment, and materials to transfer in and out of the compressed air working environment.

[0123] As seen in FIGs. 10A-D, a second sealing configuration may contain two bulkheads 1010a and 1010b positioned on either side of the interconnecting passageway. The area between the bulkheads form the working chamber (e.g., working chamber 880), and a load support structure 1440 (e.g., support system 160), which may include, e.g., ring support 420, connects the bulkheads 1010a and 1010b to brace them, and nullify air pressure loads to the main passageway in the longitudinal direction. Main passageway section 1040 illustrates how the apparatus and the bulkheads fit within a section of the main passageway. One or more airlocks (e.g., airlock 870, second chamber 120, third chamber 130) may be connected to the bulkheads of the working chamber to allow personnel, equipment and materials to transfer in and out of the compressed air working environment. In order to provide access in the main passageway for personnel, service pipes, ventilation and drainage, the passing of some small equipment, the bulkheads 1010a and 1010b may be connected with one or more of a sealed tube 1060 and a walkway, open to the free air environment of the main passageway. The passages may be provided on either side of the apparatus and sealed to the pressurized work environment of the apparatus.

[0124] In examples, each bulkhead may have a rounded, or circular structure to seal against the surrounding passageway. A bulkhead 1010a or 1010b, may include a set of first panels 1030 and a set of second panels 1020. which act together to fill a cross-sectional area of the tunnel and create the airtight, sealed area betw een the bulkheads. FIG. 10C illustrates the bulkheads in a closed position 1030, wherein the first set of panels 1030 and the second set of panels 1020 are folded downward, to create space around the cross-sectional perimeter of the main passageway. A lever 1050 may control the position of one or more of the first set of panels 1020 and one or more of the second set of panels 1030. The closedDocket No. 131682.010005 position 1030 enables movement of the apparatus along the main passageway. FIGs. 10D-E illustrates the set of panels 1020, 1030 in an open position. FIG. 10D further shows lever 1050 securing a position of panels 1020, 1030, and creating the seal for the bulkhead. In examples, a lever 1050 may be provided for one or more panels 1020, 1030, to provide flexibility and control of the bulkhead’s position. FIG. 10E illustrates a longitudinal view of the bulkhead, looking towards an end of the apparatus (i.e. , along the path of the main passageway), and a configuration with two tubes 1060, providing free air access past the apparatus along the main passageway.

[0125] In some examples, such as cases of high air pressure, where saturation diving techniques are required, provisions can be made to allow a mobile shuttle to dock to the personnel airlock and allow personnel to remain in compressed air pressure and transported to a compressed air living habitat or a portion of the personnel lock can be connected to a compressed air living ‘habitat in the tunnel adjacent to the apparatus.

[0126] The connection between the airlocks and the working chamber may have an articulation joint 1070. such as an airtight sealed articulation joint (e.g.. articulated joint 360), to allow the airlocks to align with the undulations of the main passageway, when the apparatus is parked for use, or when the apparatus is moving to the interconnecting passageway locations. In examples, an airlock articulation joint is provided between the working chamber and each airlock. The airlock articulation joint may rotate vertically and horizontally to prevent stress of additional loading to the working chamber or airlock.

[0127] In an apparatus (e.g., apparatus 100) utilizing a first sealing configuration, a support structure (e.g., support system 160) may be secured to an exterior of the working chamber (e.g., working chamber 880, first chamber 110, etc.). The support structure may brace against a wall of the main passageway and maintains a stable position of the excavation apparatus during pressurization of the working chamber. In an apparatus (e.g., apparatus 100) utilizing a second sealing configuration, if two bulkheads seal the working chamber, the support structure may act to connect the two bulkheads, and in doing so, support the bulkheads, and nullify loads on the main passageway in the longitudinal direction.

[0128] Additional design variations for the first and second sealing configurations relate to the tunnel liner support. As described herein, a tunnel may be a main passageway and an interconnecting passageway may be a cross passage. In such scenarios, the tunnel liner support options vary and can include (a) gasketed steel tunnel liner segments, where no temporary tunnel liner internal support frame is required during the excavation of the cross passage; (b) enhanced, heavily reinforced precast concrete tunnel liner segments, where noDocket No. 131682.010005 temporary' tunnel liner internal support frame is required during the excavation of the cross passage : and (c) a temporary tunnel liner internal support frame required to temporarily support the precast concrete tunnel liner segments during the excavation and concrete lining of the cross passage. In examples, the temporary tunnel liner internal support frame for the apparatus can be installed in pieces or installed as one piece using a special purpose erection device.

[0129] Additionally, or alternatively, the temporary support frame may utilize one or more of steel tunnel liners, enhanced reinforced precast tunnel liners, permanent Internal structural collar, and other temporary structures to support the tunnel lining up until the final structural collar is constructed.

[0130] Embodiments having a first sealing configuration may include a telescoping sealing frame that translates laterally to the main passageway lining, and provides an air-tight seal between the compressed air working chamber and the free air environment of the main passageway. In such configurations, the telescoping sealing frame (e.g., telescoping sealing frame 1100) may engage with the lining of the main passageway in the following several ways.

[0131] In a first embodiment, the telescoping sealing frame (e.g., telescoping sealing frame 1100) may engage directly to a tunnel lining, which may be a gasketed steel, or precast concrete segmental liner. In examples, a gasketed segmental tunnel liner may have rubber or hydrophilic gaskets surrounding each segment such that when the tunnel liner ring is assembled, the lining is sealed from the ground water and soil pressure. In additional examples, segmental tunnel liners include tunnel lining comprised of a series of ore-made segments installed, e.g., behind a TBM, and forming a circular ring of tunnel lining. The segment joints may be prepared in such a way that the joints are flush and smooth and the gaps between the segments are airtight. The tunnel lining may be installed after each phase of tunnel excavation.

[0132] In a second embodiment, the telescoping sealing frame (e.g., telescoping sealing frame 1100) may engage directly to a temporary tunnel liner internal support frame, which has flush joints for sealing against and an airtight seal to the tunnel liner segments.

[0133] In a third embodiment, the telescoping sealing frame (e.g., telescoping sealing frame 1100) may engage directly to an emergency isolation gate, such as one with flush joints for sealing against and an airtight seal to the tunnel liner segments.

[0134] In a fourth embodiment, the telescoping sealing frame (e.g., telescoping sealing frame 1100) may engage directly to a rolled plate affixed to the tunnel linerDocket No. 131682.010005 temporary' tunnel liner internal support frame (e.g., seal frame 740) or the emergency isolation gate (e.g.. emergency isolation gate 805), to the which is has not flush joints for sealing against and an airtight seal between to the tunnel liner segments.

[0135] The telescoping sealing frame (e.g., telescoping sealing frame 1100) may have seals (e g., frame seals 910, angle seal 940, outer seal 1110, inner seal 1115, etc.) around the sliding joint of the static frame (e.g., static seal frame 740) attached to the working chamber (e.g. working chamber 880), to seal the junction of the telescoping sealing frame to the working chamber. The telescoping sealing frame may also have a curvature that matches the curvature of the main passageway’s lining. The telescoping sealing frame may further provide a backing plate support for the sealing system to the main passageway, with a minimal gap that requires sealing.

[0136] The sealing system (e.g., sealing system 700) that provides the airtight seal around the entrance to the interconnecting passageway can include, for example (a) an L- shaped continuous rubber seal that is clamped to the Main Passageway with clamps optionally (i) attached to pre-installed studs in the main passageway lining, support frame, emergency isolation gate or rolled plates, or (ii) attached by drilling and anchoring the studs in situ; (b) an L-shaped continuous rubber seal that is glued to the main passageway; (c) a series of steel plates welded between the junction of the telescoping frame and the main passageway lining; (d) grout of concrete; and (e) a compressible seal which requires the telescoping sealing frame to be pushed with force.

[0137] For examples (a) to (d), the telescoping sealing frame (e g., telescoping sealing frame 1100) can free float, to free the seal of any stress, or for example (e), the telescoping sealing frame may be loaded with a force pushed from the static seal frame, to maintain the seal, using a set of spring packages, pneumatic cylinders or hydraulic cylinders.

[0138] As discussed herein (FIGs. 10A-E), embodiments having a second sealing configuration may include two bulkheads (e.g., bulkheads 1010a, 1010b) on either side of the interconnecting passageway, sealing against the lining of the main passageway and providing an airtight seal between the compressed air working chamber and the free air environment of the main passageway. For the second sealing configuration, the bulkhead sealing may be constructed once the apparatus is (e.g., apparatus 100) positioned in place and the support frame is expanded and engaged with the Main Passageway lining. The bulkheads (e.g., bulkheads 1010a, 1010b consist of a central section which is supported by a set of ring beams and lateral beams. The outer part of the bulkhead, e.g., between the ring beams and main passageway lining, are constructed.Docket No. 131682.010005

[0139] In various examples, an outer bulkhead seal may be sealed (a) directly to the main passageway lining, e.g., a main passageway way with segmental tunnel lining, with joints that are flush and airtight gaps between segments; or (b) to a pre-installed rolled plate, which may have pre-installed studs for seal clamps, and an airtight seal to the tunnel liner segments

[0140] In examples, the outer bulkhead may include a series of hinged or folding backing plates (e.g., first set of panels 1020) and a series of flexible rubber seal plates (e.g., second set of panels 1030). When the apparatus is mobile, the folding plates may be rotated to provide clearance to existing service pipes or equipment mounted in the tunnel. When the apparatus is parked in a work zone, e.g., for excavation of an interconnecting passageway, the bulkheads are centralized to ensure equal spacing around the periphery of the bulkhead. The primary set of folding plates (e.g., first set of panels 1020) may be rotated to within close proximity of the main passageway, and if a rolled plate is installed, and rolled angle included, the folding plates can bear against the angle. The secondary' set of folding plates (e.g., the second set of panels 1030) may then be rotated and close the gaps between the primary set of folding plates. Tie-rods may also be installed to anchor the secondary folding plates to the support structure, and this essentially completes the support the outer bulkhead. Purpose made segmented rubber bulkhead plates may then installed to provide the airtight seal. Rubber bulkhead plates may be bolted or clamped together, and the junction between the main passageway lining and rubber bulkhead plates is clamped to the lining or rolled plate, and the junction between the rubber bulkhead plates and the inner bulkhead are clamped. In various examples, there may be an allowance for drainage penetrations in the lower runner bulkhead plates to install drainage pipes between the bulkheads, that operate in “free air” and are sealed from the compressed air pressure.

[0141] FIGs. 11A-C illustrate additional features of an example telescoping sealing system 1100, in accordance with aspects discussed herein. FIG. 11 A illustrates a perspective view of a sealing bracket, FIG. 1 IB illustrates a close view of a sealing frame on a pressure vessel, and FIG. 11C illustrates a sealing attachment.

[0142] As seen in FIG. 11 A, an outer seal 1110 and an inner seal 1115 may be secured against a tunnel liner support frame 1120 (see also, support frame 815) via respective sets of clamps 1130a, 1130b. The sets of claims 1130a, 1130b may be provided on a base frame 1135 surrounding an opening of the w orking chamber 880. The outer seal 1110 and inner seal 1115 may include a curved section, such as a curved vertical section 1140. which may be based on a curvature of at least one of the tunnel liner support frame 1120 (see also,Docket No. 131682.010005 support frame 815), a curvature of the tunnel lining, a shape of the localized excavation apparatus, and a shape of an opening associated with the localized excavation apparatus. The outer seal 11 10 and inner seal 1115may be shaped to conform to various apparatus designs, and tunnel liner shapes, so long as the seals are able to create an airtight seal surrounding an area for excavation. The area for excavation may be at least one of: a tunnel lining (e.g., tunnel liner 820), a shaft lining, and a station lining. FIG. 1 IB illustrates another view of a sealing frame (e.g., telescoping sealing frame 1100. seal frame 740), including a close view of the outer and inner seals and clamps holding the seals in place.

[0143] FIG. 11C illustrates a top portion of telescoping sealing frame 1100) which may assist with securing the outer seal 1110 and inner seal 1115 in position. The top portion may include a first brace 1170 that may be positioned against a wall, such as the tunnel liner (e.g., tunnel liner 820). The first brace 1170 may assist with keeping the localized excavation apparatus (e.g., apparatus 100) and sealing components (e.g., outer seal 1110 and inner seal 1115) in a secure position. For example, the first brace 1170 may be biased against the outer seal frame 830 and the inner seal frame 840 to ensure they are properly positioned to create an airtight seal between the outer and inner seals.

[0144] FIGs. 12A-12C illustrate additional views of the sealing system. FIG. 12A illustrates a view wherein the seal is retracted. FIG. 12B illustrates a view wherein the seal is extended. The extended seal 1210 is positioned against the tunnel liner support 1120. FIG. 12C illustrates a view wherein the sealing system is activated, the seals are in the extended position, and clamps 1 130a, 1 130b have been added to secure the seals in place.

[0145] FIGs. 13A-C illustrate side, cross-sectional views of various designs to secure the inner seal in a position to ensure an airtight seal between the localized excavation apparatus and the tunnel liner. Although FIGs. 13A-C illustrate the seal brace against plate 920 abutting an isolation gate 805 in front of a tunnel liner support frame 1120 (see also tunnel support frame 815), it should be appreciated that various designs and configurations may be implemented. For example, the seal may abut a different component, an isolation gate 805 may or may not be included, and in some cases the seal may directly abut a tunnel liner support 815 or other frame or component against a tunnel liner.

[0146] In FIG. 13A, an angle seal 1310 (see also, angle seal 930) may be secured in position using a first clamp 1320a (see also angle seal clamp 930a) and a second clamp 1320b (see also angle seal clamp 930b). In embodiments, clamps 1320a, 1320b may be slidably positioned into place. In other words, first clamp 1320a, may extend and retract between a first, open position and a second, closed position to respectively release and secureDocket No. 131682.010005 the angle seal 1310. According to some aspects, the first clamp 1320a may be secured to the inner seal frame 840 and the second clamp 1320b may be secured to a plate 920, or other component, such as the isolation gate 805, tunnel liner support frame 815, or another frame.

[0147] FIG. 13B illustrates an example wherein the angle seal 1310 is glued into position. The angle seal’s position may be similar to that of FIG. 13A, and similarly create and stabilize the seal.

[0148] FIG. 13C illustrates an example wherein a seal 1330 is welded in position. In examples, the seal may comprise small plates welded together against a plate (e.g., plate 920) or other surface abutting an isolation gate or tunnel support liner.

[0149] FIG. 13D illustrates an example wherein a seal is formed using a sealant 1340, such as concrete or grout. One or more anchors 1350. may be applied to increase stability and security. In some examples, a mount 1360 may be secured, e.g., to the inner seal frame 840, to secure a position of the sealant 1340 and anchor(s) 1350.

[0150] FIG. 13E illustrates an example wherein a compressible seal 1370 is applied. A biasing mechanism 1380. such as a spring package or a cylinder, may provide a compression force to create the airtight seal. In examples, the biasing mechanism may provide a force against the inner seal frame, which in turn provides force against the compressible seal against a plate (e.g., plate 920) or other feature of the sealing system to create the airtight seal.

[0151] It should be appreciated that the sealing examples of FIGs. 13A-E are non- exhaustive, non-limiting examples of possible ways to create an airtight seal between the localized excavation apparatus and an excavation site, such as a tunnel liner, as discussed herein.

[0152] FIGs. 14A-14F and FIG. 15 illustrate an example process for creating a cross passage, in accordance with various aspects discussed herein. The process may be performed, for example, using apparatus 100 and any of the various examples and embodiments discussed herein. FIGs. 14A-F illustrate a cross-sectional view of the cross passage’s creation over a series of process steps. In examples, a localized excavation apparatus (also referred to herein as a pressure vessel, mobile excavation apparatus, or apparatus for compressed air excavation), may be applied to create a cross passage. In addition to cross passages, such methods and processes may also be applied to create other excavation sites, such as an adit, a connection to a particular component, e.g., a connection to a riser, and a shaft, among others.Docket No. 131682.010005

[0153] In FIG. 14A, a first passageway (also referred to as Tunnel 1) and a second passageway (also referred to as Tunnel 2) may require a cross passage between the two passageways. In the drawings, Tunnel 1 (also referred to herein as the main passageway) is the passageway from which the cross passage excavation and construction work originates. Tunnel 2 may be another, separate passageway. In examples, Tunnel 1 and Tunnel 2 may have been bored by a tunnel boring machine, and may be similar in size, shape, and / or purpose. For example. Tunnel I and Tunnel 2 may be both be roads or passageways for transport. During the various operations discussed herein, Tunnel 2 may continue its tunnelling operations, such as boring operations. Various construction efforts and operations occurring in Tunnel 2 need not be delayed, inhibited, or stopped by the cross passage construction.

[0154] As discussed herein, traditional tunnel boring machines and excavation approaches used in the main tunnel may not be applicable to create cross passages, given differences in the sizes of such passageways, their locations, orientations, and the like. Additionally, excavation operations in the main passageways (e.g., Tunnel 1 and Tunnel 2) may need to continue, e.g.. to stay on schedule, and cannot be used for construction of a cross passage. Thus, the cross passage operations, methods, and processes discussed herein enable construction of cross passages while operations continue in one or both main passageways. Also, with reference to FIGs. 14A-F, features and operations may be discussed ith respect to Tunnel 1, however similar features may also be provided and present in Tunnel 2.

[0155] FIG. 14A illustrates an initial layout and orientation of first and second passagew ays (Tunnel 1 and Tunnel 2, respectively), along with a projected view of a cross passage (see e.g., excavation line of cross passage 1402, cross passage collar 1404) to be excavated. In the initial step, the first and second passageways may include tunnel utilities 1405, such as pipes, electrical wiring, and other equipment. Such equipment may be difficult or impossible to remove, and may be required for tunnel operations, such as main tunnel excavation, equipment, such as a slurry7booster pumps, and tunnel conveyor boosters, electrical cables, pipes, tunnel boring machine, electrical equipment providing power throughout the first and second passageways, and safety equipment. Thus, in many examples, tunnel utilities 1405 are likely to be present during cross passage excavation.

[0156] A tunnel liner support (see, e.g., tunnel liner support frame 815, seal frame 740, etc), may include a temporary7tunnel liner support frame 1410 sealed against a tunnel liner 1414, and provided around an area for excavation. The area for excavation may be an opening for the cross passage through a side of the tunnel liner 1414. The area for excavationDocket No. 131682.010005 may also be at least one of: a tunnel lining, a shaft lining, and a station lining. As discussed herein, the tunnel liner support frame 1410 (e.g., tunnel liner support frame 815, seal frame 740, etc.) may include a metal frame 1412 secured (e.g., bolted, screwed, etc.) into the tunnel liner 1414 (see also, FIGs. 7-8). A seal 1415 (e.g., frame seals 910, angle seal 940, etc.) may be provided between the tunnel liner support frame 1410 and the tunnel liner 1414.

[0157] An isolation gate 1422 (see also, isolation gate 805) may be provided against the tunnel liner support frame 1410. The isolation gate 1422 provides an added safety and security feature, as it may quickly close and provide a barrier between the excavation site and the working chamber (e.g., working chamber 880, first chamber 110, etc.) or the main passageway in the event of a ground collapse, pressure leak, or the like. In the event of a ground collapse, dirt, sediment, and other materials in the cross passage excavation area may begin to fill the main passageway. The isolation gate 1422 may be configured to quickly close to prevent filling of the main passageway and danger to personnel and / or equipment. In some examples, one or more sensors may be provided to determine at least one of pressure losses, a flow of sediment, or other indicator of a ground collapse towards the main passageway. In other examples, a manual gate closure may be provided, via a button or other manual device, to initiate closure of the isolation gate.

[0158] In some examples, a seal receiving plate 1420 may be provided on an inner portion of the tunnel liner support frame 1410. In some examples, when an isolation gate 1422 is installed, the seal receiving plate may be provided in front of the isolation gate 1422. In various embodiments, the seal receiving plate 1420 may be, for example, a metal plate positioned against an isolation gate or a seal of the localized excavation apparatus.

[0159] FIG. 14B illustrates the addition of a localized excavation apparatus 1430 (see also, e g., apparatus 100) in position for excavation of the cross passage 1402. The working chamber (e.g., working chamber 880) may have an inner space 1448 sized to hold personnel and equipment. The inner space 1448, for example, may be able to hold multiple personnel, along with excavation equipment and other pressurization equipment (e.g., pipes, sensors, etc.). As discussed herein, the localized excavation apparatus may have an ovoid cross-section and include an opening on a lateral side of the working chamber, intended to align with the tunnel liner support frame 1410 and surround an area for excavation. In some examples, the opening (see, e.g., FIG. 1) may be larger than the intended area for excavation so as to surround a perimeter of the excavation area. The opening may also align with or surround an intended area for a cross passage collar (e.g., collar 1404), which may be utilized in a cross passage design. A base platform 1435 may be provided under the excavationDocket No. 131682.010005 apparatus to assist with stability and alignment of the localized excavation apparatus in an intended position. The base platform may also assist with mobility and form part of a mobility system (see, e.g., FIGs. 5-6, track 510, etc.), as discussed herein. For example, the base platform 1435 may be attached to a track 1437 (see also track 510), on which the localized excavation apparatus (e.g., apparatus 100) may travel. In other examples, the base platform may include treads, a jacking system, wheels, a shuffle system, or other devices to assist with mobility.

[0160] In various embodiment, the localized excavation apparatus 1430 may also be sized and / or positioned such that it does not prevent personnel and equipment (e.g., tunnel utilities 1405, ventilation equipment, drainage, service pipes, etc.) from passing by the localized excavation apparatus during excavation of the cross passage. For example, pipes, electrical wiring, and other equipment related to operations occurring in main passageway, such as excavation and utility equipment may be able to fit alongside and / or pass by the localized excavation apparatus. For example, the localized excavation apparatus may be positioned in the main passageway (e.g., Tunnel 1) so as to not inhibit transport, in the main passageway, of at least one of personnel, ventilation equipment, utilities, drainage, service pipes, and excavation equipment. In other examples, the positioning maintains adequate space in the main passageway for at least one of personnel, utilities, ventilation, drainage, service pipes, and equipment. In additional examples, the localized excavation apparatus (e.g.. apparatus 100) may have a rounded cross-section shape, such as an ovoid shape, which may help with positioning in the main passageway and maintaining desired space and pathways past the apparatus. The cross-section of the apparatus may also be less than a crosssection of the main passageway.

[0161] When the localized excavation apparatus 1430 (e.g., apparatus 100) is aligned with the intended area for excavation, a load support structure 1440 (see also e.g., tunnel support system 160, and FIGs. 1-4) may be applied to secure and stabilize the apparatus’s position. In some examples, the load support structure 1440 may include a ring support structure (see, e.g., ring support 420), comprising at least one ring surrounding an exterior of the excavation apparatus. The load support structure 1440 may also include a plurality of inner supports 1442 extending from an interior side of the ring support structure, and the plurality of inner supports may connect the ring support structure to the exterior of the excavation apparatus. A plurality of outer supports 1444 (e.g., lateral supports 430) may extend from an outer side of the ring support structure and brace the ring support against a wall, such as the tunnel wall.Docket No. 131682.010005

[0162] In another example, the load support structure 1440 may include one or more struts 1446 (e.g., lateral supports 430) positioned against the tunnel wall (e.g., vertically, horizontally, diagonally, etc.) and secured to an exterior of the localized excavation apparatus 1430. Any of a plurality of load support structure designs and arrangements may also be applied to secure a position of the localized excavation apparatus 1430 in a desired position for performing cross passage excavation.

[0163] In some examples, the load support structure 1440 may have a removable section or articulating section (see, e.g., adjustable arm 180) that creates additional space in the main passageway, for personnel and equipment (e.g., tunnel utilities 1405) to pass the localized excavation apparatus. As discussed herein, the removable or articulating arm section may continue to maintain a stable position of the localized excavation apparatus 1430 while in the open position or the closed position.

[0164] One or more exterior working areas (e.g., platform 165) may be installed along an exterior of the localized apparatus 1430. Such working areas may include at least one platform positioned along a side or top section of the localized apparatus. The at least one platform may provide a path for personnel and / or equipment to safely pass by the localized excavation apparatus 1430. In some examples, the at least one platform is a work deck. The at least one platform may be placed above, beside, or adjacent to equipment, such as tunnel utilities 1405, electrical wiring, main tunnel excavation equipment, and other non-movable equipment in the main passageway.

[0165] As seen in FIG. 14C, once the localized excavation apparatus 1440 is secured in its intended position against the tunnel liner, and an airtight seal is formed (see, e.g., FIGs. 7-13). compressed air 1450 may be supplied to the working chamber (e.g., working chamber 880) of the excavation apparatus (e.g., apparatus 100). The compressed air may be supplied via one or more pipes from the main passageway to the working chamber.

[0166] In various examples, the air supply may be managed manually or automatically, e.g., via a controller (see, e.g., computing system 2000 of FIG. 20), or a combination of both. For example, a controller may measure and manage pressure within the working chamber. In examples, an initial air supply may be provided within the working chamber to test for leaks and the controller, e.g., via one or more sensors, such as a pressure sensor, may track the pressure within the chamber over a period of time. Pressure fluctuations may indicate a leak and signal to personnel that adjustments may need to be made before increasing to a working pressure. A stable pressure for a period of time may indicate aDocket No. 131682.010005 satisfactory seal between the localized excavation apparatus and the tunnel liner support frame, and indicate that pressure may be safely increased to the working pressure.

[0167] When the working chamber is at the working pressure, and no leaks or safety issues exist, the tunnel liner 1414 (see also tunnel liner 820) may be removed and cross passage excavation may begin. FIG. 14D illustrates an excavation of the cross passage and compressed air 1450 pressurizing the excavated section. As the cross passage 1402 is excavated, a primary liner 1460 may be installed to stabilize and secure the cross passage. The primary liner may be installed in sections. For example, when a first section (e.g., collar 1404) is excavated, the primary liner 1460 may be installed in the collar 1404 before a next section of the cross passage is excavated. When the cross passage excavation reaches the second tunnel (Tunnel 2), and there are no air leaks, water ingresses, ground collapses, or other safety' concerns, i.e., the cross passage is structurally sound, the pressure in the working chamber may be decreased and the tunnel liner 1465 associated with the second tunnel may be removed.

[0168] The localized excavation apparatus may then be disconnected from the tunnel liner support frame, and moved or disassembled, as needed or desired, to a new position or a new excavation site. In examples, disconnecting the apparatus may occur in the reverse order of the sealing operations discussed herein (see, e.g., FIGs. 9-13).

[0169] FIG. 14E illustrates the excavated cross passage with the localized excavation apparatus disconnected and removed. After the localized excavation apparatus is disconnected and moved, work may commence to install a secondary lining 1470 in the cross passage. In some examples, rebar 1475 may be installed at the collar sections of the cross passage, and formwork for the secondary' lining may be installed. A waterproofing membrane 1477 may also be installed in the cross passage, as discussed herein. The secondary’ lining may include pouring and curing concrete, in sections, across the length of the cross passage. Once installation of the secondary' lining 1470 is complete, any' formwork in the cross passage may removed.

[0170] FIG. 14F shows a final result of the cross passage excavation. The isolation gate 1422 has been removed, and any equipment on or near the cross passages openings 1480, such as temporary tunnel liner support and the like, have been removed.

[0171] FIG. 15 illustrates an example method for compressed air excavation, in accordance with various embodiments discussed herein. At block 1510, aspects may position a working chamber of a pressure vessel in a portion of a main passageway (e.g., Tunnel 1 of FIGs. 14A-F). The working chamber (e.g., working chamber 880) may include an inner spaceDocket No. 131682.010005 sized for personnel and equipment, such as utilities, ventilation, drainage, service pipes, and other excavation equipment. The main passageway may be a first excavation path in a first direction. The main passageway may be at least one of: a tunnel, a shaft, and a station. The second passageway may be at least one of a cross passage, an adit, a connection to a riser, and a shaft. As noted herein the positioning of the working chamber in the main passagewaymay be done so as to not inhibit transport, in the main passageway, of at least one of personnel, ventilation equipment, utilities, drainage, service pipes, and excavation equipment for the main passageway.

[0172] At block 1520, aspects may align an opening on the working chamber to surround an area for excavation of a second passageway (see, e.g., cross passage 1402, FIGs. 14A-F). The second passageway may be a second excavation path in a direction different than the first excavation path.

[0173] At block 1530, aspects may form an airtight seal between the opening on the working chamber and a frame secured to the main passageway. The position of the working chamber (e.g., working chamber 880, first chamber 110) may be braced using at least one of a beam and a ring support structure (e.g., support system 160) secured to an exterior of the working chamber (e.g., working chamber 880, first chamber 100) and a wall of the main passageway. An isolation gate (e.g., isolation gate 805, isolation gate 1422) may also be installed in front of a tunnel liner support frame (e.g., tunnel liner support frame 1410). The isolation gate may be configured to block the area for excavation during at least one of an air leak, a water ingress, and a ground collapse.

[0174] At block 1540, aspects may excavate the second passageway using a compressed air operation. The second passageway may be at least one of a tunnel, an adit, a connection to a riser, and a shaft. In embodiments, excavating the second passageway may further include (i) removing a liner on an inner surface the main passageway, (ii) increasing a pressure within the working chamber to stabilize material in the second passageway, (iii) excavating material to form the second excavation path, and (iv) installing a liner on an inner surface of the second passageway. During the compressed air operation, pressure within the working chamber may be continuously monitored and the air flow may be adjusted to maintain a target pressure. The air flow may be provided via one or more pipes providing air to the working chamber, or any of a pl urality of means to deliver air and increase a pressure within the working chamber. The target pressure may be selected to prevent a ground collapse during excavation of the second passageway. For example, the target pressure may be based on a water table associated with the ground above and / or around the area associatedDocket No. 131682.010005 with the second passageway. The target pressure may also be selected to enable excavation of the second passageway without needing to treat or freeze the surrounding ground area.

[0175] After the second passageway is formed, the pressure vessel may be moved to a second position in the main passageway, and the excavation apparatus, particularly the opening on the working chamber, may be positioned to surround an area for excavation of a third passageway.

[0176] According to various examples, the apparatus may be assembled in a shaft or a station at the start of the main passageway. The complete apparatus may be moved, e g., in a collapsed state, to the locations of the secondary passageway. Once in position, the apparatus expands its support system, and engages the apparatus sealing system to enable the compressed air excavation to commence.

[0177] In another example, in cases where the secondary' passageway is a cross passage between two tunnels (e.g., two main passageways), the tunnel which does not contain the apparatus may be used to for transporting tunnel liners and other materials to the other areas or machines (e.g., Tunnel Boring Machines) located in one or both tunnels. In such examples, the shaft or station may exist forward of the apparatus, e.g., between the tunnels with the apparatus and the tunnels with the Tunnel Boring Machines.

[0178] Various embodiments may be used in tunnels which contain gasketed segmental tunnel linings, which may, for example, be constructed of at least one of: precast concrete, fabricated steel, cast steel, cast iron, cast spheroidal graphite iron (SGI), and polymer concrete.

[0179] Embodiments may also be used to tunnels constructed by pressurized Tunnel Boring Machines that operate in one of at least the following modes: earth pressure balance mode, slurry mode, variable density mode.

[0180] In examples with undersea and / or lake connections to risers shafts, system, methods, and apparatuses may7be configured to seal against an upper portion of the lining of the main passageway, and allow the excavation and connection of the main passageway to the riser shaft to be conducted in compressed air, to stabilize soils and prevent ground water ingress.

[0181] In the case where the main passageway is a shaft, and there are multiple adits (e.g., secondary7passageways) that connect to the main tunnel (e.g., another main passageway), the apparatus may be installed in the shaft, at each passageway, use a support structure that bears on the shaft walls or invert, and allow the secondary passageways to beDocket No. 131682.010005 excavated and supported in compressed air. Embodiments may be used multiple times for construction of each secondary’ passageway.

[0182] Embodiments may also eliminate the requirement for ground treatment of the soil within and around the secondary’ passageway, the ground treatment being one of at least: slurry' walls, diaphragm walls, secant piles, tangent piles, jet grouting, deep soil mixing, permeation grouting, fissure grouting, chemical grouting, tube a manchette (TAM) grouting, and ground freeze.

[0183] Embodiments may also allow for a tunneling shield or micro tunnel boring machine to be used within the apparatus to excavate and install the lining of the secondary’ passageway. Various embodiments further allows for the permanent collar that reinforces the junction of the main passageway and secondary passageway to be located on the exterior of the main passageway.

[0184] In additional examples, embodiments may allow for the permanent collar that reinforces the junction of the main passageway and secondary’ passageway to be located on the interior of the main passageway. For example, if a micro tunnel boring machine is applied, an internal collar may be constructed.

[0185] In examples, twin personnel airlocks may’ be installed, for example, to allow crew change over, whilst one crew is undergoing decompression.

[0186] In other examples, embodiments may allow for bolted hatches to be located on airlock doors, and emergency isolation gates to be installed on the free air side so as to enable access to the inside of the locks, working chamber and secondary passageway if the ground were to collapse and completely fdl the secondary’ passageway and / or work chamber. In examples, before hatches are removed, the apparatus would need to be re-pressurized, or soil or material inside the working chamber and secondary passageway would require some kind of stabilization.

[0187] Additional embodiments may’ allow for compressed air operations of high compressed air pressures where TriMix or saturation diving is required. Embodiments may be configured to allow a personnel shuttle to dock to one of the personnel locks, and the shuttle may then transport personnel under pressure to a compressed air living habitat, or the compressed air living habitat can be made mobile, and be installed in the main passageway, adjoined to the apparatus personnel airlock.

[0188] FIGs. 16A-B illustrate an example of a configuration for construction of a riser 1610, in accordance with embodiments discussed herein. A riser 1610 extending from a vertical portion of a main passageway may be constructed using the systems, methods, andDocket No. 131682.010005 apparatuses discussed herein. FIG. 16A illustrates a side view of an apparatus (e.g., apparatus 100). A working chamber 880 is positioned in a main passageway against an area for excavation. The working chamber 880 may utilize a sealing system including an emergency isolation gate 805, and a tunnel support frame 815. A load reaction structure 1440 may stabilize a position of the working chamber during pressurization operations. The apparatus may further include at least one airlock (e.g., second chamber 120, third chamber 130) and a mobility system 500 to move the working chamber along the main passageway, as needed. FIG. 16B illustrates the pressurized working zone 1620 once the working chamber is secured to and sealed against the tunnel liner. Once pressurized, excavation operations may occur, as discussed herein, to excavate the area and construct the riser.

[0189] FIGs. 16C-D illustrate an example of a configuration for construction of a cross passage collar, in accordance with embodiments discussed herein. FIGs. 16C-D provide examples which may be applied to a large tunnel, such as one approximately 14 m in diameter or larger FIG. 16E illustrates an example of an external cross passage collar 1605, and FIG. 16F illustrates an example of an internal cross passage collar 1607. In the illustrated examples, a working chamber 880 is positioned at an area for excavation. A telescoping sealing frame 1100 as discussed herein creates an airtight seal between an inner area of the working chamber 880 and the area for excavation. An emergency isolation gate 805 may be provided as well. Exterior to the working chamber 880 and the locks (e.g., personnel lock 120, material lock 130), a temporary level 1713 may be provided in the tunnel to help properly position the working chamber 880. Collar anchorage 1609 may also be provided. A load bearing pad 1611 may be provided to help brace the load reaction frame 1750 against the tunnel wall. In some examples, an end cap 1617 may be provided on a side of the w orking chamber 880. A micro tunnel boring machine 1709 may be used for excavation operations. An external cross passage collar 1605 or an internal cross passage collar 1607 may be installed, depending on the project design, tunnel liner material, and other considerations associated with the w orksite.

[0190] FIGs. 17-19 illustrate variations for excavation of shafts and adits. FIGs. 17A-17B illustrate an apparatus (e.g., apparatus 100) design for excavation and construction of at least one adit. FIG. 17A illustrates the apparatus in position for constructing a first adit 1710, and FIG. 17B illustrates the apparatus in position for constructing a second adit 1720. In examples, the working chambers are positioned inside a shaft 1702. A first adit 1710 and a second adit 1720 are constructed adjacent to tunnel 1705. A first working chamber 1730a and a second working chamber 1730b. Endcaps 1740a and 1740b may be placed, respectively onDocket No. 131682.010005 the first working chamber 1730a and the second working chamber 1730b. End caps may be provided when an airlock is not attachable to an end of a working chamber, for example, if space does not allow. A working chamber may have more than one end cap, as seen by end cap 1740c on a rear end of the second working chamber 1740b. A load reaction frame 1750, such as any of the load reaction structures discussed herein (e.g., support structure, may be provided around the working chamber to stabilize its position. One or more airlocks as discussed herein may be provided on one or both working chamber. In an example, a material lock 1760 extends from the first working chamber 1730a and a personnel lock 1770 extends from the second working chamber 1730b. An airlock articulation joint 1765 may be provided between an airlock and a working chamber. In some examples, an airlock extension may be provided as well. In various examples, a headwall 1780, such as a tympanum headwall with reinforcement may be provided against a wall of the shaft 1702. A reaction block 1785 may be provided on an opposite wall of the shaft to, for example, assist with balancing load and other forces acting on the apparatus.

[0191] FIGs. 18A-B illustrate another example variation for excavation of shafts and adits. FIG. 18A illustrates the apparatus in position for constructing a first adit 1810. and FIG. 18B illustrates the apparatus in position for constructing a second adit 1820. In examples, the working chambers are positioned inside a shaft 1802. A first adit 1810 and a second adit 1820 are constructed adjacent to tunnel 1805. A single working chamber 1830 may be provided with an L-shaped configuration of airlocks. An endcap 1870 may be provided on one or more sies of the working chamber 1830. In the illustrated example, a personnel lock 1840 extends along a first direction from the working chamber and the material lock 1850 extends from a second direction of the working chamber. Airlock articulation joints 1860a and 1860b may be provided, respectively between the working chamber and the personnel lock 1840, and the working chamber and the material lock 1850. A load reaction frame 1870, such as any of the load reaction structures discussed herein, may be provided around the working chamber to stabilize its position. A reaction block 1885 may be provided on an opposite wall of the shaft to, for example, assist with balancing load and other forces acting on the apparatus.

[0192] FIGs. 19A illustrates a three-dimensional rendered version of the shaft and riser example discussed in FIGs. 17A-B. FIG. 19A illustrates a working chamber positioned to excavate a first adit, similar to the top view provided in FIG. 17A. FIG. 19B illustrates an example of a working chamber to excavate a single adit adjacent to a amin passageway. In FIG. 19B, no airlocks are present, due to the size of the shaft.Docket No. 131682.010005

[0193] The present disclosure describes particular embodiments and their detailed construction and operation. The embodiments described herein are set forth by way of illustration only and not limitation. Those skilled in the art will recognize, in light of the teachings herein, that there may be a range of equivalents to the exemplary embodiments described herein. Most notably, other embodiments are possible, variations can be made to the embodiments described herein, and there may be equivalents to the components, parts, or steps that make up the described embodiments. For the sake of clarity and conciseness, certain aspects of components or steps of certain embodiments are presented without undue detail where such detail would be apparent to those skilled in the art in light of the teachings herein and / or where such detail would obfuscate an understanding of more pertinent aspects of the embodiments.

[0194] Some of the techniques described above can be implemented on a computing device associated with a gaming device (e.g., a roulette mechanism), a plurality of computing devices associated with a plurality7of gaming devices, a controller in communication with the gaming device(s) (e.g., a controller configured to synchronize the gaming devices(s)), or a plurality of controllers in communication with the gaming device(s). Additionally, some of the techniques may be distributed between the computing device(s) and the controller(s). FIG. 20 illustrates an exemplary7block diagram of a computing system that includes hardware modules, software module, and a combination thereof and that can be implemented as the computing device and / or as the server.

[0195] In a basic configuration, the computing system may include at least a processor, a system memory7, a storage device, input / output peripherals, communication peripherals, and an interface bus. Instructions stored in the memory7may be executed by the processor to perform a variety of methods and operations, including the shooter selection and console mirroring, as described above. The computing system components may be present in the gaming device, in a server or other component of a network, or distributed between some combinations of such devices.

[0196] In an example, computing system 2000 may be configured to maintain a target pressure within the working chamber. The controller may be in communication with at a peripheral (e.g., input / output peripherals) comprising at least one pressure sensor. The pressure sensor may be configured to generate a notification to indicate at least one of: an environmental condition and a pressure event. The controller may control operations of a compressed air line to the maintain the target pressure within the working chamber. In additional examples, at least one sensor may be configured to generate a notification toDocket No. 131682.010005 indicate at least one of: an environmental condition and a pressure event. The environmental condition may be a pressure measurement. The pressure event may be at least one of: an air leak, a target pressure, a time, and an unsafe condition.

[0197] The interface bus is configured to communicate, transmit, and transfer data, controls, and commands between the various components of the electronic device. The system memory and the storage device comprise computer readable storage media, such as RAM, ROM. EEPROM, hard-drives, CD-ROMs, optical storage devices, magnetic storage devices, flash memory, and other tangible storage media. Any of such computer readable storage medium can be configured to store instructions or program codes embodying aspects of the disclosure. Additionally, the system memory comprises an operation system and applications. The processor is configured to execute the stored instructions and can comprise, for example, a logical processing unit, a microprocessor, a digital signal processor, and the like.

[0198] The sy stem memory and the storage device may also comprise computer readable signal media. A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein. Such a propagated signal may take any of variety of forms including, but not limited to, electro-magnetic, optical, or any combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use in connection with the computing system.

[0199] Further, the input and output peripherals include user interfaces such as a keyboard, screen, microphone, speaker, other input / output devices, and computing components such as digital-to-analog and analog-to-digital converters, graphical processing units, serial ports, parallel ports, and universal serial bus. The input / output peripherals may also include a variety of sensors, such as light, proximity, GPS, magnetic field, altitude, and velocity / acceleration. RSSI, and distance sensors, as well as other types of sensors. The input / output peripherals may be connected to the processor through any of the ports coupled to the interface bus.

[0200] The user interfaces can be configured to allow a user of the computing system to interact with the computing system. For example, the computing system may include instructions that, when executed, cause the computing system to generate a user interface and carry out other methods and operations that the user can use to provide input to the computing system and to receive an output from the computing system.Docket No. 131682.010005

[0201] This user interface may be in the form of a graphical user interface that is rendered at the screen and that is coupled with audio transmitted on the speaker and microphone and input received at the keyboard. In an embodiment, the user interface can be locally generated at the computing system. In another embodiment, the user interface may be hosted on a remote computing system and rendered at the computing system. For example, the server may generate the user interface and may transmit information related thereto to the computing device that, in turn, renders the user interface to the user. The computing device may, for example, execute a browser or an application that exposes an application program interface (API) at the server to access the user interface hosted on the server.

[0202] Finally, the communication peripherals of the computing system are configured to facilitate communication between the computing system and other computing systems (e.g., between the computing device and the server) over a communications network. The communication peripherals include, for example, a network interface controller, modem, various modulators / demodulators and encoders / decoders, wireless and wired interface cards, antenna, and the like.

[0203] The communication network includes a network of any type that is suitable for providing communications between the computing device and the server and may comprise a combination of discrete networks which may use different technologies. For example, the communications network includes a cellular network, a WiFi / broadband network, a local area network (LAN), a wide area network (WAN), a telephony network, a fiber-optic network, or combinations thereof. In an example embodiment, the communication network includes the Internet and any networks adapted to communicate with the Internet. The communications network may be also configured as a means for transmitting data between the computing device and the server.

[0204] The techniques described above may be embodied in, and fully or partially automated by, code modules executed by one or more computers or computer processors. The code modules may be stored on any type of non-transitory computer-readable medium or computer storage device, such as hard drives, solid state memory, optical disc, and / or the like. The processes and algorithms may be implemented partially or wholly in applicationspecific circuitry. The results of the disclosed processes and process steps may be stored, persistently or otherwise, in any type of non-transitory computer storage such as, e.g., volatile or non-volatile storage.

[0205] In an embodiment, a localized apparatus for compressed air excavation, comprising: a pressure vessel positioned in a portion of a main passageway, the pressureDocket No. 131682.010005 vessel comprising (i) a working chamber comprising an inner space for personnel and equipment, and (ii) an opening on the working chamber that surrounds an area for excavation of a second passageway, wherein the main passageway comprises a first excavation path and the second passageway comprises a second excavation path in a direction different than the first excavation path; a sealing frame, on or secured to the pressure vessel, forming an airtight seal with the main passageway, when positioned around the area for excavation; and a load reaction structure stabilizing a position of the pressure vessel in the main passageway and maintaining the airtight seal during pressurization.

[0206] In an embodiment, wherein the load reaction structure comprises at least two ring beam frames surrounding a perimeter of the pressure vessel, and a set of supports connecting the at least two ring beam frames.

[0207] In an embodiment, wherein the load reaction structure is secured to an exterior of the pressure vessel.

[0208] In an embodiment, further comprising at least one airlock extending longitudinally from an end of the pressure vessel.

[0209] In an embodiment, wherein a first airlock is a personnel lock and a second airlock is a material lock.

[0210] In an embodiment, further comprising a safety door between the pressure vessel and the at least one airlock, wherein the safety door opens inwardly towards the pressure vessel.

[0211] In an embodiment, wherein the at least one airlock comprises a rounded shape.

[0212] In an embodiment, wherein the pressure vessel comprises an ovoid crosssection.

[0213] In an embodiment, wherein the pressure vessel comprises a cross-section having less area than a cross-section of the main passageway.

[0214] In an embodiment, wherein the position of the pressure vessel in the main passageway maintains a space in the main passageway for at least one of personnel, ventilation, drainage, service pipes, and equipment.

[0215] In an embodiment, wherein the position of the pressure vessel in the main passageway does not prevent transport past the pressure vessel, in the main passageway, of at least one of personnel, ventilation, drainage, service pipes, and equipment.

[0216] In an embodiment, further comprising a mobility system to propel the pressure vessel along a pathway in the main passageway.Docket No. 131682.010005

[0217] In an embodiment, wherein the mobility system comprises at least one of a set of wheels, treads, a jacking system, a rail, and a track.

[0218] In an embodiment, wherein the mobility system is a self-propelling system.

[0219] In an embodiment, further comprising at least one platform positioned on or secured to an exterior portion of the pressure vessel.

[0220] In an embodiment, wherein the sealing frame forms the airtight seal by attaching to a corresponding frame on a perimeter of the area for excavation.

[0221] In an embodiment, wherein the area for excavation comprises at least one of: a tunnel lining, a shaft lining, and a station lining.

[0222] In an embodiment, further comprising at least one controller managing pressure within the pressure vessel during excavation.

[0223] In an embodiment, wherein the main passageway is at least one of: a tunnel, a shaft, and a station.

[0224] In an embodiment, wherein the second passageway is at least one of a cross passage, an adit, a connection to a riser, and a shaft.

[0225] In an embodiment, a mobile apparatus used to allow localized compressed air excavation or other compressed air works of an interconnecting passageway of a main passageway, comprising: a pressure vessel positioned in a portion of a main passageway, the pressure vessel comprising (i) a working chamber comprising an inner space for personnel and equipment to work in compressed air and construct the interconnecting passageway, (ii) an adjoining personnel airlock for transfer of personnel in and out of the working chamber, (iii) an adjoining material airlock for transfer of equipment and materials in and out of the working chamber, (iv) a load reaction support structure to transfer loads generated from compressed air pressure to at least one of an internal structure of the working chamber and the main passageway, (v) a sealing system to provide an airtight seal between compressed air pressure within the working chamber and a free air work environment of the main passageway, (vi) an allowance exterior to the local apparatus in the main passageway, for at least one of: personnel, tunnel service pipes, ventilation, and drainage, and (vii) a mobility system for the apparatus to be moved to a second location in the main passageway, wherein the main passageway comprises a first excavation path, and the second passageway comprises a second excavation path in a direction different than the first excavation path.

[0226] In an embodiment, wherein the second location is a position for excavation of a second interconnecting passageway.Docket No. 131682.010005

[0227] In an embodiment, wherein the mobility system allows the apparatus to be towed or pushed along the main passageway.

[0228] In an embodiment, wherein the sealing system consists of a sliding frame which forms the airtight seal by attaching to a corresponding frame on a perimeter of the area for excavation.

[0229] In an embodiment, wherein the sealing system consists of a of two bulkheads located either side of the interconnecting passageway and create an airtight seal on the main passageway inner lining.

[0230] In an embodiment, further comprising ring beams supporting the working chamber, and a telescoping sealing frame to seal around the excavation of the interconnecting passageway, wherein the ring beams transfer loads to a tunnel liner.

[0231] In an embodiment, further comprising: a first bulkhead positioned on a first side of the interconnecting passageway, and a second bulkhead positioned at a second, opposite side of the interconnecting passageway, wherein the first bulkhead and the second bulkhead form the working chamber; and a support structure connecting the first bulkhead and the second bulkhead to brace them together, and to nullify a longitudinal air pressure loads.

[0232] In an embodiment, further comprising a sealed tube connecting the first bulkhead and the second bulkhead, wherein the sealed tube provides access for at least one of personnel, service pipes, ventilation, drainage, and equipment to travel along the main passageway.

[0233] In an embodiment, wherein the sealed tube comprises a walkway.

[0234] In an embodiment, wherein the walkway is in free air, and is sealed against the compressed air pressure in the working chamber.

[0235] In an embodiment, a method for stabilizing an excavation apparatus for compressed air excavation, comprising: positioning a working chamber of the excavation apparatus in a portion of a main passagew ay such that an opening on a lateral side of the working chamber surrounds an area for excavation of a second passageway different than the main passageway; and securing a support structure to an exterior of the working chamber, wherein the support structure braces against a wall of the main passageway and maintains a stable position of the excavation apparatus during pressurization of the working chamber.

[0236] In an embodiment, further comprising: positioning the support structure such that the support structure and the excavation apparatus do not prevent transport, in the main passageway, past the support structure and the excavation apparatus.Docket No. 131682.010005

[0237] In an embodiment, wherein the support structure is a ring support comprising at least one ring surrounding the exterior of the working chamber, a plurality of inner supports extending from an interior side of the ring support, and a plurality of outer supports extending from an outer side of the ring support.

[0238] In an embodiment, further comprising connecting the plurality of inner supports to an exterior of the excavation apparatus, and bracing the ring support, against at least one wall of the main passageway, with the plurality of outer supports.

[0239] In an embodiment, further comprising: articulating a movable section of the ring support between a first position and a second position, wherein the movable section articulates about a joint on the ring support.

[0240] In an embodiment, wherein the first position is a closed position forming a ring, and the second position creates an opening in the ring, wherein the opening creates space for when the apparatus is moved to another location, and to allow the apparatus to pass by tunnel service pipes and equipment in the main passageway

[0241] In an embodiment, wherein the first position is a closed position forming a ring, and the second position creates an opening in the ring, wherein the opening creates space, for personnel and equipment, between at least one wall of the main passageway, the excavation apparatus, and the ring support.

[0242] In an embodiment, wherein the support structure comprises a plurality of adjustable beams, which may be extended or retracted, to provide support against a wall of the main passageway.

[0243] In an embodiment, wherein when the excavation apparatus moves along the main passageway, the ring support is collapsed to provide clearance to tunnel service pipes and equipment mounted to the wall of the passageway.

[0244] In an embodiment, wherein when the excavation apparatus moves along the main passageway, the ring support, the plurality of inner supports, and the plurality’ of outer supports moves along with the excavation apparatus.

[0245] In an embodiment, wherein the main passageway comprises a first excavation path and the second passageway comprises a second excavation path in a direction different than the first excavation path.

[0246] In an embodiment, a stabilizing support system for a pressure vessel, comprising: a ring support comprising at least one ring surrounding an exterior of an excavation apparatus positioned in a portion of a main passageway, wherein the excavation apparatus comprises a working chamber and an opening on a lateral side of the excavationDocket No. 131682.010005 apparatus, wherein the opening is positioned to surround an area for excavation of a second passageway different than the main passageway; a plurality of inner supports extending from an interior side of the ring support, the plurality of inner supports connecting the ring support to an exterior of the excavation apparatus; and a plurality of outer supports extending from an outer side of the ring support, the plurality of outer supports bracing the ring support against a wall of the main passageway surrounding the ring support.

[0247] In an embodiment, further comprising: a second ring support surrounding the exterior of the excavation apparatus.

[0248] In an embodiment, further comprising: at least one support connecting the ring support and the second ring support along a length of the excavation apparatus.

[0249] In an embodiment, wherein the at least one support is a retractable beam.

[0250] In an embodiment, wherein the ring support and the second ring support are positioned on opposite sides of the opening.

[0251] In an embodiment, wherein the ring support comprises a movable section at a joint on the ring support.

[0252] In an embodiment, wherein the movable section articulates between a first position and a second position.

[0253] In an embodiment, wherein the second position creates an opening in the ring support, wherein the opening creates a passageway between the wall, the excavation apparatus, and the ring support.

[0254] In an embodiment, wherein the main passageway comprises a first excavation path and the second passageway comprises a second excavation path in a direction different than the first excavation path.

[0255] In an embodiment, a plurality of adjustable beams, which are extendable and retractable, to provide support against the wall of the main passageway.

[0256] In an embodiment, a method for securing a working chamber to an excavation site, comprising: mounting an upper bracket along a first section of an excavation site; mounting a lower bracket along a second section of an excavation site; securing a first frame to the upper bracket and the lower bracket, wherein the frame forms a perimeter around the excavation site; and securing a second frame to the first frame, wherein the second frame surrounds an opening on the working chamber, and wherein the second frame mechanically engages with the upper bracket and the lower bracket to form an airtight seal along a perimeter of the excavation site, and wherein the second frame is provided on an excavation apparatus.Docket No. 131682.010005

[0257] In an embodiment, wherein the second frame comprises an outer seal secured to an exterior of the working chamber, and an inner seal that slidably moves to engage the first frame.

[0258] In an embodiment, further comprising applying a set of clamps to the inner seal to secure a position of the second frame against the first frame.

[0259] In an embodiment, wherein the second frame mechanically engages the upper bracket and the lower bracket by at least: biasing a first elongated section of the second frame against a top protruding edge of the upper bracket; biasing a second elongated member of the second frame against a lower protruding edge of the lower bracket; and adjusting a biasing angle of at least one of the first elongated member and the second elongated member to form the seal along the perimeter of the excavation site.

[0260] In an embodiment, wherein a perimeter of the second frame comprises a rubber seal.

[0261] In an embodiment, further comprising: drilling a first plurality of anchors into a tunnel lining along the first section; and drilling a second plurality of anchors into the tunnel liner along the second section.

[0262] In an embodiment, wherein a frame or a seal plate conforms to a curvature of the excavation site.

[0263] In an embodiment, further comprising: treating the perimeter of the excavation site with sealant.

[0264] In an embodiment, wherein the excavation site comprises at least one of: a tunnel wall and a tunnel liner.

[0265] In an embodiment, a system for securing a working chamber to an excavation site, comprising: a first frame mounted within a main passageway, wherein the first frame forms a perimeter around an excavation site, and wherein the first frame comprises an upper bracket and a lower bracket; and a second frame on an opening on a working chamber of an excavation apparatus, wherein the second frame mechanically engages with the upper bracket and the lower bracket to form an airtight seal around the perimeter.

[0266] In an embodiment, wherein the second frame further comprises an outer seal secured to an exterior of the excavation apparatus, and an inner seal that slidably engages with the first frame.

[0267] In an embodiment, further comprising at least one clamp to secure a position of the inner seal and maintain the airtight seal.Docket No. 131682.010005

[0268] In an embodiment, wherein the at least one clamp comprises an angled seal secured in place by a first clamp on a frame of the inner seal, and a second clamp on a plate secured to the first frame.

[0269] In an embodiment, wherein the at least one clamp comprises a seal secured in place with at least one of glue, a weld, an anchor, and concrete.

[0270] In an embodiment, wherein the inner seal is a compressible seal receiving force from a spring positioned within the working chamber, to provide constant compression against the inner seal.

[0271] In an embodiment, wherein the first frame supports the main passageway during an excavation operation.

[0272] In an embodiment, wherein the excavation site comprises at least one of a tunnel wall and a tunnel liner.

[0273] In an embodiment, a method for securing a working chamber to an excavation site, comprising: casting a plurality of pin inserts into a tunnel liner, wherein the tunnel liner is non-planar; mounting an upper bracket along a first section of an excavation site; mounting a lower bracket along a second section of an excavation site; mounting at least two interconnecting vertical members to connect the upper bracket and the lower bracket; and sealing a junction between the upper bracket, the lower bracket, the at least two interconnecting vertical members, the tunnel lining.

[0274] In an embodiment, wherein the upper bracket is a first horizontal bracket and the lower bracket is a second horizontal bracket.

[0275] In an embodiment, further comprising: providing a first adjustment hub in the upper bracket, and a second adjustment hub in the lower bracket to allow load from the plurality of pin inserts to transfer load to the upper bracket and the lower bracket.

[0276] In an embodiment, a reusable apparatus for compressed air excavation, comprising: a movable pressure vessel comprising a mobility system and a sealing system, wherein the mobility system moves the movable pressure vessel along a main passageway to a first position, wherein the sealing system forms an airtight seal, at the first position, around an area for compressed air excavation of a second passageway, and wherein the main passageway comprises a first excavation path and the second passageway comprises a second excavation path in a direction different than the first excavation path.

[0277] In an embodiment, wherein the movable pressure vessel comprises at least one motor to propel the pressure vessel along the main passageway.Docket No. 131682.010005

[0278] In an embodiment, wherein the mobility system comprises a tow mounted to the movable pressure vessel to enable the movable pressure vessel to be towed along the main passageway.

[0279] In an embodiment, wherein the movable pressure vessel comprises a set of wheels to travel along at least one of a track, a rail, and a path along the main passageway.

[0280] In an embodiment, wherein mobility’ system positions the movable pressure vessel to align a sealing frame on the movable pressure vessel with a corresponding frame around an area for excavation of the second passageway.

[0281] In an embodiment, wherein the main passageway is at least one of: a tunnel, a shaft, and a station.

[0282] In an embodiment, wherein the second passageway is at least one of a cross passage, an adit, a connection to a riser, and a shaft.

[0283] In an embodiment, wherein the movable pressure vessel further comprises a load reaction structure stabilizing a position of the pressure vessel in the main passageway and maintaining the airtight seal during pressurization.

[0284] In an embodiment, wherein the load reaction structure is secured to the movable pressure vessel, and travels along the main passageway with the movable pressure vessel.

[0285] In an embodiment, a method for compressed air excavation, comprising: moving a pressure vessel along a main passageway to a first position, wherein the pressure vessel comprises a working chamber for personnel and equipment for compressed air excavation of a second passageway, wherein the main passageway comprises a first excavation path, and wherein the second passageway comprises a second excavation path in a direction different than the first excavation path; stabilizing, with a load reaction structure secured to and surrounding the pressure vessel, a position of the pressure vessel in the main passageway; forming, at the first position, an airtight seal between the pressure vessel and a wall of the main passageway; and excavating a second passageway using compressed air, wherein the second passageway comprises a second excavation path in a direction different than the first excavation path.

[0286] In an embodiment, wherein the movable pressure vessel comprises a lateral jacking system to allow it to propel along the main passageway

[0287] In an embodiment, further comprising: moving the pressure vessel along the main passageway to a second position for compressed air excavation of a third passageway.Docket No. 131682.010005

[0288] In an embodiment, wherein moving the pressure vessel comprises at least one of towing, pulling, or propelling the pressure vessel along the main passageway.

[0289] In an embodiment, wherein the pressure vessel moves along at least one of a track and a rail.

[0290] In an embodiment, wherein the pressure vessel moves via at least one of treads and wheels.

[0291] In an embodiment, further comprising: during moving of the pressure vessel, maintaining a pathway for at least one of personnel, equipment, ventilation, drainage, sendee pipes, and utilities throughout the main passageway.

[0292] In an embodiment, further comprising a telescoping sealing frame provided on or secured to the pressure vessel, wherein the telescoping sealing frame connects to a corresponding frame provided on the main passageway, wherein the telescoping sealing frame and the corresponding frame forms an airtight seal around the area for excavation.

[0293] In an embodiment, wherein the telescoping sealing frame is free floating and maintains an airtight seal against an entrance to the second passageway during at least one of movement and flexure of the working chamber.

[0294] In an embodiment, an apparatus for localized excavation, comprising: a working chamber comprising an ovoid cross-section, wherein the working chamber receives compressed air to pressurize the working chamber, and wherein the working chamber comprises an inner space for personnel and equipment; and an opening on a rounded side of the working chamber, the opening comprising a sealing frame to create an airtight seal against corresponding frame provided on an inner portion of a main passageway, and wherein the sealing frame is configured to maintain the airtight seal during pressurization of the working chamber.

[0295] In an embodiment, further comprising at least one airlock extending from a longitudinal end of the working chamber.

[0296] In an embodiment, wherein a first airlock is a cylindrical chamber.

[0297] In an embodiment, wherein a first airlock, extending from a first end of the working chamber, is a personnel lock and wherein a second airlock, extending from an opposite end of the working chamber is a material lock.

[0298] In an embodiment, further comprising a safety door connecting the at least one airlock to the working chamber, wherein a first door opens inwardly to the working chamber.Docket No. 131682.010005

[0299] In an embodiment, wherein the working chamber comprises a cross-section having less area than a cross-section of the main passageway.

[0300] In an embodiment, wherein the working chamber, when positioned in the main passageway, maintains a working space in the main passageway for at least one of personnel, utilities, ventilation, drainage, service pipes, and equipment.

[0301] In an embodiment, wherein the working chamber, when positioned in the main passageway, does not prevent transport, past the working chamber for, at least one of personnel, utilities, ventilation, drainage, service pipes, and equipment.

[0302] In an embodiment, further comprising at least one platform secured to the working chamber.

[0303] In an embodiment, wherein the at least one platform provides a safe passageway for at least one of personnel, utilities, ventilation, drainage, service pipes, and equipment past the working chamber.

[0304] In an embodiment, further comprising: a mobility system to move the working chamber from a first position in the main passageway to a second position in the main passageway.

[0305] In an embodiment, wherein the mobility system comprises at least one of a set of wheels, treads, a jacking system, a rail, and a track.

[0306] In an embodiment, a system for compressed air excavation, comprising: a pressure vessel positioned in a portion of a main passageway, the pressure vessel comprising (i) a working chamber comprising an inner space for personnel and equipment, and (ii) an opening on the working chamber that surrounds an area for excavation of a second passageway, wherein the main passageway comprises a first excavation path and the second passageway comprises a second excavation path in a direction different than the first excavation path, wherein the working chamber is configured to receive compressed air and maintain pressurization withing the working chamber during a compressed air excavation operation.

[0307] In an embodiment, further comprising an airlock extending from a longitudinal end of the working chamber, and a safety door between the working chamber to the airlock, wherein the safety door opens inwardly towards the working chamber and remains closed during pressurization of the working chamber.

[0308] In an embodiment, further comprising at least one controller configured to maintain a target pressure within the working chamber.Docket No. 131682.010005

[0309] In an embodiment, wherein the controller is in communication with at least one pressure sensor, and wherein the controller controls operations of a compressed air line to the maintain the target pressure within the working chamber.

[0310] In an embodiment, further comprising at least one sensor configured to generate a notification to indicate at least one of: an environmental condition and a pressure event.

[0311] In an embodiment, wherein the pressure event comprises at least one of: an air leak, a target pressure, a time, and an unsafe condition.

[0312] In an embodiment, further comprising an isolation gate positioned in front of the area for excavation, the isolation gate configured to close in an event of at least one of a ground collapse, a water ingress, and an air leak.

[0313] In an embodiment, wherein the opening is provided on a rounded side of the working chamber.

[0314] In an embodiment, wherein the opening further comprises a sealing frame to create an airtight seal against corresponding frame provided on an inner portion of the main passageway, and wherein the sealing frame is configured to maintain the airtight seal during pressurization of the working chamber.

[0315] In an embodiment, further comprising a load reaction structure stabilizing a position of the pressure vessel in the main passageway and maintaining an airtight seal around openings of the pressure vessel during pressurization.

[0316] In an embodiment, wherein the pressure vessel comprises a set of wheels to travel along at least one of a track, a rail, and a path along the main passageway.

[0317] In an embodiment, further comprising a mobility system to move the pressure vessel along the main passageway.

[0318] In an embodiment, wherein a mobility system positions the pressure vessel such that a sealing frame on or secured to the pressure vessel aligns with a corresponding frame around an area for excavation of the second passageway.

[0319] In an embodiment, wherein the mobility system comprises a tow mounted to the pressure vessel to enable the pressure vessel to be towed along the main passageway.

[0320] In an embodiment, further comprising a sealing frame provided on or secured to the pressure vessel, wherein the sealing frame connects to a corresponding frame provided on the main passageway, wherein the sealing frame and the corresponding frame forms an airtight seal around the area for excavation.Docket No. 131682.010005

[0321] In an embodiment, further comprising a telescoping sealing frame provided on or secured to the pressure vessel, wherein the telescoping sealing frame connects to a corresponding frame provided on the main passageway, wherein the telescoping sealing frame and the corresponding frame forms an airtight seal around the area for excavation.

[0322] In an embodiment, wherein the telescoping sealing frame is free floating and maintains an airtight seal against an entrance to the second passageway during at least one of movement and flexure of the working chamber.

[0323] In an embodiment, wherein the working chamber comprises an ovoid crosssection.

[0324] In an embodiment, a method for compressed air excavation, comprising: positioning a working chamber of a pressure vessel in a portion of a main passageway, wherein working chamber comprises an inner space for personnel and equipment, and wherein the main passageway comprises a first excavation path; aligning an opening on the working chamber to surround an area for excavation of a second passageway, wherein the second passageway comprises a second excavation path in a direction different than the first excavation path; forming an airtight seal between the opening on the working chamber and a frame secured to the main passageway; and excavating the second passageway using a compressed air operation.

[0325] In an embodiment, further comprising: positioning the working chamber in the main passageway so as to not inhibit transport, in the main passageway, of at least one of personnel, ventilation equipment, utilities, drainage, service pipes, and excavation equipment for the main passageway.

[0326] In an embodiment, wherein excavating the second passageway further comprises: removing a liner on an inner surface of the main passageway; increasing a pressure within the working chamber to stabilize material in the second passageway; excavating material to form the second excavation path; and installing a liner on an inner surface of the second passageway.

[0327] In an embodiment, further comprising: moving the pressure vessel to a second position in the main passageway; and aligning the opening on the working chamber to surround an area for excavation of a third passageway.

[0328] In an embodiment, wherein the pressure vessel is moved using at least one of a self-propelling system, a tow, a track, and a shuffle system.

[0329] In an embodiment, further comprising: stabilizing a position of the pressure vessel in the main passageway during the compressed air operation.Docket No. 131682.010005

[0330] In an embodiment, wherein stabilizing the position of the pressure vessel comprises bracing the pressure vessel against a wall of the main passageway using at least one of a beam and a ring support structure secured to an exterior of the pressure vessel.

[0331] In an embodiment, further comprising: during the compressed air operation, monitoring pressure within the working chamber; and adjusting air flow, via one or more pipes providing air to the working chamber, to maintain a target pressure.

[0332] In an embodiment, wherein the target pressure prevents a ground collapse during excavation of the second passageway.

[0333] In an embodiment, wherein the second passageway is a cross passage between the main passageway and a corresponding passageway.

[0334] In an embodiment, wherein the second passageway is at least one of a tunnel, an adit, a connection to a riser, and a shaft.

[0335] In an embodiment, further comprising: installing an isolation gate in front of the frame, the isolation gate configured to block the area for excavation during at least one of an air leak, a water ingress, and a ground collapse.

[0336] In an embodiment, wherein positioning the pressure vessel maintains a space in the main passageway for at least one of personnel, utilities, ventilation, drainage, sendee pipes, and equipment.

[0337] In an embodiment, wherein a position of the pressure vessel in the main passageway does not prevent transport past the pressure vessel of at least one of personnel, utilities, ventilation, drainage, service pipes, and equipment.

[0338] As previously noted, the various features and processes described above may be used independently of one another or may be combined in various ways. All possible combinations and sub- combinations are intended to fall within the scope of this disclosure. In addition, certain method or process blocks may be omitted in some implementations. The methods and processes described herein are also not limited to any particular sequence, and the blocks or states relating thereto can be performed in other sequences that are appropriate. For example, described blocks or states may be performed in an order other than that specifically disclosed, or multiple blocks or states may be combined in a single block or state. The example blocks or states may be performed in serial, in parallel, or in some other manner. Blocks or states may be added to or removed from the disclosed example embodiments. The example systems and components described herein may be configured differently than described. For example, elements may be added to. removed from, or rearranged compared to the disclosed example embodiments.Docket No. 131682.010005

[0339] Conditional language used herein, such as, among others, "can," "could," "might." "may." “e.g.,” and the like, unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements, and / or steps. Thus, such conditional language is not generally intended to imply that features, elements and / or steps are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without author input or prompting, whether these features, elements and / or steps are included or are to be performed in any particular embodiment. The terms “comprising,” “including,” “having,” and the like are synonymous and are used inclusively, in an open-ended fashion, and do not exclude additional elements, features, acts, operations, and so forth. Also, the term “or” is used in its inclusive sense (and not in its exclusive sense) so that when used, for example, to connect a list of elements, the term “or” means one, some, or all of the elements in the list.

[0340] The present disclosure describes particular embodiments and their detailed construction and operation. The embodiments described herein are set forth by way of illustration only and not limitation. Those skilled in the art will recognize, in light of the teachings herein, that there may be a range of equivalents to the exemplary embodiments described herein. Most notably, other embodiments are possible, variations can be made to the embodiments described herein, and there may be equivalents to the components, parts, or steps that make up the described embodiments. For the sake of clarity and conciseness, certain aspects of components or steps of certain embodiments are presented without undue detail where such detail would be apparent to those skilled in the art in light of the teachings herein and / or where such detail would obfuscate an understanding of more pertinent aspects of the embodiments.

[0341] The terms and descriptions used above are set forth by way of illustration only and are not meant as limitations. Those skilled in the art will recognize that those and many other variations, enhancements and modifications of the concepts described herein are possible without departing from the underlying principles of the invention. The scope of the invention should therefore be determined only by the following claims and their equivalents.

Claims

Docket No. 131682.010005What is claimed:

1. A system for compressed air excavation, comprising: a pressure vessel (100) positioned in a portion of a main passageway (810), the pressure vessel comprising (i) a working chamber (110, 880) comprising an inner space for personnel and equipment, and (ii) an opening (140) on the working chamber that surrounds an area for excavation of a second passageway (850), wherein the main passageway comprises a first excavation path and the second passageway comprises a second excavation path in a direction different than the first excavation path, wherein the working chamber is configured to receive compressed air and to maintain pressurization withing the working chamber during a compressed air excavation operation.

2. The system of claim 1. further comprising an airlock extending from a longitudinal end of the working chamber, and a safety door (150) between the working chamber to the airlock, wherein the safety door opens inwardly towards the working chamber and remains closed during pressurization of the working chamber.

3. The system of any of claims 1-2. further comprising at least one controller (2000) configured to maintain a target pressure within the working chamber.

4. The system of claim 3. wherein the at least one controller is in communication with at least one pressure sensor, and wherein the at least one controller controls operations of a compressed air line to the maintain target pressure within the working chamber.

5. The system of any of claims 1-4. further comprising at least one sensor configured to generate a notification to indicate at least one of: an environmental condition and a pressure event.

6. The system of claim 5, wherein the pressure event comprises at least one of: an air leak, a target pressure, a time, and an unsafe condition.

7. The system of any of claims 1-6, further comprising an isolation gate (805) positioned in front of the area for excavation, the isolation gate configured to close in an event of at least one of a ground collapse, a water ingress, and an air leak.Docket No. 131682.0100058. The system of any of claims 1-7. wherein the opening is provided on a rounded side of the working chamber.

9. The system of claim 8, wherein the opening further comprises a sealing frame to create an airtight seal against corresponding frame provided on an inner portion of the main passageway, and wherein the sealing frame is configured to maintain the airtight seal during pressurization of the working chamber.

10. The system of any of claims 1-9. further comprising a load reaction structure stabilizing a position of the pressure vessel in the main passageway and maintaining an airtight seal around openings of the pressure vessel during pressurization.

11. The system of any of claims 1-10, wherein the pressure vessel comprises a set of wheels to travel along at least one of a track, a rail, and a path along the main passageway.

12. The system of any of claims 1-11, further comprising a mobility system to move the pressure vessel along the main passageway.

13. The system of claim 12, wherein a mobility system positions the pressure vessel such that a sealing frame secured to the pressure vessel aligns with a corresponding frame around an area for excavation of the second passageway.

14. The system of claim 12, wherein the mobility system comprises a tow mounted to the pressure vessel to enable the pressure vessel to be towed along the main passageway.

15. The system of any of claims 1-14, further comprising a telescoping sealing frame (1100) provided secured to the pressure vessel, wherein the telescoping sealing frame connects to a corresponding frame provided on the main passageway, wherein the telescoping sealing frame and the corresponding frame forms an airtight seal around the area for excavation.

16. The system of claim 15, wherein the telescoping sealing frame is free floating and maintains an airtight seal against an entrance to the second passageway during at least one of movement and flexure of the working chamber.Docket No. 131682.01000517. The system of any of claims 1-16, wherein the working chamber comprises an ovoid cross-section.

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