Equipment for constructing tunnels

Abstract

The present invention relates to equipment for constructing tunnels, in particular lined microtunnels, comprising a boring machine adapted to bore the ground to create the tunnel, shielded service modules, and a main thrust unit. The main thrust unit is associated with a segment erector device, both likewise shielded, the main thrust unit and the segment erector being arranged behind all of the aforementioned shielded service modules, so that the thrust unit is located at the end of the shielded section opposite the boring machine.

Description

[0001] The present invention relates to equipment for constructing a lined underground excavation, in particular equipment for constructing microtunnels.

[0002] In the field, the term "tunneling" generally refers to techniques and methods for excavating to construct tunnels, i.e., underground passages that allow the transit of people, vehicles, water, gas, electrical cables or other infrastructure.

[0003] Different tunneling techniques can be applied in various contexts, such as the construction of road, railway or subway tunnels, or the laying of underground pipelines.

[0004] The main tunneling techniques currently adopted can essentially be divided into two categories: open-cut techniques and "no-dig" or "trenchless" techniques.

[0005] The former involve excavating a trench along the entire tunnel path, installing the tunnel structure in the trench and then backfilling the trench with the removed material.

[0006] Trenchless techniques allow the construction of tunnels without resorting to open-cut excavation and therefore avoid disturbing the surface ground, reducing or eliminating impacts on the pre-existing environment, whether natural (woodlands, areas of high environmental value, etc.) or man-made (existing infrastructure, areas of archaeological interest, urban settings, etc.).

[0007] The present invention concerns equipment for tunnel construction that operates according to trenchless techniques. As noted above, the invention in particular relates to equipment for constructing so-called "microtunnels," i.e., tunnels with an external diameter of less than 3 meters.

[0008] Among the main trenchless tunneling techniques, one of the most widely used-especially for microtunnels is the technique known as "pipe jacking."

[0009] This technique uses a boring machine, commonly termed a TBM (Tunnel Boring Machine), which excavates the ground to create space for the tunnel. The boring machine (TBM) is equipped with a rotating cutting head with cutting tools that disaggregate the ground during rotation and advance.

[0010] The operating sequence provides for advancing the excavation in the ground while simultaneously inserting pipe sections into the ground from outside and pushing them so that they form the tunnel lining.

[0011] The boring and pipe-pushing sequence includes the following steps. First, a vertical shaft (the jacking shaft) is excavated, from which the excavation departs, and in which the pipe-pushing devices-generally hydraulic cylinders-are installed.

[0012] The machine is then lowered into the shaft and the actual excavation begins. The thrust for advancing the cutting head is provided by the hydraulic cylinders.

[0013] The rock and soil disaggregated by the rotating cutting head are removed from the tunnel by a special system (slurry system).

[0014] Once a boring section is completed, the hydraulic cylinders push prefabricated pipe sections (generally of reinforced concrete or steel) into the ground. The pipe is progressively pushed while the excavated material is removed through the cutting head. As the first pipe is pushed into the ground just behind the cutting head, a new pipe is inserted at the shaft entry, creating a continuous body until a reception shaft is reached.

[0015] This technique is particularly appreciated for constructing microtunnels with diameters from 1 meter to 3 meters, because it allows the installation of pipelines at considerable speed without removing large quantities of soil.

[0016] A limitation of this technique is the length of the tunnel that can be achieved, which generally struggles to exceed 800-1000 meters, depending on the type of ground, due to the increasing friction on the pipeline being pushed.

[0017] Indeed, because the string of pipes inserted into the ground and the boring machine are pushed from the rear, the required forces increase with the length of the pipe string and depend on both ground conditions and the friction of the surrounding soil as well as the tunnel geometry itself. However, there is a limit to the applicable forces defined by the strength of the pipes themselves, which could otherwise collapse under excessive load.

[0018] For these reasons, to construct longer microtunnels, pipe jacking has been combined in the past with the "segmental lining" technique, already widely used in medium- and large-diameter tunnel construction. More specifically, a first tunnel portion is bored and constructed by pipe jacking. Once the limit of that technique is reached, the string of pipes inserted into the ground is consolidated (generally by grouting the annulus between the pipe portions and the surrounding ground), and the excavation and lining of the remaining tunnel portion are carried out using the aforementioned segmental lining technique.

[0019] More specifically, boring continues with the same cutting head but, unlike pipe jacking, once a boring section is complete, a new pipe portion is constructed immediately adjacent to the leading end of the pipeline already installed. This construction is performed by juxtaposing several prefabricated concrete segments to form a ring element.

[0020] The thrust to advance the boring machine (TBM) is provided by a thrust unit, termed a "push-module," comprising hydraulic actuators which, during the thrust phase, bear against the end face of the installed lining.

[0021] The assembly of the segments is performed by a device called an "erector," located in the same shield as the thrust unit, after completion of a new boring section.

[0022] In a known equipment configuration for constructing microtunnels with the above mixed technique of pipe jacking and segmental lining, the thrust unit is placed to the rear, immediately behind the boring machine.

[0023] Behind the thrust unit are arranged the so-called "back-up machines," collectively also termed the "back-up," i.e., the set of equipment and vehicles directly connected to the boring machine (TBM) to support excavation and lining operations. This equipment, which follows the TBM during advance, performs essential functions to ensure continuous operation of the excavation system.

[0024] Among these are systems for transporting excavated material to the outside, supply devices (hydraulic power packs, electrical switchboards, current transformers, compressors and other equipment to provide power, compressed air, etc.), ventilation devices, winding devices for electrical cables, and systems for controlling and monitoring the various items of equipment.

[0025] In addition, the back-up also includes all equipment for transporting and storing the prefabricated lining segments, generally including rail systems on which trolleys travel for transporting the prefabricated segments and for transporting personnel.

[0026] Microtunneling equipment configured in this way, however, presents various limitations and drawbacks.

[0027] A first main drawback concerns the placement of the thrust unit.

[0028] In fact, the proximity of the thrust unit to the boring machine entails various drawbacks. These include poor safety for operators, who must traverse the entire back-up and the assembly area itself to reach the control station for segment assembly adjacent to the thrust unit. Moreover, there is discomfort for the operator at that control station, as the area is particularly noisy due to the proximity of the operating cutting head.

[0029] Another drawback of such a configuration is the need to interrupt excavation during the segment-installation phase to construct a new ring section. As noted above, the construction of the lining with prefabricated concrete segments takes place where the thrust unit is located; therefore, before the boring machine can advance again, a new "ring" of lining must be completed on which the cylinders of the thrust unit can bear to advance the boring machine.

[0030] This condition renders such known machines unsuitable for very long tunnels. Indeed, as is known, the segmental lining construction technique is markedly slower than pipe jacking. Therefore, in most cases, completing a tunnel with the segmental technique is considered a contingency option if pipe jacking can no longer proceed or is envisaged only for short final stretches of the tunnel, to avoid a considerable increase in project time and therefore cost.

[0031] Another drawback of known equipment concerns the configuration of the system for transporting prefabricated segments from the outside to the thrust unit.

[0032] In known equipment, floor-mounted rails are provided on which a string of flat cars (also termed a "train") travels, carrying the segments. In the last stretch, about 10 meters before the thrust unit, there is a further transport device comprising an inclined guide descending from the crown of the tunnel to a height corresponding to about half the tunnel height near the segment erector device. This transport device, commonly termed the "segment crane," includes gripping means for the segments connected to a trolley sliding on the guide.

[0033] Such a configuration is first and foremost unsafe, because the segments are moved through a personnel passage zone at "head height." Moreover, transferring the segments from the floor cars to the segment crane and from there to the erector device takes time, making the equipment inefficient.

[0034] The use of floor-running cars also complicates the arrangement of all the equipment in the back-up, especially in microtunnels with a diameter of 2.5-3 meters where space is at a minimum. In addition, during segment transport there is a collision risk for personnel in the back-up.

[0035] Furthermore, this car-based transport system has a relatively limited permissible working gradient, typically below 10%.

[0036] Another drawback of known equipment is the absence of a storage area for segments awaiting installation. The segments remain on the cars until they are picked up by the segment crane. The area behind the segment crane is therefore poorly accessible to personnel and unsafe.

[0037] A further drawback of known equipment is that the concrete tank and pumps used for backfilling behind the lining are mounted on the "train" cars. When the train is moving it is therefore not possible to carry out backfilling operations. Moreover, the carrying capacity of the car is limited, making such operations slower and less simple.

[0038] Another drawback of known equipment, linked to the car-train transport system, is the need to create dedicated recesses in the tunnel sidewalls to house the slurry extraction pumps. If housed in the tunnel bore, these pumps would interfere with the passage of the cars. Creating such recesses, however, makes the work more complex and expensive to build. In addition, these pumps can no longer be moved from their initial position should the need arise.

[0039] Beyond the safety issues for operators, particularly due to moving parts and objects in passage and / or material-handling areas, known equipment does not provide a safety zone such as a rescue (or safety) chamber or the like. Therefore, in an emergency (fires, collapses, failures of air recirculation systems, etc.) all personnel must be evacuated along the entire tunnel back to the jacking shaft (entry), an operation that takes significant time.

[0040] In this contest, the object of the present invention is to provide equipment for the construction of microtunnels that overcomes the above-mentioned limitations of the prior art.

[0041] More specifically, an object of the present invention is to provide more efficient equipment, therefore faster and more productive than known solutions.

[0042] Another object of the present invention is to provide equipment capable of operating at greater gradients than known systems.

[0043] Another object of the present invention is to provide equipment suitable for working in various types of ground, including particularly strong and plastic soils, without risking blockage of the boring machine.

[0044] A further object of the present invention is to provide equipment offering more usable space for personnel operating inside the tunnel.

[0045] Yet another object of the present invention is to provide equipment that is safer both under normal operating conditions and in emergencies.

[0046] A further object of the present invention is to provide equipment that is simpler to build and maintain and more flexible in use.

[0047] These and other objects are achieved by equipment for constructing tunnels, in particular lined microtunnels, according to claim 1.

[0048] In detail, according to the invention, the equipment comprises a boring machine (TBM) adapted to bore the ground to create the tunnel, one or more shielded service modules, and a main thrust unit (i.e., the push-module, hereinafter also simply the thrust unit) associated with a segment erector device, both likewise shielded.

[0049] In the context of the present invention, "lined tunnel" means an excavation whose inner wall is lined with a pipe made of prefabricated concrete elements or equivalent materials.

[0050] The expression "shielded modules," as applied to the service modules, refers to the external structure of such modules, which has a cylindrical metal shell, commonly termed a "shield", adapted to support the tunnel walls during excavation, preventing collapses and failures.

[0051] According to the present invention, the service modules house equipment and devices needed for the operation of the boring machine, for activities associated with the installation of prefabricated segments in segmental-lining construction, and, in general, for all tunnel-construction activities.

[0052] Such service modules generally house devices such as slurry-circulation pumps, hydraulic power packs, current transformers, electrical switchboards, ventilation devices, winding devices for electrical cables, systems for pumping fluids to lubricate the shields, etc.

[0053] The external shells of the boring machine, the service modules and the main thrust unit are arranged consecutively, one next to the other, to form a single continuous cylindrical body.

[0054] The boring machine, as in the prior art, has a cutting head provided with cutting discs or blades designed to disaggregate the ground, and a system that allows removal of the fragmented material from the cutting head, the material being removed by a slurry transport system.

[0055] The thrust unit is equipped with a plurality of hydraulic cylinders arranged circumferentially along the tunnel wall, having free ends adapted to bear (in reaction) on the front face of the lining to push the boring machine and all the service modules located downstream.

[0056] A distinctive feature of the present invention is that the thrust unit and the associated segment erector device are arranged behind, i.e., to the rear of, all the aforementioned shielded service modules. In practice, in the equipment of the present invention, at one end of the external shell of the various shielded service modules there is the thrust unit, while at the opposite end of such shell there is the boring machine, with the various shielded service modules disposed between them.

[0057] Hereinafter, the terms front and rear (or "behind") refer to the tunneling direction.

[0058] Preferably, in the equipment of the present invention, all of the above service modules are arranged in front of the main thrust unit.

[0059] Compared with the prior art, in which the thrust unit lies immediately behind the boring machine, this configuration provides numerous advantages, particularly when the equipment, after installing a certain number of lining segments by pipe jacking, is converted to continue and complete the tunnel using the segmental lining technique.

[0060] A first main advantage of the configuration according to the present invention is increased efficiency and working speed of the equipment.

[0061] Indeed, by virtue of the described configuration, the equipment of the present invention allows excavation to continue while prefabricated segments are being installed.

[0062] This is possible also because at least one telescopic thrust unit can be provided among the various service modules.

[0063] In this way, when the main thrust unit (push-module) is in the extended condition, in which the segments can be connected one by one to form a new lining ring, the telescopic thrust unit can provide the boring machine with thrust to continue excavation, taking the place of the main thrust unit.

[0064] During the phase of installing one segment at a time, the reaction needed for advancing the boring machine is in any case ensured by the support of a certain number of hydraulic cylinders, generally all those that do not interfere with segment assembly (e.g., ten out of a total of twelve).

[0065] This allows a considerable reduction in project time since, as noted, the times for excavation and lining with the segmental lining technique are significantly slower than with pipe jacking.

[0066] Another significant advantage of the configuration according to the present invention concerns safety for all persons who must travel in the tunnel and / or remain there during work phases.

[0067] Indeed, as is apparent, the area of the equipment where most human activity is concentrated is near the thrust unit because, in addition to the assembly of prefabricated segments, carried out entirely by manually commanded devices, it is also necessary to manage and supervise the segment-transport system and backfilling activities behind the lining.

[0068] In known equipment, operators must traverse the entire back-up, with all related service equipment, to reach the thrust unit and the segment erector device.

[0069] In the equipment according to the present invention, by contrast, thanks to the rear position of the thrust unit, operators travel a shorter route that is less hazardous due to the presence of equipment and devices. Moreover, the operators responsible for controlling the thrust unit and the segment erector device work in a more comfortable area of the equipment, precisely where the ventilation duct generally discharges fresh air from outside the tunnel, and in closer contact with other operators who manage segment transport and other activities in the already constructed tunnel area.

[0070] According to another aspect of the invention, the equipment may comprise at least one service module that includes pumping means for pumping waste material extracted during tunnel construction, i.e., the so-called "muck."

[0071] According to another aspect of the invention, the equipment may comprise at least one service module that includes a telescopic thrust unit. As noted above, such telescopic thrust unit can serve as an alternative thrust device to advance the boring machine when the main thrust unit is not available (as during segment installation). The telescopic unit can also serve as an auxiliary thrust device to provide additional thrust to that of the main thrust unit to overcome adverse geological zones or conditions.

[0072] This telescopic thrust unit can also be used during the construction phase using pipe jacking, providing additional thrust to the external jacking systems arranged in the jacking shaft, helping to overcome friction between the various shields and the surrounding ground.

[0073] In a preferred aspect of the invention, the equipment comprises two telescopic thrust units in respective shielded service modules. One of these telescopic thrust units is preferably arranged immediately behind the boring machine.

[0074] According to another aspect of the invention, the equipment may comprise at least one service module that includes pumping means for pumping the waste material extracted during excavation, i.e., the so-called "muck." More precisely, such means pump clean slurry forward and expel slurry mixed with excavated material.

[0075] Thanks to the configuration with the main thrust unit at the tail of the shielded modules, these pumping means can be located in the shielded portion of the equipment, thus avoiding the creation of dedicated recesses in the tunnel as in known equipment. This also allows the use of larger, more powerful pumping means thanks to the greater space available.

[0076] Moreover, being located closer to the excavation face, such pumping means can operate more efficiently.

[0077] According to another aspect of the present invention, the equipment may comprise at least one service module that includes a rescue chamber for personnel operating in the tunnel. In this way, in case of emergency (fires, gas leaks, etc.), operators working in the back-up area can reach a safe zone, i.e., the rescue chamber, more quickly and easily than evacuating the tunnel through the exit of the jacking shaft (i.e., the tunnel entrance).

[0078] More specifically, the rescue chamber can operate in a "supported" mode, i.e., with electrical power supplied from outside the tunnel.

[0079] However, the rescue chamber can also operate in a "stand-alone" mode, i.e., when external power cannot be guaranteed.

[0080] In that configuration, the chamber can be pressurized, air-conditioned and supplied with oxygen cylinders and chemical devices able to absorb gases present in the rescue chamber, such as carbon dioxide produced during breathing.

[0081] These auxiliary elements for the rescue chamber are contained within a dedicated service module, typically adjacent to the module housing the rescue chamber.

[0082] According to another aspect of the present invention, the equipment comprises a transport system for transporting objects and persons between the tunnel entrance at the jacking shaft and the main thrust unit. In a preferred embodiment, the transport system may comprise a single track, fixable to the crown of the tunnel lining, and a plurality of transport modules mounted to slide on said track. More specifically, such transport modules are substantially suspended from the track and are therefore raised above the bottom of the tunnel.

[0083] This configuration provides several advantages over known equipment, particularly those equipped with a floor-running car train.

[0084] First, the various transport modules do not interfere, during movements, with any equipment present in the tunnel. Thus, such transport modules can travel without interrupting the work phases (excavation, segment installation, clogging of the tunnel extrados , etc.).

[0085] Furthermore, unlike the prior art, ducts, pipelines, cables, recessed booster pumps or other components can be arranged on the bottom of the tunnel, i.e., in a zone that does not occupy useful space, which in known equipment would interfere with personnel and material-transit areas.

[0086] The transport system is also equipped with an emergency braking system in the event of slippage between the wheels and the track.

[0087] According to another aspect of the present invention, the transport system may comprise at least one transport module configured to transport prefabricated segments. This module is movable along a path comprising at least between the tunnel entrance and a storage area for such segments.

[0088] According to the present invention, in fact the equipment can comprise storage means adapted to temporarily accommodate a number of prefabricated segments awaiting installation. In a preferred variant, such storage means comprise cradles arranged in a row on the bottom of the tunnel, behind the main thrust unit.

[0089] Such cradles are generally supported on structural elements of the back-up and are configured to advance as the tunnel excavation proceeds and the lining is extended.

[0090] Between the storage means and the main thrust unit there is provided a loading device for the prefabricated segments configured to pick up the segments from the cradles and bring them to the segment erector device.

[0091] In one embodiment, the loading device comprises a lifting device mounted to slide on the track of the transport system, and a slide arranged on the bottom of the tunnel beneath said gripping means. The slide is slidably movable between the storage means cradle nearest to the segment erector device and said segment erector device.

[0092] More specifically, the lifting device is configured to pick up a segment from a cradle, lift it and set it down onto the slide. The slide then translates to the vicinity of the segment erector device, which can grasp the segment to carry out the lining assembly.

[0093] In a preferred variant, the slide is configured to rotate the segment from the transport position, in which the axis of curvature of the segment is typically transverse to the tunnel axis, to the assembly position, where said segment axis is parallel to the tunnel axis.

[0094] The segment loading device thus configured is safer than those of the prior art and compatible with operation on gradients up to 25% or higher.

[0095] First, as already noted, the segments do not traverse the entire back-up as in known equipment. In addition, the segments are moved at a constant height along the path from the cradle to the slide.

[0096] Moreover, thanks to the above storage means, all logistics phases for transporting segments to the erector device are simplified, making the equipment more efficient.

[0097] According to another aspect of the present invention, the transport system may further comprise at least one personnel transport module including a vehicle configured to transport people between the outside of the tunnel and the back-up area behind the segment loading system.

[0098] This vehicle comprises a frame elongated in the tunnel direction, defining a compartment adapted to accommodate people. The compartment is preferably equipped with seats but can alternatively accommodate a stretcher for transporting an injured or ill person out of the tunnel.

[0099] The frame is preferably provided with enclosing walls at least on the front, rear, top and bottom. The frame is preferably provided with guards on at least one side.

[0100] The configuration of this personnel transport module, also thanks to the fact that it is connected to the single track at the crown, is safer for both the driver and the passengers and compatible with the space available inside the tunnel. As noted above, there is a significant reduction in the risk of collisions between the module and any equipment present in the tunnel. The frame structure also provides high protection for occupants.

[0101] According to one aspect of the invention, the above-mentioned transport modules are connected to one another, preferably by rigid connecting means, such as rods, crossmembers or the like, so as to form a single vehicle movable between the tunnel entrance and the area behind the main thrust unit.

[0102] According to another aspect of the invention, motion for the modules of the transport system is provided by drive units distributed alternately among the various transport modules to which the modules are connected. In particular, the transport modules are supported by such drive units.

[0103] These drive units may comprise electric motors or, preferably, hydraulic motors, which transmit torque to wheels in contact with the track.

[0104] These wheels are preferably coated with high-friction materials, typically rubber, to allow the transmission of high torques. In this manner, the transport system of the present invention can operate, i.e., transport all transport modules, including the load of prefabricated segments, even on stretches with gradients up to 25% or more, including in the presence of small-radius horizontal or vertical curves.

[0105] This is made possible by controlling the torque output of the motors so as to ensure proper friction between the wheels of the drive units and the track at all times, thereby allowing the various modules to advance under the gradient conditions described.

[0106] According to another aspect of the invention, the transport system comprises a power unit, likewise mounted to slide on the track together with the other transport modules. This power unit is configured to supply the drive units when equipped with hydraulic motors.

[0107] This power unit is preferably also rigidly connected to all the other transport modules.

[0108] Further features and details will be better understood from the following description, provided by way of non-limiting example, and from the accompanying drawings in which: Figures 1a to 1d are respective side sectional views of portions of the tunnel-construction equipment according to the present invention; Figures 2a to 2d are respective plan views of portions of the tunnel-construction equipment of Figures 1a-1d; Figures 3a to 3d are further side sectional views of portions of the tunnel-construction equipment, on the side opposite that of Figures 1a-1d; Figure 4 is a side sectional view of a detail of the thrust unit and the loading device; and Figure 5 is a plan view of a detail of the thrust unit and the loading device.

[0109] With reference to the accompanying drawings, it is noted that the equipment of the present invention, in respective Figures 1a-1d, 2a-2d and 3a-3d, is depicted in four separate views, each including a section of the equipment, to permit sufficient intelligibility of the drawings. Indeed, due to the length being markedly greater than the diameter, an overall image of the equipment would lack the detail useful to recognize the parts and devices composing it.

[0110] In the description that follows, the terms up / down, top / bottom, above / below refer to a vertical direction. The terms front, forward, facing and rear, behind, downstream, "at the back," etc. refer to the tunneling direction of the equipment indicated by the arrow and the acronym DIR in the figures.

[0111] The equipment, indicated as a whole by 1, comprises a shielded portion 100 formed by a boring machine 110, shielded service modules, and a main thrust unit, likewise shielded, indicated as a whole by 200.

[0112] The boring machine 110 is arranged at the forward end of the shielded portion 100, corresponding to the forward end of the equipment. The boring machine 110 comprises a shield 111, at the front end of which a cutting head is installed, driven by motor means installed in the shield 111, both not shown in the accompanying drawings. The boring machine 110 of the equipment according to the present invention may be a known machine and will therefore not be described in detail.

[0113] The main thrust unit 200 is instead arranged at the opposite end of the shielded portion 100. Between the boring machine 110 and the thrust unit 200 the various shielded service modules are arranged, described in more detail below.

[0114] With reference to the accompanying drawings, the equipment 1 is shown in an operating condition, i.e., during construction of a lined tunnel T. As can be seen in the figures, the shielded portion 100 of the equipment 1 extends toward the tunnel face starting from the end Te of the tunnel section T where the inner lining Tr has already been installed.

[0115] More specifically, the thrust unit 200 is located adjacent to said end Te of the tunnel T.

[0116] Below are listed the various shielded service modules in the order in which they are arranged starting from the boring machine 110 toward the main thrust unit 200, i.e., as they appear in the accompanying drawings.

[0117] The equipment 1 comprises a service module 120 that includes a first telescopic station. This telescopic station comprises a shield 121 with two shield sections 122, 123 mounted to one another in sliding, telescopic manner. The first telescopic station 120 is equipped with a plurality of actuator cylinders 124 arranged parallel to the longitudinal axis Y of the equipment, configured to exert thrust to separate or bring together the two sections of the shield 121. The actuators 124 are supplied by a hydraulic power pack 125 housed directly in the service module.

[0118] The equipment 1 further comprises a service module 130 comprising a shield 131 in which pumping means 132, 133 are housed, configured to pump to the outside of the tunnel a mixture of slurry and debris from the ground disaggregated by the boring machine.

[0119] The equipment 1 also comprises a service module 140 comprising a shield 141 housing electrical switchboards 142. These switchboards are configured to manage the distribution of electrical power at least for all devices present in the shielded portion 100 of the equipment, such as the electric motors of the hydraulic power packs, pumping means, ventilation systems, as well as any electronic control devices and lighting.

[0120] The equipment 1 further comprises a service module 150 comprising a shield 151 in which electrical transformers 152 are arranged. These transformers are configured to transform the high-voltage supply from lines outside the tunnel into low- and medium-voltage electrical power (400 V and 960 V) to power the various devices and systems present in the shielded portion 100 of the equipment.

[0121] The equipment 1 further comprises a service module 160 that includes a second telescopic station 161. This telescopic station comprises a shield 161 with two shield sections 162, 163 mounted to one another in sliding, telescopic manner. The second telescopic station 161, like the first, is equipped with a plurality of actuator cylinders 164 arranged parallel to the longitudinal axis of the equipment. These actuators 164 are likewise supplied by the same hydraulic power pack 125 that supplies the actuators 124 of the first telescopic station 121.

[0122] The equipment 1 further comprises a service module 170 comprising a shield 171 in which a compressor 172, compressed-air cylinders (not shown), and a battery pack 174 are arranged.

[0123] The equipment 1 further comprises a service module 175 comprising a shield 176 housing a rescue chamber 177. The rescue chamber 177 comprises a tight enclosure adapted to accommodate operators working in the tunnel or in the shielded portion 100, generally at least five or six persons, in case of emergency.

[0124] If necessary, the internal volume of the chamber can be pressurized and supplied with air from the compressor 172 and cylinders 173 present in service module 170. The rescue chamber 177 is also provided with emergency electrical power supplied by the battery pack 174 in the event of interruption of the electrical line from outside or failure of electrical transformation and power-management equipment (transformers, switchboards, etc.).

[0125] The service module 175 also houses motor-fans 178 of the ventilation system that distributes fresh air from outside to all the service modules. In particular, these motor-fans 178 allow fresh air from outside to be conveyed as far as the first shield 110.

[0126] The equipment 1 further comprises a service module 180 comprising a shield 181 housing a cable-winding device 182 for the high-voltage electrical cable (6000 V) supplying power from the outside. The winding device 182 is configured to unroll the high-voltage cable as the shielded portion 100 advances into the ground away from the tunnel entrance T.

[0127] The equipment 1 further comprises a service module 190 comprising a shield 191 housing a hydraulic power pack 192 configured to supply the main thrust unit 200.

[0128] As noted above, the main thrust unit 200 constitutes the last shield section of the shielded portion 100 of the equipment 1.

[0129] The main thrust unit 200 comprises a shield 201 with a terminal section 201a that surrounds the terminal section of the lining Tr of the tunnel T.

[0130] The main thrust unit 200 comprises a support frame 202 rigidly fixed to the inner walls of the shield 201, on which hydraulic actuators 203 are mounted circumferentially adjacent to said inner walls. The piston ends 203a of the hydraulic actuators 203 are configured to abut the front-end face Fr of the tunnel lining Tr, in order to push the shielded portion 100 toward the excavation face.

[0131] The shield 201 of the main thrust unit 200 also houses the segment erector device 220. The segment erector device 220 comprises an annular guide 221 connected to the support frame 202 and arranged with its axis Ye parallel to the axis Y of the equipment, preferably coincident therewith.

[0132] A gripping means 222 is mounted slidably on the annular guide 221 around an arc of 360°, configured to grasp prefabricated segments Sp with which the tunnel lining Tr is constructed.

[0133] The gripping means 222 comprises a clamp 223 configured to hold a prefabricated segment Sp. More specifically, the clamp 223 comprises an engaging member, such as a threaded pin or the like, adapted to engage a seat formed on the inner surface of the prefabricated segment Sp. The clamp 223 is connected to the guide 221 by an articulated arm 224, which allows the clamp 223 to perform the movements required to grasp a prefabricated segment Sp from a loading area and, together with rotation of the gripping means on the guide 221, position it in an assembly position to form the lining Tr.

[0134] According to the present invention, the segment erector 220 may be selected from known devices already used in existing equipment for positioning segments in the construction of linings by the segmental lining technique.

[0135] The equipment according to the present invention further comprises a transport system, indicated as a whole by 300, for transporting people and objects between the outside of the tunnel, more precisely the jacking shaft, not shown in the figures, and an area behind the main thrust unit 200.

[0136] The transport system 300 is therefore installed and operates in the already lined section of the tunnel T.

[0137] According to the present invention, the transport system 300 comprises a track 310 fixed to the inner wall of the lining at the crown. The track 310 is formed by a plurality of I-section beams arranged consecutively one after the other along the direction of the the tunnel.

[0138] The transport system 300 further comprises a plurality of drive units 320 mounted to slide on the track 310. In detail, the drive units 320 are equipped with hydraulic motors 321 connected to at least one pair of wheels 322, each in contact with a surface of the beam. In the example shown in the figures, the wheels 322 are in contact with the core of the I-profile of the track 310 (i.e., the vertical portion of the profile). In a variant not shown, the wheels 322 can be arranged to roll on a different surface, for example on the top surface of one of the two flanges of the I-profile of the beam.

[0139] To ensure transmission of the highest possible torque, the wheels 322 are coated with a layer of rubber or equivalent materials.

[0140] The transport system 300 further comprises transport modules which are connected to, and optionally supported by, the above drive units 320.

[0141] In the example in the accompanying figures, the transport system 300 comprises a pipe-carrier transport module 330 configured to accommodate elongated objects such as lengths of piping (for example pipes for circulating slurry and excavated material to be evacuated), as well as other objects and accessories.

[0142] The transport system 300 further comprises transport modules 340 for the prefabricated segments Sp.

[0143] These segment transport modules 340, three in the example in the figures, comprise a beam 341 connected at its ends to two drive units 320, which in turn supports a cradle 342 capable of accommodating one or two prefabricated segments Sp.

[0144] The transport system 300 further comprises a personnel transport module 350 including a frame 351 supported by trolleys 352 mounted slidably on the track 310.

[0145] The frame 351 is also connected to a pair of drive units 320.

[0146] The frame 351 defines a compartment 353 with seats 354 for accommodating persons. The passenger compartment can also house a stretcher 355 for transporting injured or ill persons.

[0147] The drive units 320, in the variant comprising hydraulic motors, are powered by a power unit 360, likewise mounted to slide on the track 310 together with the other transport modules.

[0148] More specifically, the power unit 360 comprises an internal-combustion engine driving a hydraulic power pack, which in turn supplies the motors of the drive units 320. Unlike electric motors, the internal-combustion engine allows the power unit to comply with regulations for explosive atmospheres (ATEX).

[0149] According to the present invention, the equipment further comprises storage means 400 adapted to temporarily accommodate a number of prefabricated segments Sp that are transported from outside by the segment transport modules 340 before being conveyed to the segment erector device 220.

[0150] The storage means 400 comprise cradles 410 arranged in a row, adjacent to one another, on the bottom of the tunnel. In the illustrated example, the equipment comprises ten cradles 410, each able to accommodate four prefabricated segments Sp. The cradles 410 are provided with wheels running on guides or rails fixed to the bottom of the tunnel T.

[0151] In the first lined stretch of the tunnel T, between the segment erector device 220 and the storage means 400, there is provided a loading device for the prefabricated segments Sp, indicated as a whole by 500, configured to pick up the segments Sp from the cradles 410 and transport them to the segment erector device 220.

[0152] In detail, the loading device 500 comprises a lifting device 510, mounted to slide on the same track 310 of the transport system 300, and a slide 550 arranged on the bottom of the tunnel.

[0153] The lifting device 510 comprises a hoist 520 supported by a trolley 525 mounted to slide on the track 310. The hoist 520 is connected to a drive unit 530 equipped with electric motors 531 which, in turn, are connected to friction wheels 532 in contact with the track 310.

[0154] The slide 550 comprises a trolley sliding on rails 552 arranged on the bottom of the tunnel and is slidable along a stretch between the first of the cradles 410 and the segment erector device 220.

[0155] The lifting device 510 can pick up one of the prefabricated segments Sp from one of the cradle 410 and set it down on the slide 550. The slide then translates to beneath the gripping means 222 of the segment erector 220, which can grasp the prefabricated segment Sp and place it in the correct assembly position to form the lining Tr.

[0156] The slide 550 is equipped with a turntable 551 configured to rotate the prefabricated segment Sp by 90° about a vertical axis before it is grasped by the segment erector device 220, so as to present it in an assembly position.

[0157] The present invention, as described and illustrated, is susceptible of numerous modifications and variations, all within the scope of the inventive concept; moreover, all details may be replaced by other technically equivalent elements.

Claims

1. Equipment (1) for constructing tunnels, in particular lined microtunnels, comprising the following components: - a boring machine (110), adapted to bore the ground to create the tunnel (T), - at least one shielded service module (120,130, 140, 150, 160, 170, 180, 190), - a main thrust unit (200), and - a segment erector device (220), associated with the thrust unit, both being shielded, said equipment being characterized in that said main thrust unit (200) and said segment erector (220) are both arranged behind all the above-mentioned shielded service modules (120,130, 140, 150, 160, 170, 180, 190), so that said thrust unit (200) is at the opposite end of the shielded section with respect to the boring machine (110).

2. The equipment (1) according to claim 1, comprising at least one service module (120,130, 140, 150, 160, 170, 180, 190) which includes pumping means (132, 133) for pumping towards the outside of the tunnel (T) the waste material extracted during the boring.

3. The equipment (1) according to claim 1 or 2, comprising at least a service module (120,130, 140, 150, 160, 170, 180, 190) which includes a telescopic thrust unit.

4. The equipment (1) according to claim 3, comprising two telescopic thrust units in respective shielded service modules (120, 160), in which one of said telescopic thrust units is arranged in a service module (120) immediately behind the boring machine (110).

5. The equipment (1) according to one of the preceding claims, comprising at least a service module (120,130, 140, 150, 160, 170, 180, 190) which includes a rescue chamber configured to house persons operating in the tunnel (T) in the event of an emergency.

6. The equipment (1) according to one of the preceding claims, comprising at least one service module (120,130, 140, 150, 160, 170, 180, 190) which includes one or more of the following apparatus: hydraulic control units, current transformers, switchboards, ventilation devices, winding devices for electric cables, and fluid pumping systems for lubricating the shields of the shielded modules.

7. The equipment (1) according to one of the preceding claims, comprising a transport system (300), configured to transport objects and persons between an entrance of the tunnel (T) and the main thrust unit (200), said transport system (300) comprising a single track, fixable in the crown of the tunnel, and a plurality of transport modules (330, 340, 350) mounted sliding on said track and kept raised with respect to the floor of said tunnel.

8. The equipment (1) according to one of the preceding claims, comprising storage means (400) configured to accommodate a certain number of prefabricated segments (Sp) used for the construction of a lining (Tr) of the tunnel (T), said storage means (400) comprising a plurality of cradles (410) arranged adjacent to one another on the floor of the tunnel (T), at the back of the main thrust unit (200).

9. The equipment (1) according to claims 7 and 8, comprising a loading device (550) for loading the prefabricated segments (Sp), arranged between the storage means(400) and the main thrust unit (200), configured to collect prefabricated segments (Sp) from the cradles and take said prefabricated segments (Sp) to the segment erector device (220), said loading device (500) comprising a lifting device (510), mounted sliding on the track of the transport system, and a slide (550), arranged on the floor of the tunnel (T) below said gripping means, slidingly movable between the storage means cradle (410) nearest to the segment erector device (220) and said segment erector device (220).

10. The equipment (1) according to the preceding claim, in which the slide (550) is configured to rotate a prefabricated segment (Sp) from a transport position, in which the axis of the arc of curvature of the prefabricated segment (Sp) is typically transverse with respect to the axis of the tunnel (T), to an assembly position, where said axis of the prefabricated segment (Sp) is parallel to said axis of the tunnel (T).

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