A construction technology for a vertical shaft with a broken rock mass

Abstract

The invention discloses a construction process for a line-out shaft under conditions of rock mass crushing, which belongs to the technical field of water conservancy and hydropower construction engineering, and comprises the following steps: S1, preparation before construction: including arranging temporary construction projects on site according to the actual construction requirements of the line-out shaft, conducting safety education and training for relevant personnel, and performing basic treatment on the bottom of the existing shaft; S2, construction of a geological drilling rig pilot hole; S3, backfilling and supporting the excavated part of the existing shaft; S4, construction of a raise drilling rig pilot hole; S5, construction of a shaft boring machine pilot hole; S6, dismantling of the shaft boring machine and the wellhead system; S7, excavation, support and lining of the entire cross-section of the wellhead locking section, and gradually completing the construction of the line-out shaft. By adopting a timely support method of excavating and supporting one layer at a time during the construction process and by timely support after excavation, the relatively short self-stabilization time of the surrounding rock under the condition of rock mass crushing is effectively utilized, and large-scale deformation and damage that may occur during the construction of the line-out shaft is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of water conservancy and hydropower construction projects, and more particularly to a process for constructing a vertical shaft for producing a lead-out line under conditions of rock mass crushing. Background Art

[0002] Due to topographical and geomorphological constraints, hydropower development in western China often utilizes underground powerhouses. High-voltage cables, after exiting the generators in the underground powerhouses, must be routed through outgoing shafts and then brought to the surface, completing the output of the underground powerhouse's electricity.

[0003] When the underground powerhouse is buried deep, the height of the outgoing line shaft is correspondingly high, which is greatly affected by the topographic and geological conditions. According to previous engineering experience, the underground powerhouse and the outgoing line shaft need to be arranged in a location with good surrounding rock conditions. This places great restrictions on the construction site selection of the hydropower station, especially in areas with high seismic intensity. At the same time, due to the influence of the fault zone, the surrounding rock conditions are not good, and the outgoing line shaft cannot be constructed, which has created a huge obstacle to the development of water conservancy and hydropower in my country. Summary of the Invention

[0004] The purpose of the present invention is to provide a process for constructing a lead-out shaft under conditions of broken rock mass, which can realize the construction of the lead-out shaft under the premise of balancing safety, economy and efficiency under conditions of broken rock mass and poor surrounding rock conditions.

[0005] In order to solve the above problems, the present invention adopts the following technical solutions:

[0006] A process for constructing a vertical shaft for a cable outlet under rock mass crushing conditions includes the following steps:

[0007] S1. Pre-construction preparation: This includes arranging temporary construction works on site according to the actual construction requirements of the outlet shaft, providing safety education and training to relevant personnel, and carrying out foundation treatment on the bottom of the existing shaft;

[0008] S2, geological drilling rig pilot hole construction;

[0009] S3, the existing shaft has been partially excavated and backfilled for support;

[0010] S4, raise drilling rig pilot well construction;

[0011] S5. Shaft boring machine pilot shaft construction;

[0012] S6, dismantling of the shaft boring machine and the wellhead system;

[0013] S7, full section excavation, support and lining of the wellhead lock section;

[0014] S8. Installation and commissioning of gantry crane and winch at wellhead;

[0015] S9, shaft section excavation and support;

[0016] S10. Self-inspection and acceptance.

[0017] As a preferred solution of the present invention, the geological drilling rig pilot hole construction in S2 includes the following steps:

[0018] (1) The current wellbore excavation support depth is 12m. After excavating 2m from the center, the geological drilling rig construction conditions can be reached;

[0019] (2) Pour 2 meters of concrete at the bottom of the wellbore to connect with the existing wellbore wall to form the foundation for geological drilling construction;

[0020] (3) Place the geological drilling rig in the wellbore for construction. The construction process is to first excavate a mud pool and a water pool at the bottom of the well foundation, then lower the geological drilling rig and the mud pump to the bottom of the well, debug and run the hole, and finally sweep the hole to the required size to complete the geological drilling rig pilot hole construction.

[0021] As a preferred solution of the present invention, the construction procedure of S3 takes into account the narrow space for installing the shaft boring machine in the shaft, the inconvenience of installation in the shaft, the heavy weight of the shaft boring machine, etc. In order to ensure the safety of the installation workers and the subsequent construction of the pilot shaft and the shaft boring machine, the excavated shaft needs to be backfilled to EL1128m, 50cm above the natural ground, to form sufficient working space with the ground. At the same time, a 6m diameter shaft is reserved in the center of the shaft as the starting shaft of the shaft boring machine.

[0022] As a preferred embodiment of the present invention, the raise boring machine pilot well construction in S4 includes the following steps:

[0023] (1) Drilling rig selection and installation. In addition to completing the 1.4m pilot well, the raise boring rig also needs to bear the task of lifting the vertical shaft boring machine, including the weight of the drill rod. It needs to meet the necessary lifting capacity. H-shaped steel is used to process and install the wellhead cross beam. After the hoisting position of the cage is reserved, it is sealed with steel plates to form the wellhead sealing plate and the raise boring rig working plate. The raise boring rig is fixed on the cross beam.

[0024] (2) Based on the geological drilling rig construction, the hole sweeping construction is carried out. The pilot drill bit and the stable drill rod are connected together with threads to perform the hole opening operation. Low drilling pressure and low torque are used to steadily open the hole to further ensure the verticality of the hole until the hole is swept to the lower level;

[0025] (3) During the hole enlargement construction of the raise drilling rig, slowly transport the reaming drill bit to the lower level and connect it to the drill pipe. After the reaming drill bit is connected, slowly lift the drill tool until the cutter begins to contact the rock, then stop lifting, rotate it at the lowest speed, and slowly feed it forward to ensure that the drill cutter is not damaged by excessive impact. When the cutter breaks the protruding rock, continue feeding it forward and slowly enlarge the hole upward until the drill bit is exposed to the ground.

[0026] (4) After the hole is reamed, fix the reaming drill bit on the wellhead beam, remove the auxiliary equipment of the main machine, and remove all the oil cylinders and motor oil pipes except the main push cylinder. Install the drilling rig lifting rod, operate the main push cylinder valve control handle, make the main push cylinder move upward slowly, drive the power faucet upward, slowly lower the main machine, remove the main push cylinder oil pipe and motor cable after lowering it, push the main pump station, oil tank auxiliary pump station, operating table and main machine away from the working position, then lift the reaming drill bit from the wellhead, slowly lower the reaming drill bit to the flatbed truck and push it away from the wellhead to a safe area, close the wellhead, clean up the site, and all the well guidance work of the reverse drilling rig is completed.

[0027] As a preferred solution of the present invention, the vertical shaft boring machine pilot shaft construction in S5 includes the following steps:

[0028] (1) Positioning: Based on the results of the wellbore azimuth measurement, calculate and determine the extension and support force of each support cylinder, and adjust them at any time during the drilling process to ensure the drilling direction and accuracy requirements and prevent the shoe plate from sliding relative to the wellbore;

[0029] (2) Drilling: Start the motor to drive the drill bit to rotate, and the cutter begins to break the rock. According to the physical and mechanical properties of the rock and its drillability, the thrust cylinder applies the corresponding drilling pressure to achieve the rock breaking state of the cutter until the main thrust cylinder extends to the maximum stroke. When the rock conditions are poor or the deviation is corrected, the thrust cylinder can be slowly extended and retracted to sweep the hole;

[0030] (3) Support structure movement: When the main push cylinder reaches the maximum setting stroke position, rotate the drill bit to contact the rock steadily, then lock the main push cylinder and gradually loosen the 8 support cylinders. When the support force of each support cylinder is zero, gradually retract the 4 push cylinders to move the support frame downward. At the same time, the ground lifting equipment lowers the drill pipe and the push cylinders to keep synchronization. After all the push cylinders are in place, start positioning for the next drilling cycle.

[0031] As a preferred solution of the present invention, the dismantling method in S6 is that after the shaft boring machine completes the excavation construction of the entire shaft, the raise boring machine lifts all the equipment to the wellhead position, fixes the underground equipment on the wellhead cross beam, removes the drill bit, and uses a crane to lift the raise boring machine away from the wellhead. Finally, the crane is used to lift the working hoisting platform, the tunnel boring machine power head device, the drill bit, etc. out of the shaft in turn, and the control system, etc. are dismantled on the ground.

[0032] As a preferred solution of the present invention, the expansion in S7 and S9 adopts a hand drill to drill vertical holes and charge blasting, the borehole diameter is Φ42mm, a collapse hole is directly drilled in the middle, smooth blasting is adopted on the periphery, the collapse holes are arranged at equal intervals, the ratio of the minimum resistance line to the hole spacing is controlled between 1.0 and 1.2m, the blocking material is a uniform mixture of yellow mud and sand, the blasting adopts non-electric millisecond plastic detonating cords in series and parallel to form a blasting network to achieve micro-difference blasting, and electromagnetic detonator is used for detonation. In order to reduce the particle size of slag and reduce the occurrence of well blocking accidents, the blasting is carried out by drilling more holes and charging less. In the actual construction process, the spacing between the blast holes is strictly controlled, and the drilling and blasting of the vertical shaft expansion construction is carried out.

[0033] As a preferred solution of the present invention, during the construction process in S2 to S9, the construction progress is cyclically carried out by excavating one layer and supporting one layer. During the support construction, the next layer is used as the construction platform. The next cycle of excavation can only be carried out after the support is completed.

[0034] As a preferred solution of the present invention, the main forms of the support construction are system anchor rods, steel mesh, keel bars and sprayed concrete.

[0035] As a preferred solution of the present invention, during the construction process of S2 to S5, management measures for preventing and controlling hole deviation are adopted, with prevention as the main approach and correction as the auxiliary approach, and bent screws and non-magnetic drill collars are used to correct the deviation.

[0036] Compared with the prior art, the advantages of the present invention are:

[0037] Under the condition of broken rock, this plan uses the coordinated construction of raise boring machine pilot shaft excavation, shaft boring machine pilot shaft excavation and full-section excavation to gradually complete the construction of the outgoing vertical shaft. Through the timely support method of excavating one layer at a time during the construction process and the timely support after excavation, the shorter self-stabilization time of the surrounding rock under the condition of broken rock is effectively utilized, avoiding large-scale deformation and damage that may occur during the construction of the outgoing vertical shaft, ensuring the local self-stability of the outgoing vertical shaft, reducing the deformation and damage suffered by the outgoing vertical shaft, and ensuring the normal progress of the outgoing vertical shaft construction. DETAILED DESCRIPTION

[0038] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are also within the scope of protection of the present invention.

[0039] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "provided with," "mounted / connected," and "connected" should be understood in a broad sense. For example, "connected" can mean a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be internal communication between two components. Those skilled in the art will be able to understand the specific meanings of the above terms in the present invention in specific circumstances.

[0040] Example:

[0041] A process for constructing a vertical shaft for a cable outlet under rock mass crushing conditions includes the following steps:

[0042] S1. Pre-construction preparation: This includes arranging temporary construction works on site according to the actual construction requirements of the outlet shaft, providing safety education and training to relevant personnel, and carrying out foundation treatment on the bottom of the existing shaft;

[0043] According to the actual construction needs of the outlet shaft site, temporary construction projects are arranged on site, mainly including: construction roads, construction production and living auxiliary facilities and construction site layout, construction air, water and electricity supply systems, construction ventilation, construction drainage, construction communication systems, well transportation, etc. The routes along the on-site transportation roads within the construction roads meet the requirements for the transportation of large equipment.

[0044] S2, geological drilling rig pilot hole construction, including the following steps:

[0045] (1) The current wellbore excavation support depth is 12m. After excavating 2m from the center, the geological drilling rig construction conditions can be reached;

[0046] (2) Pour 2 meters of concrete at the bottom of the wellbore to connect with the existing wellbore wall to form the foundation for geological drilling construction;

[0047] (3) Place the geological drilling rig in the wellbore for construction. The construction process is to first excavate a mud pool and a water pool at the bottom of the well foundation, then lower the geological drilling rig and the mud pump to the bottom of the well, debug and run the hole, and finally sweep the hole to the required size to complete the geological drilling rig pilot hole construction.

[0048] The geological drilling rig adopts a tower-type drill tool combination structure when drilling pilot holes, which can effectively relieve the stress concentration of the drill tool, increase the stability of the drill tool rotation, effectively prevent the hole from deflecting, and provide sufficient drilling pressure. The drill tool combination used by drill bits of different specifications is shown in the table below:

[0049] Drilling Tool Assembly

[0050]

[0051] Note: The drilling tool assembly can be adjusted appropriately according to actual conditions.

[0052] During construction, inclination measurement was performed using wireless MWD technology. The inclinometer used was the Modena MDN-48KZ mud pulse inclinometer. The wireless MWD system enables timely monitoring, allowing us to stop the pump and measure wellbore trajectory parameters at any point. This saves drilling time, ensures accurate wellbore trajectory measurement, and reduces doglegs. If borehole deflection exceeds the limit, we promptly analyze and identify the cause, implement further measures, and immediately use the screw drill to correct the deflection, ensuring that the pilot hole deflection does not exceed the limit. Single-point inclinometer technology is also used to verify the hole's inclination.

[0053] During the construction process, in order to deepen the borehole in the designed direction, although the principle of "prevention first" was implemented, due to the complexity of the factors causing borehole bending, some boreholes or hole sections will still deviate from the original design direction. When the borehole is found to be deviated, the following measures will be taken: timely adjustment of the measurement interval, increase of measurement points, and identification of the borehole bending position and change value so as to take necessary measures to correct it and keep the borehole bending within the allowable range; MDN-48KZ mud pulse inclinometer monitors well inclination. Once there is a trend of exceeding the deviation standard, a bent screw and a non-magnetic drill collar are used to correct the inclination. This is the most effective correction method.

[0054] S3, the existing shaft has been partially excavated and backfilled for support;

[0055] Considering the limited space for installing a shaft boring machine in the shaft, the inconvenience of installation in the shaft, and the heavy weight of the shaft boring machine, in order to ensure the safety of the installation workers and the subsequent construction of the pilot shaft and shaft boring machine, the excavated shaft needs to be backfilled to EL1128m, 50cm above the natural ground, to form sufficient working space with the ground. At the same time, a 6m diameter shaft is reserved in the center of the shaft as the starting shaft of the shaft boring machine.

[0056] The specific construction method is as follows: When backfilling concrete, a 6m diameter area is left unfilled in the center of the shaft, which serves as a passage for the shaft boring machine to enter the shaft after installation. The backfill concrete width is 2.1m, and the backfill concrete volume per meter of the shaft is 53.4m3. To ensure that the backfill concrete is fully separated from the existing concrete shaft wall, a layer of plywood is installed on the surface of the original cast shaft wall before backfilling concrete to ensure sufficient isolation and prevent damage to the structure and appearance of the existing shaft wall concrete during subsequent expansion.

[0057] The backfill concrete is C20, which is mixed by a mixing station and transported to the wellhead by a 6m3 concrete mixer truck. The backfill is carried out in layers, with each layer 1500mm high. The concrete in the wellbore is transported to the well using Ф219×6 seamless steel pipes. The concrete is poured in series with bamboo tubes and chutes in the well to prevent segregation of the concrete. A frequency converter is used for vibration.

[0058] The formwork is supported by 3015 steel, with a section height of 1500mm. A 12-channel steel ring is used on the outside of the formwork to ensure its integrity and stability. Double-row scaffolding is erected along the ring, with scissor braces and diagonal braces for secure connection. Ø12 tie rods are used on the concrete side to connect to the original concrete wall, ensuring the formwork's reliable strength, preventing displacement and leakage, and guaranteeing the quality of the backfill concrete.

[0059] S4, Raise Boring Machine Pilot Well Construction, including the following steps:

[0060] (1) Drilling rig selection and installation. In addition to completing the 1.4m pilot well, the raise boring rig also needs to bear the task of lifting the vertical shaft boring machine, including the weight of the drill rod. It needs to meet the necessary lifting capacity. H-shaped steel is used to process and install the wellhead cross beam. After the hoisting position of the cage is reserved, it is sealed with steel plates to form the wellhead sealing plate and the raise boring rig working plate. The raise boring rig is fixed on the cross beam.

[0061] (2) Based on the geological drilling rig construction, the hole sweeping construction is carried out. The pilot drill bit and the stable drill rod are connected together with threads to perform the hole opening operation. Low drilling pressure and low torque are used to steadily open the hole to further ensure the verticality of the hole until the hole is swept to the lower level;

[0062] (3) During the hole enlargement construction of the raise drilling rig, slowly transport the reaming drill bit to the lower level and connect it to the drill pipe. After the reaming drill bit is connected, slowly lift the drill tool until the cutter begins to contact the rock, then stop lifting, rotate it at the lowest speed, and slowly feed it forward to ensure that the drill cutter is not damaged by excessive impact. When the cutter breaks the protruding rock, continue feeding it forward and slowly enlarge the hole upward until the drill bit is exposed to the ground.

[0063] (4) After the hole is reamed, fix the reaming drill bit on the wellhead beam, remove the auxiliary equipment of the main machine, and remove all the oil cylinders and motor oil pipes except the main push cylinder. Install the drilling rig lifting rod, operate the main push cylinder valve control handle, make the main push cylinder move upward slowly, drive the power faucet upward, slowly lower the main machine, remove the main push cylinder oil pipe and motor cable after lowering it, push the main pump station, oil tank auxiliary pump station, operating table and main machine away from the working position, then lift the reaming drill bit from the wellhead, slowly lower the reaming drill bit to the flatbed truck and push it away from the wellhead to a safe area, close the wellhead, clean up the site, and all the well guidance work of the reverse drilling rig is completed.

[0064] When reaming begins, a dedicated person will monitor the situation and promptly notify the operator. Drilling can only proceed properly once the drill bit is fully and evenly in contact with the rock. To ensure the lifespan of the drill rig and cutter, the system pressure is generally limited to 16 MPa. During reaming, if the rock is hard, the drilling pressure can be increased appropriately; otherwise, it can be reduced. During reaming, slag must be removed promptly to prevent hole blockage. The reaming process also involves removing the drill pipe, which must be cleaned, oiled, and properly capped.

[0065] When the drill bit expands the hole to 2.5m away from the foundation, reduce the drilling pressure and drill slowly, observe carefully. If any abnormal phenomenon occurs around the foundation, take timely measures to deal with it, and continue to expand the hole slowly until the drill bit is exposed to the ground.

[0066] S5, the construction of the pilot shaft of the vertical shaft boring machine, includes the following steps:

[0067] (1) Positioning: Based on the results of the wellbore azimuth measurement, calculate and determine the extension and support force of each support cylinder, and adjust them at any time during the drilling process to ensure the drilling direction and accuracy requirements and prevent the shoe plate from sliding relative to the wellbore;

[0068] (2) Drilling: Start the motor to drive the drill bit to rotate, and the cutter begins to break the rock. According to the physical and mechanical properties of the rock and its drillability, the thrust cylinder applies the corresponding drilling pressure to achieve the rock breaking state of the cutter until the main thrust cylinder extends to the maximum stroke. When the rock conditions are poor or the deviation is corrected, the thrust cylinder can be slowly extended and retracted to sweep the hole;

[0069] (3) Support structure movement: When the main push cylinder reaches the maximum setting stroke position, rotate the drill bit to contact the rock steadily, then lock the main push cylinder and gradually loosen the 8 support cylinders. When the support force of each support cylinder is zero, gradually retract the 4 push cylinders to move the support frame downward. At the same time, the ground lifting equipment lowers the drill pipe and the push cylinders to keep synchronization. After all the push cylinders are in place, start positioning for the next drilling cycle.

[0070] Using a raise boring rig to create a pilot shaft, a vertical shaft boring machine was used to drill a Φ5.8m secondary pilot shaft from top to bottom. Crushed rock debris fell by its own weight through the primary slag chute to the bottom of the shaft, where it was discharged by underground transportation equipment through the access tunnel of the outgoing vertical shaft. A BMC600 raise boring rig and a dedicated multi-functional hoisting platform were used for auxiliary operations, achieving rock drilling, slag removal, temporary support, and auxiliary drilling work.

[0071] On the ground, 50-ton and 160-ton cranes were used to assemble the power head and support devices, install the control platform, and debug the system. A 300-ton crane was used to sequentially lift the 5.8m drill bit and power head support device into the shaft. The drill bit and power head support device were connected, and the system was activated to properly position the shoe plate, ensuring the overall centering and stability of the TBM. The support hoisting platform, hoist cage, and wellhead crossbeam were then installed. Finally, the raise boring machine was secured to the crossbeam, the system was activated, and the drill pipe was lowered to connect to the shaft TBM, completing the safe lifting of the TBM.

[0072] A shaft boring machine (TBM) uses toothed roller cutters for rock breaking. The TBM includes support, propulsion, rotation, and control systems, primarily responsible for rock breaking. The roller cutters are arranged in a regular pattern on the TBM drill head. They crush the rock through a combination of squeezing, shearing, and scraping, breaking it and separating it from the rock mass. The motor drives the gearbox to reduce gears, rotating the drill head. The propulsion cylinder, via the propulsion drive, slides up and down along the TBM support columns, transmitting propulsion force to the drill head. The main frame is supported against the shaft wall by cylinders. The upper and lower support systems withstand the rock breaking reaction thrust and torque. After the propulsion cylinder completes one stroke, the main frame moves downward along the shaft axis for a distance. The support cylinder then pushes the support plate to maintain support against the shaft wall. After alignment, the next rock breaking cycle begins. During drilling, the support cylinder extends, tightening the support shoe plate against the rock wall, securing the mainframe and transmitting the reaction force required by the propulsion cylinder to propel the cutterhead forward and the rotational reaction torque required for the cutterhead's rotation to the rock mass. Each support shoe can be independently adjusted to control the machine's attitude and direction, ensuring drilling along the designed axis. TBM parameters are adjusted appropriately based on rock mass conditions to prevent damage to the rock beneath the shoe, which could lead to instability. Each tunneling section is 1 meter high. The TBM's drill bit is conical, and crushed rock debris slides along the conical surface at the bottom of the shaft, enters the primary pilot shaft, and falls to the bottom of the shaft, where it is transported via the outgoing shaft transportation system.

[0073] S6, dismantling of the shaft boring machine and the wellhead system;

[0074] After the shaft boring machine completes the entire shaft excavation, a BMC600 raise boring rig hoists all equipment to the wellhead. The downhole equipment is secured to the wellhead's truss beam. After removing the drill bit, the raise boring rig is hoisted out of the wellhead using a crane. Finally, a 300t crane is used to sequentially lift the work platform, the roadheader power unit, and the drill bit out of the shaft, allowing the control system and other equipment to be dismantled on the surface.

[0075] S7, full section excavation, support and lining of the wellhead lock section;

[0076] The vertical shaft is excavated from top to bottom. When the vertical shaft is expanded, the wellhead needs to be equipped with a hoisting system, and a coal mine Ф1200 hoist is used. A wire rope hoist cage is used for lifting personnel, and personnel ascend and descend via the cage. Equipment, materials, and tools are transported up and down the well using a 20t gantry crane. Personnel and materials cannot be transported simultaneously. The cage and gantry crane must undergo a load test and pass the test before being put into use. A wellhead construction safety platform is installed at the wellhead. It is safely constructed using 16# I-beams on a lockable concrete surface and covered with δ3.5mm anti-skid steel plates. A dedicated person is assigned to guard the wellhead to transport personnel in and out.

[0077] S8. Installation and commissioning of gantry crane and winch at wellhead;

[0078] The winch foundation is cleaned to the bedrock surface, and the concrete foundation is 20cm above the ground to facilitate drainage during construction. The concrete surface should be flat, and the convex and concave changes should not exceed 1.5cm. When installing the winch and its auxiliary equipment, the winch wire rope should be in a straight line with the pulley, and the angle should meet the requirements of the regulations; the ground anchor should be The steel bar is inserted into the rock 2m deep. The winch safety device is installed. The safety device generally includes a load limiter, a stroke limiter, etc. The permissible overload value of the winch is generally set to not exceed 10% of the rated lifting capacity. Therefore, when the actual load reaches 110% of the rated lifting capacity, the load limiter should automatically cut off the power supply and stop the motor. The upper and lower travel limits generally use a travel switch controller. When the winch lifts or lowers beyond the specified limit, the travel switch controller will automatically cut off the power supply and stop the motor. After the winch is installed, it must pass the acceptance inspection before it can be used.

[0079] S9, shaft section excavation and support;

[0080] After the wellhead section and wellhead layout of the outgoing line shaft were completed, the shaft expansion construction was carried out according to the "one row of blasting, one support" method. The blastholes were drilled manually using a YT-28 hand-held pneumatic drill. The drilling direction was roughly parallel to the centerline of the outgoing line shaft. The excavation cycle drilling depth was 2.5m. Smooth blasting was used. After blasting, manual slag removal and surface cleaning were carried out. The slag flowed through the pilot shaft to the outgoing line flat tunnel at the bottom of the shaft. A 3.0m3 loader was used to load the slag into a 20t dump truck and transport it to the designated slag site. The main construction measures are as follows:

[0081] (1) Surveying and setting out: Control surveys use a total station to create a wire control network, while construction surveys use a laser pointer and plumb line for control. The laser pointer is located on the wellhead truss beam. Surveying operations are carefully performed by professionals. Before each drilling, the location of each hole is marked on the tunnel face with red paint. Additionally, a survey check is conducted during each shift to ensure the quality of the surveying process.

[0082] (2) Drilling: Skilled drillers are selected and drilled strictly according to the design. Each driller is assigned a zone and a division to locate and drill, and a strict economic responsibility system for drilling quality is implemented. Each row of blasting is inspected by the on-duty technician according to the requirements of the blasting map. The deviation of the peripheral holes shall not exceed 5cm, and the deviation of the blasting holes shall not exceed 10cm. After the slagging is completed, the pilot shaft is closed by using a lifting operation plate hoist to pull a 7m diameter protective plate.

[0083] (3) Charging and blasting: Blasters carefully follow the drilling and blasting design parameters, using rock emulsion explosives. Continuous charging is used for caving holes and slot holes using 32mm diameter cartridges. Peripheral holes use 25mm diameter cartridges and intermittent charging. After charging is complete, technicians and professional blasters conduct area-by-area inspections, connect the blasting network, and evacuate equipment and materials to a safe area before detonation.

[0084] (4) Ventilation and smoke dispersion: After blasting, natural wind is used for ventilation, and the blasting slag pile is manually sprinkled with water to remove dust.

[0085] (5) Slag removal: Slag removal is done manually. When removing slag, personnel must take safety precautions, fasten their safety belts, and firmly connect to the safety rope under the plate, and strictly follow the operating procedures.

[0086] (6) Safety treatment: After blasting, safety officers and skilled workers will handle the slag and loose rocks on the well wall. After the slag is removed, safety inspections and support will be carried out again to prepare for the next drilling cycle.

[0087] Support construction follows excavation, with support layer added as each layer is excavated. Anchor bolts are drilled using a YT-28 hand drill, manually inserted, and grouting is performed using an MZ1 grouting pump. Shotcrete is sprayed using a PZ-6 concrete sprayer, manually sprayed with a handheld nozzle. Initially, 5cm of concrete is sprayed, followed by anchor bolts, mesh installation, and finally, re-spraying to the designed thickness. During support construction, the excavated working surface is used as a working platform. Excavation of the next layer can only begin after the upper layer is fully supported. Excavation of the next layer is strictly prohibited without completing the support of the upper layer. Shotcrete material is transported from the mixing station to the wellhead and then slid to the working surface using a chute located within the well.

[0088] The excavation and support procedures are as follows: excavation, slag removal, initial spraying of 5cm concrete, drilling, grouting and installation of anchor rods, hanging of steel mesh, and re-spraying of 5cm concrete to the designed thickness.

[0089] S10. Self-inspection and acceptance: During the entire construction process, safety measures and construction quality must be inspected. Only after completion of the acceptance can the next step of construction be carried out to ensure the construction quality of the outlet shaft.

[0090] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes based on the technical solutions and improved concepts of the present invention within the technical scope disclosed by the present invention, and these changes should be covered by the scope of protection of the present invention.

Claims

1. A process for constructing a vertical shaft for a cable outlet under rock mass crushing conditions, characterized in that: It includes the following steps: S1. Pre-construction preparation: This includes arranging temporary construction works on site according to the actual construction requirements of the outlet shaft, providing safety education and training to relevant personnel, and carrying out foundation treatment on the bottom of the existing shaft; S2, geological drilling rig pilot hole construction; S3, the existing shaft has been partially excavated and backfilled for support; S4, raise drilling rig pilot well construction; S5. Shaft boring machine pilot shaft construction; S6, dismantling of the shaft boring machine and the wellhead system; S7, full section excavation, support and lining of the wellhead lock section; S8. Installation and commissioning of gantry crane and winch at wellhead; S9, shaft section excavation and support; S10, self-inspection and acceptance; The construction procedure of S3 takes into account the narrow space for installing the shaft boring machine in the shaft, the inconvenience of installation in the shaft, and the heavy weight of the shaft boring machine. To ensure the safety of the installation workers and the subsequent construction of the pilot shaft and shaft boring machine, the excavated shaft needs to be backfilled to EL1128m, 50cm above the natural ground, to form sufficient working space with the ground. At the same time, a 6m diameter shaft is reserved in the center of the shaft as the starting shaft of the shaft boring machine.

2. The process for constructing a vertical shaft for a cable outlet under rock mass crushing conditions according to claim 1, characterized in that: The geological drilling rig pilot hole construction in S2 includes the following steps: (1) The current shaft excavation support depth is 12m, and the construction conditions of the geological drilling rig will be reached after excavating 2m from the center; (2) Pour 2 meters deep concrete at the bottom of the wellbore to connect with the existing well wall to form the foundation for geological drilling construction; (3) Place the geological drilling rig in the wellbore for construction. The construction process is to first excavate a mud pool and a water pool at the bottom of the well foundation, then lower the geological drilling rig and the mud pump to the bottom of the well, debug and run the hole, and finally sweep the hole to the required size to complete the geological drilling rig pilot hole construction.

3. The process for constructing a vertical shaft for a cable outlet under rock mass crushing conditions according to claim 1, characterized in that: The raise boring machine pilot well construction in S4 includes the following steps: (1) Drilling rig selection and installation. In addition to completing the 1.4m pilot well, the raise boring rig also needs to undertake the task of lifting the vertical shaft boring machine, including the weight of the drill rod. It needs to meet the necessary lifting capacity. H-shaped steel is used to process and install the wellhead cross beam. After the hoisting position of the cage is reserved, it is sealed with steel plates to form the wellhead sealing plate and the raise boring rig working plate. The raise boring rig is fixed on the cross beam. (2) Based on the geological drilling rig construction, the hole sweeping construction is carried out. The pilot drill bit and the stable drill rod are connected together with threads to perform the hole opening operation. Low drilling pressure and low torque are used to steadily open the hole to further ensure the verticality of the hole until the hole is swept to the lower level; (3) For hole enlargement with a raise drilling rig, slowly transport the reaming drill bit to the lower level and connect it to the drill pipe. After the reaming drill bit is connected, slowly lift the drill bit until the cutter begins to contact the rock. Then stop lifting it, rotate it at the lowest speed, and feed it slowly to ensure that the drill cutter is not damaged by excessive impact. When the cutter breaks the protruding rock, continue feeding it and slowly enlarge the hole upwards until the drill bit is exposed to the ground. (4) After the hole is reamed, fix the reaming drill bit on the wellhead beam, remove the auxiliary equipment of the main machine, and remove all the oil cylinders and motor oil pipes except the main push cylinder. Install the drilling rig lifting rod, operate the main push cylinder valve control handle, make the main push cylinder move upward slowly, drive the power faucet upward, slowly lower the main machine, remove the main push cylinder oil pipe and motor cable after lowering it, push the main pump station, oil tank auxiliary pump station, operating table and main machine away from the working position, then lift the reaming drill bit from the wellhead, slowly lower the reaming drill bit to the flatbed truck and push it away from the wellhead to a safe area, seal the wellhead, clean up the site, and all the well guidance work of the reverse drilling rig is completed.

4. The process for constructing a vertical shaft for a cable outlet under rock mass crushing conditions according to claim 1, characterized in that: The pilot shaft construction of the shaft boring machine in S5 includes the following steps: (1) Positioning: Based on the results of the wellbore orientation measurement, calculate and determine the extension and support force of each support cylinder, and adjust them at any time during the drilling process to ensure the drilling direction and accuracy requirements and prevent the shoe plate from sliding relative to the wellbore wall; (2) Drilling: Start the motor to drive the drill bit to rotate, and the cutter begins to break the rock. According to the physical and mechanical properties of the rock and its drillability, the thrust cylinder applies the corresponding drilling pressure to achieve the rock breaking state of the cutter volume, until the main push cylinder extends to the maximum stroke. When the rock conditions are poor or the deviation is corrected, the thrust cylinder can be slowly extended and retracted to sweep the hole; (3) Support structure movement: When the main push cylinder reaches the maximum setting stroke position, rotate the drill bit to contact the rock smoothly, then lock the main push cylinder and gradually loosen the 8 support cylinders. When the support force of each support cylinder is zero, gradually retract the 4 propulsion cylinders to move the support frame downward. At the same time, the ground winch equipment lowers the drill pipe and the propulsion cylinders synchronously. After all the propulsion cylinders are in place, start positioning for the next drilling cycle.

5. The process for constructing a vertical shaft for a cable outlet under rock mass crushing conditions according to claim 1, characterized in that: The dismantling method in S6 is that after the shaft boring machine completes the excavation of the entire shaft, the raise boring machine lifts all the equipment to the wellhead position, fixes the underground equipment on the wellhead cross beam, removes the drill bit, and then uses a crane to lift the raise boring machine away from the wellhead. Finally, the crane is used to lift the working hoisting platform, the tunnel boring machine power head device, and the drill bit out of the shaft in sequence, and the control system is dismantled on the ground.

6. The process for constructing a vertical shaft for a cable outlet under rock mass crushing conditions according to claim 1, characterized in that: The expansion in S7 and S9 adopts hand drill to drill vertical holes and charge blasting, the borehole diameter is Φ42mm, the collapse hole is directly drilled in the middle, smooth blasting is adopted on the periphery, the collapse holes are arranged at equal intervals, the ratio of minimum resistance line to hole spacing is controlled between 1.0 and 1.2m, the blocking material is a uniform mixture of yellow mud and sand, the blasting adopts non-electric millisecond plastic detonating cords connected in series and parallel to form a blasting network to achieve micro-difference blasting, and electromagnetic detonator is used for detonation. In order to reduce the particle size of slag and reduce the occurrence of well blocking accidents, the blasting is carried out by drilling more holes and charging less. In the actual construction process, the spacing between the blast holes is strictly controlled, and the drilling and blasting of the vertical shaft expansion construction is carried out.

7. The process for constructing a vertical shaft for a cable outlet under rock mass crushing conditions according to claim 1, characterized in that: During the construction process of S2 to S9, the method of excavating one layer and supporting one layer is adopted to cyclically advance the construction. During the support construction, the next layer is used as the construction platform. The next cycle of excavation can only be carried out after the support is completed.

8. The process for constructing a vertical shaft for a cable outlet under rock mass crushing conditions according to claim 7, characterized in that: The main forms of support construction are system anchor rods, steel mesh, keel bars and sprayed concrete.

9. The process for constructing a vertical shaft for a cable outlet under rock mass crushing conditions according to claim 1, characterized in that: During the construction process of S2 to S5, management measures to prevent and control hole deviation were adopted, with prevention as the main approach and correction as the auxiliary approach, and bent screws and non-magnetic drill collars were used to correct the deviation.

Images