Mechanical construction method of multi-stage shaft structure of water diversion system of pumped storage power station

Abstract

The application provides a mechanized construction method of a multi-stage vertical shaft structure of a water diversion system of a pumped storage power station, adopts a full-mechanized construction method of "directional drilling + reverse shaft drilling + vertical shaft reaming heading machine", and is a feasible technical approach to solving problems of many underground operation personnel of an existing vertical shaft blasting well construction, complex process, difficult safety control, and environmental pollution and the like; the directional drilling can significantly improve the perpendicularity of a deep vertical shaft, and further control the inclination rate of the vertical shaft; and the reverse shaft drilling machine and the vertical shaft reaming heading machine are representative technologies and equipment of a development direction of "fewer personnel, mechanization, standardization, and intelligence", have outstanding advantages in quality, construction period, safety, environmental protection, and civilized construction, realize integrated construction operation of excavation, slag removal, support, and guidance, the construction speed of the heading machine method is 3-4 times that of the drilling and blasting method, the excavation efficiency of the vertical shaft is significantly improved, and the method is an effective approach to realizing the mechanization and intelligent construction of the vertical shaft of the pumped storage power station.

Description

Technical Field

[0001] This invention belongs to the field of pumped storage power station construction technology, and in particular relates to a mechanized construction method for multi-stage vertical shaft structures in the water diversion system of a pumped storage power station. Background Technology

[0002] Currently, the water diversion systems of pumped storage power stations under construction in China generally adopt a multi-stage inclined shaft layout. The design parameters of the inclined shafts are generally: inclination angle of 45~60°, diameter of 6~10 m, and length of about 400 m. They are characterized by steep inclination angle, large diameter, and long length, making construction extremely difficult. Most of the domestic water diversion inclined shaft excavation adopts the construction method of pilot shaft + drill-blasting expansion. Its main disadvantages are: (1) the deviation rate error of the inclined shaft pilot shaft is large, and the guidance and correction control are difficult; (2) the safety of blasting construction is poor, the tunnel flatness is poor, the ventilation and smoke dissipation conditions are poor, the construction speed is slow, and the problems of blockage of inclined pilot holes and over- and under-excavation are common. These factors restrict the safe and efficient construction of the water diversion inclined shafts of pumped storage power stations and easily lead to the water diversion inclined shaft becoming the critical line of the project.

[0003] Compared with inclined shaft construction, vertical shaft construction has the following advantages: (1) Vertical pilot shaft construction is convenient, the bending moment of self-weight load is zero, the accuracy of the pilot shaft is controllable, the requirements for drilling equipment are low, and the construction difficulty is low; (2) Vertical pilot shaft is convenient for slag removal, and the slag removal efficiency is high; (3) The vertical shaft lifting system does not require the installation of rails, the lifting speed is fast, and the construction risk is low compared with the rail-mounted excavation trolley. In addition, the starting point of the steel lining of a single-stage vertical shaft is located in the upper horizontal tunnel of the water diversion, while the starting point of the steel lining of a multi-stage vertical shaft is located in the middle horizontal tunnel of the water diversion. The multi-stage vertical shaft layout can save the length of the steel lining of the water diversion system and reduce the project investment. In summary, in terms of construction difficulty, deviation rate control, hole blockage risk, construction safety, and project investment, the multi-stage vertical shaft layout scheme of the water diversion system has significant advantages. At the same time, the multi-stage vertical shaft layout also provides favorable conditions for mechanized excavation.

[0004] However, there are relatively few research results on the layout structure and construction methods of multi-stage water diversion shafts in pumped storage power stations. Most of the research focuses on the layout and construction methods of single-stage water diversion inclined / vertical shafts. For example, Chinese patent CN214695483U proposes a single-stage water diversion inclined shaft layout structure for hydropower stations. This layout structure results in a long inclined shaft, which poses a high risk to construction safety. It uses inclined shaft TBMs for bottom-up reverse excavation, and it is difficult to deal with accidents such as machine jamming and collapse if adverse geological conditions are encountered. Chinese patent CN111677512A proposes a vertical shaft water diversion tunnel excavation method, which makes the axis of the slag chute and the axis of the vertical shaft form an angle greater than zero degrees, thereby reducing the large-scale expansion of the drilling rig working chamber. This method still uses the reverse shaft pilot hole + drill and blast expansion construction method, and the safety of explosives construction is difficult to control.

[0005] At present, non-blasting rock breaking technology, represented by shaft reaming tunneling machines, is an important direction for the development of shaft construction technology. It has the advantages of low safety risk, fast construction efficiency, small disturbance to surrounding rock, and high level of mechanization. At present, the application of shaft reaming tunneling machines in China is relatively small, and there are no construction cases of using shaft reaming tunneling machines to construct multi-stage shafts. Summary of the Invention

[0006] The purpose of this invention is to provide a mechanized construction method for the multi-stage vertical shaft structure of the water intake system of a pumped storage power station, so as to solve the problems of high construction risk, large number of workers, and low degree of mechanization in the construction of multi-stage vertical shafts of pumped storage power stations.

[0007] Therefore, the above-mentioned objective of the present invention is achieved through the following technical solution:

[0008] Based on the multi-stage vertical shaft structure of the water intake system of a pumped storage power station, a mechanized construction method for the multi-stage vertical shaft structure of the water intake system of a pumped storage power station is proposed.

[0009] The pumped storage power station's water intake system comprises a multi-stage vertical shaft structure, including an upper water intake shaft and a lower water intake shaft. The upper part of the upper water intake shaft is connected to the upper horizontal tunnel. The lower part of the upper water intake shaft and the upper part of the lower water intake shaft are connected through the middle horizontal tunnel. The lower part of the lower water intake shaft is connected to the lower horizontal tunnel. The lower horizontal tunnel connects to the main powerhouse.

[0010] A water diversion surge well is provided above the water diversion vertical shaft, and the water diversion surge well is connected to the ground surface;

[0011] The water diversion horizontal tunnel and the water diversion lower horizontal tunnel are respectively connected to the first construction adit and the second construction adit;

[0012] The mechanized construction method for the multi-stage vertical shaft structure of the pumped storage power station's water intake system includes the following steps:

[0013] S1: Excavate and support the slope of the water diversion surge tank platform. Excavate the first launching well downward from the top of the water diversion surge tank. Construct the lock and ring beam foundation at the opening of the first launching well. Arrange a gantry crane system above the first launching well to hoist mechanical equipment. Use a hydraulic breaker and a long-arm excavator to excavate downward to form the first launching well with a depth of 10 m and a diameter of 8 m. Form the first launching platform below the first launching well.

[0014] S2: Repeat the construction steps in step S1 to excavate a second launching well and a second launching platform with a depth of 10 m and a diameter of 8 m at the upper end of the water diversion shaft.

[0015] S3: Install a directional drilling rig on the first starting platform. Drill a 410 mm directional hole from top to bottom along the central axis of the water diversion vertical shaft to meet the drill rod diameter required for the raise shaft drilling rig construction. After the directional hole exceeds 30 m, install a wireless drilling rig to control the borehole trajectory under the guidance of its measurement parameters, thereby improving the accuracy of the directional hole. Continue until the directional hole penetrates to the horizontal tunnel of the water diversion, at which point the directional hole construction is completed. Remove the directional drill bit and the matching inclination and correction equipment, and use a gantry crane system to dismantle the directional drilling rig and auxiliary equipment.

[0016] S4: Transport the dismantled directional drilling rig and auxiliary equipment to the second starting platform of the water diversion shaft, and repeat the construction steps in step S3 to form a φ410 mm pilot hole for the water diversion shaft.

[0017] S5: Install the main unit of the raise boring machine, main and auxiliary pump stations, and other equipment on the first launching platform. Use the raise boring machine to construct a φ1.5 m pilot well from bottom to top along the φ410 mm pilot hole. Lower the drill rod of the raise boring machine along the φ410 mm pilot hole to the lower end of the upper vertical shaft of the water diversion. Transport the φ1.5 m diameter raise boring reaming bit through the construction adit and the horizontal tunnel of the water diversion to the lower end of the upper vertical shaft of the water diversion, connect it to the drill rod of the raise boring machine, and then slowly lift the reaming bit to carry out the reaming construction from bottom to top. After the φ1.5 m pilot well is reamed, use the gantry crane system to dismantle the raise boring machine and auxiliary equipment.

[0018] S6: Transport the dismantled reverse drilling rig and auxiliary equipment to the second starting platform of the water diversion shaft, and repeat the construction steps in step S5 to form a φ1.5 m pilot shaft for the water diversion shaft;

[0019] S7: Assemble and debug the shaft expansion tunneling machine inside the first starting shaft. Use the shaft expansion tunneling machine to excavate and perform initial support from top to bottom. Expand the water diversion shaft to the designed diameter of 8 m. The broken rock debris falls into the water diversion tunnel by its own weight through a 1.5 m guide shaft. It is then transported out by underground transportation equipment through the water diversion tunnel and the first construction adit.

[0020] S8: After the excavation of the upper shaft for water diversion is completed, the tunneling machine equipment will be dismantled sequentially in the horizontal tunnel of the water diversion.

[0021] The disassembly sequence is as follows: cutterhead, support propulsion system, main drive system, anchor bolt system, shotcrete system, and auxiliary systems; the disassembled shaft tunneling machine equipment is transported to the second launching platform via a water diversion tunnel.

[0022] S9: Repeat the assembly, debugging and excavation support process in step S7: Assemble and debug the shaft expansion tunneling machine inside the second starting shaft, and use the shaft expansion tunneling machine to expand the water diversion shaft from top to bottom to the design diameter. The broken rock debris falls into the water diversion tunnel by its own weight through the φ1.5 m guide shaft, and is transported out by underground transportation equipment through the water diversion tunnel and the second construction adit.

[0023] S10: After the excavation of the water diversion shaft is completed, the tunneling machine is dismantled in sequence in the water diversion horizontal tunnel and transported out of the site through the water diversion horizontal tunnel and the second construction adit.

[0024] While adopting the above technical solutions, the present invention may also adopt or combine the following technical solutions:

[0025] As a preferred technical solution of the present invention: the upper vertical shaft for water diversion is lined with concrete, and the horizontal tunnel for water diversion and the lower vertical shaft for water diversion are lined with steel plates;

[0026] When the thickness of the overlying rock mass of the water diversion tunnel meets the minimum overburden thickness, the water diversion tunnel should be lowered as much as possible so that the length of the upper water diversion shaft is greater than the length of the lower water diversion shaft, thereby reducing the steel lining length of the lower water diversion shaft and lowering the project investment.

[0027] As a preferred embodiment of the present invention: in step S7 or S9, the assembly process of the vertical shaft reaming tunneling machine is as follows:

[0028] 1) The rock-breaking cutterhead, support propulsion system, and main drive system are sequentially hoisted into the well using a gantry crane system and assembled into the main unit of the vertical shaft reaming tunneling machine;

[0029] 2) Install a steel strand lifting system on the foundation of the lock ring beam, and connect the steel strand lifting system to the main machine of the tunneling machine to ensure that the overall posture of the main machine of the tunneling machine is centered and stable;

[0030] 3) The anchor bolt system, shotcrete system, and subsequent supporting systems are installed sequentially using a gantry crane system;

[0031] 4) After the shaft reaming machine is fully assembled, connect the electrical wiring to the ground control room and confirm the assembly, ensuring that the power supply lines and hydraulic lines are connected correctly and reliably.

[0032] As a preferred embodiment of the present invention, the commissioning process of the vertical shaft reaming tunneling machine in step S7 or S9 is as follows:

[0033] The commissioning of the vertical shaft reaming machine is mainly divided into four steps: power supply commissioning, control commissioning, hydraulic commissioning, and functional commissioning. After the equipment commissioning is completed, the center of the starting shaft and the center of the equipment are re-measured before starting excavation.

[0034] 1) Power supply commissioning: Confirm that all power supply systems are functioning normally and meet power supply requirements;

[0035] 2) Control and commissioning: Confirm that all power supply switches and protection devices are operating normally and reliably;

[0036] 3) Hydraulic commissioning: Confirm that the hydraulic pump station is operating normally;

[0037] 4) Functional debugging: Confirm that the excavation, propulsion, and slag removal systems of the equipment are functioning normally.

[0038] As a preferred embodiment of the present invention: in step S7 or S9, the excavation and support process of the shaft reaming machine is as follows:

[0039] 1) Positioning: Based on the azimuth measurement results of the starting well, calculate and determine the extension amount and support force of the hydraulic cylinder of the support system, and adjust them at any time during the excavation of the vertical shaft reaming machine to ensure the drilling direction and accuracy requirements;

[0040] 2) Excavation and muck removal: This operation is located in the ground control room. When the shaft reaming machine is excavating, the support system is tightened and the cutterhead is started. The excavation construction needs to find the matching speed and penetration depth according to the strata. The equipment is designed with a cutterhead rated speed of 3 r / min. The cutterhead has a conical structure. The broken rock muck slides along the conical surface at the bottom of the shaft and falls into the 1.5 m pilot shaft. The muck is then transported out by the horizontal tunnel transportation system.

[0041] 3) Support structure changeover: When changing steps, the support system tensioning force needs to be increased. At the same time, the cutterhead stops rotating. After the tunneling machine stops running, the support system tensioning cylinder is retracted, the propulsion cylinder is retracted, the support system is lowered to complete the changeover, the support system is re-tensioned, the equipment attitude is checked, the cutterhead is restarted, and the next cycle of tunneling is carried out.

[0042] 4) Well wall support: The well wall support is designed independently from the tunneling machine. The support operation area is located on the rear support platform and is not affected by the tunneling machine.

[0043] As a preferred technical solution of the present invention: in the support structure change step of the excavation support process of the vertical shaft expansion tunneling machine, the maximum tunneling change step distance is 1.5 m, and the section height of each support is 1.5 m.

[0044] As a preferred technical solution of the present invention: in the excavation support process of the shaft expansion tunneling machine, the temporary support is determined according to the exposed surrounding rock conditions, and the support method is mainly adopted for anchor mesh spraying.

[0045] As a preferred technical solution of the present invention: In the shaft wall support of the excavation support process of the shaft expansion tunneling machine, when the exposed surrounding rock is Class V during the construction of the shaft tunneling machine, the following support measures are adopted: C25 L=2.0 m mortar anchor bolts are used, with 1.9 m embedded into the rock and 0.1 m exposed outside, with a spacing of @1.2 m×1.2 m, A8@15 cm×15 cm wire mesh, and C30 polyethylene fiber concrete with a thickness of 20 cm.

[0046] This invention provides a mechanized construction method for a multi-stage vertical shaft structure in the water intake system of a pumped storage power station, which has the following advantages compared with the prior art:

[0047] (1) The multi-stage vertical shaft arrangement structure of the water diversion system provided by the present invention can reduce the steel lining length of the water diversion system, reduce the project investment, and avoid the initiation and assembly of equipment in the tunnel in the vertical shaft of the water diversion, so as to solve the problem of limited mechanical installation and working space in the tunnel, and save the amount of rock excavation.

[0048] (2) Compared with inclined shafts, the vertical shaft layout structure of the water diversion system is less difficult to construct, has lower safety risks, is convenient for slag removal in the vertical shaft, and has a fast construction efficiency, realizing the construction of vertical shafts with fewer people and mechanization.

[0049] (3) The fully mechanized construction method of “directional drilling + reverse drilling + shaft reaming machine” is a feasible technical approach to solve the problems of large number of personnel, complex procedures, difficult safety management and environmental pollution in the existing shaft blasting construction. Directional drilling can significantly improve the verticality of deep shafts and further control the deviation rate of shafts. As representative technologies and equipment of the development direction of “less manpower, mechanization, standardization and intelligence”, reverse drilling machines and shaft reaming machines have outstanding advantages in terms of quality, construction period, safety, environmental protection and civilized construction. They realize integrated construction operations such as excavation, slag removal, support and guidance. The construction speed of the tunneling machine method is 3 to 4 times that of the drill-blast method, which significantly improves the excavation efficiency of shafts and is an effective way to realize the mechanized and intelligent construction of pumped storage power station shafts. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the multi-stage vertical shaft arrangement structure of the pumped storage power station water diversion system in an embodiment of the present invention;

[0051] Figures 2-8 This is a schematic diagram of the multi-stage vertical shaft mechanized construction process in an embodiment of the present invention;

[0052] 1-Water diversion upper horizontal tunnel, 2-Water diversion pressure regulating well, 3-Water diversion upper vertical shaft, 4-Water diversion middle horizontal tunnel, 5-Water diversion lower vertical shaft, 6-Water diversion lower horizontal tunnel, 7-Main plant, 8-No. 1 starting shaft, 9-No. 2 starting shaft, 10-No. 1 construction adit, 11-No. 2 construction adit, 12-Gantry crane system, 13-Directional drilling main unit, 14-Water diversion upper vertical shaft pilot hole, 15-Directional drilling rig drill rod, 16-Directional drill bit, 17-Raising drilling main unit, 18-Raising drilling rig drill rod, 19-Raising drilling reaming drill bit, 20-Water diversion upper vertical shaft pilot hole, 21-Loader, 22-Dump truck, 23-Stone chips, 24-Vertical shaft reaming tunneling machine, 24-1-Cutout, 24-2-Main drive system, 25-Water diversion lower vertical shaft pilot hole, 26-Transfer flatbed truck. Detailed Implementation

[0053] The present invention will be described in further detail with reference to the accompanying drawings and specific examples.

[0054] The pumped storage power station's water intake system has a multi-stage vertical shaft layout, arranged in two stages, including an upper water intake shaft 3 and a lower water intake shaft 5. The upper part of the upper water intake shaft 3 is connected to the upper water intake tunnel 1. The lower part of the upper water intake shaft 3 and the upper part of the lower water intake shaft 5 are connected through the middle water intake tunnel 4. The lower part of the lower water intake shaft 5 is connected to the lower water intake tunnel 6, and the lower water intake tunnel 6 is connected to the main powerhouse 7.

[0055] The upper vertical shaft 3 of the water diversion is lined with concrete, while the middle horizontal tunnel 4 and the lower vertical shaft 5 of the water diversion are lined with steel plates. In order to reduce the length of the steel lining of the lower vertical shaft 5 of the water diversion and reduce the project investment, the middle horizontal tunnel 4 of the water diversion should be lowered as much as possible, provided that the thickness of the overlying rock mass of the middle horizontal tunnel 4 of the water diversion meets the minimum overlying layer requirement. The length of the upper vertical shaft 3 of the water diversion is greater than that of the lower vertical shaft 5 of the water diversion.

[0056] The water diversion surge well 2 and the water diversion upper vertical shaft 3 are arranged together and located directly above the water diversion upper vertical shaft 3. The water diversion surge well 2 is connected to the ground surface. The mechanical excavation equipment is arranged from the upper end of the water diversion surge well 2 and excavates the water diversion surge well 2 and the water diversion upper vertical shaft 3 downward in sequence to solve the problem of limited space for mechanical installation and operation in the tunnel, and also to reduce the amount of rock excavation in the tunnel.

[0057] The water diversion tunnel 4 and the water diversion lower tunnel 6 are connected to the No. 1 construction adit 10 and the No. 2 construction adit 11, respectively.

[0058] Construction adit 10 (No. 1) and construction adit 11 (No. 2) serve as transportation channels for mechanical equipment and channels for removing slag (stone slag 23).

[0059] This invention also provides a mechanized construction method for multi-stage vertical shafts. To reduce the shaft's inclination rate and improve the quality of the shaft's tunneling and the degree of mechanization, a fully mechanized construction process of "directional drilling + reverse drilling + shaft reaming machine" is adopted to improve the level of manpower reduction and mechanization in vertical shaft construction, ensure construction safety, accelerate construction efficiency, and achieve green construction. Specifically, the method includes the following steps:

[0060] S1: First, excavation and support construction are carried out on the slope of the platform of the water diversion surge well 2. In order to facilitate the assembly of tunneling machinery and equipment, the No. 1 launching shaft 8 is excavated downward from the upper part of the water diversion surge well 2. The lock and ring beam foundation are constructed at the opening of the No. 1 launching shaft 8. The gantry crane system 12 is arranged above the No. 1 launching shaft 8 to lift the machinery and equipment. The No. 1 launching shaft 8 with a depth of 10 m and a diameter of 8 m is formed by excavating downward using a hydraulic breaker and a long-arm excavator. The No. 1 launching platform is formed at the lower part of the No. 1 launching shaft 8.

[0061] S2: Repeat the construction steps in step S1 to excavate the No. 2 launching shaft 9 and the No. 2 launching platform at the upper end of the water diversion vertical shaft 5, with a depth of 10 m and a diameter of 8 m.

[0062] S3: Install the directional drilling host 13 on the No. 1 starting platform. Use the drill rod 15 of the directional drilling host 13 to drill a 410 mm directional hole (i.e., the guide hole 14 of the water diversion vertical shaft 3) from top to bottom along the central axis of the water diversion vertical shaft 3 to meet the diameter of the drill rod 18 of the raise boring machine 17 required for construction. After the directional hole exceeds 30 m, install a wireless drilling rig and, under the guidance of its measurement parameters, perform directional control on the drilling trajectory to improve the accuracy of the directional hole. Continue until the directional hole penetrates to the water diversion horizontal tunnel 4. The directional hole construction is completed. Remove the directional drill bit 16 and the matching inclination measurement and correction equipment. Use the gantry crane system 12 to remove the directional drilling host 13 and auxiliary equipment.

[0063] S4: Transport the dismantled directional drilling host 13 and auxiliary equipment to the starting platform of the water diversion shaft 52#, and repeat the construction steps in step 3 to form the 5φ410 mm pilot hole of the water diversion shaft.

[0064] S5: Install the raise boring machine 17, main and auxiliary pump stations, and other equipment on the No. 1 launching platform. Use the raise boring machine to construct the φ1.5 m pilot well (i.e., the pilot well 20 of the water diversion vertical shaft) from bottom to top along the φ410 mm pilot hole. Lower the raise boring machine drill rod 18 along the φ410 mm pilot hole to the lower end of the water diversion vertical shaft 3. Transport the φ1.5 m diameter raise boring reaming drill bit 19 through the construction adit and the water diversion horizontal tunnel 4 to the lower end of the water diversion vertical shaft 3 and connect it with the raise boring machine drill rod 18. Then slowly lift the reaming drill bit 19 to carry out the reaming construction from bottom to top. After the φ1.5 m pilot well is reamed, use the gantry crane system 12 to dismantle the raise boring machine 17 and auxiliary equipment.

[0065] S6: Transport the dismantled reverse drilling rig 17 and auxiliary equipment to the starting platform of the water diversion shaft 52#, repeat the construction steps in step 5, and form a φ1.5 m pilot shaft for the water diversion shaft;

[0066] S7: Assemble and debug the shaft enlargement tunneling machine 24 inside the No. 1 starting shaft 8. Use the shaft enlargement tunneling machine 24 to drill from top to bottom to enlarge the water diversion shaft 3 to the designed diameter of 8 m. The crushed rock debris (stone debris 23) falls into the water diversion tunnel 4 through a 1.5 m guide shaft by its own weight. The loader 21 loads the stone debris 23 into the dump truck 22. The fully loaded dump truck 22 is transported out through the water diversion tunnel 4 and the No. 1 construction adit 10.

[0067] In step S7, the assembly process of the shaft reaming tunneling machine is as follows:

[0068] 1) The rock-breaking cutterhead 24-1, the support propulsion system, and the main drive system 24-2 are sequentially hoisted into the well using the gantry crane system 12 and assembled into the main unit of the vertical shaft reaming tunneling machine;

[0069] 2) Install a steel strand lifting system on the foundation of the lock ring beam, and connect the steel strand lifting system to the main machine of the tunneling machine to ensure that the overall posture of the main machine of the tunneling machine is centered and stable;

[0070] 3) Use the gantry crane system 12 to sequentially hoist the anchor bolt system, shotcrete system, and subsequent supporting systems;

[0071] 4) After the shaft reaming machine is fully assembled, connect the electrical wiring to the ground control room and confirm the assembly, ensuring that the power supply lines and hydraulic lines are connected correctly and reliably.

[0072] Step S7, the commissioning process of the shaft reaming machine:

[0073] The commissioning of the vertical shaft reaming machine is mainly divided into four steps: power supply commissioning, control commissioning, hydraulic commissioning, and functional commissioning. After the equipment commissioning is completed, the center of the starting shaft and the center of the equipment are re-measured before starting excavation.

[0074] 1) Power supply commissioning: Confirm that each power supply system is normal and meets the power supply requirements.

[0075] 2) Control and debugging: Confirm that all power supply switches and protection devices are operating normally and reliably.

[0076] 3) Hydraulic commissioning: Confirm that the hydraulic pump station is operating normally.

[0077] 4) Functional debugging: Confirm that the excavation, propulsion, and slag removal systems of the equipment are functioning normally.

[0078] In step S7, the excavation and support process of the shaft reaming machine is as follows:

[0079] 1) Positioning: Based on the azimuth measurement results of the starting well, calculate and determine the extension amount and support force of the hydraulic cylinder of the support system, and adjust it at any time during the excavation of the vertical shaft reaming machine to ensure the drilling direction and accuracy requirements.

[0080] 2) Excavation and muck removal: This operation is located in the ground control room. When the shaft reaming machine is excavating, the support system is tightened and the cutterhead is started. The excavation construction needs to find the matching speed and penetration depth according to the strata. The equipment is designed with a cutterhead rated speed of 3 r / min. The cutterhead has a conical structure. The broken rock muck slides along the conical surface at the bottom of the shaft and falls into the 1.5 m pilot shaft. The muck is then transported out by the water diversion tunnel 4 transportation system.

[0081] 3) Support Structure Step Change: During step change, the support system's tensioning force needs to be increased. Simultaneously, the cutterhead stops rotating. After the tunneling machine stops running, the support system's tensioning cylinder is retracted, the propulsion cylinder is retracted, and the support system is lowered to complete the step change. The support system is then re-tensioned, the equipment's attitude is checked, and the cutterhead is restarted for the next tunneling cycle. The maximum step change distance is 1.5m, and the height of each support section is 1.5m.

[0082] 4) Shaft Wall Support: The shaft wall support is designed independently from the tunneling machine. The support operation area is located on the rear support platform and is not affected by the tunneling machine. Temporary support is determined based on the exposed surrounding rock conditions, mainly using anchor-mesh-shotcrete method. During shaft tunneling, when the exposed surrounding rock is Class V, the following support measures are used: C25 L=2.0 m mortar anchor bolts, 1.9 m into the rock, 0.1 m exposed, with a spacing of @1.2 m×1.2 m, A8 @15 cm×15 cm mesh, and 20 cm thick C30 polyethylene fiber reinforced concrete sprayed.

[0083] S8: After the excavation of the upper shaft 3 for water diversion is completed, the tunneling machine equipment will be dismantled sequentially in the horizontal tunnel 4 for water diversion.

[0084] The disassembly sequence is as follows: cutterhead, support propulsion system, main drive system 24-2, anchor bolt system, sprayed concrete system, and rear supporting system; the disassembled shaft tunneling machine equipment is transported to the No. 2 starting platform via transfer flatbed truck 26 through the water diversion tunnel 4.

[0085] S9: Repeat the assembly, debugging, and excavation support process in step S7. Assemble and debug the shaft expansion tunneling machine inside the No. 2 starting shaft 9. Use the shaft expansion tunneling machine to expand the water diversion shaft 5 from top to bottom to the design diameter. The crushed rock debris 23 falls to the water diversion horizontal tunnel 6 by its own weight through the φ1.5 m guide shaft (that is, the guide shaft 25 of the water diversion shaft). The loader 21 loads the rock debris 23 into the dump truck 22. The fully loaded dump truck 22 is transported out through the water diversion horizontal tunnel 6 and the No. 2 construction adit 11.

[0086] S10: After the excavation of the water diversion shaft 5 is completed, the tunneling machine equipment will be dismantled in sequence in the water diversion horizontal tunnel 6, and transported out of the site through the water diversion horizontal tunnel 6 and the No. 2 construction adit 11.

[0087] The above specific embodiments are used to explain and illustrate the present invention, and are only preferred embodiments of the present invention, not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made to the present invention within the spirit and scope of the claims shall fall within the protection scope of the present invention.

Claims

1. A mechanized construction method for a multi-stage vertical shaft structure in the water diversion system of a pumped storage power station, characterized by: The mechanized construction method for the multi-stage vertical shaft structure of the pumped storage power station's water intake system is based on the multi-stage vertical shaft structure of the pumped storage power station's water intake system. The pumped storage power station's water intake system comprises a multi-stage vertical shaft structure, including an upper water intake shaft and a lower water intake shaft. The upper part of the upper water intake shaft is connected to the upper horizontal tunnel. The lower part of the upper water intake shaft and the upper part of the lower water intake shaft are connected through the middle horizontal tunnel. The lower part of the lower water intake shaft is connected to the lower horizontal tunnel. The lower horizontal tunnel connects to the main powerhouse. A water diversion surge well is provided above the water diversion vertical shaft, and the water diversion surge well is connected to the ground surface; The water diversion horizontal tunnel and the water diversion lower horizontal tunnel are respectively connected to the first construction adit and the second construction adit; The mechanized construction method for the multi-stage vertical shaft structure of the pumped storage power station's water intake system includes the following steps: S1: Excavate and support the slope of the water diversion surge tank platform. Excavate the first launching well downward from the top of the water diversion surge tank. Construct the lock and ring beam foundation at the opening of the first launching well. Arrange a gantry crane system above the first launching well to hoist mechanical equipment. Use a hydraulic breaker and a long-arm excavator to excavate downward to form the first launching well with a depth of 10 m and a diameter of 8 m. Form the first launching platform below the first launching well. S2: Repeat the construction steps in step S1 to excavate a second launching well and a second launching platform with a depth of 10 m and a diameter of 8 m at the upper end of the water diversion shaft. S3: Install a directional drilling rig on the first starting platform. Drill a 410 mm directional hole from top to bottom along the central axis of the water diversion vertical shaft to meet the drill rod diameter required for the raise shaft drilling rig construction. After the directional hole exceeds 30 m, install a wireless drilling rig to control the borehole trajectory under the guidance of its measurement parameters, thereby improving the accuracy of the directional hole. Continue until the directional hole penetrates to the horizontal tunnel of the water diversion, at which point the directional hole construction is completed. Remove the directional drill bit and the matching inclination and correction equipment, and use a gantry crane system to dismantle the directional drilling rig and auxiliary equipment. S4: Transport the dismantled directional drilling rig and auxiliary equipment to the second starting platform of the water diversion shaft, and repeat the construction steps in step S3 to form a φ410 mm pilot hole for the water diversion shaft. S5: Install the main unit of the raise boring machine and the main and auxiliary pump stations on the first launching platform. Use the raise boring machine to construct a φ1.5 m pilot well from bottom to top along the φ410 mm pilot hole. Lower the drill rod of the raise boring machine along the φ410 mm pilot hole to the lower end of the upper vertical shaft of the water diversion. Transport the φ1.5 m diameter raise boring reaming bit through the construction adit and the horizontal tunnel of the water diversion to the lower end of the upper vertical shaft of the water diversion, connect it to the drill rod of the raise boring machine, and then slowly lift the reaming bit to carry out the reaming construction from bottom to top. After the φ1.5 m pilot well is reamed, use the gantry crane system to dismantle the raise boring machine and auxiliary equipment. S6: Transport the dismantled reverse drilling rig and auxiliary equipment to the second starting platform of the water diversion shaft, and repeat the construction steps in step S5 to form a φ1.5 m pilot shaft for the water diversion shaft; S7: Assemble and debug the shaft expansion tunneling machine inside the first starting shaft. Use the shaft expansion tunneling machine to excavate and perform initial support from top to bottom. Expand the water diversion shaft to the designed diameter of 8 m. The broken rock debris falls into the water diversion tunnel by its own weight through a 1.5 m guide shaft. It is then transported out by underground transportation equipment through the water diversion tunnel and the first construction adit. S8: After the excavation of the upper shaft for water diversion is completed, the tunneling machine equipment will be dismantled sequentially in the horizontal tunnel of the water diversion. The disassembly sequence is as follows: cutterhead, support propulsion system, main drive system, anchor bolt system, spray mixing system, and subsequent supporting systems; The disassembled shaft tunneling machine equipment was transported to the second launching platform via a water diversion tunnel. S9: Repeat the assembly, debugging and excavation support process in step S7: Assemble and debug the shaft expansion tunneling machine inside the second starting shaft, and use the shaft expansion tunneling machine to expand the water diversion shaft from top to bottom to the design diameter. The broken rock debris falls into the water diversion tunnel by its own weight through the φ1.5 m guide shaft, and is transported out by underground transportation equipment through the water diversion tunnel and the second construction adit. S10: After the excavation of the water diversion shaft is completed, the tunneling machine is dismantled in sequence in the water diversion horizontal tunnel and transported out of the site through the water diversion horizontal tunnel and the second construction adit.

2. The mechanized construction method for the multi-stage vertical shaft structure of the pumped storage power station water intake system according to claim 1, characterized in that: The upper vertical shaft for water diversion is lined with concrete, while the middle horizontal tunnel and the lower vertical shaft for water diversion are lined with steel plates. When the thickness of the overlying rock mass of the water diversion tunnel meets the minimum overburden thickness, the water diversion tunnel should be lowered as much as possible so that the length of the upper vertical shaft is greater than the length of the lower vertical shaft.

3. The mechanized construction method for the multi-stage vertical shaft structure of the pumped storage power station water diversion system according to claim 1, characterized in that: In step S7 or S9, the assembly process of the shaft reaming tunneling machine is as follows: 1) The rock-breaking cutterhead, support propulsion system, and main drive system are sequentially hoisted into the well using a gantry crane system and assembled into the main unit of the vertical shaft reaming tunneling machine; 2) Install a steel strand lifting system on the foundation of the lock ring beam, and connect the steel strand lifting system to the main machine of the tunneling machine to ensure that the overall posture of the main machine of the tunneling machine is centered and stable; 3) The anchor bolt system, shotcrete system, and subsequent supporting systems are installed sequentially using a gantry crane system; 4) After the shaft reaming machine is fully assembled, connect the electrical wiring to the ground control room and confirm the assembly, ensuring that the power supply lines and hydraulic lines are connected correctly and reliably.

4. The mechanized construction method for the multi-stage vertical shaft structure of the pumped storage power station water diversion system according to claim 1, characterized in that: In step S7 or S9, the commissioning process of the vertical shaft reaming tunneling machine is as follows: The commissioning of the vertical shaft reaming machine is mainly divided into four steps: power supply commissioning, control commissioning, hydraulic commissioning, and functional commissioning. After the equipment commissioning is completed, the center of the starting shaft and the center of the equipment are re-measured before starting excavation. 1) Power supply commissioning: Confirm that all power supply systems are functioning normally and meet power supply requirements; 2) Control and commissioning: Confirm that all power supply switches and protection devices are operating normally and reliably; 3) Hydraulic commissioning: Confirm that the hydraulic pump station is operating normally; 4) Functional debugging: Confirm that the excavation, propulsion, and slag removal systems of the equipment are functioning normally.

5. The mechanized construction method for the multi-stage vertical shaft structure of the pumped storage power station water diversion system according to claim 1, characterized in that: In step S7 or S9, the excavation and support process of the shaft reaming machine is as follows: 1) Positioning: Based on the azimuth measurement results of the starting well, calculate and determine the extension amount and support force of the hydraulic cylinder of the support system, and adjust them at any time during the excavation of the vertical shaft reaming machine to ensure the drilling direction and accuracy requirements; 2) Excavation and muck removal: This operation is located in the ground control room. When the shaft reaming machine is excavating, the support system is tightened and the cutterhead is started. The excavation construction needs to find the matching speed and penetration depth according to the strata. The equipment is designed with a cutterhead rated speed of 3 r / min. The cutterhead has a conical structure. The broken rock muck slides along the conical surface at the bottom of the shaft and falls into the 1.5 m pilot shaft. The muck is then transported out by the horizontal tunnel transportation system. 3) Support structure changeover: When changing steps, the support system tensioning force needs to be increased. At the same time, the cutterhead stops rotating. After the tunneling machine stops running, the support system tensioning cylinder is retracted, the propulsion cylinder is retracted, the support system is lowered to complete the changeover, the support system is re-tensioned, the equipment attitude is checked, the cutterhead is restarted, and the next cycle of tunneling is carried out. 4) Well wall support: The well wall support is designed independently from the tunneling machine. The support operation area is located on the rear support platform and is not affected by the tunneling machine.

6. The mechanized construction method for the multi-stage vertical shaft structure of the pumped storage power station water diversion system according to claim 5, characterized in that: In the support structure replacement process of the excavation and support of the shaft expansion tunneling machine, the maximum tunneling replacement distance is 1.5m, and the section height of each support is 1.5m.

7. The mechanized construction method for the multi-stage vertical shaft structure of the pumped storage power station water diversion system according to claim 5, characterized in that: In the excavation and support process of shaft expansion tunneling machines, the temporary support is determined according to the exposed surrounding rock conditions, and the main support method is anchor mesh spraying.

8. The mechanized construction method for the multi-stage vertical shaft structure of the pumped storage power station water diversion system according to claim 5, characterized in that: In the shaft wall support process of the excavation support of the shaft expansion tunneling machine, when the exposed surrounding rock is Class V, the following support measures are adopted: C25 L=2.0 m mortar anchor bolts are used, with 1.9 m embedded into the rock and 0.1 m exposed outside, with a spacing of @1.2 m×1.2 m, A8@15 cm×15 cm wire mesh, and C30 polyethylene fiber concrete with a thickness of 20 cm.

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