Open-type TBM shield reserving in-situ disassembling method for water conveyance tunnel in fractured stratum

Abstract

The invention discloses an open-type TBM shield reserving in-situ dismantling method for a broken stratum water conveying tunnel. The method comprises the steps that firstly, a collapsed cavity in the top of a shield is backfilled, and broken surrounding rock is subjected to grouting reinforcement; 2, integrally welding the shield; 3, mounting a TBM host and a bridge area hoisting facility; 4, TBM rear matched hoisting facilities are installed, and TBM rear matched equipment is dismantled; fifthly, a main beam and a rear support of the TBM host are dismantled; sixthly, a main drive and a cutterhead of the TBM host are dismounted; and seventhly, grouting reinforcement is conducted on the top area of the cutter head and the top area of the shield. According to the method, the top shield, the side shield and the bottom shield are integrally welded through profile steel before dismantling, the shields are not dismantled and are reserved as permanent supporting bodies during dismantling, various hoisting devices are matched, in-situ safe and efficient dismantling in the TBM hole is achieved, the stability of rock around the hole is fully guaranteed, the construction risk is greatly reduced, and the construction safety and the construction progress are effectively guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of tunnel construction, and in particular relates to an in-situ dismantling method of an open-type TBM shield-retaining water conveyance tunnel in a broken stratum. Background Art

[0002] At present, the TBM method has been widely used in water conveyance tunnels. Due to the particularity of TBM equipment, the TBM in-tunnel dismantling machine usually disconnects the belt after the TBM completes the main tunnel excavation task, and the TBM is retreated a certain distance to excavate the main engine dismantling chamber. After the excavation of the dismantling chamber is completed, an electric hoist is arranged on the top of the dismantling chamber, and the main engine components are dismantled using winches, jacks and other equipment. After the supporting trolleys are separated section by section, they are dismantled on site. This method requires that the dismantling tunnel section and space are large enough, the construction is difficult, and the construction period is long. When the surrounding rock is extremely broken during TBM excavation and it is impossible to form a dismantling chamber, and the TBM has reached the scrap standard and the shield is stuck, the use of traditional methods to forcibly dismantle the machine will face great construction risks. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide an in-situ dismantling method for an open-type TBM water conveyance tunnel in a broken stratum with shields retained, in view of the deficiencies in the above-mentioned prior art. The top, side and bottom shields are integrally welded with steel sections before dismantling. During dismantling, the shields are not removed but retained as permanent support bodies. In combination with a variety of lifting and hoisting equipment, safe and efficient in-situ dismantling of the TBM tunnel is achieved, the stability of the rock around the tunnel is fully guaranteed, the construction risk is greatly reduced, the construction safety and construction progress are effectively guaranteed, good engineering results are achieved, and it has a strong reference role for similar projects.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: an in-situ dismantling method of an open-type TBM shield-retaining water conveyance tunnel in a broken stratum, characterized in that the method comprises the following steps: Step 1: Backfill the collapsed cavity at the top of the shield and reinforce the broken surrounding rock with grouting. The process is as follows: Step 101: Before dismantling the machine, the collapsed cavity on the top of the shield is backfilled with spray mix; then, a plurality of first grouting anchor rods are drilled at the tail of the shield using a hand drill, and the plurality of first grouting anchor rods are arranged along the circumferential direction of the tunnel, and the plurality of first grouting anchor rods are arranged on the top of the shield; cement slurry is injected into the top of the shield and the cutter head using the first grouting anchor rods to perform grouting reinforcement on the broken surrounding rock on the top of the shield and the cutter head; Step 102, after the grouting reinforcement is completed, the steel arch frame at the tail of the shield is connected with steel bars and steel sections, and the steel arch frame at the tail of the shield that is not sealed with sprayed concrete is sealed with sprayed concrete; Step 2: Shield overall welding: first use the connecting steel plate to connect the seams of the side shield and the top shield; then use the connecting steel to weld the top shields, the side shields and the top shield, and the side shields and the bottom shield to form a surrounding rock steel support body; Step 3: Installation of lifting facilities in the TBM mainframe and bridge area: two groups of lifting anchor points are set on the top of the tunnel corresponding to the TBM mainframe and bridge area, and each group of lifting anchor points is evenly arranged along the extension direction of the tunnel; the first track beam is installed using the lifting anchor points, and the lifting hand chain hoist pulley is installed on the first track beam to complete the installation of the lifting facilities in the TBM mainframe and bridge area; Step 4: Installation of TBM rear supporting lifting facilities and removal of TBM rear supporting equipment. The process is as follows: Step 401: simultaneously, two groups of fixed lifting point groups are set on the top of the tunnel corresponding to the TBM rear supporting area, and each group of the fixed lifting point groups is evenly arranged along the circumferential direction of the tunnel; multiple hand hoists are installed on the fixed lifting point groups to complete the installation of the lifting facilities in the TBM rear supporting area; after the installation is completed, the upper equipment of the TBM rear supporting area is dismantled in sequence and transported out of the tunnel; Step 402, welding the lifting lugs on the frame structure of the TBM rear supporting equipment and installing the guide chain; after the installation is completed, dismantling the TBM rear supporting lower equipment and transporting it out of the cave; Step 403: After the TBM rear supporting equipment is dismantled, the TBM rear supporting frame structure is dismantled and transported out of the tunnel in sequence using the TBM rear supporting lifting facilities; Step 5: Remove the main beam and rear support of the TBM mainframe. The process is as follows: Step 501: multiple support columns are arranged at the bottom of the main beam, and the multiple support columns are arranged along the extension direction of the main beam; the top of the main beam is connected with a wire rope and a lifting hand chain block pulley; Step 502, adjust the length of the wire rope, use the lifting hand chain hoist to tighten the main beam and the rear support, remove the main push cylinder and the support shoe and transport them out of the cave; Step 503, remove the connecting bolts between the rear support and the second main beam, remove the rear support, turn it over and place it at the bottom of the tunnel, split and dismember the rear support in the tunnel and transport it out of the tunnel in sequence; wherein the main beam includes the first main beam and the second main beam; Step 504, disassemble and remove the saddle frame and transport them out of the cave in sequence, and finally disassemble and dismember the main beam 2 and the main beam 1 and transport them out of the cave in sequence; Step 6: Dismantle the main drive and cutterhead of the TBM main machine: First, cut and dismantle the steel structure and motor reducer on the main drive from back to front and from top to bottom, and use the hoisting frame to transfer the removed parts to the cart and transport them out of the hole; then, cut the remaining parts of the cutterhead and main drive from top to bottom and from back to front, and use the hoisting frame to transfer the cut parts to the cart and transport them out of the hole; Step seven, grouting reinforcement of the top area of ​​the cutter head and the shield: drill multiple groups of grouting holes on the top of the cutter head and the shield, the multiple groups of grouting holes are arranged in a plum blossom shape, each group of the grouting holes includes multiple grouting holes, and the multiple grouting holes are arranged along the circumferential direction of the tunnel; insert the second grouting anchor rod into the grouting hole, and use the second grouting anchor rod to perform cement grouting, grouting reinforcement of the top broken surrounding rock area of ​​the cutter head and the shield, and complete the dismantling of the machine.

[0005] The above-mentioned method for in-situ dismantling of an open-type TBM with shield in a broken stratum water conveyance tunnel is characterized in that: in step 101, the circumferential spacing between two adjacent first grouting anchors is 0.5m~1m, the length of the first grouting anchor is 2.0m~6.0m, the inclination angle of the first grouting anchor is 10°~45°, and the first grouting anchor is inclined forward along the extension direction of the tunnel; the angle between the first grouting anchors on both sides is 120°~150°; when injecting cement slurry using the first grouting anchor, the grouting pressure is not greater than 3MPa.

[0006] The above-mentioned in-situ dismantling method of an open-type TBM with shield retained in a broken stratum water conveyance tunnel is characterized in that: in step three, anti-derailment steel plates are provided at both ends of the first track beam.

[0007] The above-mentioned method for in-situ dismantling of an open-type TBM with shield in a broken stratum water conveyance tunnel is characterized in that: in step three, the first track beam is installed on the top of the tunnel through a plurality of first mounting parts, and the plurality of first mounting parts are evenly arranged along the extension direction of the first track beam; four mounting holes are drilled on each of the lifting anchor points, and the first mounting parts include a first mounting plate arranged at the lifting anchor point, a first fixed anchor rod arranged between the first mounting plate and the mounting hole, and a rib plate arranged on the first mounting plate and arranged on the side away from the first fixed anchor rod.

[0008] The above-mentioned method for in-situ dismantling of an open-type TBM with shield in a broken stratum water conveyance tunnel is characterized in that: in step 401, the fixed lifting point group includes four fixed lifting point groups arranged along the circumferential direction of the tunnel; the hand chain hoist is installed on the top of the tunnel through a second mounting member, and the number of the second mounting members is equal to the number of the hand chain hoists and corresponds one to one; the second mounting members each include a second mounting plate arranged on the fixed lifting point, a second fixed anchor rod arranged between the second mounting plate and the fixed lifting point, and two mounting anchor rods both arranged on the second mounting plate and arranged on a side away from the second fixed anchor rod; one end of the two mounting anchor rods is fixed on the second mounting plate, and the hand chain hoist is installed between the other ends of the two mounting anchor rods.

[0009] The above-mentioned method for in-situ dismantling of an open-type TBM with shield retained in a water conveyance tunnel in a broken stratum is characterized in that: in step six, the hoisting frame is a gate-shaped hoisting frame, and the hoisting frame includes a plurality of hoisting frame bodies, and the plurality of hoisting frame bodies are arranged along the extension direction of the tunnel, and a second track beam is arranged between the plurality of hoisting frame bodies; the hoisting frame includes a horizontally arranged hoisting crossbeam and a supporting vertical beam vertically arranged at the bottom of the hoisting crossbeam, the hoisting crossbeam and the supporting vertical beam are connected by bolts, and an oblique support is obliquely arranged between the hoisting crossbeam and the supporting vertical beam; the second track beam is arranged at the bottom of the hoisting crossbeam.

[0010] The above-mentioned method for in-situ dismantling of an open TBM with a shield in a broken stratum water diversion tunnel is characterized in that: in step seven, the angle between the grouting holes on both sides is 180°; the length of the second grouting anchor is 3.5m, and the tail of the second grouting anchor is welded to the shield; the spacing between two adjacent groups of grouting holes is 1.25m~1.5m.

[0011] The beneficial effects of the present invention are that the top, side and bottom shields are integrally welded with steel sections before dismantling, and the shields are not removed during dismantling but retained as permanent support bodies, and combined with a variety of lifting and hoisting equipment, safe and efficient in-situ dismantling of the TBM tunnel is achieved, the stability of the rock around the tunnel is fully guaranteed, the construction risk is greatly reduced, the construction safety and progress are effectively guaranteed, good engineering results are achieved, and it has a strong reference role for similar projects.

[0012] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram of the position layout of the first grouting anchor rod in the tunnel of the present invention.

[0014] Figure 2It is a schematic diagram of the construction status of the overall welding of the shield of the present invention.

[0015] Figure 3 This is a schematic diagram of the installation position of the first track beam of the present invention.

[0016] Figure 4 This is a schematic diagram of the installation position of the TBM rear supporting lifting facilities in the tunnel of the present invention.

[0017] Figure 5 This is a schematic diagram of the construction status of dismantling the main beam and rear support of the TBM main machine according to the present invention.

[0018] Figure 6 It is a structural schematic diagram of the hoisting frame of the present invention.

[0019] Figure 7 This is a schematic diagram of the construction status of dismantling the steel structure and motor reducer on the main drive of the TBM main machine of the present invention.

[0020] Figure 8 This is a schematic diagram of the construction status of dismantling the middle and lower part of the main drive and the middle and lower part of the cutter disc of the TBM main machine according to the present invention.

[0021] Fig. 9 The figure is a flowchart of the method of the present invention.

[0022] Description of reference numerals: 1—shield; 2—first grouting anchor; 3—tunnel; 4—connecting steel plate; 5—side shield; 6—top shield; 7—bottom shield; 9—first track beam; 10—first mounting plate; 11—first fixing anchor rod; 12—rib plate; 13—hand chain hoist; 14—second mounting plate; 15—second fixing anchor rod; 16—installation anchor rod; 17—main beam; 18—support column; 19—main push cylinder; 20—support shoe; 21—main beam 2; 22—rear support; 23—main beam 1; 24—main drive; 25—cutter head; 26—second track beam; 27—hoisting beam; 28—supporting vertical beam; 29—diagonal support; 31—connecting steel; 32—Working platform. DETAILED DESCRIPTION

[0023] like Figures 1 to 9 The method for dismantling an open-type TBM in a broken stratum water conveyance tunnel with a shield in situ is shown, and the method comprises the following steps: Step 1: Backfill the collapsed cavity at the top of the shield and reinforce the broken surrounding rock with grouting. The process is as follows: Step 101: Before dismantling the machine, the collapsed cavity on the top of the shield 1 is backfilled with spray mix; then, a plurality of first grouting anchor rods 2 are drilled at the tail of the shield 1 using a hand drill, and the plurality of first grouting anchor rods 2 are arranged along the circumferential direction of the tunnel 3, and the plurality of first grouting anchor rods 2 are arranged on the top of the shield 1; cement slurry is injected into the top of the shield 1 and the cutter head using the first grouting anchor rods 2, and the broken surrounding rock on the top of the shield 1 and the cutter head is reinforced by grouting; Step 102: After the grouting reinforcement is completed, the steel arch frame at the rear of the shield 1 is connected with steel bars and steel sections, and the steel arch frame at the rear of the shield 1 that is not sealed with sprayed concrete is sealed with sprayed concrete; Step 2: Shield overall welding: first use the connecting steel plate 4 to connect the seams of the side shields 5 and the top shield 6; then use the connecting steel 31 to weld the top shields 6, the side shields 5 and the top shield 6, and the side shields 5 and the bottom shield 7 to form a surrounding rock steel support body; Step 3: Installation of lifting facilities in the TBM host and bridge area: two groups of lifting anchor points are set at the top of the tunnel corresponding to the TBM host and bridge area, and each group of lifting anchor points is evenly arranged along the extension direction of the tunnel 3; the first track beam 9 is installed using the lifting anchor points, and the lifting hand chain hoist pulley is installed on the first track beam 9 to complete the installation of the lifting facilities in the TBM host and bridge area; Step 4: Installation of TBM rear supporting lifting facilities and removal of TBM rear supporting equipment. The process is as follows: Step 401: simultaneously, two groups of fixed lifting point groups are set on the top of the tunnel corresponding to the TBM rear supporting area, and each group of the fixed lifting point groups is evenly arranged along the circumferential direction of the tunnel 3; multiple hand chain hoists 13 are installed on the fixed lifting point groups to complete the installation of the lifting facilities in the TBM rear supporting area; after the installation is completed, the upper equipment of the TBM rear supporting area is dismantled in sequence and transported out of the tunnel; Step 402, welding the lifting lugs on the frame structure of the TBM rear supporting equipment and installing the guide chain; after the installation is completed, dismantling the TBM rear supporting lower equipment and transporting it out of the cave; Step 403: After the TBM rear supporting equipment is dismantled, the TBM rear supporting frame structure is dismantled and transported out of the tunnel in sequence using the TBM rear supporting lifting facilities; Step 5: Remove the main beam and rear support of the TBM mainframe. The process is as follows: Step 501: a plurality of support columns 18 are arranged at the bottom of the main beam 17, and the plurality of support columns 18 are arranged along the extension direction of the main beam 17; the top of the main beam 17 is connected with a wire rope and a lifting hand chain block pulley; Step 502, adjust the length of the wire rope, use the lifting hand chain hoist to tighten the main beam 17 and the rear support 22, remove the main push cylinder 19 and the support shoe 20 and transport them out of the cave; Step 503, remove the connecting bolts between the rear support 22 and the second main beam 21, remove the rear support 22, turn it over and place it at the bottom of the tunnel 3, cut and dismember the rear support 22 in the tunnel 3 and transport it out of the tunnel in sequence; wherein the main beam 17 includes the first main beam 23 and the second main beam 21; Step 504, disassemble and remove the saddle frame and transport them out of the cave in sequence, and finally disassemble and dismember the second main beam 21 and the first main beam 23 and transport them out of the cave in sequence; Step 6: Dismantle the main drive and cutterhead of the TBM main machine: First, cut and dismantle the steel structure and motor reducer on the upper part of the main drive 24 in order from back to front and from top to bottom, and use the hoisting frame to transfer the removed parts to the cart and transport them out of the hole; then, cut the cutterhead 25 and the remaining part of the main drive 24 in order from top to bottom and from back to front, and use the hoisting frame to transfer the cut parts to the cart and transport them out of the hole; Step seven, grouting reinforcement is performed on the top area of ​​the cutter head and the shield: multiple groups of grouting holes are drilled on the top of the cutter head 25 and the shield 1, and the multiple groups of grouting holes are arranged in a plum blossom shape, each group of the grouting hole group includes multiple grouting holes, and the multiple grouting holes are arranged along the circumferential direction of the tunnel 3; a second grouting anchor is inserted into the grouting hole, and cement grouting is performed using the second grouting anchor to grout the top broken surrounding rock area of ​​the cutter head 25 and the shield 1 to complete the disassembly.

[0024] The present invention pioneered a method of dismantling the machine in situ while retaining the shields. Before dismantling the machine, the top, side and bottom shields are integrally welded with steel sections. During dismantling, the shields are not removed but retained as permanent support bodies. Combined with a variety of lifting and hoisting equipment, safe and efficient in-situ dismantling of the TBM tunnel is achieved, which fully ensures the stability of the rock around the tunnel, greatly reduces construction risks, effectively ensures construction safety and progress, and achieves good engineering results. It has a strong reference role for similar projects.

[0025] In step 102, the steel arch frame that is not sealed with sprayed concrete is a steel arch frame within the range of 150° to 270° of the top arch, and can be sealed by spraying 20 cm thick M35 mortar.

[0026] In step 2, after the surrounding rock steel support body is formed, it is necessary to remove the guide seat, cylinder, pipeline, etc. in the shield 1 as the working space for the main drive of cutting.

[0027] In step three, the first track beam 9 is made of HW175 steel, and two track beams are planned to be arranged on the top of the tunnel. The distance between the two track beams is 1.8m and the length is 36m.

[0028] In step 401, the design load capacity of a single fixed lifting point is 5t, and the lifting point test is the same as the main machine disassembly and lifting facilities. Eight 6t hand chain hoists are installed on the fixed lifting points as lifting equipment, which are mainly used for the lifting of the supporting upper equipment and steel structure. When the supporting lower equipment is dismantled, the lifting lugs or track beams are welded on the supporting frame structure, and the fall chain or manual hoist is installed to lift the lower equipment.

[0029] In step 402, when the rear-mounted lower equipment is dismantled, a lifting lug or track beam may be welded on the rear-mounted frame structure, and a fall chain or manual hoist may be installed to hoist the lower equipment.

[0030] In step three and step 401, during the installation of the TBM main machine and bridge area lifting facilities and the TBM rear supporting lifting facilities, in order to ensure the subsequent normal use of the two, the TBM main machine and bridge area lifting facilities and the TBM rear supporting lifting facilities need to be installed and tested during the installation process. Therefore, the two can be carried out simultaneously during the installation process, and the installation and testing process can also be repeated.

[0031] In steps 4, 5 and 6, the main beam and rear support of the TBM main machine, as well as the main drive and cutter head of the TBM main machine are dismantled in sequence according to the construction sequence. When the TBM rear supporting equipment is dismantled, it can be carried out simultaneously with the dismantling of the main beam and rear support of the TBM main machine in step 5, which further saves dismantling time and improves dismantling efficiency.

[0032] In step six, when dismantling the upper part of the main drive 24, the motor reducer, gears and bearings, the top steel structure at the rear end of the main drive, the top steel structure at the front end of the main drive, the adapter steel structure, the cutter disc connecting bolts, bearings, and the motor reducer, gears and bearings are dismantled in turn and the dismantled parts are transferred to the cart and transported out of the hole in turn using a lifting frame; when dismantling the remaining parts of the cutter disc 25 and the main drive 24 subsequently, the top steel structure of the cutter disc, the middle and upper steel structure of the main drive, the middle and upper part of the cutter disc, the middle and lower part of the main drive, the middle and lower part of the cutter disc, and the bottom of the cutter disc 25 and the main drive 24 are dismantled in turn.

[0033] In step 6, the electrical and hydraulic components in the shield are to be removed before the cutterhead and main drive base are removed. The side shield cylinder and wedge cylinder are removed first, then the wedge base is removed to increase the working space, and then the bottom connecting pin is removed. The cutterhead and main drive base are disassembled into small pieces on site and hoisted and transported out of the cave.

[0034] In step seven, after the dismantling work is completed, the steel structures such as the reinforcement plates on the inner side of the shield that invade the lining section will be cut off. If necessary, secondary lining and consolidation grouting will be carried out in time.

[0035] It should be noted that during the dismantling of the TBM rear supporting equipment, the steel structure size of the TBM rear supporting connection bridge is: 5.5m wide × 3.9m high, the steel structure size of the spray-mix bridge is: 5.5m wide × 3.8m high, and the steel structure size of the trolley is: 5.0m wide × 3.6m high. When the rear supporting steel structure is transported as a whole, the wind belt and belt slag system arranged along the line are dismantled. When the belt slag system is dismantled, the water supply and drainage pipes and transformers are dismantled, and the lighting along the line will be cut off. There is no lighting, drainage pump stations, water tanks, etc. need to be dismantled. In addition, there is a risk of water seepage from the tunnel wall crushing the wind belt due to long-term wind stoppage. In addition, the rear supporting equipment and the main machine are dismantled synchronously. Once the ventilation in the tunnel stops, the harmful gases generated by the electric welding operation will not be discharged. At the same time, the temperature of the working surface rises, and all construction personnel need to evacuate. Considering the above factors, after the rear supporting steel structure is disassembled, the steel structure connection bolts are dismantled and disassembled, or the welds are planed and disassembled and transported out of the tunnel.

[0036] In step 4, during the dismantling of the TBM rear supporting equipment, the main tunnel continuous belt conveyor, the branch tunnel fixed belt conveyor, the tunnel slag transfer belt conveyor, and the power supply system need to be dismantled simultaneously. Among them, the belt conveyor system dismantling mainly includes: the tunnel slag transfer belt conveyor, the branch tunnel fixed belt conveyor and the main tunnel continuous belt system dismantling; the process is as follows.

[0037] Main tunnel continuous belt conveyor removal Belt removal: The total length of the belt in the main tunnel is about 36km. The belt is rolled up one by one by a belt reel and then transported out of the tunnel. After the TBM is stopped and the belt conveyor is ready for removal, about 20m of belt is dragged out from the head of the belt bin and cut off. Two belt reels are placed at the head of the belt bin. The belt is first rolled to the first belt reel by the first belt reel and driven by the drive motor. After being rolled into a large roll of 540 meters, the belt is divided into two rolls of 270m by the second belt reel to facilitate the transportation of the belt out of the tunnel. Due to the small transportation space in the branch tunnel, the transportation height requirement of the 540m large roll belt cannot be met.

[0038] Belt conveyor bracket removal: After the belt under the main tunnel continuous belt is wound up, the belt conveyor bracket is removed from the inside to the outside. A simple belt conveyor bracket removal work platform is installed on the diesel locomotive, and the belt conveyor bracket, rollers, chains, etc. are removed manually.

[0039] Dismantling of the intermediate drive relay station: After the belt on the main tunnel continuous belt is collected to the intermediate drive relay station, the belt conveyor intermediate drive relay station system will be dismantled. It is planned to weld the lifting lugs on the steel arch frame arranged in the intermediate drive relay station area, and install the fall chain to dismantle the intermediate drive relay station.

[0040] Dismantling of main drive and belt bin: After the continuous belt in the main tunnel is completely rolled up, the belt bin and main drive station system arranged in the main branch tunnel intersection section will be dismantled. The main drive station and belt bin are to be dismantled manually with the help of a 25t gantry crane and a 25t truck crane arranged in the main branch tunnel intersection section.

[0041] Removal of fixed belt conveyor in branch tunnel and slag transfer belt conveyor outside the tunnel Belt removal: The total length of the belt in the branch tunnel is about 5.2km, and the belt winding method is the same as that of the continuous belt in the main tunnel. Considering the large slope of the branch tunnel, the lower belt is prone to slip during the belt winding process. In order to ensure construction safety, the upper and lower belts are planned to be wound separately. Before the belt is wound, the upper belt is fixed at the tensioning station with a fixing card, and the lower belt is fixed section by section. After the belt is fixed, the belt is cut from the tensioning platform of the tunnel entrance belt machine and the tail of the branch tunnel belt return station. After the belt is cut, the upper belt is wound in the same way as the continuous belt of the main tunnel. After the upper belt is wound to the tensioning platform at the entrance, the remaining upper belt and the lower belt joint are butt-jointed and vulcanized, and then the lower belt is wound. When the belt is wound, prevent it from slipping. After each roll of the belt is wound, use a fixing card to fix the belt before cutting it. The belt can be cut only after it is fixed.

[0042] Belt conveyor support dismantling: After the belt in the branch hole is rolled up, the belt conveyor support dismantling will begin. It is planned to install a simple belt conveyor support dismantling work platform on the forklift, and manually dismantle the belt conveyor support, rollers, chains, etc.

[0043] Dismantling of the branch tunnel belt drive station, trusses and slag transfer belt conveyor: After the branch tunnel belt is wound up, the dismantling of the branch tunnel belt drive station, tensioning device, trusses outside the tunnel and slag transfer belt conveyor will begin. The above structures are planned to be dismantled manually with the help of a 25t truck crane.

[0044] Finally, the power supply system was dismantled. The task of dismantling the TBM power supply system was to dismantle a 20kV high-voltage cable about 20.4km long on the right side of the tunnel wall in the direction of entering the tunnel and a 20kV high-voltage switchgear installed in the intersection section of the main and branch tunnels. After the TBM stops excavating and the conditions for dismantling the power supply system are met, the power supply is cut off first, and then the high-voltage cables are rolled up one by one from the inside to the outside and transported out of the tunnel. When the 20kV high-voltage cable is rolled up, the high-voltage cable reel is placed on a flatbed truck pulled by a diesel locomotive, and the cable is rolled up one by one manually. The 20kV high-voltage switchgear is dismantled manually with the help of a 25t truck crane.

[0045] In this embodiment, in step 101, the circumferential spacing between two adjacent first grouting anchor rods 2 is 0.5m~1m, the length of the first grouting anchor rod 2 is 2.0m~6.0m, the inclination angle of the first grouting anchor rod 2 is 10°~45°, and the first grouting anchor rod 2 is inclined forward along the extension direction of the tunnel 3; the angle between the first grouting anchor rods 2 on both sides is 120°~150°; when the first grouting anchor rod 2 is used to inject cement slurry, the grouting pressure is not greater than 3MPa.

[0046] In this embodiment, in step three, both ends of the first track beam 9 are provided with anti-derailment steel plates.

[0047] In this embodiment, in step three, the first track beam 9 is installed on the top of the tunnel 3 through a plurality of first mounting parts, and the plurality of first mounting parts are evenly arranged along the extension direction of the first track beam 9; four mounting holes are drilled on each of the lifting anchor points, and the first mounting parts include a first mounting plate 10 arranged at the lifting anchor point, a first fixed anchor rod 11 arranged between the first mounting plate 10 and the mounting hole, and a rib plate 12 arranged on the first mounting plate 10 and arranged on the side away from the first fixed anchor rod 11.

[0048] In actual use, the upper end of the first track beam 9 is welded to the first fixed anchor rod 11 and the first mounting plate 10, one side of the first mounting plate 10 is welded to the first fixed anchor rod 11, and a rib plate 12 is added to the other side; and 16mm thick anti-derailment steel plates are welded at both ends of the first track beam 9 as plugs to prevent the lifting hand chain hoist pulley from derailing. Two 10t hand chain hoist pulleys are arranged on each guide rail for lifting and turning over of various structural parts. The diameter of the first fixed anchor rod 11 is Φ22, L=2.5m cement roll / ordinary mortar anchor rod, the anchor rod is HRB400 grade threaded steel, the total length of the anchor rod is 2.5m, of which 0.5m is exposed, the rock anchoring length is ≥2m, and the longitudinal spacing of the anchor rod is 2m. After the installation of the sling is completed and passed the quality inspection and dynamic and static load tests, the main engine is dismantled in turn.

[0049] In this embodiment, in step 401, the fixed lifting point group includes four fixed lifting point groups arranged along the circumferential direction of the tunnel 3; the hand winch 13 is installed on the top of the tunnel 3 through a second mounting member, and the number of the second mounting members is equal to and corresponds to the number of the hand winches 13; the second mounting members include a second mounting plate 14 arranged at the fixed lifting point, a second fixed anchor rod 15 arranged between the second mounting plate 14 and the fixed lifting point, and two mounting anchor rods 16 both arranged on the second mounting plate 14 and arranged on the side away from the second fixed anchor rod 15; one end of the two mounting anchor rods 16 is fixed on the second mounting plate 14, and the hand winch 13 is installed between the other ends of the two mounting anchor rods 16.

[0050] In this embodiment, in step six, the hoisting frame is a gate-shaped hoisting frame, which includes multiple hoisting frame bodies, and the multiple hoisting frame bodies are arranged along the extension direction of the tunnel 3, and a second track beam 26 is arranged between the multiple hoisting frame bodies; the hoisting frame includes a horizontally arranged hoisting beam 27 and a vertically arranged supporting beam 28 at the bottom of the hoisting beam 27, the hoisting beam 27 and the supporting beam 28 are connected by bolts, and an oblique support 29 is obliquely arranged between the hoisting beam 27 and the supporting beam 28; the second track beam 26 is arranged at the bottom of the hoisting beam 27.

[0051] like Figure 6 As shown, a plurality of working platforms 32 are also horizontally arranged on the supporting vertical beam 28 .

[0052] In this embodiment, in step seven, the angle between the grouting holes on both sides is 180°; the length of the second grouting anchor is 3.5m, and the tail of the second grouting anchor is welded to the shield 1; the spacing between two adjacent groups of grouting holes is 1.25m~1.5m.

[0053] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural change made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A method for dismantling an open-type TBM in a broken stratum water delivery tunnel with shield left in situ, characterized in that: The method comprises the following steps: Step 1: Backfill the collapsed cavity at the top of the shield and reinforce the broken surrounding rock with grouting. The process is as follows: Step 101: Before dismantling the machine, the collapsed cavity at the top of the shield (1) is backfilled with spray mix; then, a plurality of first grouting anchor rods (2) are drilled at the tail of the shield (1) using a hand drill, and the plurality of first grouting anchor rods (2) are arranged along the circumferential direction of the tunnel (3), and the plurality of first grouting anchor rods (2) are all arranged at the top of the shield (1); cement slurry is injected into the top of the shield (1) and the cutter head using the first grouting anchor rods (2), and the broken surrounding rock at the top of the shield (1) and the cutter head is reinforced by grouting; Step 102, after the grouting reinforcement is completed, the steel arch frame at the rear of the shield (1) is connected with steel bars and steel sections, and the steel arch frame at the rear of the shield (1) that is not sealed with sprayed concrete is sealed with sprayed concrete; Step 2: Welding the shield as a whole: first, use the connecting steel plate (4) to connect the joints of the side shields (5) and the top shield (6); then use the connecting steel (31) to weld the top shields (6), the side shields (5) and the top shield (6), and the side shields (5) and the bottom shield (7) to form a surrounding rock steel support body; Step 3: Installation of lifting facilities in the TBM mainframe and bridge area: two groups of lifting anchor points are set on the top of the tunnel corresponding to the TBM mainframe and bridge area, and each group of lifting anchor points is evenly arranged along the extension direction of the tunnel (3); the first track beam (9) is installed using the lifting anchor points, and a lifting hand chain hoist pulley is installed on the first track beam (9), thereby completing the installation of the lifting facilities in the TBM mainframe and bridge area; Step 4: Installation of TBM rear supporting lifting facilities and removal of TBM rear supporting equipment. The process is as follows: Step 401: simultaneously, two groups of fixed lifting point groups are set on the top of the tunnel corresponding to the TBM rear supporting area, and each group of the fixed lifting point groups is evenly arranged along the circumferential direction of the tunnel (3); a plurality of hand chain hoists (13) are installed on the fixed lifting point groups to complete the installation of the lifting facilities in the TBM rear supporting area; after the installation is completed, the TBM rear supporting upper equipment is dismantled in sequence and transported out of the tunnel; Step 402, welding the lifting lugs on the frame structure of the TBM rear supporting equipment and installing the guide chain; after the installation is completed, dismantling the TBM rear supporting lower equipment and transporting it out of the cave; Step 403: After the TBM rear supporting equipment is dismantled, the TBM rear supporting frame structure is dismantled and transported out of the tunnel in sequence using the TBM rear supporting lifting facilities; Step 5: Remove the main beam and rear support of the TBM mainframe. The process is as follows: Step 501: a plurality of support columns (18) are arranged at the bottom of the main beam (17), and the plurality of support columns (18) are arranged along the extension direction of the main beam (17); the top of the main beam (17) is connected with a steel wire rope and a lifting hand chain hoist pulley; Step 502, adjusting the length of the steel wire rope, tightening the main beam (17) and the rear support (22) using a lifting hand chain hoist, removing the main push cylinder (19) and the support shoe (20) and transporting them out of the cave; Step 503, remove the connecting bolts between the rear support (22) and the second main beam (21), remove the rear support (22), turn it over and place it at the bottom of the tunnel (3), and cut and dismember the rear support (22) in the tunnel (3) and transport them out of the tunnel in sequence; wherein the main beam (17) includes the first main beam (23) and the second main beam (21); Step 504, disassemble and remove the saddle frame and transport them out of the cave in sequence, and finally disassemble and dismember the second main beam (21) and the first main beam (23) and transport them out of the cave in sequence; Step 6: Dismantle the main drive and cutterhead of the TBM main machine: First, cut and dismantle the steel structure and motor reducer on the upper part of the main drive (24) in order from back to front and from top to bottom, and use a hoisting frame to transfer the removed parts to a cart and transport them out of the hole; then, cut the remaining part of the cutterhead (25) and the main drive (24) in order from top to bottom and from back to front, and use a hoisting frame to transfer the cut parts to a cart and transport them out of the hole; Step 7: Grouting reinforcement of the top area of ​​the cutter head and the shield: Drill multiple groups of grouting holes on the top of the cutter head (25) and the shield (1), the multiple groups of grouting holes are arranged in a plum blossom shape, each group of the grouting holes includes multiple grouting holes, and the multiple grouting holes are arranged along the circumferential direction of the tunnel (3); insert a second grouting anchor rod into the grouting hole, and use the second grouting anchor rod to perform cement grouting to grout the top broken surrounding rock area of ​​the cutter head (25) and the shield (1), and complete the dismantling of the machine.

2. The method for dismantling an open-type TBM in a broken stratum water delivery tunnel according to claim 1, characterized in that: In step 101, the circumferential spacing between two adjacent first grouting anchor rods (2) is 0.5 m to 1 m, the length of the first grouting anchor rod (2) is 2.0 m to 6.0 m, the inclination angle of the first grouting anchor rod (2) is 10° to 45°, and the first grouting anchor rod (2) is inclined forward along the extension direction of the tunnel (3); the angle between the first grouting anchor rods (2) located on both sides is 120° to 150°; when cement slurry is injected using the first grouting anchor rod (2), the grouting pressure is not greater than 3 MPa.

3. The method for dismantling an open-type TBM in a broken stratum water delivery tunnel according to claim 1, characterized in that: In step three, anti-derailment steel plates are provided at both ends of the first track beam (9).

4. The method for dismantling an open-type TBM in a broken stratum water delivery tunnel with shield left in situ according to claim 3 is characterized by: In step three, the first track beam (9) is installed on the top of the tunnel (3) through a plurality of first mounting parts, and the plurality of first mounting parts are evenly arranged along the extension direction of the first track beam (9); four mounting holes are drilled on each of the lifting anchor points, and the first mounting parts include a first mounting plate (10) arranged at the lifting anchor point, a first fixing anchor rod (11) arranged between the first mounting plate (10) and the mounting hole, and a rib plate (12) arranged on the first mounting plate (10) and arranged on a side away from the first fixing anchor rod (11).

5. The method for dismantling an open-type TBM in a broken stratum water delivery tunnel in-situ with shield retained according to claim 1 is characterized by: In step 401, the fixed lifting point group includes four fixed lifting point groups arranged along the circumferential direction of the tunnel (3); the hand chain hoist (13) is installed on the top of the tunnel (3) through a second mounting member, and the number of the second mounting members is equal to the number of the hand chain hoists (13) and corresponds one to one; the second mounting members each include a second mounting plate (14) arranged at the fixed lifting point, a second fixed anchor rod (15) arranged between the second mounting plate (14) and the fixed lifting point, and two mounting anchor rods (16) each arranged on the second mounting plate (14) and arranged on a side away from the second fixed anchor rod (15); one end of the two mounting anchor rods (16) is fixed on the second mounting plate (14), and the hand chain hoist (13) is installed between the other ends of the two mounting anchor rods (16).

6. The method for dismantling an open-type TBM in a broken stratum water delivery tunnel in-situ with shield retained according to claim 1 is characterized by: In step six, the hoisting frame is a gate-shaped hoisting frame, the hoisting frame comprises a plurality of hoisting frame bodies, the plurality of hoisting frame bodies are arranged along the extension direction of the tunnel (3), and a second track beam (26) is arranged between the plurality of hoisting frame bodies; the hoisting frame comprises a horizontally arranged hoisting cross beam (27) and a supporting vertical beam (28) arranged vertically at the bottom of the hoisting cross beam (27), the hoisting cross beam (27) and the supporting vertical beam (28) are connected by bolts, and an oblique support (29) is obliquely arranged between the hoisting cross beam (27) and the supporting vertical beam (28); the second track beam (26) is arranged at the bottom of the hoisting cross beam (27).

7. The method for dismantling an open-type TBM in a broken stratum water delivery tunnel in-situ with shield retained according to claim 1 is characterized by: In step seven, the angle between the grouting holes on both sides is 180°; the length of the second grouting anchor is 3.5 m, and the tail of the second grouting anchor is welded to the shield (1); and the spacing between two adjacent groups of grouting holes is 1.25 m to 1.5 m.

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