Method for disassembling main drive of double-shield TBM (tunnel boring machine) in tunnel

Abstract

The invention relates to a method for disassembling a main drive of a double-shield TBM (tunnel boring machine) in a tunnel, which belongs to the field of disassembly and assembly and comprises the following steps: (1) preparation work; (2) cutting an anterior shield; (3) lifting lugs are welded, and lifting points are arranged; (4) disassembling and turning over by a main driving method; and (5) transporting a main drive. The in-hole dismounting key technology for the double-shield TBM main drive has the advantages that the problem of non-destructive dismounting of the main drive in a narrow space of an equipment shield body is well solved, secondary use of core components is guaranteed, the recovery cost after in-hole shell abandoning and machine dismounting is greatly saved, and the in-hole dismounting key technology is safe, economical and feasible and has wide application prospects. And the method can be used for subsequent dismounting construction of the main drive in similar in-hole shell abandoning and dismounting machines.

Description

Technical Field

[0001] The invention relates to a method for disassembling a main drive of a double-shield TBM in a hole, belonging to the field of shield body disassembly. Background Art

[0002] Double shield TBM is a double shield hard rock tunnel boring machine. Taking the excavation diameter of Φ6300mm as an example, the length of the whole machine is 135 meters, which is composed of the main machine and the supporting equipment. The TBM main machine is a combination of the cutter head, shield body, hydraulic components, etc. The main machine is about 13 meters long and weighs about 450 tons; the supporting equipment consists of 12 trolleys, each of which has 4 wheels at the bottom to move forward with the excavation. The equipment of each system is placed on the trolley and connected by pipelines.

[0003] Most of the dismantling of tunnel boring machines (also known as equipment dismantling) is done after the equipment has completed excavation and exited the tunnel. In an open space such as a dismantling cavern or a more spacious starting tunnel (where there is a large available dismantling space), auxiliary lifting equipment such as truck cranes and gantry cranes are used to systematically dismantle the tunnel boring machine into blocks according to the original design, and then transport it away by transport vehicles.

[0004] The main drive is heavy, bulky and very bulky. In addition, the space is narrow and the potential safety risks are high. The entire demolition operation is full of challenges. There is no experience to draw on for the main drive disassembly work, and disassembly and transportation are both big problems.

[0005] In order to solve the problems of connecting the central urban area subway construction to the existing operating stations, the small construction space that makes it impossible to lift out the equipment, compressing the construction period, and demolition and resettlement, it is necessary to implement the double shield TBM in-tunnel shell dismantling solution when dismantling the equipment. Summary of the invention

[0006] In order to overcome the defects of the prior art, the present invention provides a double shield TBM main drive in-hole disassembly method, the technical solution of the present invention is: A method for disassembling a main drive of a double-shield TBM in a hole, comprising the following steps: (1) preparation; (2) cutting the front shield; (3) welding lifting lugs and setting lifting points; (4) Disassembly and turning over by main drive method; (5) Transport main drive.

[0007] The step (1) is specifically as follows: 1.1 assessing the size of the space in the tunnel and the main drive; 1.2 Prepare the necessary tools and equipment, including but not limited to electric hoists, welding equipment, cutting tools and transport carts; 1.3 Provide safety and technical training to operators.

[0008] 3. The double shield TBM main drive in-hole disassembly method according to claim 1 is characterized in that the step (2) specifically comprises: 2.1 Draw a cutting line on the front shield and keep the connecting flange between the main drive and the front shield to facilitate welding of the lifting lugs and use it as a lifting load-bearing flange; 2.2 Three points for fixing the main drive are reserved, namely the first fixing point, the second fixing point and the third fixing point, so as to prevent the main drive from tipping over; the first fixing point, the second fixing point and the third fixing point are evenly distributed along the circumference of the front shield as a whole; 2.3 Use cutting tools to cut along the designated cutting line to ensure that the cutting surface is flat and safe; 2.3 After cutting, clean up the site to ensure no debris remains.

[0009] The step (3) is specifically as follows: 3.1 The hanging point of the front shield is set at the root of the load-bearing plate and at the location where there is a structural intersection; 3.2 Weld four main drive lifting lugs at the upper, lower, left and right positions of the reserved connection flange, and perform flaw detection on the lifting lugs after welding: 3.3 Set up one 80-ton lifting point on each side of the front shield connection flange, named front shield lifting point left point 1 and front shield lifting point right point 2, for lifting the lifting point above the main drive, and later use a 50-ton electric hoist for lifting; 3.4 Set up an 80-ton lifting point at 50 degrees to the left and right of the annular flange plate at the rear end of the support shield, named support shield lifting point left point 1 and support shield lifting point right point 2, respectively, for lifting the lifting point below the main drive, and use a 50-ton electric hoist for lifting later; 3.5 When the front shield is cut, the reserved connection flange on the main drive is used to set the main drive's own lifting point. The main drive lifting lug left point A and the main drive lifting lug right point B are set at the outer side of the main drive and front shield connection bolts, that is, 50 degrees to the left and right above the flange plate. The lifting lug motherboard is perpendicular to the connection flange. After welding, flaw detection is carried out; 3.6 Set the main drive's own lifting point on the reserved flange plate on the main drive, and set the main drive lifting lug left point C and the main drive lifting lug right point D on the outside of the main drive and front shield connecting bolts, that is, 50 degrees to the left and right below the connecting flange. The lifting lug mother plate is perpendicular to the reserved connecting flange. Perform flaw detection after welding is completed.

[0010] The step (4) is specifically as follows: 4.1 Use electric hoists to connect the left point 1 of the front shield lifting point with the left point A of the main drive lifting lug, and the right point 2 of the front shield lifting point with the right point B of the main drive lifting lug. The hoists should be maintained before use; 4.2 The hoists are all tightened. When the main drive and front shield hoisting electric hoist is holding force, continue to cut the structure and completely cut off the first fixing point of the main drive and front shield; 4.3 Then cut off the second and third fixed points symmetrically. During the cutting process, make sure to tighten all the electric hoists to prevent the main drive from tilting. 4.4 Before completely cutting off the second and third fixing points, move the support shield hanging point to the left by 1 point. Use electric hoists to connect the left C point of the main drive lifting lug, and the right 2 points of the support shield lifting point and the right D point of the main drive lifting lug. The hoists should be maintained before use; 4.5 After all the main drive fixing points are cut, all hoisting hoists should be held tight; during the cutting process, pay attention to tightening all electric hoists to prevent the main drive from tilting; 4.6 When performing turning hoisting, the hoist should be operated alternately according to the principle of loosening and tightening.

[0011] The step (5) is specifically as follows: 5.1 Tighten the left and right hoists on the support shield in order, and slowly lift the bottom of the main drive to change the main drive from radial standing to up and down tilting; 5.2 Move the transport trolley to the bottom of the main drive to facilitate turning the main drive over and placing it on the trolley; 5.3 The left and right hoists on the support shield stop working, and at this time the main drive end face has an angle with the ground; 5.4 Extend the left and right hoist chains on the front shield so that the main drive is placed from tilted to horizontal front and back, that is, the front and rear end surfaces when standing are parallel to the top surface of the transport trolley; 5.5 Finally, alternate the left and right hoists on the support shield and the left and right hoists on the front shield to place the main drive flat on the transport trolley to complete the turning over of the main drive.

[0012] The step (6) is specifically as follows: 6.1 Before transportation, the safety and fastening of the entire track shall be checked. When laying the track inside the shield, the sleepers shall be arranged densely; 6.2 When using a tractor to move or transport components, the components should be prevented from rolling and reinforced; 6.3 The flatbed trolley moves slowly during transportation. When passing through obstacles, on-site personnel should observe in time whether it can pass.

[0013] The advantages of the present invention are: The key technology for in-hole disassembly of the main drive of the double-shield TBM has effectively solved the problem of non-destructive disassembly of the main drive in the narrow space of the equipment shield, ensuring the secondary use of core components and greatly saving the restoration costs after in-hole shell disassembly. It is safe, economical and feasible, and can be used for subsequent disassembly construction of the main drive in similar in-hole shell disassembly.

[0014] It has the following advantages: Efficient space utilization: This method disassembles the main drive inside the tunnel and does not require additional spacious space. It is particularly suitable for application in space-constrained environments such as urban subway construction.

[0015] Protecting the tunnel structure: Since no additional lifting points are set and no chamber expansion is done, the integrity of the tunnel is protected and the risk of damage to the tunnel structure is avoided.

[0016] High operational safety: Using the TBM's own shield as a support point for dismantling and turning over reduces the need for external lifting equipment, reduces operational risks, and improves operational safety.

[0017] Economical: This method greatly saves the cost of recovery after the shell is abandoned and the machine is dismantled in the tunnel, because it reduces the modification of the tunnel and the use of additional equipment, thus reducing costs.

[0018] Improved reusability of core components: This method ensures non-destructive disassembly of the main drive, so that the main drive can be reassembled and used after it is out of the hole, improving the economic value and sustainability of the core components of the equipment.

[0019] Shorten construction period: Since disassembly work is carried out directly in the tunnel, the time for equipment transportation and reassembly is reduced, which helps to speed up the project progress and shorten the construction period.

[0020] Small environmental impact: This method reduces interference with the surrounding environment, such as reducing the generation of noise and dust, and is more environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the main structure of the disassembly and assembly front shield of the present invention.

[0022] Figure 2 It is a schematic diagram of the main structure of the disassembly and assembly support shield of the present invention.

[0023] Figure 3 It is a schematic diagram of the main drive of the present invention being in a vertical state when hoisted.

[0024] Figure 4 It is a schematic diagram of the main drive of the present invention being in an inclined state during hoisting.

[0025] Figure 5 It is a schematic diagram of the main drive of the present invention being in a horizontal state when hoisted. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with specific embodiments, and the advantages and features of the present invention will become clearer as the description proceeds. However, these embodiments are exemplary only and do not constitute any limitation to the scope of the present invention. It should be understood by those skilled in the art that the details and forms of the technical solution of the present invention may be modified or replaced without departing from the spirit and scope of the present invention, but these modifications and replacements all fall within the scope of protection of the present invention.

[0027] See also Figures 1 to 5 The present invention relates to a method for disassembling a main drive of a double-shield TBM in a hole, comprising the following steps: (1) preparation; (2) cutting the front shield; (3) welding lifting ears and setting lifting points; (4) disassembling and turning over the main drive; and (5) transporting the main drive.

[0028] The present invention provides a completely new method for disassembling a heavy TBM main drive in a narrow tunnel environment, which is innovative in the field of tunnel construction at home and abroad.

[0029] Optimization of space utilization: This method makes full use of the limited space in the tunnel, without the need for additional dismantling caverns or spacious sites, thus solving the problem of limited space in urban subway construction.

[0030] Improved operational safety: By using the TBM’s own shield structure as a support and lifting point, the reliance on external large-scale lifting equipment is reduced, the operational risks are reduced, and the operational safety is improved.

[0031] Significant improvement in economic benefits: This method avoids additional equipment dismantling and transportation costs and reduces the need for tunnel structure modification, thereby significantly reducing project costs.

[0032] Minimization of environmental impact: This method reduces disturbance to the surrounding environment, such as noise, dust and space occupation, and meets the requirements of modern engineering for environmental protection.

[0033] Effective reduction of construction period: This method helps to shorten the construction period of the entire project by reducing the time for disassembly and reassembly of equipment and avoiding complex logistics arrangements.

[0034] The step (1) is specifically as follows: 1.1 assessing the size of the space in the tunnel and the main drive; 1.2 Prepare the necessary tools and equipment, including but not limited to electric hoists, welding equipment, cutting tools and transport carts; 1.3 Provide safety and technical training to operators.

[0035] The step (2) is specifically as follows: 2.1 Draw a cutting line on the front shield and keep the connecting flange between the main drive and the front shield to facilitate welding of the lifting lugs and use it as a lifting load-bearing flange; 2.2 Three points for fixing the main drive are reserved, namely the first fixing point, the second fixing point and the third fixing point, so as to prevent the main drive from tipping over; the first fixing point, the second fixing point and the third fixing point are evenly distributed along the circumference of the front shield as a whole; 2.3 Use cutting tools to cut along the designated cutting line to ensure that the cutting surface is flat and safe; 2.3 After cutting, clean up the site to ensure no debris remains.

[0036] The setting of step (2) achieves: Precise cutting positioning: By marking the precise cutting line on the front shield and retaining the connecting flange between the main drive and the front shield, the accuracy of the cutting process and the safety of subsequent lifting can be ensured.

[0037] Enhanced structural stability: Three evenly distributed fixing points are reserved to effectively enhance the stability of the main drive during disassembly and prevent tipping or accidents caused by instability.

[0038] Improve cutting efficiency: Using cutting tools to work along the designated cutting line can improve cutting efficiency and reduce manpower and time consumption.

[0039] Ensure cutting quality: Ensure the flatness and safety of the cut surface, provide a high-quality cut surface for subsequent welding and hoisting work, and reduce the possible need for secondary processing.

[0040] The step (3) is specifically as follows: 3.1 The hanging point of the front shield is set at the root of the load-bearing plate and at the location where there is a structural intersection; 3.2 Weld four main drive lifting lugs at the upper, lower, left and right positions of the reserved connection flange, and perform flaw detection on the lifting lugs after welding: 3.3 Set up one 80-ton lifting point on each side of the front shield connection flange, named front shield lifting point left 1 point 1 and front shield lifting point right 2 point 2, for lifting the lifting point above the main drive, and later use a 50-ton electric hoist for lifting; 3.4 Set up an 80-ton lifting point at 50 degrees to the left and right of the annular flange plate at the rear end of the support shield, named support shield lifting point left 1 point 8 and support shield lifting point right 2 point 9, respectively, for lifting the lifting point below the main drive 7, and use a 50-ton electric hoist for lifting later; 3.5 When the front shield is cut, the reserved connection flange on the main drive is used to set the main drive's own lifting point. The main drive lifting lug left point A 3 and the main drive lifting lug right point B 4 are set at the outer side of the main drive 7 and the front shield connection bolt, that is, 50 degrees to the left and right above the flange plate. The lifting lug mother plate is perpendicular to the connection flange. After welding, flaw detection is carried out; 3.6 Set the main drive's own lifting point on the reserved flange plate on the main drive 7, and set the main drive lifting lug left point C 5 and the main drive lifting lug right point D 6 on the outside of the main drive and front shield connection bolts, that is, 50 degrees to the left and right below the connection flange. The lifting lug mother plate is perpendicular to the reserved connection flange, and flaw detection is carried out after welding is completed.

[0041] The setting of step (3) achieves: Optimization of structural strength: Setting the lifting point at the intersection of the root of the load-bearing plate and the structure ensures the strength and reliability of the lifting point and reduces possible structural damage during the lifting process.

[0042] Evenly distributed stress: By welding four main drive lifting lugs at the upper, lower, left and right positions of the connecting flange, even distribution of stress on the main drive during lifting is achieved, reducing the risk of local stress concentration.

[0043] Improve welding quality: Perform flaw detection on the welded lifting lugs to ensure that the welding quality meets the requirements of high-load lifting and enhances the safety of the structure.

[0044] Adapt to different lifting requirements: Setting lifting points in different positions can adapt to the lifting requirements above and below the main drive, increasing the flexibility of the operation.

[0045] Use high-load electric hoist: Use 80-ton lifting points and 50-ton electric hoists for lifting, which provides sufficient safety margin and ensures the safety of lifting operations.

[0046] Accurate lifting point position: Accurately set the position of the main drive's own lifting point to ensure the stability and balance of the main drive during lifting The step (4) is specifically as follows: 4.1 Use electric hoists to connect the left point 1 of the front shield lifting point with the left point A of the main drive lifting lug, and the right point 2 of the front shield lifting point with the right point B of the main drive lifting lug. The hoists should be maintained before use; 4.2 The hoists are all tightened. When the main drive and front shield hoisting electric hoist is holding force, continue to cut the structure and completely cut off the first fixing point of the main drive and front shield; 4.3 Then cut off the second and third fixed points symmetrically. During the cutting process, make sure to tighten all the electric hoists to prevent the main drive from tilting. 4.4 Before completely cutting off the second and third fixing points, move the support shield hanging point to the left by 1 point. Use electric hoists to connect the left C point of the main drive lifting lug, and the right 2 points of the support shield lifting point and the right D point of the main drive lifting lug. The hoists should be maintained before use; 4.5 After all the main drive fixing points are cut, all hoisting hoists should be held tight; during the cutting process, pay attention to tightening all electric hoists to prevent the main drive from tilting; 4.6 When performing turning hoisting, the hoist should be operated alternately according to the principle of loosening and tightening.

[0047] Step (4) "Main drive disassembly and turning over" is the core step in the double shield TBM main drive in-hole disassembly method. Its advantages include: Safety of gradual lifting: By connecting and tightening the lifting points in steps using electric hoists, the main drive is gradually stressed during the removal process, reducing the risk of sudden instability.

[0048] Structural stability: Ensuring the holding force of the electric hoist before cutting the fixed point enhances the stability of the main drive during the cutting process and prevents accidental movement or tilting caused by cutting.

[0049] Balance of cutting: Symmetrical cutting of the second and third fixed points maintains the balance of the main drive and avoids structural damage caused by asymmetric force.

[0050] Comprehensive equipment maintenance: Perform maintenance before using the electric hoist to ensure the good working condition of the lifting equipment and reduce the risk of failure during the lifting process.

[0051] Accurate force control: Pay attention to the force and tightening of the electric hoist during the cutting process, realize the precise control of the main drive force, and ensure the smoothness of the lifting process.

[0052] The step (5) is specifically as follows: 5.1 Tighten the left and right hoists on the support shield in order, and slowly lift the bottom of the main drive to change the main drive from radial standing to up and down tilting; 5.2 Move the transport trolley to the bottom of the main drive to facilitate turning the main drive over and placing it on the trolley; 5.3 The left and right hoists on the support shield stop working, and at this time the main drive end face has an angle with the ground; 5.4 Extend the left and right hoist chains on the front shield so that the main drive is placed from tilted to horizontal front and back, that is, the front and rear end surfaces when standing are parallel to the top surface of the transport trolley; 5.5 Finally, alternate the left and right hoists on the support shield and the left and right hoists on the front shield to place the main drive flat on the transport trolley to complete the turning over of the main drive.

[0053] Step (5) "transporting the main drive" is a key step in achieving safe transfer of the main drive in the double shield TBM main drive in-hole disassembly method. Its advantages include: Fine lifting control: By orderly tensioning the hoists on the support shield, precise lifting and tilting of the main drive is achieved, ensuring a smooth and controlled lifting process.

[0054] Improve operational safety: Move the transport trolley to the bottom of the main drive to avoid the risk of the main drive falling during the turning process, thus improving operational safety.

[0055] Effective space utilization: By precisely adjusting the posture of the main drive, the main drive can land smoothly on the transport trolley, effectively utilizing the limited tunnel space.

[0056] Reduce the pressure on the ground: The main drive end face forms an angle with the ground, which reduces the pressure on the ground and avoids damage to the tunnel ground.

[0057] Smooth turning operation: By lengthening the hoist chain on the front shield, the main drive is smoothly transformed from an inclined state to a horizontal state, reducing the impact and vibration during the turning process.

[0058] The step (6) is specifically as follows: 6.1 Before transportation, the safety and fastening of the entire track shall be checked. When laying the track inside the shield, the sleepers shall be arranged densely; 6.2 When using a tractor to move or transport components, the components should be prevented from rolling and reinforced; 6.3 The flatbed trolley moves slowly during transportation. When passing through obstacles, on-site personnel should observe in time whether it can pass.

[0059] The present invention can smoothly and safely dismantle the main drive during the TBM's in-hole shell abandonment and dismantling process, meeting the conditions for reassembly and use of the main drive after exiting the hole; it includes the following steps: dismantling the main drive, and transporting the main drive to the rear starting hole position after turning it over in the hole. The present invention does not set up additional lifting points, does not perform any chamber expansion, and ensures the integrity of the tunnel. The double-shield TBM's own shield body is used as a support point to dismantle and turn over the main drive in the hole, meeting the in-hole disassembly requirements when the tunnel end does not have the receiving conditions.

[0060] The working principle of the present invention is mainly based on the following core steps, each of which is carefully designed to ensure safe and efficient removal and transportation of heavy TBM main drives in the narrow tunnel environment: Preparation (Step 1): First, a detailed assessment of the space in the tunnel and the dimensions of the main drive were carried out to determine the most appropriate removal plan.

[0061] Prepare the necessary tools and equipment, including electric hoists, welding equipment, cutting tools and transport trolleys, and ensure all equipment is in good working condition.

[0062] Provide safety and technical training to operators to ensure they understand all safety regulations and technical requirements during the disassembly process.

[0063] Cutting the front shield (step 2): Draw precise cutting lines on the front shield, retain the connecting flange between the main drive and the front shield, and provide a force point for the subsequent welding of the lifting lugs.

[0064] Three evenly distributed fixing points are reserved to enhance the stability of the main drive during disassembly and prevent tipping.

[0065] Use cutting tools to cut along the marked cutting line, ensure the cutting surface is flat and safe, and clean up the site after cutting is completed.

[0066] Welding lifting lugs and setting lifting points (step 3): The lifting point is set at the structural intersection of the front shield and the supporting shield to ensure the strength and reliability of the lifting point.

[0067] Four main drive lifting lugs are welded at the upper, lower, left and right positions of the connecting flange, and flaw detection is performed to ensure welding quality.

[0068] Multiple lifting points are set up to meet the lifting requirements above and below the main drive, and high-load electric hoists are used for lifting to ensure safety.

[0069] Main drive disassembly and turning over (step 4): Use an electric hoist to connect the lifting points of the front shield and the support shield, gradually tighten the hoist to ensure that the main drive is gradually stressed during the disassembly process.

[0070] Cut off the fixing points symmetrically to maintain the balance of the main drive and avoid structural damage caused by asymmetric force.

[0071] During turning over and hoisting, perform alternating operations according to the principle of loosening and tightening to ensure smooth turning of the main drive.

[0072] Transport the main drive (step 5): By sequentially tightening the hoist, lift the bottom of the main drive so that it changes from radial standing to up and down tilting, and move the transport trolley under the main drive.

[0073] Adjust the posture of the main drive so that it is placed horizontally on the transport trolley to complete the turnover.

[0074] During transportation, move the trolley slowly to ensure the stability and safety of the components.

[0075] Site clean-up and follow-up (step 6): After the main drive is transported to the designated location, the site is cleaned and all temporary facilities and equipment are removed.

[0076] Inspect and maintain the tracks on the transportation routes to ensure smooth progress of subsequent work.

[0077] Carry out necessary cleaning and maintenance on the disassembled main drive in preparation for subsequent reassembly or use.

[0078] Through these steps, the present invention provides a method for efficiently and safely disassembling and transporting a heavy TBM main drive in a narrow space, which reduces dependence on external large-scale lifting equipment, reduces operational risks, improves operational safety, and significantly reduces engineering costs and shortens construction periods.

[0079] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A double shield TBM main drive in-hole disassembly method, characterized in that: The process includes the following steps: (1) preparation; (2) cutting the front shield; (3) welding the lifting lugs and setting the lifting points; (4) Disassembly and turning over by main drive method; (5) Transport main drive.

2. The double shield TBM main drive in-hole disassembly method according to claim 1 is characterized in that: The step (1) is specifically as follows: 1.1 assessing the size of the space in the tunnel and the main drive; 1.2 Prepare the necessary tools and equipment, including but not limited to electric hoists, welding equipment, cutting tools and transport carts; 1.3 Provide safety and technical training to operators.

3. The double shield TBM main drive in-hole disassembly method according to claim 1 is characterized in that: The step (2) is specifically as follows: 2.1 Draw a cutting line on the front shield and keep the connecting flange between the main drive and the front shield to facilitate welding of the lifting lugs and use it as a lifting load-bearing flange; 2.2 Three points for fixing the main drive are reserved, namely the first fixing point, the second fixing point and the third fixing point, so as to prevent the main drive from tipping over; the first fixing point, the second fixing point and the third fixing point are evenly distributed along the circumference of the front shield as a whole; 2.3 Use cutting tools to cut along the designated cutting line to ensure that the cutting surface is flat and safe; 2.3 After cutting, clean up the site to ensure no debris remains.

4. The double shield TBM main drive in-hole disassembly method according to claim 1 is characterized in that: The step (3) is specifically as follows: 3.1 The hanging point of the front shield is set at the root of the load-bearing plate and at the location where there is a structural intersection; 3.2 Weld four main drive lifting lugs at the upper, lower, left and right positions of the reserved connection flange, and perform flaw detection on the lifting lugs after welding: 3.3 Set up one 80-ton lifting point on each side of the front shield connection flange, named front shield lifting point left point 1 and front shield lifting point right point 2, for lifting the lifting point above the main drive, and later use a 50-ton electric hoist for lifting; 3.4 Set up an 80-ton lifting point at 50 degrees to the left and right of the annular flange plate at the rear end of the support shield, named support shield lifting point left point 1 and support shield lifting point right point 2, respectively, for lifting the lifting point below the main drive, and use a 50-ton electric hoist for lifting later; 3.5 When the front shield is cut, the reserved connection flange on the main drive is used to set the main drive's own lifting point. The main drive lifting lug left point A and the main drive lifting lug right point B are set at the outer side of the main drive and front shield connection bolts, that is, 50 degrees to the left and right above the flange plate. The lifting lug motherboard is perpendicular to the connection flange. After welding, flaw detection is carried out; 3.6 Set the main drive's own lifting point on the reserved flange plate on the main drive, and set the main drive lifting lug left point C and the main drive lifting lug right point D on the outside of the main drive and front shield connecting bolts, that is, 50 degrees to the left and right below the connecting flange. The lifting lug mother plate is perpendicular to the reserved connecting flange. Perform flaw detection after welding is completed.

5. The double shield TBM main drive in-hole disassembly method according to claim 1 is characterized in that: The step (4) is specifically as follows: 4.1 Use electric hoists to connect the left point 1 of the front shield lifting point with the left point A of the main drive lifting lug, and the right point 2 of the front shield lifting point with the right point B of the main drive lifting lug. The hoists should be maintained before use; 4.2 All hoists are tightened. When the main drive and front shield hoisting electric hoist has reached the required force, continue with the structural cutting and completely cut off the first fixing point of the main drive and front shield. 4.3 Then cut off the second and third fixed points symmetrically. During the cutting process, make sure to tighten all the electric hoists to prevent the main drive from tilting. 4.4 Before completely cutting off the second and third fixing points, move the support shield hanging point to the left by 1 point. Use electric hoists to connect the left C point of the main drive lifting lug, and the right 2 points of the support shield lifting point and the right D point of the main drive lifting lug. The hoists should be maintained before use; 4.5 After all the main drive fixing points are cut, all hoisting hoists should be held tight; during the cutting process, pay attention to tightening all electric hoists to prevent the main drive from tilting; 4.6 When performing turning hoisting, the hoist should be operated alternately according to the principle of loosening and tightening.

6. The double shield TBM main drive in-hole disassembly method according to claim 1 is characterized in that: The step (5) is specifically as follows: 5.1 Tighten the left and right hoists on the support shield in order, and slowly lift the bottom of the main drive to change the main drive from radial standing to up and down tilting; 5.2 Move the transport trolley to the bottom of the main drive to facilitate turning the main drive over and placing it on the trolley; 5.3 The left and right hoists on the support shield stop working, and at this time the main drive end face has an angle with the ground; 5.4 Extend the left and right hoist chains on the front shield so that the main drive is placed from tilted to horizontal front and back, that is, the front and rear end surfaces when standing are parallel to the top surface of the transport trolley; 5.5 Finally, alternate the left and right hoists on the support shield and the left and right hoists on the front shield to place the main drive flat on the transport trolley to complete the turning over of the main drive.

7. The double shield TBM main drive in-hole disassembly method according to claim 1 is characterized in that: The step (6) is specifically as follows: 6.1 Before transportation, the safety and fastening of the entire track shall be checked. When laying the track inside the shield, the sleepers shall be arranged densely; 6.2 When using a tractor to move or transport components, the components should be prevented from rolling and reinforced; 6.3 The flatbed trolley moves slowly during transportation. When passing through obstacles, on-site personnel should observe in time whether it can pass.

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