A tunneling machine and a tunnel excavation device for a circular-arched straight-wall cross section and a construction method

Abstract

This invention discloses a tunnel boring machine (TBM) and a device for excavating a tunnel with a quasi-circular arch and straight wall cross-section, as well as a construction method. The device includes a TBM main unit, a rock cutter with a rounded corner, a rear-mounted trailer, a muck removal system, and a cutting machine support system. The TBM main unit is installed at the front of the excavation device, and the cutting machine support system is installed at the rear. The TBM main unit and the cutting machine support system are connected via the rear-mounted trailer. The rock cutter with a rounded corner is mounted on the cutting machine support system and is used to cut the tunnel under the control of the cutting machine support system. The TBM main unit, the cutting machine support system, and the rear-mounted trailer all have muck removal systems installed inside. The construction method includes three processes: excavation, step switching, and muck removal. This invention offers high forming efficiency, a short construction cycle, and more flexible rock cutting capabilities, adapting to rocks of different areas and sizes. Furthermore, the excavation and step switching processes of the TBM main unit and the rock cutter with a rounded corner are independent and do not interfere with each other. The structure is simple and the cost is low.

Description

Technical Field

[0001] This invention relates to the field of tunnel excavation, specifically to a tunnel boring machine, a device for excavating tunnels with a quasi-circular arch and straight wall cross section, and a construction method thereof. Background Technology

[0002] Circular arch tunnels with straight walls are widely used in numerous construction projects due to their strong structural load-bearing capacity and 15%-20% higher space utilization compared to traditional circular tunnels. There are two main methods for excavating traditional circular arch tunnels with straight walls: First, a large-diameter circular tunnel capable of encompassing the arch-shaped straight wall section is excavated using a circular cross-section TBM, followed by backfilling with concrete poured inside the tunnel using specialized formwork to form the final arch-shaped straight wall section. Second, a circular cross-section tunnel with a diameter similar to the width of the arch-shaped straight wall tunnel is excavated using a circular cross-section TBM, followed by using a drill-and-blast method to remove and widen the lower sides of the circular tunnel to create the final arch-shaped straight wall section.

[0003] Traditional construction methods for circular arch tunnels with straight walls typically involve two steps: TBM excavation followed by backfilling / enlargement. This complex process and extensive backfilling / enlargement work prolong the construction period. In the aforementioned method of excavating with a TBM first and then backfilling, the TBM excavation diameter must be large enough to encompass the circular arch and straight wall cross-section, resulting in high equipment and overall project costs. In the method of excavating with a TBM first and then enlarging, the time cost of the secondary excavation is significant, and the quality of the drill-and-blast method is difficult to guarantee. Summary of the Invention

[0004] To address the problems existing in the background art, the present invention provides a tunnel boring machine, a device for excavating tunnels with a quasi-circular arch and straight wall cross-section, and a construction method thereof.

[0005] The technical solution adopted in this invention is:

[0006] I. A tunnel boring machine and a device for excavating tunnels with a circular arch-like straight wall cross section.

[0007] The device includes a TBM main unit, a rock cutting machine, a rear-mounted trailer, a muck removal system, and a cutting machine support system. The TBM main unit is installed at the front of the excavation device, and the cutting machine support system is installed at the rear of the excavation device. The TBM main unit and the cutting machine support system are connected by the rear-mounted trailer. The rock cutting machine is installed on the cutting machine support system and is used to cut the tunnel under the control of the cutting machine support system. The muck removal system is installed inside the TBM main unit, the cutting machine support system, and the rear-mounted trailer.

[0008] The TBM main unit includes a front shield, a support shield, a main cutter head, a step-changing support shoe, a propulsion cylinder, and a propulsion support shoe. The front shield is located at the front of the TBM main unit, the main cutter head is mounted on the front end of the front shield, the support shield is mounted behind the front shield and the front shield and the support shield are connected by the propulsion cylinder, the propulsion support shoe is located inside the support shield, the step-changing support shoe is located on the rear end face of the front shield, and the support shield and the cutting machine support system are connected by a rear-mounted trailer.

[0009] The rear-mounted trailer is connected to the rear of the TBM main unit, and the rear of the trailer is connected to the cutting machine support system via a towing cylinder.

[0010] The cylinder body of the towing cylinder is mounted on the rear trailer, and the cylinder rod is connected to the cutting machine support system.

[0011] The cutting machine support system includes an auxiliary propulsion shoe, a main beam, two sliding box moving mechanisms, a front support frame, and a rear support frame. The front support frame and the rear support frame are fixedly connected by the main beam, which is arranged parallel to the tunnel excavation direction. An auxiliary propulsion shoe is arranged at the upper end of the front support frame, and the auxiliary propulsion shoe is connected to the front support frame via a hydraulic cylinder. Sliding box moving mechanisms are symmetrically installed on both sides of the main beam. Each sliding box moving mechanism includes a push-pull hydraulic cylinder, a sliding box, and a guide rail. The guide rail is fixedly installed on the main beam, and its direction is parallel to the tunnel excavation direction. A sliding box is slidably installed on the guide rail. A rock cutting machine with an offset angle is arranged on the side of the sliding box facing the tunnel. The sliding box and the rear support frame are connected by a push-pull hydraulic cylinder.

[0012] The oblique angle rock cutting machine includes a rock saw, a lifting guide rod module, a transverse guide rod module, a rock saw turntable, and a swing hinge. Both the lifting guide rod module and the transverse guide rod module are mainly composed of a guide rod section and a slide section. The guide rod section of the lifting guide rod module is fixed to the side of the slide box, and the axis of the guide rod section is perpendicular to the tunnel excavation direction and extends vertically. The transverse guide rod is fixed to the lifting guide rod module, and its axis extends horizontally and is perpendicular to the tunnel excavation direction. The rock saw turntable is fixed to the transverse guide rod. The rock saw and the rock saw turntable are connected by a swing hinge, and the hinge axis of the swing hinge extends horizontally and is perpendicular to the tunnel excavation direction.

[0013] The slag removal system includes a main conveyor belt, a rear auxiliary conveyor belt, and a crane. The main conveyor belt is installed inside the TBM main unit, with one end close to the main cutter head and the other end extending from inside the TBM main unit close to the rear auxiliary trailer. The rear auxiliary trailer and the cutting machine support system are equipped with a rear auxiliary conveyor belt for transporting slag. The rear auxiliary conveyor belt extends from the front of the rear auxiliary trailer to the rear of the cutting machine support system. The portion of the rear auxiliary conveyor belt inside the cutting machine support system passes through the middle of the main beam. The crane is fixed on the rear support frame.

[0014] It also includes a main drive device and two auxiliary drive devices. The main drive device is located at the rear end of the front shield and is connected to the main cutter head. The two auxiliary drive devices are respectively installed inside the two sliding boxes, and the two rock saws are respectively connected to the two auxiliary drive devices.

[0015] II. A construction method using a tunnel boring machine and a circular arch-shaped straight wall section tunnel excavation device.

[0016] The method includes the following steps:

[0017] S1. Excavation process: The main cutterhead of the TBM machine excavates the circular cross-section tunnel at the front. The propulsion support shoe presses against the inner wall of the tunnel, drives the propulsion cylinder to extend, and the main drive equipment drives the main cutterhead to rotate and cut, thereby realizing the excavation of the circular cross-section tunnel. The corner rock cutter at the rear performs secondary excavation on the corner rocks on both sides of the lower part of the circular tunnel cross-section, removes the corner rocks, and forms a semi-circular arch straight wall cross-section tunnel.

[0018] S2. Slag Removal Process: During the TBM main excavation process, the main conveyor belt transports the slag cut by the main cutter head to the rear-mounted conveyor belt. The crane lifts the slag cut by the corner rock cutter to the rear-mounted conveyor belt. The rear-mounted conveyor belt continues to transport the slag produced by the main cutter head and the corner rock cutter from front to back to the dump truck or tunnel conveyor belt, and finally the dump truck or tunnel conveyor belt transports it to the outside of the tunnel.

[0019] S3. Step Change Process: The propulsion support shoe and auxiliary propulsion support shoe extend to tighten the tunnel wall, the step change support shoe retracts, the propulsion cylinder extends, and the main cutterhead and front shield are pushed to excavate in the tunnel excavation direction; When the TBM main unit changes steps, the step change support shoe extends to tighten against the tunnel inner wall, the propulsion support shoe retracts, the propulsion cylinder retracts, and the support shield, together with the rear trailer, is dragged in the tunnel excavation direction. At this time, the cylinder rod of the drag cylinder also extends, the auxiliary propulsion support shoe tightens against the tunnel inner wall, and the corner rock cutter remains stationary and continues to work. After the corner rock cutter finishes its work, the auxiliary propulsion support shoe retracts, the drag cylinder retracts, and the cutting machine support system is dragged forward in the tunnel excavation direction to prepare for the next cutting process.

[0020] The specific steps for the secondary excavation of the irregularly shaped rock in step S1 are as follows:

[0021] Step 1: The initial position of the rock saw is that the cutter head is horizontally parallel to the tunnel excavation direction, and the rock saw is located inside the circular tunnel. By adjusting the push-pull cylinder, lifting guide rod, lateral guide rod, cutting machine turntable and swing hinge, the cutter head of the rock saw is positioned vertically parallel to the tunnel excavation direction, and the cutter head of the rock saw is placed behind the rock at the offset angle along the tunnel excavation direction. Then the rock saw is started, and the push-pull cylinder is used to make the rock saw cut in the tunnel excavation direction. After cutting is completed, it returns to the initial position.

[0022] Step 2: By adjusting the push-pull cylinder, lifting guide rod, lateral guide rod, cutting machine turntable and swing hinge, the rock saw is placed in the position where it was cut in Step 1. The difference is that the cutter head of the rock saw is on the horizontal plane. Then the rock saw is started and the rock saw is cut in the tunnel excavation direction by pushing and pulling the cylinder. The cutting depth is the same as in Step 1. After cutting is completed, it returns to the initial position.

[0023] Step 3: Adjust the push-pull cylinder, lifting guide rod, horizontal guide rod, cutting machine turntable and swing hinge to make the cutter head of the rock saw in a vertical plane and perpendicular to the tunnel excavation direction. Then start the rock saw and use the vertical guide rod to make the rock saw cut vertically from the top of the corner rock until the corner rock is completely cut off.

[0024] The beneficial effects of this invention are:

[0025] 1. A circular TBM excavates a circular cross-section tunnel with a diameter equal to the width of a quasi-circular arch straight-wall tunnel. An angle rock cutter removes the angled rock on both sides of the circular cross-section. The two work together to form a quasi-circular arch straight-wall tunnel, achieving one-time excavation and shaping. The shape of the quasi-circular arch straight-wall tunnel is similar to a circular arch straight wall, requiring only minimal backfilling to form the final tunnel. Compared to traditional methods, this significantly reduces secondary operations, improves construction efficiency, increases forming efficiency, shortens the construction cycle, and reduces the need for subsequent backfilling or widening.

[0026] 2. By combining push-pull hydraulic cylinders, vertical guide rods, horizontal guide rods, cutting machine turntables, and swing hinges, three linear degrees of freedom and two rotational degrees of freedom are achieved, allowing the rock saw to adjust its position and posture arbitrarily within a given workspace to move flexibly to a suitable position in the space. This makes the cutting of angular rocks more flexible and can adapt to angular rocks of different areas and sizes.

[0027] 3. The tandem configuration of the corner rock cutter and the rear trailer is achieved by using a towing cylinder, which allows the excavation of a circular tunnel and the cutting of corner rocks to be completed simultaneously. Furthermore, the excavation and step-changing processes of the circular TBM main unit and the corner rock cutter are independent of each other and do not interfere with each other.

[0028] 4. The slag discharge of the corner rock cutter is achieved by combining a crane with a rear-mounted belt conveyor. The slag discharge of the corner rock cutter utilizes the rear-mounted belt conveyor on the original TBM. The corner rock slag discharge system and the slag discharge of the circular TBM host share a single rear-mounted belt conveyor, which simplifies the system structure.

[0029] 5. The offset rock cutting machine is connected to the rear of the trailer, with strong structural independence. The front circular TBM host is similar to the traditional circular cross-section tunnel boring machine. The cost of modifying the traditional circular cross-section tunnel boring machine into a quasi-circular arch straight wall cross-section tunnel boring machine is relatively low. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0031] Figure 2 This is a partial structural diagram of the offset rock cutting machine of the present invention;

[0032] Figure 3 for Figure 1 Schematic diagram of section AA;

[0033] Figure 4 This is a diagram illustrating the first step of cutting a rock with a coarse angle, as described in this invention.

[0034] Figure 5 This is a diagram illustrating the second cutting step of the coarse-angled rock according to the present invention;

[0035] Figure 6 This is a diagram illustrating the third step of cutting a rock with a coarse angle, as described in this invention.

[0036] Figure 7 This is a cross-sectional view of a circular tunnel.

[0037] Figure 8 This is a cross-sectional view of a tunnel with a straight wall and a circular arch-like structure.

[0038] Figure 9 This is a cross-sectional view of a tunnel with a circular arch and straight walls.

[0039] In the diagram: 1. Main cutter head; 2. Stepping support shoe; 3. Main drive unit; 4. Propulsion cylinder; 5. Propulsion support shoe; 6. Main machine belt conveyor; 7. Rear trailer; 8. Rear belt conveyor; 9. Traction cylinder; 10. Cutting machine support system; 11. Main beam; 12. Guide rail; 13. Rock saw; 14. Sliding box; 15. Push-pull cylinder; 16. Crane; 17. Lifting guide rod; 18. Lateral guide rod; 19. Rock saw turntable; 20. Swing hinge; 100. Circular cross-section tunnel; 200. Quasi-circular arch straight wall cross-section tunnel; 300. Angle rock; 400. Circular arch straight wall cross-section tunnel; 500. Backfill area. Detailed Implementation

[0040] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] Figures 1-3 The basic structure of the designed arched straight-wall tunnel excavation device is shown, including a circular TBM main unit, a rock cutting machine with offset angles, a rear trailer 7, a muck removal system, and a cutting machine support system 10. The circular TBM main unit is installed at the front of the excavation device, and the cutting machine support system 10 is installed at the rear of the excavation device. The circular TBM main unit and the cutting machine support system 10 are connected by the rear trailer 7. The rock cutting machine with offset angles is installed on the cutting machine support system and is used to cut the tunnel under the control of the cutting machine support system 10. The circular TBM main unit, the cutting machine support system 10, and the rear trailer 7 are all equipped with muck removal systems.

[0042] The circular TBM main unit and the tandem configuration of the angled rock cutter allow for simultaneous circular tunnel excavation and angled rock cutting, significantly reducing secondary backfilling and improving construction efficiency. The circular TBM main unit and the angled rock cutter are connected by a hydraulic cylinder 9, ensuring that their excavation and transition processes are independent and do not interfere with each other. The muck removal from the angled rock cutter utilizes the existing rear-mounted belt conveyor 8 on the TBM, allowing both units to share the same conveyor for muck removal, thus simplifying the system structure.

[0043] The circular TBM main unit includes a front shield, a support shield, a main cutterhead 1, a step-changing support shoe 2, a propulsion cylinder 4, and a propulsion support shoe 5. The front shield is located at the front of the circular TBM main unit, with the main cutterhead 1 mounted on its front end. The support shield is mounted behind the front shield, and the two are connected by the propulsion cylinder 4. The propulsion support shoe 5 is located inside the support shield, and the step-changing support shoe 2 is located on the rear end face of the front shield. The propulsion cylinder 4 serves as the propulsion device for the circular TBM main unit. When the main unit advances forward, the piston rod of the propulsion cylinder 4 extends, providing thrust to the main cutterhead 1. The propulsion support shoe 5 is used to press against the tunnel wall when the main unit advances forward, providing a reaction force to the propulsion cylinder 4. The step-changing support shoe 2 is used to press against the tunnel wall when the main unit changes steps, so that the propulsion support shoe 5 can drive the entire machine to change steps forward. The support shield and the cutting machine support system 10 are connected by a rear-mounted trailer 7.

[0044] A rear-mounted trailer 7 is connected to the rear of the circular TBM main unit. The rear of the trailer 7 is connected to a cutting machine support system 10 via a towing cylinder 9. The trailer 7 is equipped with auxiliary equipment supporting the tunneling machine's operation, including ventilation and drainage devices, an electrical control cabinet, a hydraulic station, and a grease pump. The cylinder body of the towing cylinder 9 is mounted on the trailer 7, and the cylinder rod is connected to the cutting machine support system 10.

[0045] The cutting machine support system 10 includes an auxiliary propulsion support shoe, a main beam 11, two sliding box moving mechanisms, a front support frame, and a rear support frame. The front and rear support frames are fixedly connected by the main beam 11. The front and rear support frames are arranged perpendicular to the tunnel excavation direction, while the main beam 11 is arranged parallel to the tunnel excavation direction. An auxiliary propulsion support shoe is arranged at the upper end of the front support frame, and the auxiliary propulsion support shoe is connected to the front support frame via a hydraulic cylinder. Specifically, the front end of the main beam 11 passes through the upper part of the front support frame, and the rear end of the main beam 11 passes through the upper part of the rear support frame. Sliding box moving mechanisms are symmetrically installed on both sides of the main beam 11. Each sliding box... The moving mechanism includes a push-pull cylinder 15, a sliding box 14, and a guide rail 12. The guide rail 12 is fixedly installed on the main beam 11, and the direction of the guide rail 12 is parallel to the tunnel excavation direction. The sliding box 14 is slidably installed on the guide rail 12, and the sliding box 14 and the guide rail 12 are slidably engaged. The two sliding boxes 14 can move back and forth independently along the guide rail 12. A rock cutting machine with an offset angle is set on the side of the sliding box 14 facing the tunnel. The sliding box 14 and the rear support frame are connected by the push-pull cylinder 15. The movement of the sliding box 14 is achieved by the push-pull cylinder 15. One end of the push-pull cylinder 15 is connected to the sliding box 14, and the other end is connected to the frame of the cutting machine trailer 10.

[0046] The offset rock cutting machine includes a rock saw 13, a lifting guide rod module 17, a transverse guide rod module 18, a rock saw turntable 19, and a swing hinge 20. Both the lifting guide rod module 17 and the transverse guide rod module 18 are mainly composed of a guide rod section and a sliding table section. The guide rod section of the lifting guide rod module 17 is fixed to the side of the sliding box 14 and can move back and forth with the sliding box 14. The axis of the guide rod section of the lifting guide rod 17 is perpendicular to the tunnel excavation direction and extends vertically. The lifting guide rod 17 is equipped with a sliding table, which can move vertically up and down along the lifting guide rod 17. The horizontal guide rod 18 is fixed to the slide table of the lifting guide rod module 17 and can move vertically along the lifting guide rod 17. The axis of the horizontal guide rod 18 extends horizontally and is perpendicular to the tunnel excavation direction. The horizontal guide rod 18 is equipped with a slide table that can move laterally along the horizontal guide rod 18. The rock saw turntable 19 is fixed to the slide table of the horizontal guide rod 18 and can move laterally along the horizontal guide rod 18. The rock saw 13 and the rock saw turntable 19 are connected by a swing hinge 20. The hinge axis of the swing hinge 20 extends horizontally and is perpendicular to the tunnel excavation direction. In other embodiments, the lifting guide rod 17 and the horizontal guide rod 18 can also be replaced by a linear guide rail 12 mechanism.

[0047] The rock saw turntable 19 can rotate with its axis of rotation parallel to the tunnel excavation direction. The rock saw 13, together with the swing hinge 20, can also rotate with its axis of rotation parallel to the tunnel excavation direction via the rock saw turntable 19. Simultaneously, the rock saw 13 can also swing within a 180° range via the swing hinge 20. Relying on the push-pull cylinder 15, lifting guide rod 17, lateral guide rod 18, rock saw turntable 19, and swing hinge 20, the rock saw 13 has five degrees of freedom: 3 linear and 2 rotational. It can move to any position within the workspace and be adjusted to any given cutting direction, flexibly moving to a suitable position within the space to cut the offset rock 300 within a given area.

[0048] The slag removal system includes a main conveyor belt 6, a rear auxiliary conveyor belt 8, and a crane 16. The main conveyor belt 6 is located inside the circular TBM main unit. One end of the main conveyor belt 6 is close to the main cutter head 1, and the other end extends from inside the circular TBM main unit close to the rear auxiliary trailer 7. This conveyor belt 6 transports the slag cut by the main cutter head 1 to the rear auxiliary conveyor belt 8. The rear auxiliary trailer 7 and the cutting machine support system 10 both contain the rear auxiliary conveyor belt 8 for transporting slag. The rear auxiliary conveyor belt 8 extends from the front of the rear auxiliary trailer 7 to the rear of the cutting machine support system 10. The portion of the rear auxiliary conveyor belt 8 inside the cutting machine support system 10 passes through the middle of the main beam 11 to reduce space occupation. The crane 16 is fixed to the rear support frame. The slag cut by the rock saw 13 can be transported to the rear auxiliary conveyor belt 8 via the crane 16. The rear auxiliary conveyor belt 8 carries the slag backward to a dump truck or tunnel conveyor belt, and is ultimately transported outside the tunnel by the dump truck or tunnel conveyor belt for slag removal.

[0049] It also includes a main drive device 3 and two auxiliary drive devices. The main drive device 3 is located at the rear end of the front shield and is connected to the main cutterhead 1. The main drive device 3 drives the main cutterhead 1 to rotate, thereby excavating the circular cross-section tunnel 100. The two auxiliary drive devices are respectively installed inside two sliding boxes 14, and two rock saws 13 are respectively connected to the two auxiliary drive devices.

[0050] S1. Excavation Process: The tunnel excavated by this method has a circular tunnel cross-section 100. The main cutterhead 1 of the circular TBM host excavates the circular cross-section tunnel 100 as the excavation object at the front. The propulsion support shoe 5 presses against the inner wall of the tunnel. The hydraulic system drives the propulsion cylinder 4 to extend. The main drive equipment 3 drives the main cutterhead 1 to rotate and cut, thereby realizing the excavation of the circular cross-section tunnel 100. The rocks at the lower part of both sides of the circular tunnel cross-section 100 are angular rocks 300. The angular rock cutting machine at the rear performs secondary excavation on the angular rocks 300 at the lower part of both sides of the circular tunnel cross-section 100, removes the angular rocks 300, and forms a semi-circular arch straight wall cross-section tunnel 200.

[0051] Specifically, the circular TBM main unit is used for excavation such as Figure 7 The circular cross-section tunnel 100 shown generates thrust that pulls the entire machine forward. The angular rock cutter is used for secondary excavation of the circular cross-section tunnel 100 excavated by the circular TBM main unit, removing the angular rock 300 to form a shape as shown... Figure 8 The tunnel 200 has a quasi-circular arch straight wall cross-section, as shown. After obtaining the quasi-circular arch straight wall cross-section tunnel 200, only a small backfill area 500 needs to be poured with concrete to form the final tunnel as shown. Figure 9 The illustrated tunnel 400 has a circular arch and a straight wall cross-section. This method allows for the single-stage excavation and formation of a tunnel 200 resembling a circular arch and a straight wall. The shape of the tunnel 200 is similar to that of a circular arch and a straight wall, requiring only minimal backfilling to form the final tunnel 400. Compared to traditional methods, this significantly reduces the amount of secondary work and improves construction efficiency.

[0052] The specific steps for the secondary excavation of the angular rock 300 in step S1 are as follows:

[0053] Step 1: As Figure 4As shown, the initial position of the rock saw 13 is that the cutter head of the rock saw 13 is parallel to the tunnel excavation direction in the horizontal direction, and the rock saw 13 is located inside the circular tunnel. By adjusting the push-pull cylinder 15, lifting guide rod 17, transverse guide rod 18, cutting machine turntable and swing hinge 20, the cutter head of the rock saw 13 is positioned in the vertical plane parallel to the tunnel excavation direction, and the cutter head of the rock saw 13 is placed behind the residual angle rock 300 along the tunnel excavation direction. Then the rock saw 13 is started, and the rock saw 13 is cut to a certain depth in the tunnel excavation direction by pushing and pulling the cylinder 15. After the cutting is completed, it returns to the initial position.

[0054] Step 2: As Figure 5 As shown, by adjusting the push-pull cylinder 15, lifting guide rod 17, horizontal guide rod 18, cutting machine turntable and swing hinge 20, the rock saw 13 is placed in the position where it was cut in step 1. The difference is that the cutter head of the rock saw 13 is on the horizontal plane. Then the rock saw 13 is started, and the rock saw 13 is cut in the tunnel excavation direction by pushing and pulling the cylinder 15. The cutting depth is the same as in step 1. After the cutting is completed, it returns to the initial position.

[0055] Step 3: As Figure 6 As shown, by adjusting the push-pull cylinder 15, lifting guide rod 17, horizontal guide rod 18, cutting machine turntable and swing hinge 20, the cutter head of the rock saw 13 is positioned in a vertical plane and perpendicular to the tunnel excavation direction. Then, the rock saw 13 is started, and the rock saw 13 is made to cut downwards from the corner rock 300 in a vertical direction through the vertical guide rod until the corner rock 300 is completely cut off.

[0056] S2. Slag Removal Process: During the excavation process of the circular TBM main unit, the main unit belt conveyor 6 transports the slag cut by the main cutter head 1 to the rear supporting belt conveyor 8. The crane 16 lifts the slag cut by the corner rock cutter to the rear supporting belt conveyor 8. The rear supporting belt conveyor 8 continues to transport the slag produced by the main cutter head 1 and the corner rock cutter from front to back to the dump truck or tunnel belt conveyor, and finally the dump truck or tunnel belt conveyor transports it to the outside of the tunnel.

[0057] S3, Step-changing process: The propulsion support shoe 5 and the auxiliary propulsion support shoe extend to tighten the tunnel wall, and the step-changing support shoe 2 retracts to provide the necessary support reaction force for tunneling. When the propulsion cylinder 4 extends, it pushes the main cutter head 1 and the front shield to advance in the direction of tunnel excavation. When the circular TBM main unit changes steps, the step change support shoe 2 extends and presses against the inner wall of the tunnel. The propulsion support shoe 5 retracts, and the hydraulic system drives the propulsion cylinder 4 to retract, so that the support shield and the rear trailer 7 are dragged in the direction of tunnel excavation. At this time, the cylinder rod of the drag cylinder 9 also extends due to the pressure relief of the drag cylinder 9, which helps the propulsion support shoe press against the inner wall of the tunnel. The corner rock cutter remains stationary and continues to work. After the corner rock cutter finishes its work, the auxiliary propulsion support shoe retracts, the drag cylinder 9 retracts, and the cutting machine support system 10 is dragged forward one stroke in the direction of tunnel excavation. At the same time, the push-pull cylinder 15 releases pressure, and the slide box 14 and the cutting mechanism on the slide box 14 remain stationary. The slide box 14 moves backward relative to the guide rail (12) and returns to the starting point of the guide rail (12) to prepare for the next cutting process.

[0058] When the circular TBM main unit changes steps, the rear-mounted trailer 7 follows. If the corner rock cutter is still operating at this time, the drag cylinder 9 can be depressurized, allowing the piston rod of the drag cylinder 9 to extend and retract freely within the cylinder body. This allows the circular TBM main unit and the rear-mounted trailer 7 to move forward first, while the corner rock cutter remains in place to continue operating. After the corner rock cutter completes its work, the drag cylinder 9 presses up again, dragging the cutting machine support system 10 forward to complete the step change of the corner rock cutter. By adjusting the pressure of the drag cylinder 9 in a timely manner, the corner rock cutter and the circular TBM main unit can be allowed to change steps at different times, achieving a flexible match between the cutting rate and the tunneling rate of the circular TBM main unit, applicable to more working conditions. In other embodiments, the drag cylinder 9 can also be replaced with a cylinder, lead screw nut, or other mechanisms.

[0059] The presence of the towing cylinder 9 allows the relative positions of the circular TBM main unit and the corner rock cutter to float within a certain range. Therefore, this invention allows the circular TBM main unit and the corner rock cutter to have asynchronous operating cycles: the corner rock cutter can still carry out excavation operations when the circular TBM main unit is changing steps, and the corner rock cutter can still execute the step-changing process when the circular TBM main unit is excavating. The two are independent of each other and do not interfere with each other.

Claims

1. A tunnel boring machine and a device for excavating tunnels with a circular arch-like straight wall cross section, characterized in that: The device includes a TBM main unit, a rock cutting machine, a rear trailer (7), a slag removal system, and a cutting machine support system (10). The TBM main unit is installed at the front of the excavation device, and the cutting machine support system (10) is installed at the rear of the excavation device. The TBM main unit and the cutting machine support system (10) are connected by the rear trailer (7). The rock cutting machine is installed on the cutting machine support system and is used to cut the tunnel under the control of the cutting machine support system (10). The slag removal system is installed inside the TBM main unit, the cutting machine support system (10), and the rear trailer (7). The TBM main unit includes a front shield, a support shield, a main cutter head (1), a step-changing support shoe (2), a propulsion cylinder (4), and a propulsion support shoe (5); the front shield is provided at the front of the TBM main unit, the main cutter head (1) is installed on the front end of the front shield, the support shield is installed behind the front shield and the front shield and the support shield are connected by the propulsion cylinder (4), the propulsion support shoe (5) is provided inside the support shield, the step-changing support shoe (2) is provided on the rear end face of the front shield, and the support shield and the cutting machine support system (10) are connected by a rear matching trailer (7); The cutting machine support system (10) includes an auxiliary propulsion support shoe, a main beam (11), two sliding box moving mechanisms, a front support frame, and a rear support frame; the front support frame and the rear support frame are fixedly connected through the main beam (11), the main beam (11) is arranged parallel to the tunnel excavation direction, the upper end of the front support frame is provided with an auxiliary propulsion support shoe, and the auxiliary propulsion support shoe is connected to the front support frame through a hydraulic cylinder; the main beam (11) is symmetrically installed with sliding box moving mechanisms on both sides, each sliding box moving mechanism includes a push-pull hydraulic cylinder (15), a sliding box (14), and a guide rail (12); the guide rail (12) is fixedly installed on the main beam (11), the direction of the guide rail (12) is parallel to the tunnel excavation direction, the sliding box (14) is slidably installed on the guide rail (12), and the side of the sliding box (14) facing the tunnel is provided with a rock cutting machine with an offset angle, the sliding box (14) and the rear support frame are connected through a push-pull hydraulic cylinder (15); The oblique angle rock cutting machine includes a rock saw (13), a lifting guide rod module (17), a transverse guide rod module (18), a rock saw turntable (19), and a swing hinge (20). The lifting guide rod module (17) and the transverse guide rod module (18) are mainly composed of a guide rod part and a slide part. The guide rod part of the lifting guide rod module (17) is fixed on the side of the slide box (14), and the axis of the guide rod part of the lifting guide rod module (17) is perpendicular to the tunnel excavation direction. And extending vertically, the transverse guide rod module (18) is fixed on the lifting guide rod module (17), the axis of the transverse guide rod module (18) extends horizontally and is perpendicular to the tunnel excavation direction, the rock saw turntable (19) is fixed on the transverse guide rod module (18), the rock saw (13) and the rock saw turntable (19) are connected by a swing hinge (20), the hinge axis of the swing hinge (20) extends horizontally and is perpendicular to the tunnel excavation direction; The slag removal system includes a main conveyor belt (6), a rear-mounted conveyor belt (8), and a crane (16). The main conveyor belt (6) is installed inside the TBM main unit. One end of the main conveyor belt (6) is close to the main cutter head (1), and the other end extends from inside the TBM main unit and is close to the rear-mounted trailer (7). The rear-mounted trailer (7) and the cutting machine support system (10) are equipped with a rear-mounted conveyor belt (8) for transporting slag. The rear-mounted conveyor belt (8) extends from the front of the rear-mounted trailer (7) to the rear of the cutting machine support system (10). The part of the rear-mounted conveyor belt (8) inside the cutting machine support system (10) passes through the middle of the main beam (11). The crane (16) is fixed on the rear support frame. It also includes a main drive device (3) and two auxiliary drive devices. The main drive device (3) is provided at the rear end of the front shield and is connected to the main cutter head (1). The two auxiliary drive devices are respectively installed inside the two slide boxes (14). The two rock saws (13) are respectively connected to the two auxiliary drive devices.

2. The tunnel boring machine and arch-shaped straight-wall tunnel excavation device according to claim 1, characterized in that: The rear-mounted trailer (7) is connected to the rear of the TBM host, and the rear of the rear-mounted trailer (7) is connected to the cutting machine support system (10) via a towing cylinder (9).

3. The tunnel boring machine and arch-shaped straight-wall tunnel excavation device according to claim 2, characterized in that: The cylinder body of the towing cylinder (9) is mounted on the rear trailer (7), and the cylinder rod is connected to the cutting machine support system (10).

4. A construction method using a tunnel boring machine and a circular arch-shaped straight wall section tunnel excavation device as described in any one of claims 1-3, characterized in that, The method includes the following steps: S1. Excavation process: The main cutter head (1) of the TBM host excavates the circular cross-section tunnel (100) at the front. The propulsion support shoe (5) presses against the inner wall of the tunnel and drives the propulsion cylinder (4) to extend. The main drive equipment (3) drives the main cutter head (1) to rotate and cut, thereby realizing the excavation of the circular cross-section tunnel (100). The corner rock cutter performs secondary excavation on the corner rocks (300) at the lower part of both sides of the circular cross-section tunnel (100) at the rear, removes the corner rocks (300), and forms a semi-circular arch straight wall cross-section tunnel (200). S2. Slag Removal Process: During the TBM main excavation process, the main conveyor belt (6) transports the slag cut by the main cutter head (1) to the rear supporting conveyor belt (8). The crane (16) lifts the slag cut by the corner rock cutter to the rear supporting conveyor belt (8). The rear supporting conveyor belt (8) continues to transport the slag produced by the main cutter head (1) and the corner rock cutter from front to back to the dump truck or tunnel conveyor belt, and finally transports it to the outside of the tunnel by the dump truck or tunnel conveyor belt. S3, Step Change Process: The propulsion support shoe (5) and auxiliary propulsion support shoe extend to tighten the tunnel wall, the step change support shoe (2) retracts, the propulsion cylinder (4) extends, and the main cutter head (1) and the front shield are pushed to tunnel in the direction of tunnel excavation; when the TBM main unit changes steps, the step change support shoe (2) extends to tighten against the inner wall of the tunnel, the propulsion support shoe (5) retracts, the propulsion cylinder (4) retracts, so that the support shield together with the rear trailer (7) is dragged in the direction of tunnel excavation, and at this time the cylinder rod of the drag cylinder (9) also extends, the auxiliary propulsion support shoe tightens against the inner wall of the tunnel, the corner rock cutter remains stationary and continues to work, after the corner rock cutter finishes its work, the auxiliary propulsion support shoe retracts, the drag cylinder (9) retracts, and the cutting machine support system (10) is dragged forward in the direction of tunnel excavation to prepare for the next cutting process.

5. The construction method of a tunnel boring machine and a tunnel excavation device for a circular arch-shaped straight wall section according to claim 4, characterized in that: The specific steps for the secondary excavation of the angular rock (300) in step S1 are as follows: Step 1: The initial position of the rock saw (13) is that the cutter head of the rock saw (13) is parallel to the tunnel excavation direction in the horizontal direction, and the rock saw (13) is located in the circular tunnel. By adjusting the push-pull cylinder (15), the lifting guide rod module (17), the horizontal guide rod module (18), the rock saw turntable (19) and the swing hinge (20), the cutter head of the rock saw (13) is located in the vertical plane parallel to the tunnel excavation direction, and the cutter head of the rock saw (13) is placed behind the corner rock (300) along the tunnel excavation direction. Then the rock saw (13) is started, and the rock saw (13) is cut in the tunnel excavation direction by pushing and pulling the cylinder (15). After cutting, it returns to the initial position. Step 2: By adjusting the push-pull cylinder (15), lifting guide rod module (17), lateral guide rod module (18), rock saw turntable (19) and swing hinge (20), the rock saw (13) is positioned at the location where it was cut in Step 1. The difference is that the cutter head of the rock saw (13) is on the horizontal plane. Then, the rock saw (13) is started, and the rock saw (13) is cut in the tunnel excavation direction by pushing and pulling the cylinder (15). The cutting depth is the same as in Step 1. After cutting, it returns to the initial position. Step 3: Adjust the push-pull cylinder (15), lifting guide rod module (17), horizontal guide rod module (18), rock saw turntable (19) and swing hinge (20) to make the cutter head of the rock saw (13) be in the vertical plane and perpendicular to the tunnel excavation direction. Then start the rock saw (13) and use the vertical guide rod to make the rock saw (13) cut downwards from the corner rock (300) in the vertical direction until the corner rock (300) is completely cut off.

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