Forepoling method for continuous tunneling of broken surrounding rocks

Abstract

The invention discloses a broken surrounding rock continuous tunneling forepoling method which comprises the following steps: S1, advanced detection: when a geophysical prospecting result predicts that a weak surrounding rock exists in front, constructing an advanced exploring hole for verification, and determining a tunneling measure according to an exploring hole coring analysis condition; s2, advanced supporting: firstly, driving a pipe shed in advance in the tunneling direction of the TBM, driving a steel pipe in front of the TBM along a top arch of an excavation contour line to form a shed frame, supporting the tail part by a steel arch, reserving a grouting pipe on the steel arch, primarily spraying surrounding rock by using an advanced spraying and mixing system of the TBM, and tunneling again by the TBM after concrete is solidified, according to the method, forepoling is conducted on the area in the modes of shed frame building, steel arch frame building, spraying and mixing reinforcement, grouting reinforcement and the like in sequence, the stability of surrounding rock in the area is improved, deformation of the surrounding rock before the surrounding rock goes out of a shield can be effectively controlled, large-area collapse of the surrounding rock can be prevented, and tunnel construction safety is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of TBM construction, and particularly relates to a method for continuous tunneling and advanced support of broken surrounding rock. Background Technique

[0002] It is inevitable to encounter broken surrounding rock during tunnel construction. During the construction of a full-face tunnel boring machine (TBM), it is necessary to timely check the advanced geological forecast, and give a briefing on the advanced geological forecast to the on-site technical duty personnel and the full-face tunnel boring machine team in a timely manner for the sections with poor surrounding rock. Pay attention to the broken parts of the surrounding rock in advance and take measures to adapt to the adverse geology such as broken surrounding rock in advance. When encountering adverse geology such as broken surrounding rock, corresponding measures should be taken for construction to ensure that the shield is exposed in time for support in the broken section, and closed into a ring to avoid long-term exposure of the rock and ensure the safety of tunnel construction. If the surrounding rock conditions in front of the full-face tunnel boring machine are poor based on the feedback of the muck classification model, or the full-face tunnel boring machine jamming risk warning model continuously predicts a medium-high risk jamming risk value, it is very likely that the phenomenon of surrounding rock falling and collapse will occur, which will cause the full-face tunnel boring machine jamming disaster. Timely carrying out advanced support of the full-face tunnel boring machine to reinforce the surrounding rock can greatly reduce the risk of large deformation and the risk of the full-face tunnel boring machine jamming.

[0003] The traditional reinforcement method is mostly to directly spray concrete into the weak and broken surrounding rock area in front of the tunneling, and wait for the concrete to solidify before carrying out the grouting reinforcement operation. Since the location of this area belongs to a fault, there is a risk of surrounding rock falling and collapse at any time, and this method cannot guarantee the construction safety during the shotcrete operation. Therefore, the present application provides a method for continuous tunneling and advanced support of broken surrounding rock. Summary of the Invention

[0004] To solve the technical problems raised in the above background technique, the present invention provides a method for continuous tunneling and advanced support of broken surrounding rock.

[0005] The present invention is realized by the following technical solutions: A method for continuous tunneling and advanced support of broken surrounding rock, including the following steps:

[0006] S1. Advanced detection: When the geophysical exploration result predicts that the front is weak surrounding rock, advanced exploration holes are constructed for verification, and the tunneling measures are determined according to the core analysis of the exploration holes;

[0007] S2. Advanced support: First, drive pipe roofs in advance in the tunneling direction of the TBM tunneling machine, drive steel pipes along the top arch of the excavation contour line towards the front of the TBM tunneling machine to form a shed frame, the tail is supported by steel arch frames, and grouting pipes are reserved on the steel arch frames. Use the advanced shotcrete system of the TBM tunneling machine to conduct initial spraying on the surrounding rock. When the concrete solidifies, the TBM tunnels again until the broken section reaches the shotcrete bridge of the TBM tunneling machine, and then grout the broken zone through the grouting pipes for reinforcement.

[0008] As a further improvement of the above solution, in step S2, a plurality of radially distributed anchor holes are reserved on the inner wall of the broken rock layer on the outer peripheral side of the steel arch in the bending span direction of the steel arch. Anchor rods are inserted into each anchor hole, and a pipe hole for the grouting pipe to penetrate and insert to communicate with the anchor hole is provided inside the rod body of the anchor rod.

[0009] As a further improvement of the above solution, through holes for the grouting pipe to pass through are provided on the steel arch, and a slurry supply pipe is inserted into the through holes. The output end of the slurry supply pipe can be hermetically sleeved on the input end of the grouting pipe.

[0010] A locking device is provided on the slurry supply pipe. When the slurry supply pipe is sleeved on the grouting pipe, the locking device can simultaneously lock and fix the slurry supply pipe and the grouting pipe, and the slurry supply pipe and the steel arch.

[0011] As a further improvement of the above solution, the locking device includes a positioning plate sleeved and fixed on the outer peripheral side of the slurry supply pipe. A rod hole is provided on the positioning plate, and a screw rod is inserted into the rod hole. A threaded hole matching the screw rod is provided on the inner peripheral side wall of the steel arch.

[0012] As a further improvement of the above solution, two positioning blocks are relatively fixed on the outer peripheral side of the slurry supply pipe. A positioning groove that communicates with the through hole and is in an enlarged hole shape is provided on the inner peripheral side of the steel arch. The positioning block is in snap-fit with the positioning groove.

[0013] As a further improvement of the above solution, a blind plug adapted to the aperture of the anchor hole is sleeved on the outer side of the anchor rod, and a sealing ring is provided around the outer peripheral side of the blind plug.

[0014] As a further improvement of the above solution, the blind plug is in a ring structure. An annular groove is provided on the outer peripheral side of the blind plug. The sealing ring is arranged at the notch of the annular groove to completely cover the notch of the annular groove. A pressurized area is formed between the sealing ring and the annular groove. An oil pressure medium is accommodated in the pressurized area. Two plug grooves communicating with the annular groove are oppositely provided in the blind plug. A piston is provided in the plug groove. An adjusting mechanism is provided in the positioning block. When the screw rod rotates and is screwed into the threaded hole, the adjusting mechanism can push the piston in the plug groove towards the annular groove direction, so that the sealing ring is pressurized and expands and deforms to block the anchor hole.

[0015] As a further improvement of the above solution, the adjusting mechanism includes two insertion rods parallel to the axial direction of the slurry supply pipe. The two insertion rods are relatively inserted on the end face of the slurry supply pipe close to the anchor hole. A jack for the insertion rod to insert is provided on the blind plug. A sliding groove is provided in the blind plug. A transmission plate is slidably connected in the sliding groove; the side of the transmission plate close to the plug groove is connected to the piston through a connecting rod, and the other side is in contact and cooperation with the insertion rod.

[0016] As a further improvement of the above solution, a spring is sleeved outside the connecting rod, and two ends of the spring are respectively connected to the wall of the plug groove and the outer wall of the piston.

[0017] As a further improvement of the above solution, a synchronous plate is connected below the positioning plate through a telescopic rod. A ejector rod parallel to the axial direction of the slurry supply pipe is slidably inserted on the positioning block. A transmission rod perpendicular to the ejector rod is horizontally slidably arranged in the positioning block. One end of the transmission rod close to the ejector rod has a first slope in pressure contact with the ejector rod, and the bottom of the insertion rod has a second slope in pressure contact with the other end of the transmission rod; the bottom of the ejector rod penetrates through the positioning plate and is fixed on the top of the synchronous plate.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] In the advanced support method for continuous tunneling of broken surrounding rock of the present invention, when it is analyzed that the front is a soft and broken surrounding rock area during TBM tunneling, the area is advancedly supported in sequence by building a shed frame, a steel arch frame, shotcrete reinforcement and grouting reinforcement, etc., to improve the self-stability of the surrounding rock in this area, effectively control the deformation of the surrounding rock before it exits the shield, prevent its large-area collapse, and ensure the safety of tunnel construction.

[0020] In the advanced support method for continuous tunneling of broken surrounding rock of the present invention, by arranging a slurry supply pipe, a positioning block, a positioning plate and a locking device on the steel arch frame, when the screw is screwed into the screw hole, the mutual docking between the slurry supply pipe and the grouting pipe and the locking and fixing between the slurry supply pipe and the steel arch frame can be completed synchronously.

[0021] In the advanced support method for continuous tunneling of broken surrounding rock of the present invention, by arranging an ejector rod, a transmission rod, an insertion rod, a piston and an adjusting mechanism, etc., when the screw is screwed into the screw hole, the piston can be driven to move in the plug groove towards the direction of the annular groove, so that the sealing ring is pressurized and expands and deforms to effectively block the anchor hole, so as to smoothly complete the subsequent grouting reinforcement operation and ensure the safety of tunnel construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic flow chart of the method of the present invention;

[0023] Figure 2 is a schematic cross-sectional structure diagram when the broken surrounding rock is grouted and reinforced by using the steel arch frame in cooperation with the grouting pipe in step S2 of the method of the present invention;

[0024] Figure 3 is Figure 2 a partial structural schematic diagram in

[0025] Figure 4 is Figure 3 a schematic cross-sectional structure diagram of the anchor bolt and the sealing ring in

[0026] Figure 5 For Figure 3 Structural schematic diagram when the slurry supply pipe in the

[0027] Figure 6 For Figure 5 Partial sectional structural schematic diagram when the slurry supply pipe in the

[0028] Figure 7 For Figure 6 Enlarged structural schematic diagram at location A in the

[0029] Figure 8 For Figure 6 Enlarged structural schematic diagram at location B in the

[0030] Main symbol description:

[0031] 1, broken rock layer; 3, steel arch frame; 4, anchor hole; 5, anchor bolt; 6, grouting pipe; 7, blind plug; 8, sealing ring; 9, through hole; 10, slurry supply pipe; 11, positioning groove; 12, positioning block; 13, positioning plate; 14, ejector rod; 16, transmission rod; 17, insertion rod; 18, insertion hole; 19, sliding groove; 20, transmission plate; 21, annular groove; 22, plug groove; 23, connecting rod; 24, piston; 25, synchronous plate; 27, screw rod; 28, screw hole. Specific implementation manners

[0032] Next, in combination with the accompanying drawings and specific implementation manners, the present invention will be further described. It should be noted that, on the premise of no conflict, any combination of the following-described embodiments or technical features can form a new embodiment.

[0033] Embodiment 1

[0034] Please refer to Figure 1 , the method for advanced support of continuous tunneling in broken surrounding rock includes the following steps:

[0035] S1. Advanced detection: When the geophysical exploration result predicts that the front is soft surrounding rock, advanced exploration holes are constructed for verification, and the tunneling measures are determined according to the core analysis of the exploration holes.

[0036] S2. Advanced support: First, pipe roofs are driven ahead in the tunneling direction of the TBM tunneling machine, steel pipes are driven into the front of the TBM tunneling machine along the top arch of the excavation contour line to form a shed frame, the tail is supported by a steel arch frame, and a grouting pipe is reserved on the steel arch frame. The advanced shotcrete system of the TBM tunneling machine is used to conduct initial shotcreting on the surrounding rock. When the concrete solidifies, the TBM tunnels again until the broken section reaches the shotcrete bridge of the TBM tunneling machine, and then the broken zone is grouted and reinforced through the grouting pipe.

[0037] Embodiment 2

[0038] Please combine with Figures 2 to 8 In step S2 of Embodiment 1, a plurality of radially distributed anchor holes 4 are reserved on the inner wall of the broken rock layer 1 on the outer peripheral side of the steel arch 3 along the bending span direction of the steel arch 3. A bolt 5 is inserted into each anchor hole 4, and a pipe hole for a grouting pipe 6 to penetrate and insert to communicate with the anchor hole 4 is provided inside the rod body of the bolt 5.

[0039] A through hole 9 through which the grouting pipe 6 can pass is formed in the steel arch 3, and a slurry supply pipe 10 is inserted into the through hole 9. The output end of the slurry supply pipe 10 can be hermetically sleeved on the input end of the grouting pipe 6.

[0040] A locking device is provided on the slurry supply pipe 10. When the slurry supply pipe 10 is sleeved on the grouting pipe 6, the locking device can simultaneously lock and fix the slurry supply pipe 10 and the grouting pipe 6, and the slurry supply pipe 10 and the steel arch 3.

[0041] The locking device includes a positioning plate 13. The positioning plate 13 is sleeved and fixed on the outer peripheral side of the slurry supply pipe 10. A rod hole is formed in the positioning plate 13, and a screw rod 27 is inserted into the rod hole. A screw hole 28 matched with the screw rod 27 is formed on the inner peripheral side wall of the steel arch 3.

[0042] Two positioning blocks 12 are relatively fixed on the outer peripheral side of the slurry supply pipe 10. A positioning groove 11 which is communicated with the through hole 9 and is in an enlarged hole shape is formed on the inner peripheral side of the steel arch 3. The positioning blocks 12 are in clamping fit with the positioning groove 11.

[0043] A blind plug 7 adapted to the aperture of the anchor hole 4 is sleeved outside the bolt. A sealing ring 8 is provided around the outer peripheral side of the blind plug 7.

[0044] The blind plug 7 is in a ring structure. An annular groove 21 is formed on the outer peripheral side of the blind plug 7. The sealing ring 8 is arranged at the notch of the annular groove 21 to completely cover the notch of the annular groove 21. A pressurized area is formed between the sealing ring 8 and the annular groove 21, and an oil pressure medium is accommodated in the pressurized area. Two plug grooves 22 communicating with the annular groove 21 are relatively formed in the blind plug 7. A piston 24 is arranged in the plug groove 22. An adjusting mechanism is arranged in the positioning block 12. When the screw rod 27 rotates and is screwed into the screw hole 28, the adjusting mechanism can push the piston 24 in the plug groove 22 towards the annular groove 21, so that the sealing ring 8 is pressurized and expands and deforms to block the anchor hole 4.

[0045] The adjusting mechanism includes two insertion rods 17 parallel to the axial direction of the slurry supply pipe 10. The two insertion rods 17 are relatively inserted on the end face of the slurry supply pipe 10 close to the anchor hole 4. A jack 18 for the insertion rod 17 to insert is formed on the blind plug 7. A sliding groove 19 is formed in the blind plug 7, and a transmission plate 20 is slidably connected in the sliding groove 19; the side of the transmission plate 20 close to the plug groove 22 is connected with the piston 24 through a connecting rod 23, and the other side is in contact and cooperation with the insertion rod 17.

[0046] A spring is sleeved outside the connecting rod 23, and two ends of the spring are respectively connected to the groove wall of the plug groove 22 and the outer wall of the piston 24.

[0047] A synchronous plate 25 is connected below the positioning plate 13 through a telescopic rod. A push rod 14 parallel to the axial direction of the slurry supply pipe 10 is slidably inserted on the positioning block 12. A transmission rod 16 perpendicular to the push rod 14 is horizontally slidably arranged in the positioning block 12. One end of the transmission rod 16 close to the push rod 14 has a first slope in contact and cooperation with the push rod 14, and the bottom of the insertion rod 17 has a second slope in contact and cooperation with the other end of the transmission rod 16; the bottom of the push rod 14 penetrates through the positioning plate 13 and is fixed to the top of the synchronous plate 25.

[0048] In this embodiment, during the advanced support period, after the steel arch 3 is erected, a plurality of anchor holes 4 are drilled in the inner wall of the broken rock layer 1 along the bending span direction of the steel arch 3, and anchor rods 5 with blind plugs 7 are inserted into the respective anchor holes 4.

[0049] Before grouting reinforcement is required in the later stage, the grouting pipe 6 is sequentially passed through the positioning groove 11 and the through hole 9 of the steel arch 3 to be inserted into the pipe hole of the anchor rod 5. Subsequently, the output end of the slurry supply pipe 10 is docked with the input end of the grouting pipe 6 by using the positioning block 12 and the positioning groove 11, and the insertion rod 17 is kept in a just-touching state between the insertion hole 18 and the transmission plate 20. Subsequently, the screw rod 27 is rotated and screwed into the screw hole 28 to complete the locking and fixing between the slurry supply pipe 10 and the grouting pipe 6 and between the slurry supply pipe 10 and the steel arch 3. Under the movement action of the rotation and screwing of the screw rod 27 and with the limiting action of the telescopic rod, the synchronous plate 25 follows the screw rod 27 and translates in the direction close to the positioning plate 13, driving the push rod 14 to press the first slope at one end of the transmission rod 16, so that the other end of the transmission rod 16 presses the second slope of the insertion rod 17, and then the insertion rod 17 moves to apply pressure to the synchronous plate 25, driving the piston 24 to move in the plug groove 22 in the direction of the annular groove 21 through the connecting rod 23, so that the sealing ring 8 is pressurized and expands and deforms to effectively block the anchor hole 4.

[0050] During grouting reinforcement, the slurry supply pipe 10 is connected to the advanced shotcrete system of the TBM tunneling machine through a pipeline to complete the grouting reinforcement operation.

[0051] The above embodiments are only the preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art on the basis of the present invention belong to the scope of protection required by the present invention.

Claims

1. A method for continuous excavation and advance support of broken surrounding rock, characterized in that: The steps include: S1. Advance exploration: when the geophysical exploration results predict that the surrounding rock ahead is weak, advance exploration holes are drilled to verify the situation, and excavation measures are determined based on the core analysis of the exploration holes; S2. Advance support: first drive a pipe shed ahead of the TBM's excavation direction, and then drive steel pipes along the top arch of the excavation contour to the front of the TBM to form a shed. The tail is supported by a steel arch frame, and grouting pipes are reserved on the steel arch frame. The TBM's advance spraying system is used to spray the surrounding rock for the first time. After the concrete solidifies, the TBM advances again until the broken section reaches the TBM's spraying bridge, and then the broken zone is grouting reinforced through the grouting pipe.

2. The method for continuous excavation and advance support of broken surrounding rock according to claim 1, characterized in that: In step S2, a plurality of radially distributed anchor holes are reserved along the curved span direction of the steel arch frame on the inner wall of the broken rock layer located on the outer peripheral side of the steel arch frame, and an anchor rod is inserted in each anchor hole. The inner side of the anchor rod body has a pipe hole for a grouting pipe to be inserted through so as to communicate with the anchor hole.

3. The method for continuous excavation and advance support of broken surrounding rock according to claim 2, characterized in that: The steel arch frame is provided with a through hole through which a grouting pipe can pass, a grouting pipe is inserted in the through hole, and the output end of the grouting pipe can be sealed and sleeved on the input end of the grouting pipe. The slurry supply pipe is provided with a locking device. When the slurry supply pipe is sleeved on the grouting pipe, the locking device can simultaneously realize the locking and fixing between the slurry supply pipe and the grouting pipe, and between the slurry supply pipe and the steel arch frame.

4. The method for continuous excavation and advance support of broken surrounding rock according to claim 3, characterized in that: The locking device comprises a positioning plate, which is sleeved and fixed on the outer peripheral side of the slurry supply pipe. The positioning plate has a rod hole, in which a screw is inserted, and a screw hole matching the screw is opened on the inner peripheral side wall of the steel arch.

5. The method for continuous excavation and advance support of broken surrounding rock according to claim 4, characterized in that: Two positioning blocks are relatively fixed on the outer peripheral side of the slurry supply pipe, and a positioning groove with a communicating through hole and an expanded hole shape is opened on the inner peripheral side of the steel arch frame, and the positioning block is snap-fitted with the positioning groove.

6. The method for continuous excavation and advance support of broken surrounding rock according to claim 5, characterized in that: A blind plug matching the diameter of the anchor hole is sleeved on the outer side of the anchor rod, and a sealing ring is surrounded on the outer circumference of the blind plug.

7. The method for continuous excavation and advance support of broken surrounding rock according to claim 6, characterized in that: The blind plug is an annular structure, and a circle of annular grooves is provided on the outer peripheral side of the blind plug. The sealing ring is arranged at the notch of the annular groove to completely cover the notch of the annular groove. A pressurized area is formed between the sealing ring and the annular groove, and oil pressure medium is accommodated in the pressurized area. Two plug grooves connected to the annular grooves are relatively provided in the blind plug, and a piston is provided in the plug groove. An adjusting mechanism is provided in the positioning block. When the screw is rotated and screwed into the screw hole, the adjusting mechanism can push the piston in the plug groove toward the annular groove, so that the sealing ring is pressurized, expanded and deformed to seal the anchor hole.

8. The method for continuous excavation and advance support of broken surrounding rock according to claim 7, characterized in that: The adjustment mechanism includes two plug rods parallel to the axial direction of the slurry supply pipe, the two plug rods are relatively inserted on the end surface of the slurry supply pipe close to the anchor hole, the blind plug is provided with a plug hole for inserting the plug rod, the blind plug is provided with a slide groove, and a transmission plate is slidably connected in the slide groove; the side of the transmission plate close to the plug groove is connected to the piston through a connecting rod, and the other side is press-fitted with the plug rod.

9. The method for continuous excavation and advance support of broken surrounding rock according to claim 8, characterized in that: A spring is sleeved on the outer side of the connecting rod, and two ends of the spring are respectively connected to the wall of the plug groove and the outer wall of the piston.

10. The method for continuous excavation and advance support of broken surrounding rock according to claim 8, characterized in that: A synchronous plate is connected to the bottom of the positioning plate through a telescopic rod, a push rod parallel to the axial direction of the slurry supply pipe is slidably inserted on the positioning block, a transmission rod perpendicular to the push rod is horizontally slidably arranged in the positioning block, one end of the transmission rod close to the push rod has a first slope that is pressed and matched with the push rod, and the bottom of the insertion rod has a second slope that is pressed and matched with the other end of the transmission rod; the bottom of the push rod passes through the positioning plate and is fixed on the top of the synchronous plate.

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