Removal method for open TBM (Tunnel Boring Machine) encountering unfavorable geology jamming

Abstract

The invention relates to the technical field of open-type TBM (Tunnel Boring Machine) detrapping, and provides a detrapping method for an open-type TBM stuck in unfavorable geology, which comprises the following steps: arranging a self-propelled hollow grouting anchor rod above a TBM shield and a cutterhead, and injecting cement paste and chemical double-liquid slurry to reinforce surrounding rock to form a stable supporting body; after reinforcement is completed, top pilot tunnel manual expanding excavation is conducted, steel arch support is implemented, and meanwhile accumulated slag is removed; judging whether the TBM exits or not through a trial rotation cutter head, if not, sequentially expanding and excavating the right pilot tunnel and the left pilot tunnel, and continuously matching with supporting and slag removal until the TBM recovers tunneling; and after escape is completed, tunnel passing section surrounding rock convergence and settlement parameter monitoring is enhanced. By means of the method, the safety problem caused when workers enter the cutterhead to remove slag under the condition of poor protective measures is avoided, the operation safety is improved, meanwhile, the open TBM detrapping speed is increased, and the construction progress is prevented from being affected; in addition, used materials are universal, the construction technology is mature, and the advantages of being controllable in cost, simple in structure, high in applicability and the like are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of freeing an open-type TBM from a jam, and in particular to a method for freeing an open-type TBM from a jam when encountering adverse geological conditions. Background Art

[0002] TBMs utilize the reaction force of the rock wall to achieve the reverse thrust and reverse torque required for tunneling. Under normal temperature and pressure, they achieve one-step tunneling, initial support, and slag transportation. They integrate mechanical, electrical, hydraulic, and gas functions to automate tunnel construction. Excavation operations can proceed continuously, resulting in faster construction speeds and shorter construction periods. This feature is particularly evident when constructing over long distances in stable surrounding rock.

[0003] During open TBM excavation construction, when excavation encounters unfavorable geological conditions, loose geology can easily lead to slag collapse, causing the cutterhead scraper chamber to be squeezed by the surrounding rock, making it impossible for the cutterhead to rotate. Construction is slow and the collapsed slag needs to be handled, affecting the construction progress. If manual labor enters the front of the cutterhead through the scraper mouth to clean up the fallen slag, it will be more serious and threaten the safety of construction workers, posing a construction risk.

[0004] Therefore, the present invention provides a water-tightness test for a large-span radial gate to protect the safety of construction workers, while increasing the escape speed of an open-type TBM to avoid affecting the construction progress. Summary of the Invention

[0005] The purpose of the present invention is to provide a water-tightness test for a large-span radial gate to protect the safety of construction workers and at the same time increase the escape speed of an open-type TBM to avoid affecting the construction progress.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: A method for freeing an open-type TBM from a jam in adverse geological conditions comprises the following steps: S1. Install self-propelled hollow grouting anchors behind the TBM shield and near the main beam to reinforce the surrounding rock by grouting the top arch area above the TBM shield and cutterhead. S2. After completing the surrounding rock reinforcement of the shield and the top arch area above the cutterhead, carry out manual expansion of the top pilot hole, and excavate the top pilot hole to the curved surface of the cutterhead; S3. While excavating the top pilot tunnel, steel arch support is carried out within the top pilot tunnel. After the steel arch support is completed, the accumulated slag is cleaned to reduce the resistance of the surrounding rock to the cutterhead; S4. After the accumulated slag is cleared, the TBM cutterhead is tested. If the escape is successful, the top pilot tunnel steel arch support is removed and normal excavation operation is resumed. If the cutterhead cannot rotate, continue excavating the right pilot tunnel and install steel arch support. After the steel arch support is completed, clean the accumulated debris to reduce the resistance of the surrounding rock to the cutterhead. After the accumulated debris is cleaned, perform another TBM cutterhead test rotation. If it is successful, remove the top and right steel arch support and resume normal excavation construction. If the cutterhead still cannot rotate, continue to excavate the left pilot tunnel and carry out steel arch support. After the steel arch support is completed, clean the accumulated debris to reduce the resistance of the surrounding rock to the cutterhead. After the accumulated debris is cleaned, conduct another trial rotation of the TBM cutterhead. After successfully escaping the predicament, remove the top, right and left steel arch supports and resume normal excavation construction.

[0007] Preferably, the S1 specifically includes the following steps: S1.1. Drive two rows of self-propelled hollow anchors along the tunnel axis within a 120° range in the top arch area in the direction of TBM excavation at a rock penetration angle of 20° to 25°. The anchors are 10 m long and filled with cement grout to withstand the downward pressure of the collapsed mass. S1.2. Two rows of self-propelled anchors (7.5 m long) are deployed at a 45° rock penetration angle within the same range of the top arch. Chemical double-liquid slurry is injected to solidify the surrounding rock and reduce shield pressure. The chemical double-liquid slurry solidifies the surrounding rock and prevents cement slurry from flowing back to the rear of the TBM shield near the main beam.

[0008] Preferably, the specification of the self-propelled hollow anchor in S1.1 is Φ32×10m, the axial spacing of two rows of self-propelled hollow anchors along the tunnel is 50cm, and the radial spacing of the self-propelled anchors in the same row along the tunnel is 15cm; The specification of the self-propelled hollow anchor rods in S1.2 is Φ32×10m, the axial spacing of two rows of self-propelled hollow anchor rods along the tunnel is 100cm, and the radial spacing of the self-propelled anchor rods in the same row along the tunnel is 15cm.

[0009] Preferably, the water-cement ratio of the cement slurry in S1.1 is 0.5:1, and the grouting pressure is 5-10 MPa; the chemical double-liquid slurry in S1.2 is HCH-Ⅱ type chemical double-liquid slurry, which is a mixture of cement slurry and water glass in a ratio of 1:1, and the grouting pressure is not greater than 6 MPa.

[0010] Preferably, the step S2 specifically includes the following steps: S2.1. Before excavating the top pilot tunnel, deploy Φ32 self-propelled anchor bolts with a length of 4.5m and a spacing of 0.4m above the pre-set top pilot tunnel in the direction of excavation. Use cement-water glass grout for grouting to prevent blasting or excavation from dispersing the reinforced surrounding rock in S1. S2.2. The top pilot tunnel is manually expanded by first excavating the middle pilot tunnel, and then expanding along the left and right sides of the middle pilot tunnel to eventually form a top pilot tunnel with a circumferential angle of 120° and a height of not less than 1.5m.

[0011] Preferably, the steel arch support in S3 is an H125 steel arch, the axial spacing of the H125 steel arch along the tunnel is 50 cm, the H125 steel arch is provided with Φ25mm closely packed steel bars close to the surrounding rock surface, the H125 steel arches are connected with 12# channel steel, and diagonal braces are provided at the corners of the H125 steel arch.

[0012] Preferably, before excavating the right or left pilot tunnel in S4, Φ32 self-propelled anchor rods are arranged above the preset pilot tunnel along the excavation direction with a length of 4m and a spacing of 0.4m, and cement-water glass double liquid slurry is used for grouting; the width of the artificially expanded right and left pilot tunnels is not less than 1.2m, and the height is not less than 1.7m.

[0013] Preferably, the steel arch support used in S4 uses H125 steel as vertical support, and the vertical support is spaced 50 cm along the axial direction of the tunnel.

[0014] Preferably, after resuming normal excavation construction in S4, monitoring of the tunnel passage section is strengthened; the monitoring content includes the convergence deformation of the surrounding rock and the settlement trend of the tunnel.

[0015] The present invention discloses a method for escaping an open-type TBM from being stuck in adverse geological conditions, which has the following beneficial effects.

[0016] The present invention includes: laying self-propelled hollow grouting anchor rods above the TBM shield and cutterhead, injecting cement slurry and chemical double-liquid slurry to reinforce the surrounding rock and form a stable support body; after the reinforcement is completed, the top pilot hole is manually excavated and steel arch support is implemented, and the accumulated slag is cleared at the same time; through the trial rotation of the cutterhead, it is determined whether it is out of trouble. If it is not out of trouble, the right and left pilot holes are excavated in turn, and the support and slag removal are continuously coordinated until the TBM resumes excavation; after the excavation is completed, the monitoring of the surrounding rock convergence and settlement parameters of the tunnel passing section is strengthened. This method avoids the safety issues of manual entry into the cutterhead to remove slag without adequate protective measures, improves operational safety, and at the same time increases the speed of the open TBM out of trouble, avoiding affecting the construction progress; and the materials used are universal, the construction technology is mature, and it has the characteristics of controllable cost, simple structure, and strong applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a flow chart of a method for freeing an open TBM from a jam in adverse geological conditions according to the present invention; Figure 2 This is a cross-sectional view of the pilot tunnel excavation of the present invention; Figure 3 This is a longitudinal section diagram of the pilot tunnel excavation of the present invention.

[0018] In the attached figure: 1. TBM shield; 2. TBM main beam; 3. Self-propelled anchor rod; 4. H125 steel; 5. 12# channel steel; 6. Close-packed steel bars. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0020] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention. Example

[0021] like Figure 1-Figure 3 As shown, a method for freeing an open TBM when it is stuck in adverse geological conditions includes the following steps: S1. Drive self-propelled hollow grouting anchor rods behind the TBM shield 1 and near the main beam 2 to perform grouting reinforcement on the surrounding rock of the TBM shield 1 and the top arch area above the cutterhead. In this embodiment, the self-propelled hollow grouting anchor rods are driven by a hand drill.

[0022] Preferably, in this embodiment, S1 specifically includes the following steps: S1.1. Drive two rows of self-propelled hollow anchors along the tunnel axis within a 120° range in the top arch area in the direction of TBM excavation at a rock penetration angle of 20° to 25°. The anchors are 10 m long and filled with cement grout to withstand the downward pressure of the collapsed mass. S1.2. Two rows of self-propelled anchors (3) with a length of 7.5 m are installed at a 45° rock penetration angle within the same range of the top arch. Chemical double-liquid slurry is injected to solidify the surrounding rock and reduce shield pressure. The chemical double-liquid slurry solidifies the surrounding rock and prevents cement slurry from flowing back to the rear of the TBM shield (1) near the main beam (2).

[0023] It should be noted that, in this embodiment, by setting the rock entry angle of the self-propelled hollow anchor in S1.1 to 20°~25° and the anchor length to 10m, and setting the rock entry angle of the self-propelled hollow anchor in S1.2 to 45° and the anchor length to 7.5m, the solidified layer formed by the chemical double-liquid slurry is placed between the solidified layer formed by the cement slurry and the excavated tunnel, which can prevent the cement slurry with good fluidity from returning to the side behind the TBM shield 1 close to the main beam 2, thereby improving the surrounding rock grouting reinforcement effect.

[0024] Preferably, in this embodiment, the specification of the self-propelled hollow anchor in S1.1 is Φ32×10m, the axial spacing of two rows of self-propelled hollow anchors along the tunnel is 50cm, and the radial spacing of the self-propelled anchors 3 in the same row along the tunnel is 15cm; In this embodiment, the specification of the self-propelled hollow anchor in S1.2 is Φ32×10m, the axial spacing of two rows of self-propelled hollow anchors along the tunnel is 100cm, and the radial spacing of the self-propelled anchors 3 in the same row along the tunnel is 15cm.

[0025] Preferably, in this embodiment, the water-cement ratio of the cement slurry in S1.1 is 0.5:1, and the grouting pressure is 5-10 MPa; the chemical double-liquid slurry in S1.2 is HCH-Ⅱ type chemical double-liquid slurry, which is a mixture of cement slurry and water glass in a ratio of 1:1, and the grouting pressure is not more than 6 MPa; in this embodiment, if grouting or abnormal resistance occurs inside the cutter head during the grouting process, the grouting operation needs to be stopped and checked.

[0026] S2. After completing the surrounding rock reinforcement of the shield and the top arch area above the cutterhead, carry out manual excavation of the top pilot hole, and excavate the top pilot hole to the curved surface of the cutterhead; Preferably, in this embodiment, S2 specifically includes the following steps: S2.1. Before excavating the top pilot tunnel, deploy 3 Φ32 self-propelled anchor bolts above the pre-set top pilot tunnel in the direction of excavation. The rock penetration angle is determined based on the actual site conditions, with a length of 4.5 m and a spacing of 0.4 m. Grouting is performed using cement-water glass dual-liquid grout to form a pre-reinforced protective layer to prevent blasting or excavation from dispersing the reinforced surrounding rock in S1. It should be noted that in order to improve the excavation efficiency during the top pilot tunnel excavation, when blasting is required on site, blasting is used to excavate the pilot tunnel to improve the excavation efficiency. In order to control the blasting without disturbing the reinforcement layer, it is recommended to use smooth blasting or small nonel blasting, appropriately reduce the amount of explosives per blast hole, and use multi-stage blasting to advance in stages to avoid overall vibration. The blast hole arrangement should follow the principle of "sparse periphery and concentrated in the middle". When blasting is not suitable, mechanical excavation can be used, and excavation can be carried out by using a small hydraulic rock machine combined with a breaker hammer and manual stripping. S2.2. The top pilot tunnel is manually expanded by first excavating the middle pilot tunnel, and then expanding along the left and right sides of the middle pilot tunnel to eventually form a top pilot tunnel with a circumferential angle of 120° and a height of not less than 1.5m.

[0027] It should be noted that the top pilot tunnel is excavated because TBMs often encounter poor geology during excavation. At the same time, the tunnel is buried about 1,000 meters deep. Under the action of ground stress, the broken rock mass continues to collapse during the excavation process. During the TBM excavation, the cutter head is stuck, and the shield steel plate is deformed by the rock mass, making it impossible for the TBM to escape. At this time, it is necessary to use manual excavation of the pilot tunnel to remove the broken rock mass in the cutter chamber and shield area, reduce the shield pressure and achieve the purpose of TBM escape.

[0028] S3. While excavating the top pilot tunnel, steel arch support is carried out within the top pilot tunnel. After the steel arch support is completed, the accumulated slag is cleaned to reduce the resistance of the surrounding rock to the cutterhead; like Figure 2 As shown, as a preference, in this embodiment, the steel arch frame support in S3 is 4 H125 steel arch frames, the spacing between the 4 H125 steel arch frames is 50 cm, the 4 H125 steel arch frames are provided with Φ25mm closely packed steel bars 6 close to the surrounding rock surface, the 4 H125 steel arch frames are connected by 12# channel steel 5, and diagonal braces are provided at the corners of the 4 H125 steel arch frames.

[0029] In this embodiment, the bottom of the H125 steel arch 4 is welded to the TBM shield 1.

[0030] S4. After the accumulated slag is cleared, the TBM cutterhead is tested. If the escape is successful, the top pilot tunnel steel arch support is removed and normal excavation operation is resumed. If the cutterhead cannot rotate, continue excavating the right pilot tunnel and install steel arch support. After the steel arch support is completed, clean the accumulated debris to reduce the resistance of the surrounding rock to the cutterhead. After the accumulated debris is cleaned, perform another TBM cutterhead test rotation. If it is successful, remove the top and right steel arch support and resume normal excavation construction. If the cutterhead still cannot rotate, continue to excavate the left pilot tunnel and carry out steel arch support. After the steel arch support is completed, clean the accumulated debris to reduce the resistance of the surrounding rock to the cutterhead. After the accumulated debris is cleaned, conduct another trial rotation of the TBM cutterhead. After successfully escaping the predicament, remove the top, right and left steel arch supports and resume normal excavation construction.

[0031] It should be noted that, in this embodiment, there is no strict order restriction for excavating the right pilot tunnel and the left pilot tunnel. When excavating the right pilot tunnel or the left pilot tunnel, it is preferred to choose a location where the surrounding rock is relatively broken and construction conditions are met, which can facilitate slag removal and material transportation.

[0032] Preferably, in this embodiment, before the excavation of the right or left pilot tunnel in S4, a Φ32 self-propelled anchor rod 3 with a length of 4m and a spacing of 0.4m is arranged above the preset pilot tunnel along the excavation direction, and cement-water glass double liquid slurry is used for grouting to form a pre-reinforced protective layer; the width of the right and left pilot tunnels is not less than 1.2m, and the height is not less than 1.7m. In this embodiment, the H125 steel 4 used in S4 is used as the vertical support for the steel arch support, and the vertical support is spaced 50cm along the axial direction of the tunnel. The 12# channel steel 5 is used to connect the steel arch support in S4, and φ25mm densely packed steel bars 6 are used near the surrounding rock surface. Specifically, in this embodiment, Figure 2As shown in Figure 4, the steel arch support used in S4 is a rectangular support, which is welded to the TBM shield 1 on the side close to the TBM shield 1. It should be noted that when the top, right, and left steel arch supports are removed after the rescue is successful, the welding points between the top, right, and left steel arch supports and the TBM shield 1 need to be disconnected.

[0033] Preferably, in this embodiment, after S4 resumes normal excavation, monitoring of the tunnel section is strengthened; monitoring includes surrounding rock convergence and deformation and tunnel settlement trends. In this embodiment, laser profilers or total station measurements are used to monitor surrounding rock convergence and deformation. Three to five convergence monitoring points are set at locations such as the tunnel vault, haunch, and sidewalls to analyze whether the surrounding rock continues to deform after the TBM passes through and to determine surrounding rock stability. Settlement measurement points are set at tunnel vault settlement intervals of 10 to 20 meters along the tunnel axis, and a level or automatic settlement sensor is used to monitor tunnel settlement trends.

[0034] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Replacement may be partial structure, device, or method step replacement, or it may be a complete technical solution. Equivalent replacements or modifications based on the technical solution and inventive concept of the present invention are all within the scope of protection of the present invention.

Claims

1. A method for escaping an open TBM stuck in adverse geological conditions, characterized in that: The following steps are involved: S1. Install self-propelled hollow grouting anchors behind the TBM shield and near the main beam to reinforce the surrounding rock by grouting the top arch area above the TBM shield and cutterhead. S2. After completing the surrounding rock reinforcement of the shield and the top arch area above the cutterhead, carry out manual expansion of the top pilot hole, and excavate the top pilot hole to the curved surface of the cutterhead; S3. While excavating the top pilot tunnel, steel arch support is carried out within the top pilot tunnel. After the steel arch support is completed, the accumulated slag is cleaned to reduce the resistance of the surrounding rock to the cutterhead; S4. After the accumulated slag is cleared, the TBM cutterhead is tested. If the escape is successful, the top pilot tunnel steel arch support is removed and normal excavation operation is resumed. If the cutterhead cannot rotate, continue excavating the right pilot tunnel and install steel arch support. After the steel arch support is completed, clean the accumulated debris to reduce the resistance of the surrounding rock to the cutterhead. After the accumulated debris is cleaned, perform another TBM cutterhead test rotation. If it is successful, remove the top and right steel arch support and resume normal excavation construction. If the cutterhead still cannot rotate, continue to excavate the left pilot tunnel and carry out steel arch support. After the steel arch support is completed, clean the accumulated debris to reduce the resistance of the surrounding rock to the cutterhead. After the accumulated debris is cleaned, conduct another trial rotation of the TBM cutterhead. After successfully escaping the predicament, remove the top, right and left steel arch supports and resume normal excavation construction.

2. The method for escaping an open TBM stuck in adverse geological conditions according to claim 1, characterized in that: The S1 specifically includes the following steps: S1.

1. Drive two rows of self-propelled hollow anchors along the tunnel axis within a 120° range in the top arch area in the direction of TBM excavation at a rock penetration angle of 20° to 25°. The anchors are 10 m long and filled with cement grout to withstand the downward pressure of the collapsed mass. S1.

2. Two rows of self-propelled anchors (7.5 m long) are deployed at a 45° rock penetration angle within the same range of the top arch. Chemical double-liquid slurry is injected to solidify the surrounding rock and reduce shield pressure. The chemical double-liquid slurry solidifies the surrounding rock and prevents cement slurry from flowing back to the rear of the TBM shield near the main beam.

3. The method for escaping an open TBM stuck in adverse geological conditions according to claim 2, characterized in that: The specification of the self-propelled hollow anchor in S1.1 is Φ32×10m, the axial spacing of two rows of self-propelled hollow anchors along the tunnel is 50cm, and the radial spacing of self-propelled anchors in the same row along the tunnel is 15cm; The specification of the self-propelled hollow anchor rods in S1.2 is Φ32×10m, the axial spacing of two rows of self-propelled hollow anchor rods along the tunnel is 100cm, and the radial spacing of the self-propelled anchor rods in the same row along the tunnel is 15cm.

4. The method for escaping an open TBM stuck in adverse geological conditions according to claim 2, characterized in that: The water-cement ratio of the cement slurry in S1.1 is 0.5:1, and the grouting pressure is 5-10 MPa; the chemical double-liquid slurry in S1.2 is HCH-Ⅱ type chemical double-liquid slurry, which is a mixture of cement slurry and water glass in a ratio of 1:1, and the grouting pressure is not greater than 6 MPa.

5. The method for escaping an open TBM stuck in adverse geological conditions according to claim 2, characterized in that: The S2 specifically includes the following steps: S2.

1. Before excavating the top pilot tunnel, deploy Φ32 self-propelled anchor bolts with a length of 4.5m and a spacing of 0.4m above the pre-set top pilot tunnel in the direction of excavation. Use cement-water glass grout for grouting to prevent blasting or excavation from dispersing the reinforced surrounding rock in S1. S2.

2. The top pilot tunnel is manually expanded by first excavating the middle pilot tunnel, and then expanding along the left and right sides of the middle pilot tunnel to eventually form a top pilot tunnel with a circumferential angle of 120° and a height of not less than 1.5m.

6. The method for escaping an open TBM stuck in adverse geological conditions according to claim 1, characterized in that: The steel arch support in S3 is H125 steel arch. The axial spacing of H125 steel arch along the tunnel is 50cm. H125 steel arch is provided with Φ25mm closely packed steel bars close to the surrounding rock surface. H125 steel arches are connected with 12# channel steel. Diagonal braces are provided at the corners of H125 steel arch.

7. The method for escaping an open TBM stuck in adverse geological conditions according to claim 1, characterized in that: Before excavating the right or left pilot tunnel in S4, Φ32 self-propelled anchor rods with a length of 4m and a spacing of 0.4m are arranged above the preset pilot tunnel along the excavation direction, and cement-water glass double liquid slurry is used for grouting; the width of the artificially expanded right and left pilot tunnels is not less than 1.2m, and the height is not less than 1.7m.

8. The method for escaping an open TBM stuck in adverse geological conditions according to claim 1, characterized in that: The steel arch support used in S4 adopts H125 steel as vertical support, and the vertical support is spaced 50 cm along the axial direction of the tunnel.

9. The method for escaping an open TBM stuck in adverse geological conditions according to claim 1, characterized in that: After S4 resumes normal excavation construction, the monitoring of the tunnel passage section will be strengthened; the monitoring content includes the convergence deformation of the surrounding rock and the tunnel settlement trend.

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