TBM tunnel rock plug intercepting method

Abstract

The present application relates to the technical field of tunnel construction, in particular to a TBM tunnel rock plug intercepting method, comprising the following steps: step one, bedrock treatment; step two, TBM arrival observation; step three, TBM retreat and punching and cutting operation; step four, TBM forward movement and auxiliary support installation; and step five, rock plug pushing out and hoisting away. The present application divides the sampling rock plug and the surrounding rock mass through punching and cutting operation, and then pushes out the divided rock plug by moving the RBM equipment, so as to achieve the purpose of rapid and complete sampling and overcome the problem of incomplete sampling rock plug in the prior art.

Description

Technical Field

[0001] This invention relates to the field of tunnel construction technology, specifically to a method for removing rock plugs in a TBM tunnel. Background Technology

[0002] With the development of my country's economy and society, there is an increasing number of major underground engineering projects such as long railway and highway tunnels, water diversion tunnels, and urban subways. The construction technology for tunnels with exceptionally long lengths, large cross-sections, and complex geological conditions is becoming increasingly challenging, while the requirements for excavation speed, safety, environmental protection, quality, and efficiency are also rising. Therefore, TBMs are increasingly being used in long tunnels. Hard rock tunnel boring machines, also known as rock excavators, are generally called TBMs in China. They are full-face rock tunnel boring machines that excavate through rock formations. They typically utilize a rotating cutterhead, aided by the force of a propulsion device, to cut or break the rock surface with roller cutters on the cutterhead, achieving the purpose of tunnel excavation. In engineering projects, rock plugs bearing TBM cutter marks are often collected for scientific research, display, or documentation.

[0003] Currently, the method of drilling holes outside the TBM excavation outline using a rock drill and then using the TBM to rotate and push out the cutting material is adopted. This method is prone to breaking the tool marks and damaging the rock mass, resulting in incomplete rock sampling plugs. Summary of the Invention

[0004] To address the current method of using a rock drill to drill holes outside the TBM excavation outline and then rotating the TBM to extract rock plugs, which easily leads to broken tool marks and damage to the rock mass, resulting in incomplete rock plugs, this invention proposes a TBM tunnel rock plug extraction method. This method overcomes the problem of incomplete rock plugs in previous sampling methods, achieving the goal of rapid and complete sampling.

[0005] To achieve the above objectives, the technical solution of the invention is as follows:

[0006] The method for removing rock plugs in TBM tunnels includes the following steps:

[0007] Step 1: Bedrock Treatment

[0008] Use a pneumatic drill to chisel and cut the rock surface at the TBM exit point; at the same time, observe the joint condition of the surrounding rock. If the rock is incomplete or the joints are well developed, grouting treatment is required, and the grouting reinforcement depth must meet the requirements.

[0009] Step 2: TBM arrival and observation

[0010] When the TBM reaches a distance of L1 from the exit point, its advancing speed and thrust are reduced, and the tunnel axis is re-measured according to the actual situation. Then the TBM continues to advance and when it reaches a distance of L2 from the exit point, it stops advancing and the cutterhead rotates at low speed to grind the rock and produce tool marks.

[0011] After the tool marks are ground, the TBM is retracted to a predetermined position of one stroke. During the retraction, the cutter head spray water is turned on to rinse the working face. Then, the operator enters the working face area through the cutter head manhole to observe the surrounding rock and tool marks. If the conditions for removing rock plugs are met or the conditions are met after auxiliary treatment, proceed to step three.

[0012] If the requirements are still not met after auxiliary processing, then sampling should be abandoned;

[0013] Step 3: TBM retraction and drilling / cutting operations

[0014] The TBM retracts until a working area is formed between the face and the TBM to meet the needs of construction operations. Then, the workers transport the corresponding tools and materials from the cutterhead manhole to the working area and start drilling from the rear edge of the side cutter trajectory to drill N evenly distributed round holes.

[0015] Insert the wire saw into the exit end of the tunnel and cut the rock mass between two adjacent circular holes symmetrically from bottom to top. Make corresponding N-shaped cuts to the rock plug and insert steel plates into the lower part of the rock mass. After the rock plug is cut, remove the tools and materials used for drilling and cutting from the cutter head manhole to the work area.

[0016] Step 4: Move the TBM forward and install auxiliary supports

[0017] Remove the two external side blades of the cutterhead and tie square timber to the front panel of the cutterhead, then move the TBM forward to the working face area;

[0018] Step 5: Push out the rock plug and transfer / lift it away.

[0019] The rock plug is slowly pushed out by controlling the thrust, and the cutterhead does not rotate during the pushing process. Then, the pushed-out rock plug is moved to the gantry crane operation area by a loader, hoisted onto a vehicle and driven away from the TBM assembly chamber to complete the sampling.

[0020] Furthermore, in step one, the diameter of the chiseling area is D+2L and the depth is H, where D is the TBM excavation diameter, L≥20cm, and H is 10cm~50cm.

[0021] Furthermore, in step one, the grouting reinforcement depth is required to be ≥2B, where B is the thickness of the sampling rock plug.

[0022] Furthermore, in step two, 2B > L1 < 3B, and L2 = B.

[0023] Furthermore, in step three, N≥16, and there is an angle α between the center line of the circular hole and the tunnel axis, which expands the subsequent cutting profile.

[0024] Furthermore, in step four, when the TBM moves forward to the working face area, the following preliminary work is completed: slag is piled up or tires are placed at the end of the TBM assembly chamber to absorb the impact force.

[0025] The beneficial effects of the invention through the above technical solution are as follows:

[0026] This invention separates the sampling rock plug from the surrounding rock mass through drilling and cutting operations, and then pushes out the separated rock plug by moving the RBM equipment to achieve the purpose of rapid and complete sampling, overcoming the problems of incomplete sampling rock plugs and high construction difficulty in the past. Attached Figure Description

[0027] Figure 1 This is a flowchart of the TBM tunnel rock plug interception method of the present invention;

[0028] Figure 2 This is a schematic diagram of the chiseling area in step one of the TBM tunnel rock plug interception method of the present invention;

[0029] Figure 3 This is a schematic diagram of the TBM reaching the site in step two of the TBM tunnel rock plug interception method of the present invention;

[0030] Figure 4 This is a schematic diagram of the position of the circular hole in step three of the TBM tunnel rock plug interception method of the present invention;

[0031] Figure 5 This is a schematic diagram of the cutting shape in step three of the TBM tunnel rock plug interception method of the present invention;

[0032] Figure 6 This is a schematic diagram of the forward movement of the TBM cutterhead after binding the square timber in step four of the TBM tunnel rock plug removal method of the present invention.

[0033] Figure 7 This is a schematic diagram of the TBM pushing out the sampling rock plug in step five of the TBM tunnel rock plug interception method of the present invention. Detailed Implementation

[0034] The invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0035] In the description of the invention, it should be understood that the terms "left," "right," "up," "down," "horizontal," and "vertical," etc., indicate the orientation or positional relationship based on the appendix. Figure 1 The orientations or positional relationships shown are for the purpose of facilitating the description of the invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the invention.

[0036] Example 1

[0037] like Figures 1 to 7 As shown, the method for removing rock plugs in TBM tunnels includes the following steps:

[0038] Step 1: Bedrock Treatment

[0039] Use a pneumatic drill to chisel and cut the rock surface at the TBM exit point; at the same time, observe the joint condition of the surrounding rock. If the rock is incomplete or the joints are well developed, grouting treatment is required, and the grouting reinforcement depth must meet the requirements.

[0040] Step 2: TBM arrival and observation

[0041] When the TBM reaches a distance of L1 from the exit point, its advancing speed and thrust are reduced, and the tunnel axis is re-measured according to the actual situation. Then the TBM continues to advance and when it reaches a distance of L2 from the exit point, it stops advancing and the cutterhead rotates at low speed to grind the rock and produce tool marks.

[0042] After the tool marks are ground, the TBM is retracted to a predetermined position of one stroke. During the retraction, the cutter head spray water is turned on to rinse the working face. Then, the operator enters the working face area through the cutter head manhole to observe the surrounding rock and tool marks. If the conditions for removing rock plugs are met or the conditions are met after auxiliary treatment, proceed to step three.

[0043] If the requirements are still not met after auxiliary processing, then sampling should be abandoned;

[0044] Step 3: TBM retraction and drilling / cutting operations

[0045] The TBM retracts until a working area is formed between the face and the TBM to meet the needs of construction operations. Then, the workers transport the corresponding tools and materials from the cutterhead manhole to the working area and start drilling from the rear edge of the side cutter trajectory to drill N evenly distributed round holes.

[0046] Insert the wire saw into the exit end of the tunnel and cut the rock mass between two adjacent circular holes symmetrically from bottom to top. Make corresponding N-shaped cuts to the rock plug and insert steel plates into the lower part of the rock mass. After the rock plug is cut, remove the tools and materials used for drilling and cutting from the cutter head manhole to the work area.

[0047] Step 4: Move the TBM forward and install auxiliary supports

[0048] Remove the two external side blades of the cutterhead and tie square timber to the front panel of the cutterhead, then move the TBM forward to the working face area;

[0049] Step 5: Push out the rock plug and transfer / lift it away.

[0050] The rock plug is slowly pushed out by controlling the thrust, and the cutterhead does not rotate during the pushing process. Then, the pushed-out rock plug is moved to the gantry crane operation area by a loader, hoisted onto a vehicle and driven away from the TBM assembly chamber to complete the sampling.

[0051] Please refer to it again. Figure 2 In step one, the diameter of the chiseling area is D+2L and the depth is H, where D is the TBM excavation diameter, L≥20cm, and H is 10cm~50cm.

[0052] In step one, the required grouting reinforcement depth is ≥2B, where B is the thickness of the sampling rock plug.

[0053] In step two, 2B > L1 < 3B, L2 = B.

[0054] In step three, N≥16, and there is an angle α between the center line of the circular hole and the tunnel axis, so that the subsequent cutting profile spreads outward in the radial direction, which facilitates the ejection of the sampling rock plug.

[0055] When the TBM moves forward to the working face area in step four, the following preliminary work is completed: muck is piled up or tires are placed at the end of the TBM assembly chamber. This can absorb the impact force when the sampling rock plug is tilted, and prevent the sampling rock plug from being damaged.

[0056] The embodiments described above are merely preferred embodiments of the invention and are not intended to limit the scope of the invention. Therefore, any equivalent changes or modifications made to the structure, features and principles described in the invention patent claims should be included within the scope of the invention patent application.

Claims

1. A method for removing rock plugs in TBM tunnels, characterized in that, Includes the following steps: Step 1: Bedrock Treatment Use a pneumatic drill to chisel and cut the rock surface at the TBM exit point; at the same time, observe the joint condition of the surrounding rock. If the rock is incomplete or the joints are well developed, grouting treatment is required, and the grouting reinforcement depth must meet the requirements. Step 2: TBM arrival and observation When the TBM reaches a distance of L1 from the exit point, its advancing speed and thrust are reduced, and the tunnel axis is re-measured according to the actual situation. Then the TBM continues to advance and when it reaches a distance of L2 from the exit point, it stops advancing and the cutterhead rotates at low speed to grind the rock and produce tool marks. After the tool marks are ground, the TBM is retracted to a predetermined position of one stroke. During the retraction, the cutter head spray water is turned on to rinse the working face. Then, the operator enters the working face area through the cutter head manhole to observe the surrounding rock and tool marks. If the conditions for removing rock plugs are met or the conditions are met after auxiliary treatment, proceed to step three. If the requirements are still not met after auxiliary processing, then sampling should be abandoned; Step 3: TBM retraction and drilling / cutting operations The TBM retracts until a working area is formed between the face and the TBM to meet the needs of construction operations. Then, the workers transport the corresponding tools and materials from the cutterhead manhole to the working area and start drilling from the rear edge of the side cutter trajectory to drill N evenly distributed round holes. Insert the wire saw into the exit end and cut the rock mass between two adjacent circular holes symmetrically from bottom to top. Make corresponding N-shaped cuts to the rock plug and insert steel plates into the lower part of the rock mass. After the rock plug is cut, remove the tools and materials used for drilling and cutting from the cutter head manhole to the work area. Step 4: Move the TBM forward and install auxiliary supports Remove the two external side blades of the cutterhead and tie square timber to the front panel of the cutterhead, then move the TBM forward to the working face area; Step 5: Push out the rock plug and transfer / lift it away. The rock plug is slowly pushed out by controlling the thrust, and the cutterhead does not rotate during the pushing process. Then, the pushed-out rock plug is moved to the gantry crane operation area by a loader, hoisted onto a vehicle and driven away from the TBM assembly chamber to complete the sampling.

2. The method for removing rock plugs in a TBM tunnel according to claim 1, characterized in that, In step one, the diameter of the chiseling area is D+2L and the depth is H, where D is the TBM excavation diameter, L≥20cm, and H is 10cm~50cm.

3. The method for removing rock plugs in a TBM tunnel according to claim 1, characterized in that, In step one, the required grouting reinforcement depth is ≥2B, where B is the thickness of the sampling rock plug.

4. The method for removing rock plugs in a TBM tunnel according to claim 3, characterized in that, In step two, 2B > L1 < 3B, L2 = B.

5. The method for removing rock plugs in a TBM tunnel according to claim 1, characterized in that, In step three, N ≥ 16, and there is an angle α between the center line of the circular hole and the tunnel axis.

6. The method for removing rock plugs in a TBM tunnel according to claim 1, characterized in that, When the TBM moves forward to the working face area in step four, the following preliminary work is completed: muck piling or tire padding is performed at the TBM assembly chamber end.

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