TBM multi-gripper control method adapting to changes in surrounding rock conditions

Abstract

The present invention discloses a TBM multi-gripper control method that adapts to changes in the state of broken surrounding rock. A vacuum suction cup body is installed on the working surface of the gripper, a grouting hole is opened on the side of the vacuum suction cup body, and a grouting machine is connected to the grouting hole. The gripper is supported on the surrounding rock in a single support manner, the TBM machine is started to excavate the tunnel, and measuring points are arranged on the surrounding rock. According to the displacement rate of the measuring points, it is judged whether the surrounding rock is in a completely broken state. If so, support grouting is performed on the broken surrounding rock, and the friction between the surrounding rock and the gripper is calculated to judge whether it is greater than the critical friction. If so, construction is continued. Otherwise, the vacuum suction cup is adsorbed on the surrounding rock, and the gripper displacement rate is measured. If it is less than or equal to the theoretical displacement rate, construction is continued. If it is greater than the theoretical displacement rate, the front and rear grippers are supported on the tunnel top and both side walls in a multi-point force manner, and then construction is continued. This solves the problems that the TBM grippers are easy to slip when used in complex geological conditions and the holding force between the grippers and the surrounding rock is insufficient.

Description

Technical Field

[0001] The invention belongs to the technical field of TBM construction and relates to a TBM multi-gripper control method that adapts to changes in the state of broken surrounding rock. Background Art

[0002] With the development of water conservancy and society in my country, people's demand for space is increasing, especially underground space. As the development of above-ground space has become increasingly limited, people's demand and development of underground space has become urgent. As an important underground space development equipment, TBM (full-section tunnel boring machine) is particularly important in complex geological conditions. TBM can complete tunnel construction efficiently and accurately, especially in hard rock and soft rock formations. The application of TBM can effectively improve construction efficiency and quality and reduce the impact on the environment.

[0003] The support mechanism is a key sub-component for continuous tunnel boring machines (TBMs). During the advancement of the TBM, the support system extends grippers to hold the surrounding rock tight, providing the force required for the cutterhead to advance and the torque required for its rotation. Gripper shoes are key components of the support mechanism, contacting the tunnel wall to ensure the stability and safety of the TBM during excavation. Gripper shoes need to extend from the machine core to support the entire machine body and be able to flexibly adjust during excavation to adapt to the shape and conditions of different tunnel walls. Therefore, the gripper shoe system needs to have strong support force, stability, and flexibility. However, existing gripper shoe systems are prone to uneven force on the surrounding rock, inability to support the sidewalls, and unstable gripper shoe support when in contact with the surrounding rock. This is especially true for highly abrasive formations and complex geological conditions such as karst and fault fracture zones. Gripper shoes are prone to slipping and insufficient holding force between the gripper shoe and the surrounding rock. Summary of the Invention

[0004] The purpose of the present invention is to provide a TBM multi-gripper control method that adapts to changes in the state of broken surrounding rock, thereby solving the problems of slipping of existing TBM grippers when used in complex geology and insufficient tightening force between the grippers and the surrounding rock.

[0005] The technical solution adopted by the present invention is a TBM multi-gripper control method that adapts to changes in the state of broken surrounding rock, comprising the following steps:

[0006] Step 1: Install a vacuum cup body on the TBM gripper working surface. The vacuum cup body has multiple vacuum nozzles in the middle, grouting holes are opened on the side of the vacuum cup body, the vacuum nozzles are connected to the vacuum generation system, and the grouting holes are connected to the grouting machine.

[0007] Step 2: Use a single support method to support the TBM gripper on the tunnel surrounding rock, then start the TBM machine to excavate the tunnel. At this time, the vacuum generating system and grouting machine are in the off state;

[0008] Step 3: Arrange measuring points on the surrounding rock and monitor the displacement rate of the measuring points;

[0009] Step 4: Evaluate the degree of surrounding rock fragmentation based on the displacement rate of the measuring point to determine whether the surrounding rock is in a completely broken state. If not, proceed to step 5. If so, start the grouting machine, which delivers slurry to the grouting hole to support and grout the broken surrounding rock, and then proceed to step 5.

[0010] Step 5: Calculate the friction force F between the surrounding rock and the gripper to determine whether it is greater than the critical friction force. If so, continue construction. If not, start the vacuum generating system to allow the vacuum suction cup to adhere to the surrounding rock.

[0011] Step 6: Measure the displacement rate of the single-support gripper and compare it with the theoretical displacement rate of the gripper. If the gripper displacement rate is less than or equal to the theoretical displacement rate, continue construction. If the gripper displacement rate is greater than the theoretical displacement rate, use the front and rear grippers to support the tunnel top and both side walls at multiple points, and then continue construction.

[0012] Among them, the grouting hole is connected to the discharge port of the grouting machine through a grouting pipe, and the slurry is transported to the grouting hole through negative pressure to complete the support grouting of the broken surrounding rock.

[0013] Step 3 involves arranging multiple measuring points on the surrounding rock at different locations at the same depth of the tunnel, monitoring the displacement of each measuring point using a total station, and then calculating the average displacement rate of these measuring points. v .

[0014] In step 4, determine whether the surrounding rock is in a completely broken state or whether there is a partitioned cracking phenomenon. If not, proceed to step 5. If so, start the grouting machine.

[0015] When the average displacement rate of all measuring points v When ≤0.1mm / d, it indicates that the surrounding rock is in a stable and complete state. When 0.1mm / d< v When ≤0.15mm / d, it indicates that the surrounding rock is in a micro-fracture state. At this time, the monitoring frequency of the displacement of the measuring point should be increased. When 0.15mm / d< v When the deformation is less than 0.2 mm / d, it indicates that the surrounding rock is in a state of rapid deformation. At this time, the slurry needs to be prepared and the surrounding rock needs to be grouting supported at any time. v When it is greater than 0.20 mm / d, it indicates that the surrounding rock is in a completely broken state.

[0016] When the displacement rate difference between different measuring points exceeds 0.10 mm / d, and v When ≤0.20mm / d, it indicates that the surrounding rock has zonal cracking phenomenon.

[0017] The first vibrating screen, second vibrating screen, third vibrating screen and storage bin are installed in sequence at the output end of the TBM belt conveyor. A storage bucket is placed at the bottom of each vibrating screen. The first vibrating screen is used to screen small-grained rocks with a particle size less than 0.0625mm, the second vibrating screen is used to screen medium-grained rocks with a particle size between 0.0625mm and 2mm, and the third vibrating screen is used to screen coarse-grained rocks with a particle size between 2mm and 20mm. The storage bin is used to receive crushed stones with a particle size greater than 20mm. When preparing the slurry, the rocks in the storage bucket are directly used for slurry preparation.

[0018] The grouting machine transports the slurry to the grouting hole. The slurry is a quick-setting slurry containing a quick-setting agent.

[0019] In step 5, the friction force F between the surrounding rock and the gripper is calculated as follows:

[0020]

[0021]

[0022] Where μ is the coefficient of kinetic friction, F n is the normal pressure on the gripper surface, P is the critical friction force, E is the elastic modulus, I is the contact surface area between the gripper and the surrounding rock, and L is the length from the contact surface between the gripper and the surrounding rock to the end of the compression rod.

[0023] The vacuum suction cup body is arc-shaped and fits the working surface of the support shoe. A porous rubber striped adhesive pad is attached to the surface of the vacuum suction cup body. The holes of the porous rubber striped adhesive pad correspond one-to-one to the vacuum suction nozzle on the vacuum suction cup body.

[0024] The beneficial effects of the present invention are as follows:

[0025] (1) By installing a vacuum suction cup on the working surface of the gripper, when the friction between the surrounding rock and the gripper is less than the critical friction, the vacuum generation system is turned on to make the vacuum suction cup firmly adsorbed on the surrounding rock, thereby increasing the friction between the surrounding rock and the gripper and preventing the gripper from slipping;

[0026] (2) By arranging measuring points on the surrounding rock, the degree of surrounding rock fragmentation is evaluated based on the displacement rate of the measuring points. If the surrounding rock is in a completely fragmented state, support grouting is performed on the fragmented surrounding rock to improve the stability of the surrounding rock.

[0027] (3) By measuring the displacement rate of the single-support shoe and comparing it with the theoretical displacement rate, if the displacement rate of the single-support shoe is greater than the theoretical displacement rate, the front and rear shoe are supported at the top and both side walls of the tunnel by multi-point force, which meets the requirements for the stability and reliability of the shoe, reduces the maintenance cost of the shoe, and balances the uneven force between the shoe and the surrounding rock, thereby improving the tunneling efficiency of the tunnel boring machine in broken surrounding rock. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a flow chart of the TBM multi-gripper control method for adapting to changes in the state of broken surrounding rock according to the present invention;

[0029] Figure 2 This is a diagram (side view) showing the positional relationship between the vibrating screen and the TBM grippers in the TBM multi-gripper control method adapted to changes in the state of the broken surrounding rock according to the present invention;

[0030] Figure 3 It is a schematic structural diagram of the vacuum suction cup body in the TBM multi-gripper control method adapted to changes in the state of the broken surrounding rock according to the present invention;

[0031] Figure 4 Schematic diagram of the working condition of four grippers supporting simultaneously in a tunnel in Example 3 of the present invention;

[0032] Figure 5 It is a schematic diagram of the three-dimensional structure of the front and rear TBM grippers subjected to four-point force in Example 6 of the present invention.

[0033] In the figure, 1. TBM support shoe, 2. Vacuum suction cup body, 3. Vacuum suction nozzle, 4. Grouting hole, 5. Grouting pipe, 6. Grouting machine, 7. TBM machine, 8. Belt conveyor, 9. First vibrating screen, 10. Second vibrating screen, 11. Third vibrating screen, 12. Storage bin. DETAILED DESCRIPTION

[0034] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] Example 1

[0036] A TBM multi-gripper control method that adapts to the changing state of the surrounding rock, see Figure 1 , including the following steps:

[0037] Step 1: Install a vacuum cup body on the TBM gripper working surface. The vacuum cup body has multiple vacuum nozzles in the middle, grouting holes are opened on the side of the vacuum cup body, the vacuum nozzles are connected to the vacuum generation system, and the grouting holes are connected to the grouting machine.

[0038] Step 2: Use a single support method to support the TBM gripper on the tunnel surrounding rock, then start the TBM machine to excavate the tunnel. At this time, the vacuum generating system and grouting machine are in the off state;

[0039] Step 3: Arrange measuring points on the tunnel surrounding rock and monitor the displacement rate of the measuring points;

[0040] Step 4: Evaluate the degree of surrounding rock fragmentation based on the displacement rate of the measuring point to determine whether the surrounding rock is in a completely broken state. If not, proceed to step 5. If so, start the grouting machine, which delivers slurry to the grouting hole to support and grout the broken surrounding rock, and then proceed to step 5.

[0041] Step 5: Calculate the friction force F between the surrounding rock and the gripper to determine whether it is greater than the critical friction force. If so, continue construction. If not, activate the vacuum generating system to allow the vacuum suction cup to adhere to the surrounding rock, thereby increasing the friction and gripping force between the gripper and the surrounding rock.

[0042] Step 6: Measure the displacement rate of the single-support TBM gripper and compare it with the theoretical displacement rate of the TBM gripper. If the TBM gripper displacement rate is less than or equal to the theoretical displacement rate, continue construction. If the TBM gripper displacement rate is greater than the theoretical displacement rate, use the front and rear TBM grippers to support the tunnel top and both side walls at multiple points, and then continue construction.

[0043] Example 2

[0044] A TBM multi-gripper control method adapted to changes in the state of broken surrounding rock includes the following steps:

[0045] Step 1: Install a vacuum cup body on the TBM gripper working surface. The vacuum cup body has multiple vacuum nozzles in the middle, and grouting holes are opened on the side of the vacuum cup body. The vacuum nozzles are connected to the vacuum generation system, and the grouting holes are connected to the grouting machine through the grouting pipe.

[0046] Step 2: Use a single support method to support the TBM gripper on the tunnel surrounding rock, then start the TBM machine to excavate the tunnel. At this time, the vacuum generating system and grouting machine are in the off state;

[0047] Step 3: Arrange multiple measuring points on the surrounding rock at different locations at the same depth of the tunnel, use a total station to monitor the displacement of each measuring point, and then calculate the average displacement rate of these measuring points v ;

[0048] Step 4: Based on the average displacement rate v Assess the degree of surrounding rock fragmentation to determine whether the surrounding rock is completely broken or has zonal cracking. If not, proceed to step 5. If so, start the grouting machine, which uses negative pressure to transport slurry to the grouting holes, completing the support grouting of the broken surrounding rock, and then proceed to step 5.

[0049] Step 5: Calculate the friction force F between the surrounding rock and the gripper to determine whether it is greater than the critical friction force. If so, continue construction. If not, start the vacuum generating system to allow the vacuum suction cup to adhere to the surrounding rock.

[0050] Step 6: Measure the displacement rate of the single-support TBM gripper and compare it with the theoretical displacement rate of the TBM gripper. If the TBM gripper displacement rate is less than or equal to the theoretical displacement rate, continue construction. If the TBM gripper displacement rate is greater than the theoretical displacement rate, use a three-point force method to support the front and rear TBM grippers on the tunnel top and both side walls, and then continue construction.

[0051] Example 3

[0052] A TBM multi-gripper control method adapted to changes in the state of broken surrounding rock includes the following steps:

[0053] Step 1, see Figure 2 and Figure 3 A vacuum cup body 2 is installed on the working surface of the TBM gripper shoe 1. A plurality of vacuum nozzles 3 are provided in the middle of the vacuum cup body 2. Grouting holes 4 are opened on the side of the vacuum cup body 2. The vacuum nozzles are connected to a vacuum generating system. The vacuum generating system is placed at the junction of the gripper shoe and the sub-beam. The grouting holes 4 are connected to a grouting machine 6 through a grouting pipe 5.

[0054] At the output end of the belt conveyor 8 of the TBM machine 7, a first vibrating screen 9, a second vibrating screen 10, a third vibrating screen 11 and a storage bin 12 are installed in sequence. The first vibrating screen 9, the second vibrating screen 10 and the third vibrating screen 11 are all tilted to facilitate the crushed stones on the screen to roll onto the next screen. A storage bucket is placed at the bottom of each vibrating screen. The first vibrating screen is used to screen small-grained rocks with a particle size of less than 0.0625 mm, the second vibrating screen is used to screen medium-grained rocks with a particle size between 0.0625 mm and 2 mm, and the third vibrating screen is used to screen coarse-grained rocks with a particle size between 2 mm and 20 mm. The storage bin 12 is used to receive crushed stones with a particle size greater than 20 mm. When configuring the slurry, the rocks in the storage bin are directly used for slurry configuration, so as to achieve the effect of reasonably recycling and utilizing the crushed rocks.

[0055] Step 2: Use a single support method to support the TBM gripper on the tunnel surrounding rock, then start the TBM machine to excavate the tunnel. At this time, the vacuum generating system and grouting machine are in the off state;

[0056] Step 3: Arrange multiple measuring points on the surrounding rock at different locations at the same depth of the tunnel, use a total station to monitor the displacement of each measuring point, and then calculate the average displacement rate of these measuring points v ;

[0057] Step 4: Based on the average displacement rate v Assess the degree of surrounding rock fragmentation to determine whether the surrounding rock is completely broken or has partitioned cracking. If not, proceed to step 5. If so, start the grouting machine 6, which delivers slurry to the grouting hole 4 through negative pressure to complete the support grouting of the broken surrounding rock, and then proceed to step 5.

[0058] Step 5: Calculate the friction force F between the surrounding rock and the gripper to determine whether it is greater than the critical friction force. If so, continue construction. If not, start the vacuum generating system to allow the vacuum suction cup to adhere to the surrounding rock.

[0059] Step 6: Measure the displacement rate of the single-support TBM gripper and compare it with the theoretical displacement rate of the TBM gripper. If the displacement rate of the TBM gripper is less than or equal to the theoretical displacement rate, continue construction. If the displacement rate of the TBM gripper is greater than the theoretical displacement rate, use the front and rear TBM grippers to support the tunnel roof and both side walls at multiple points and continue construction. Figure 4 , four support shoes are put into use at the same time, thereby improving the stability of TBM construction.

[0060] Example 4

[0061] A TBM multi-gripper control method adapted to changes in the state of broken surrounding rock includes the following steps:

[0062] Step 1: Install a vacuum cup body on the TBM gripper working surface. The vacuum cup body has multiple vacuum nozzles in the middle, and grouting holes are opened on the side of the vacuum cup body. The vacuum nozzles are connected to the vacuum generation system, and the grouting holes are connected to the grouting machine through the grouting pipe.

[0063] The vacuum suction cup body is arc-shaped and fits well with the working surface of the gripper shoe. A porous rubber striped adhesive pad is applied to the surface of the vacuum suction cup body. The holes of the porous rubber striped adhesive pad correspond one-to-one with the vacuum suction nozzle on the vacuum suction cup body. The porous rubber striped adhesive pad has good elasticity and can fill the tiny gap between the suction cup and the surface of the adsorbed object. When the suction cup fits the object, the porous rubber striped adhesive pad deforms under the action of pressure and fits tightly to the unevenness of the object's surface, effectively preventing air leakage and allowing the vacuum system to work normally.

[0064] The first, second, and third vibrating screens and a storage bin are installed in sequence at the output end of the TBM's belt conveyor. A storage bucket is placed at the bottom of each vibrating screen. The first vibrating screen is used to screen small-sized rocks with a particle size less than 0.0625mm, the second vibrating screen is used to screen medium-sized rocks with a particle size between 0.0625mm and 2mm, and the third vibrating screen is used to screen coarse-sized rocks with a particle size between 2mm and 20mm. The storage bin is used to receive crushed rocks with a particle size greater than 20mm. When preparing the slurry, the rocks in the storage bin are directly used for slurry preparation, achieving the purpose of rationally recycling and utilizing the crushed rocks.

[0065] Step 2: Use a single support method to support the TBM gripper on the tunnel surrounding rock, then start the TBM machine to excavate the tunnel. At this time, the vacuum generating system and grouting machine are in the off state;

[0066] Step 3: Arrange multiple measuring points on the surrounding rock at different locations at the same depth of the tunnel, use a total station to monitor the displacement of each measuring point, and then calculate the average displacement rate of these measuring points v ;

[0067] Step 4: Based on the average displacement rate v Assess the degree of surrounding rock fragmentation to determine whether the surrounding rock is completely broken or has zonal cracking. If not, proceed to step 5. If so, start the grouting machine, which uses negative pressure to transport slurry to the grouting holes, completing the support grouting of the broken surrounding rock, and then proceed to step 5.

[0068] Step 5: Calculate the friction force F between the surrounding rock and the gripper to determine whether it is greater than the critical friction force. If so, continue construction. If not, start the vacuum generating system to allow the vacuum suction cup to adhere to the surrounding rock.

[0069] Step 6: Measure the displacement rate of the single-support TBM gripper and compare it with the theoretical displacement rate of the TBM gripper. If the TBM gripper displacement rate is less than or equal to the theoretical displacement rate, continue construction. If the TBM gripper displacement rate is greater than the theoretical displacement rate, use the front and rear TBM grippers to support the tunnel top and both side walls at multiple points, and then continue construction.

[0070] Example 5

[0071] A TBM multi-gripper control method adapted to changes in the state of broken surrounding rock includes the following steps:

[0072] Step 1: Install a vacuum cup body on the TBM gripper working surface. The vacuum cup body has multiple vacuum nozzles in the middle, and grouting holes are opened on the side of the vacuum cup body. The vacuum nozzles are connected to the vacuum generation system, and the grouting holes are connected to the grouting machine through the grouting pipe.

[0073] The vacuum suction cup body is arc-shaped and fits well with the working surface of the gripper shoe. A porous rubber striped adhesive pad is applied to the surface of the vacuum suction cup body. The holes of the porous rubber striped adhesive pad correspond one-to-one with the vacuum suction nozzle on the vacuum suction cup body. The porous rubber striped adhesive pad has good elasticity and can fill the tiny gap between the suction cup and the surface of the adsorbed object. When the suction cup fits the object, the porous rubber striped adhesive pad deforms under the action of pressure and fits tightly to the unevenness of the object's surface, effectively preventing air leakage and allowing the vacuum system to work normally.

[0074] The first, second, and third vibrating screens and a storage bin are installed in sequence at the output end of the TBM's belt conveyor. A storage bucket is placed at the bottom of each vibrating screen. The first vibrating screen is used to screen small-sized rocks with a particle size less than 0.0625mm, the second vibrating screen is used to screen medium-sized rocks with a particle size between 0.0625mm and 2mm, and the third vibrating screen is used to screen coarse-sized rocks with a particle size between 2mm and 20mm. The storage bin is used to receive crushed rocks with a particle size greater than 20mm. When preparing the slurry, the rocks in the storage bin are directly used for slurry preparation, achieving the purpose of rationally recycling and utilizing the crushed rocks.

[0075] Step 2: Use a single support method to support the TBM gripper on the tunnel surrounding rock, then start the TBM machine to excavate the tunnel. At this time, the vacuum generating system and grouting machine are in the off state;

[0076] Step 3: Arrange multiple measuring points on the surrounding rock at different locations at the same depth of the tunnel, use a total station to monitor the displacement of each measuring point, and then calculate the average displacement rate of these measuring points v ;

[0077] Step 4: Based on the average displacement rate v Assess the degree of surrounding rock fragmentation to determine whether the surrounding rock is completely broken or has zonal cracking. If not, proceed to step 5. If so, start the grouting machine, which uses negative pressure to transport slurry to the grouting holes, completing the support grouting of the broken surrounding rock, and then proceed to step 5.

[0078] Step 5: Calculate the friction force F between the surrounding rock and the gripper. The calculation process is as follows:

[0079]

[0080]

[0081] Where μ is the coefficient of kinetic friction, F n is the normal pressure on the gripper surface, P is the critical friction force, E is the elastic modulus, I is the contact surface area between the gripper and the surrounding rock, and L is the length from the contact surface between the gripper and the surrounding rock to the end of the compression rod.

[0082] Determine whether the friction force F between the surrounding rock and the gripper is greater than the critical friction force. If so, continue construction. If not, start the vacuum generation system to make the vacuum suction cup adhere to the surrounding rock.

[0083] Step 6: Measure the displacement rate of the single-support TBM gripper and compare it with the theoretical displacement rate of the TBM gripper. If the TBM gripper displacement rate is less than or equal to the theoretical displacement rate, continue construction. If the TBM gripper displacement rate is greater than the theoretical displacement rate, use a three-point force method to support the front and rear TBM grippers on the tunnel top and both side walls, and then continue construction.

[0084] Example 6

[0085] A TBM multi-gripper control method adapted to changes in the state of broken surrounding rock includes the following steps:

[0086] Step 1: Install a vacuum cup body on the working surface of the TBM gripper. The vacuum cup body has multiple vacuum nozzles in the middle and grouting holes on the sides. The grouting holes are located on opposite sides of the TBM gripper. The vacuum nozzles are connected to a vacuum generating system. The grouting holes are connected to the grouting machine through grouting pipes.

[0087] The vacuum suction cup body is arc-shaped and fits well with the working surface of the gripper shoe. A porous rubber striped adhesive pad is applied to the surface of the vacuum suction cup body. The holes of the porous rubber striped adhesive pad correspond one-to-one with the vacuum suction nozzle on the vacuum suction cup body. The porous rubber striped adhesive pad has good elasticity and can fill the tiny gap between the suction cup and the surface of the adsorbed object. When the suction cup fits the object, the porous rubber striped adhesive pad deforms under the action of pressure and fits tightly to the unevenness of the object's surface, effectively preventing air leakage and allowing the vacuum system to work normally.

[0088] The first, second, and third vibrating screens and a storage bin are installed in sequence at the output end of the TBM's belt conveyor. A storage bucket is placed at the bottom of each vibrating screen. The first vibrating screen is used to screen small-sized rocks with a particle size less than 0.0625mm, the second vibrating screen is used to screen medium-sized rocks with a particle size between 0.0625mm and 2mm, and the third vibrating screen is used to screen coarse-sized rocks with a particle size between 2mm and 20mm. The storage bin is used to receive crushed rocks with a particle size greater than 20mm. When preparing the slurry, the rocks in the storage bin are directly used for slurry preparation, achieving the purpose of rationally recycling and utilizing the crushed rocks.

[0089] Step 2: Use a single support method to support the TBM gripper on the tunnel surrounding rock, then start the TBM machine to excavate the tunnel. At this time, the vacuum generating system and grouting machine are in the off state;

[0090] Step 3: Arrange multiple measuring points on the surrounding rock at different locations at the same depth of the tunnel, use a total station to monitor the displacement of each measuring point, and then calculate the average displacement rate of these measuring points v ;

[0091] Step 4: Based on the average displacement rate v Assess the degree of surrounding rock fragmentation when the average displacement rate v When ≤0.1mm / d, it indicates that the surrounding rock is in a stable and complete state. When 0.1mm / d< v When ≤0.15mm / d, it indicates that the surrounding rock is in a micro-fracture state. At this time, the monitoring frequency of the displacement of the measuring point should be increased. When 0.15mm / d<v When the deformation is less than 0.2 mm / d, it indicates that the surrounding rock is in a state of rapid deformation. At this time, the slurry needs to be prepared and the surrounding rock needs to be grouting supported at any time. v When it is greater than 0.20 mm / d, it indicates that the surrounding rock is in a completely broken state.

[0092] The slurry is a quick-setting slurry, which is composed of a mixture of water, cement, quick-setting agent and rocks in a storage barrel, and can solidify in a short time.

[0093] When the displacement rate difference between different measuring points exceeds 0.10 mm / d, and v When ≤0.20mm / d, it indicates that the surrounding rock has zonal cracking phenomenon.

[0094] Determine whether the surrounding rock is completely broken or has zonal cracking. If not, proceed to step 5. If so, start the grouting machine, which quickly delivers slurry to the grouting hole through negative pressure, completing the support grouting of the broken surrounding rock around the grouting hole, effectively avoiding the aggravation of local surrounding rock crushing and uneven force between the support shoe and the surrounding rock, thereby improving the stability of the support shoe, and then proceed to step 5.

[0095] Step 5: Calculate the friction force F between the surrounding rock and the gripper. The calculation process is as follows:

[0096]

[0097]

[0098] Where μ is the coefficient of kinetic friction, F n is the normal pressure on the gripper surface, P is the critical friction force, E is the elastic modulus, I is the contact surface area between the gripper and the surrounding rock, and L is the length from the contact surface between the gripper and the surrounding rock to the end of the compression rod.

[0099] Determine whether the friction force F between the surrounding rock and the gripper is greater than the critical friction force. If so, continue construction. If not, start the vacuum generation system to make the vacuum suction cup adhere to the surrounding rock.

[0100] Step 6: Measure the displacement rate of the single-support TBM gripper and compare it with the theoretical displacement rate of the TBM gripper. If the displacement rate of the TBM gripper is less than or equal to the theoretical displacement rate, continue construction. If the displacement rate of the TBM gripper is greater than the theoretical displacement rate, use the front and rear TBM grippers to support the tunnel roof and both side walls in a four-point load-bearing manner and continue construction. Figure 5 The two front grippers are supported on the top and side wall of the right side of the tunnel, and the two rear grippers are supported on the top and side wall of the left side of the tunnel, thereby increasing the holding force and improving the excavation efficiency of the tunnel boring machine in broken surrounding rock.

Claims

1. A TBM multi-gripper control method that adapts to changes in the state of broken surrounding rock, characterized by: The following steps are involved: Step 1: Install a vacuum suction cup body (2) on the working surface of the TBM support shoe (1), wherein a plurality of vacuum suction nozzles (3) are provided in the middle of the vacuum suction cup body (2), a grouting hole (4) is provided on the side of the vacuum suction cup body (2), the vacuum suction nozzle (3) is connected to a vacuum generating system, and the grouting hole (4) is connected to a grouting machine (6); Step 2: support the TBM support shoe (1) on the tunnel surrounding rock using a single support method, then start the TBM machine to excavate the tunnel, while the vacuum generating system and the grouting machine are in a closed state; Step 3: Arrange measuring points on the surrounding rock and monitor the displacement rate of the measuring points; Step 4, assessing the degree of surrounding rock fragmentation based on the displacement rate of the measuring point, and determining whether the surrounding rock is in a completely broken state or whether there is a partitioned cracking phenomenon. If not, proceed to step 5. If so, start the grouting machine (6), which transports the slurry to the grouting hole (4) to support and grout the broken surrounding rock, and then proceed to step 5. Step 5: Calculate the friction force F between the surrounding rock and the gripper to determine whether it is greater than the critical friction force. If so, continue construction. If not, start the vacuum generating system to allow the vacuum suction cup to adhere to the surrounding rock. Step 6: Measure the displacement rate of the single-support gripper and compare it with the theoretical displacement rate of the TBM gripper. If the gripper displacement rate is less than or equal to the theoretical displacement rate, continue construction. If the gripper displacement rate is greater than the theoretical displacement rate, use a multi-point force method with front and rear grippers to support the tunnel top and both side walls, and then continue construction.

2. The TBM multi-gripper control method adapted to the change of the broken surrounding rock state according to claim 1 is characterized in that: The grouting hole is connected to the discharge port of the grouting machine through a grouting pipe, and the slurry is transported to the grouting hole by negative pressure to complete the support grouting of the broken surrounding rock.

3. The TBM multi-gripper control method adapted to the change of the broken surrounding rock state according to claim 1 is characterized in that: Step 3 includes arranging multiple measuring points on the surrounding rock at different positions at the same depth of the tunnel, monitoring the displacement of each measuring point using a total station, and then calculating the average displacement rate of these measuring points. v .

4. The TBM multi-gripper control method adapted to the change of the broken surrounding rock state according to claim 1 is characterized in that: When the average displacement rate of the measuring point v When ≤0.1mm / d, it indicates that the surrounding rock is in a stable and complete state. When 0.1mm / d< v When ≤0.15mm / d, it indicates that the surrounding rock is in a micro-fracture state. At this time, the monitoring frequency of the displacement of the measuring point should be increased. When 0.15mm / d< v When the deformation is less than 0.2 mm / d, it indicates that the surrounding rock is in a state of rapid deformation. At this time, the slurry needs to be prepared and the surrounding rock needs to be grouting supported at any time. v When it is greater than 0.20 mm / d, it indicates that the surrounding rock is in a completely broken state.

5. The TBM multi-gripper control method adapted to the change of the state of the broken surrounding rock according to claim 4 is characterized in that: When the displacement rate difference between different measuring points exceeds 0.10 mm / d, and v When ≤0.20mm / d, it indicates that the surrounding rock has zonal cracking phenomenon.

6. The TBM multi-gripper control method adapted to the change of the broken surrounding rock state according to claim 5 is characterized in that: The first vibrating screen, second vibrating screen, third vibrating screen and storage bin are installed in sequence at the output end of the TBM belt conveyor. A storage bucket is placed at the bottom of each vibrating screen. The first vibrating screen is used to screen small-grained rocks with a particle size less than 0.0625mm, the second vibrating screen is used to screen medium-grained rocks with a particle size between 0.0625mm and 2mm, and the third vibrating screen is used to screen coarse-grained rocks with a particle size between 2mm and 20mm. The storage bin is used to receive crushed stones with a particle size greater than 20mm. When preparing the slurry, the rocks in the storage bucket are directly used for slurry preparation.

7. The TBM multi-gripper control method adapted to the change of the broken surrounding rock state according to claim 1 or 6, characterized in that: The grouting machine transports the slurry to the grouting hole. The slurry is a quick-setting slurry containing a quick-setting agent.

8. The TBM multi-gripper control method adapted to the change of the broken surrounding rock state according to claim 1 is characterized in that: In step 5, the friction force F between the surrounding rock and the gripper is calculated. The calculation process is as follows: Where μ is the coefficient of kinetic friction, F n is the normal pressure on the gripper surface, P is the critical friction force, E is the elastic modulus, I is the contact surface area between the gripper and the surrounding rock, and L is the length from the contact surface between the gripper and the surrounding rock to the end of the compression rod.

9. The TBM multi-gripper control method adapted to the change of the broken surrounding rock state according to claim 1 is characterized in that: The vacuum suction cup body is arc-shaped and fits the working surface of the support shoe. A porous rubber striped adhesive pad is applied to the surface of the vacuum suction cup body. The holes of the porous rubber striped adhesive pad correspond one-to-one to the vacuum suction nozzles on the vacuum suction cup body.

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