A method for full-section rock-breaking excavation in inclined shafts with weakly cemented rock formations

Abstract

The present invention provides a method for full-section rock-breaking excavation in an inclined shaft in a weakly cemented rock formation, which relates to the field of tunneling engineering. The method for full-section rock-breaking excavation in an inclined shaft in a weakly cemented rock formation includes the following steps: S1, starting the hydraulic cylinder to slowly advance the cutterhead of an open large-section tunnel boring machine close to the face of the tunnel, and after the cutterhead is completely in contact with the rock surface, increasing the thrust of the hydraulic cylinder to perform tunneling operations, and simultaneously starting surrounding rock support, rail laying, slag cleaning, and wind, water, and electricity extension operations during tunneling of the open large-section tunnel boring machine. By increasing the contact area between the support shoe and the surrounding rock, sufficient support reaction force is provided for the horizontal support system, and by expanding and excavating on both sides of the shield to form a pilot hole and grouting the bottom of the main machine to reinforce it, the problem of head-diving when the open large-section tunnel boring machine is excavating in a weakly cemented rock formation is solved. By increasing the excavation volume of the open large-section tunnel boring machine, the gap between the main machine shield and the surrounding rock is increased, thereby preventing the occurrence of machine jamming accidents.

Description

Technical Field

[0001] The present invention relates to the field of tunneling engineering, and in particular to a method for full-section rock breaking during tunneling of an inclined shaft in a weakly cemented rock stratum. Background Art

[0002] Due to the special diagenetic environment and sedimentary process, a type of weakly cemented soft rock formation with a low degree of cementation, such as the Mesozoic Jurassic and Cretaceous systems, is widely distributed in western my country. Weakly cemented soft rock formations are a type of formation with poor mineral properties, short sedimentary age, poor cementation, low strength, poor integrity, and mostly mud-cemented fillings. They are prone to cracks after being disturbed.

[0003] In the process of using an open large-section tunnel boring machine to construct weakly cemented rock strata, due to the poor density and integrity of the weakly cemented rock strata, there is a possibility of large deformation of the weakly cemented soft rock tunnel. At the same time, the weakly cemented rock strata may not be able to provide sufficient propulsion support reaction force for the horizontal support system. When the excavation speed needs to be reduced or the machine needs to be shut down due to various reasons, the rapid extrusion deformation of the surrounding rock may exceed the reserved deformation between the shield and the surrounding rock, and may even cause the shield to be strongly squeezed, resulting in a machine jam. At the same time, due to the soft characteristics of the rock strata, when the surrounding rock strength is low, it may not be enough to support the weight of the main machine of the open large-section tunnel boring machine, causing the cutterhead and the main machine to sink, resulting in the occurrence of head dive. Summary of the Invention

[0004] (1) Technical problems solved

[0005] In response to the shortcomings of the existing technology, the present invention provides a full-section rock breaking method for inclined shaft excavation in weakly cemented rock strata, which solves the problem that when an open large-section tunnel boring machine equipment is excavating in a weakly cemented rock stratum, the stratum cannot provide sufficient reaction force support, the surrounding rock deformation is large, causing the shield to be stuck, and the cutter head and main machine position of the open large-section tunnel boring machine sink, causing the head to fall.

[0006] (2) Technical solution

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions: A method for full-section rock breaking by inclined shaft excavation in weakly cemented rock formations, comprising the following method steps:

[0008] S1. Start the hydraulic cylinder to slowly advance the cutterhead of the open large-section TBM toward the tunnel face. After the cutterhead is completely in contact with the rock face, increase the thrust of the hydraulic cylinder to start the tunneling operation. During the tunneling operation of the open large-section TBM, anchor support, shotcrete, rail laying, slag removal, and wind, water, and electricity extension operations are simultaneously carried out.

[0009] S2. When the open - type large - section tunneling machine is tunneling in the weakly cemented rock stratum, first determine the data of the surrounding rock deformation. Then, appropriately increase the excavation amount of the open - type large - section tunneling machine to increase the gap between the shield and the surrounding rock, so that the main machine can tunnel smoothly. At the same time, timely master the geological conditions in front of the working face through geological advanced detection and forecasting;

[0010] S3. After the tunneling process is completed, stop the propulsion and make the cutter head retreat 3 - 5 cm. Stop the cutter head water spraying, drive motor, and cutter head rotation in sequence according to the positive order;

[0011] S4. Determine that the auxiliary construction for tunneling is completed and meets the requirements for continuing tunneling, and prepare to start the next tunneling process. The footage per cycle is 440 mm - 460 mm.

[0012] According to an embodiment of the present application, in the step S1, a laser guiding device is used to guide the open - type large - section tunneling machine to track and control the tunnel axis, and the operator adjusts the tunneling direction of the open - type large - section tunneling machine according to the guiding system data and guiding measures for direction adjustment.

[0013] According to an embodiment of the present application, in the step S2, after the catheter grouting is completed, auxiliary reinforcement is carried out using a steel bar shed, I - shaped steel, or cast - in - place concrete structure.

[0014] According to an embodiment of the present application, in the step S2, when the open - type large - section tunneling machine does not carry out excavation, the gap value between the main machine and the surrounding rock is expressed as Smin, and when the open - type large - section tunneling machine carries out maximum excavation, the gap value is expressed as Smax. During the tunneling process in the weakly cemented rock stratum, the excavation or advance treatment of the open - type large - section tunneling machine follows the following principles:

[0015] a. When the deformation amount U is less than the general gap Smin, the open - type large - section tunneling machine does not need to carry out excavation;

[0016] b. When Smin < U < Smax, excavation needs to be carried out, and the excavation amount D > U - Smin; [[ID=SS]]

[0017] c. When U > Smax, excavation cannot meet the requirements, and advance pilot - hole excavation measures are taken for treatment.

[0018] According to an embodiment of the present application, in the step S2, when the open - type large - section tunneling machine is tunneling in the weakly cemented rock stratum, the pressure of the hydraulic cylinder is increased from 9 - 12 MPa to 18 - 20 MPa.[[ID=SS]]

[0019] According to an embodiment of the present application, in the step S2, when the open - type large - section tunneling machine has a nose - diving phenomenon, pilot - holes are excavated on both sides of the shield to grout and reinforce the bottom of the main machine position.

[0020] (III) Beneficial effects

[0021] The present invention provides a method for full-section rock-breaking by digging an inclined shaft in a weakly cemented rock formation. It has the following beneficial effects:

[0022] 1. The present invention strengthens the support structure of the support shoe by increasing the contact area between the support shoe and the surrounding rock and using a conduit grouting method to reinforce the stratum near the support shoe. It also uses steel bar racks, I-beams or cast-in-place concrete structures for auxiliary reinforcement, providing sufficient propulsion support reaction force for open large-section tunnel boring machine equipment in weakly cemented rock formations.

[0023] 2. The present invention increases the gap between the main machine shield and the surrounding rock by appropriately increasing the excavation volume of the open large-section tunnel boring machine in weakly cemented strata. On the one hand, it can enable the main machine to advance smoothly and prevent machine jamming accidents. On the other hand, it also provides good conditions for the subsequent installation of pipe segments and surrounding rock reinforcement.

[0024] 3. The present invention timely grasps the geological conditions in front of the working face through geological advance detection and forecasting. At the same time, it adopts the method of expanding and excavating pilot holes on both sides of the shield body and grouting reinforcement on the bottom of the main machine position. This solves the problem that when an open large-section tunnel boring machine is excavating in a weakly cemented rock layer, the cutterhead and the main machine position may sink due to the low strength of the surrounding rock, causing the head to fall. DETAILED DESCRIPTION

[0025] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] Example 1:

[0027] A method for full-section rock breaking by digging an inclined shaft in a weakly cemented rock formation, comprising the following steps:

[0028] S1. Start the hydraulic cylinder to slowly push the cutterhead of the open large-section TBM closer to the face. After the cutterhead is completely in contact with the rock surface, increase the thrust of the hydraulic cylinder to start the tunneling operation. During the tunneling of the open large-section TBM, surrounding rock support, rail laying, slag removal, wind and water extension operations are started simultaneously. In this step, the surrounding rock support process adopts the form of "one-button drilling and anchoring + automatic spray mixing", which is specifically manifested as follows: the anchor drilling rig system is divided into two blocks. The first drilling rig block has two drilling rigs, which are arranged on both sides of the main beam of the equipment. Each drilling rig is independently controlled by a control handle, while the second drilling rig block is equipped with four drilling rigs, which are located at the rear of the rear support of the equipment. The concrete spraying system is installed on the spray-mixing bridge to realize the synchronous concrete spraying support with the tunneling of the open large-section TBM, 55 meters away from the cutterhead face. m, the nozzle is 0.9m away from the tunnel wall, and a remote-controlled automatic spray-mixing method is adopted. The sensors installed on each joint of the open large-section tunnel boring machine spray-mixing equipment and the kinematic modeling technology are used to obtain the spatial position information of the terminal torch in real time. At the same time, the kinematic joint space trajectory planning technology is used to enable the open large-section tunnel boring machine spray-mixing equipment to automatically complete the motion trajectory planning according to the set working trajectory limit conditions, and control the corresponding joint movements to automatically complete the concrete spraying construction, so that the concrete completely covers the surface to be sprayed and reaches 15 cm shotcrete thickness improves the supporting effect of surrounding rock. After the surrounding rock support is completed, steel rails are laid to facilitate the transportation of subsequent equipment and materials. The slag generated during the excavation process is mainly discharged through the belt conveyor system. The receiving end of the continuous belt conveyor is installed on the rear of the open large-section tunnel boring machine, and the unloading end is located at the intersection of the main tunnel and the ground. The continuous belt conveyor is transferred, and the slag is transported to the temporary waste dump at the tunnel entrance by the continuous belt conveyor, and then transported to the permanent waste dump by dump trucks for treatment. The ventilation, water and electricity extension operation steps are mainly to extend the ventilation system, water source and power system through the connection of pipeline lines. During the extension process, attention should be paid to the sealing of the connection and the protection of the line. The wrapping and elevation methods can be used to reduce the wear of the equipment;

[0029] S2. When an open-type large-section TBM is excavating in weakly cemented rock formations, the surrounding rock deformation data must be determined first. The surrounding rock deformation during tunneling is generally calculated based on the parameters affecting the radial displacement of the tunnel wall, time effect, and spatial effect. Surveying technicians conduct safety monitoring and data statistics every three hours, examining the cumulative displacement data, deformation rate, and stability of the surrounding rock deformation, and gaining real-time understanding of surrounding rock changes. Based on the data obtained, the excavation volume of the open-type large-section TBM is appropriately increased to increase the gap between the shield and the surrounding rock, allowing the main machine to advance smoothly. At the same time, geological advance detection and forecasting are used to timely understand the geological conditions ahead of the working face. Detection methods include advance drilling and geophysical methods. Given the characteristics of weakly cemented rock formations, geophysical methods, which have little impact on excavation work and will not damage the geology, can be selected as the main forecasting method. Specific implementation methods include electromagnetic waves and infrared detection, which are more effective.

[0030] S3. After the tunneling stroke ends, stop the propulsion and retract the cutter head by 3 cm. Stop the cutter head water spraying, the drive motor, and the cutter head rotation in sequence.

[0031] S4. Determine that the auxiliary construction for tunneling is completed and meets the requirements for continuous tunneling. Prepare to start the next tunneling stroke. The footage per cycle is 450 mm. For the first cycle of tunneling with newly installed cutters, it is necessary to stop the machine to check the operation of the cutters. If normal, check the cutter wear every four cycles to ensure the normal progress of subsequent tunneling work.

[0032] In step S1, use a laser guiding device to guide the open - type large - section tunneling machine to track and control the tunnel axis. The operator adjusts the tunneling direction of the open - type large - section tunneling machine according to the guiding system data and the guiding measures for direction adjustment. In this step, by irradiating the laser beam on a special electronic target placed inside the shield, measure the positional relationship between the laser beam and the target, then calculate the attitude of the shield machine, and then transmit the data information to the operation terminal. During the equipment tunneling process, the operator needs to timely master the attitude change data of the shield, and then adjust the tunneling direction of the open - type large - section tunneling machine according to the obtained data, so as to improve the accuracy of controlling the tunnel axis.

[0033] In step S2, after the catheter grouting is completed, use steel bar bents, I - shaped steel, or cast - in - place concrete structures for auxiliary reinforcement to further enhance the support stability of the horizontal support system.

[0034] In step S2, when the open - type large - section tunneling machine does not carry out excavation enlargement, the clearance value between the main machine and the surrounding rock is expressed as Smin, and when the open - type large - section tunneling machine carries out maximum excavation enlargement, the clearance value is expressed as Smax. During the tunneling process in weakly cemented rock formations, the excavation enlargement or advance treatment of the open - type large - section tunneling machine follows the following principles:

[0035] a. When the deformation amount U is less than the general clearance Smin, the open - type large - section tunneling machine does not need to carry out excavation enlargement.

[0036] b. When Smin < U < Smax, excavation enlargement is required, and the excavation enlargement amount D > U - Smin.

[0037] c. When U > Smax, excavation enlargement cannot meet the requirements, and adopt the measure of advance pilot - tunnel excavation enlargement for treatment.

[0038] In step S2, when the open - type large - section tunneling machine tunnels in weakly cemented rock formations, the pressure of the hydraulic cylinder is increased from 9 MPa to 18 MPa. By appropriately increasing the pressure of the propulsion hydraulic cylinder, the open - type large - section tunneling machine can quickly pass through the weakly cemented rock formation.

[0039] In step S2, when the open-type large-section tunnel boring machine plunges, pilot holes are excavated on both sides of the shield body, and grouting is performed to reinforce the bottom of the main machine.

[0040] In weakly cemented strata, this solution increases the excavation volume of the open large-section tunnel boring machine, thereby increasing the gap between the main machine shield and the surrounding rock. This allows the main machine to advance smoothly and prevents machine jams. It also provides good conditions for subsequent segment installation and surrounding rock reinforcement.

[0041] Example 2:

[0042] A method for full-section rock breaking by digging an inclined shaft in a weakly cemented rock formation, comprising the following steps:

[0043] S1. Start the hydraulic cylinder to slowly push the cutter head of the open large-section tunnel boring machine close to the tunnel face. After the cutter head is completely in contact with the rock surface, increase the thrust of the hydraulic cylinder to carry out tunneling operations. During the tunneling of the open large-section tunnel boring machine, surrounding rock support, rail laying, slag removal, wind, water and electricity extension operations are started simultaneously. In this step, the surrounding rock support process adopts the form of "one-button drilling and anchoring + automatic spray mixing", which is specifically manifested as follows: the anchor drilling rig system is divided into two blocks. The first drilling rig block has two drilling rigs, which are arranged on both sides of the main beam of the equipment. Each drilling rig is independently controlled by a control handle, while the second drilling rig block is equipped with four drilling rigs, which are located at the rear of the rear support of the equipment. Concrete spraying The system is installed on the spray-mix bridge to realize the synchronous concrete spraying support with the excavation of the open large-section roadheader. It is 58m away from the cutter head face and 0.7m away from the tunnel wall. It adopts the remote control automatic spray-mixing method. The sensors installed on each joint of the open large-section roadheader spray-mixing equipment and the kinematic modeling technology are used to obtain the spatial position information of the terminal torch in real time. At the same time, the kinematic joint space trajectory planning technology is used to enable the open large-section roadheader spray-mixing equipment to automatically complete the motion trajectory planning according to the set working trajectory limit conditions, and control the corresponding joint movements to automatically complete the concrete spraying construction, so that the concrete completely covers the surface to be sprayed and reaches 18 cm shotcrete thickness improves the supporting effect of surrounding rock. After the surrounding rock support is completed, steel rails are laid to facilitate the transportation of subsequent equipment and materials. The slag generated during the excavation process is mainly discharged through the belt conveyor system. The receiving end of the continuous belt conveyor is installed on the rear of the open large-section tunnel boring machine, and the unloading end is located at the intersection of the main tunnel and the ground. The continuous belt conveyor is transferred, and the slag is transported to the temporary waste dump at the tunnel entrance by the continuous belt conveyor, and then transported to the permanent waste dump by dump trucks for treatment. The ventilation, water and electricity extension operation steps are mainly to extend the ventilation system, water source and power system through the connection of pipeline lines. During the extension process, attention should be paid to the sealing of the connection and the protection of the line. The wrapping and elevation methods can be used to reduce the wear of the equipment;

[0044] S2. When an open-type large-section TBM is excavating in weakly cemented rock formations, the surrounding rock deformation data must be determined first. The surrounding rock deformation during tunneling is generally calculated based on the parameters affecting the radial displacement of the tunnel wall, time effect, and spatial effect. Surveying technicians conduct safety monitoring and data statistics every 4 hours, examining the cumulative displacement data, deformation rate, and stability of the surrounding rock deformation, and gaining real-time understanding of surrounding rock changes. Based on the data obtained, the excavation volume of the open-type large-section TBM is appropriately increased to increase the gap between the shield and the surrounding rock, allowing the main machine to advance smoothly. At the same time, geological advance detection and forecasting are used to timely understand the geological conditions ahead of the working face. Detection methods include advance drilling and geophysical methods. Given the characteristics of weakly cemented rock formations, geophysical methods, which have little impact on excavation work and will not damage the geology, can be selected as the main forecasting method. Specific implementation methods include electromagnetic waves and infrared detection, which are more effective.

[0045] S3. After the excavation process is completed, the advancement is stopped and the cutterhead is retreated 5 cm. The water spraying, drive motor and cutterhead rotation are stopped in the correct order.

[0046] S4. Confirm that the auxiliary construction of excavation is completed and meets the needs of continuing excavation, and prepare to start the next excavation process. The advance per cycle is 460mm. For the first cycle of excavation with a newly installed tool, it is necessary to stop the machine to check the operation of the tool. If it is normal, check the tool wear every four cycles to ensure the normal progress of subsequent excavation work.

[0047] In step S1, a laser guidance device is used to guide the open large-section tunnel boring machine to track and control the tunnel axis. The operator adjusts the excavation direction of the open large-section tunnel boring machine according to the guidance system data and guidance and adjustment measures. In this step, the laser beam is irradiated on a special electronic target placed in the shield to measure the position relationship between the laser beam and the target, and then the shield machine posture is calculated, and then the data information is transmitted to the operation end. During the excavation process of the equipment, the operator needs to timely grasp the shield posture change data, and then adjust the excavation direction of the open large-section tunnel boring machine according to the obtained data, thereby improving the accuracy of controlling the tunnel axis.

[0048] In step S2, after the grouting of the conduit is completed, auxiliary reinforcement is carried out using steel bar racks, I-beams or cast-in-place concrete structures to further enhance the support stability of the horizontal support system.

[0049] In step S2, when the open large-section roadheader is not expanding, the clearance value between the main machine and the surrounding rock is expressed as Smin. When the open large-section roadheader is expanding to the maximum extent, the clearance value is expressed as Smax. During the excavation process of weakly cemented rock formations, the expansion or advance processing of the open large-section roadheader shall follow the following principles:

[0050] a. When the deformation amount U is less than the general clearance Smin, the open - type large - section tunneling machine does not need to expand the excavation.

[0051] b. When Smin < U < Smax, excavation expansion is required, and the expansion amount D > U - Smin.

[0052] c. When U > Smax, the excavation expansion cannot meet the requirements, and advanced pilot - tunnel excavation measures are taken for treatment.

[0053] In step S2, when the open - type large - section tunneling machine is tunneling in the weakly cemented rock stratum, the pressure of the hydraulic cylinder is increased from 12 MPa to 20 MPa. By appropriately increasing the pressure of the propulsion hydraulic cylinder, the open - type large - section tunneling machine can quickly pass through the weakly cemented rock stratum.

[0054] In step S2, after the open - type large - section tunneling machine has a nose - diving phenomenon, pilot - tunnels are excavated on both sides of the shield body, and grouting reinforcement is carried out at the bottom of the main machine position.

[0055] For the construction of the weakly cemented large - deformation tunnel section, it is necessary to pay attention to the coordinated control of the tunneling speed and the support speed of the open - type large - section tunneling machine. Within the allowable deformation amount of the shield body retraction, the construction speed is increased to enable the open - type large - section tunneling machine to pass through as soon as possible, ensuring construction safety and rock - breaking efficiency.

[0056] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for full-section rock-breaking by inclined shaft excavation in weakly cemented rock formations, characterized by: It includes the following method steps: S1. Start the hydraulic cylinder to slowly push the cutter head of the open large-section tunneling machine close to the tunnel face. After the cutter head is completely fitted to the rock face, increase the thrust of the hydraulic cylinder for tunneling operations. During the tunneling of the open large-section tunneling machine, simultaneously start the surrounding rock support, rail laying, slag cleaning, and extension operations of the wind, water, and electricity; S2. When the open large-section tunneling machine tunnels in the weakly cemented rock formation, first determine the data of the surrounding rock deformation amount, and then appropriately increase the excavation amount of the open large-section tunneling machine to increase the gap between the shield and the surrounding rock, so that the main machine can tunnel smoothly. At the same time, timely master the geological conditions in front of the working face through geological advanced detection and forecasting; S3. After the tunneling process is completed, stop the propulsion and make the cutter head retreat 3 - 5 cm. Stop the cutter head water spraying, drive motor, and cutter head rotation in sequence; S4. Determine that the auxiliary construction of tunneling is completed and meets the requirements for continuous tunneling, and prepare to start the next tunneling process. The advance per cycle is 440 mm - 460 mm; In the step S1, use a laser guiding device to guide the open large-section tunneling machine to track and control the tunnel axis, and the operator adjusts the tunneling direction of the open large-section tunneling machine according to the data of the guiding system and the guiding measures for direction adjustment; In the step S2, after the duct grouting is completed, use a steel bar bent frame, I-shaped steel or cast-in-place concrete structure for auxiliary reinforcement; when the open large-section tunneling machine does not carry out excavation, the gap value between the main machine and the surrounding rock is expressed as Smin, and when the open large-section tunneling machine carries out maximum excavation, the gap value is expressed as Smax. During the tunneling process in the weakly cemented rock formation, the excavation or advance treatment of the open large-section tunneling machine follows the following principles: a. When the deformation amount U is less than the general gap Smin, the open large-section tunneling machine does not need to be excavated; b. When Smin < U < Smax, excavation is required, and the excavation amount D > U - Smin; c. When U > Smax, excavation cannot meet the requirements, and advance pilot tunnel excavation measures are taken for treatment; When the open large-section tunneling machine tunnels in the weakly cemented rock formation, the pressure of the hydraulic cylinder is increased from 9 - 12 MPa to 18 - 20 MPa; When the open large-section tunneling machine has a diving phenomenon, pilot tunnels are excavated on both sides of the shield to grout and reinforce the bottom of the main machine position.