Tunnel penetrating goose column type fault activation dislocation water inrush and mud inrush test system and method

Abstract

The invention discloses a system and a method for testing water inrush and mud inrush of activation dislocation of a tunnel penetrating a goose column type fault, belongs to the field of geotechnical engineering and geological disaster prevention and control, and is used for solving the problem that space linkage and activation processes of a goose column type fault group under engineering disturbance and a water inrush and mud inrush catastrophe mechanism of the goose column type fault group are difficult to truly simulate. The system comprises a test box body, a plurality of fault simulation devices which are arranged in a goose column manner, a cylindrical rigid body, a stress loading device, a water supply device, a collection device and a detection device, a geological structure is simulated by filling a fault and surrounding rock similar material; a digital hydraulic pump station is used for independently controlling multiple sets of rigid jacking, and a three-dimensional non-uniform stress field is applied; a high-pressure aquifer is simulated through controllable water supply; tunnel excavation disturbance is simulated by pulling the cylindrical rigid body; the whole process of sequential activation, dislocation penetration and water inrush and mud inrush induction of the wild goose column type fault under engineering disturbance can be reproduced, synchronous monitoring is performed by means of a sensor, and a reliable test means is provided for revealing the disaster forming mechanism and prevention and control of such disasters.

Description

A test system and method for detecting water and mud inrushes during tunneling through a goose-shaped fault activation fault. Technical Field

[0001] This invention belongs to the fields of geotechnical engineering and geological disaster prevention, and specifically relates to a test system and method for detecting water and mud inrushes caused by fault activation and displacement in tunnels crossing a goose-shaped fault. Background Technology

[0002] In crustal tectonic activity, en echelon fault groups, as a complex geological structural system, consist of multiple faults arranged in a goose-like formation. The en echelon arrangement refers to multiple faults obliquely staggered, forming a spatial layout resembling a flock of geese. Influenced by their unique geometric distribution and complex mechanical interaction mechanisms, under tectonic stress or engineering disturbances, the faults within the fault group often undergo sequential activation and displacement, thereby forming continuous water-conducting channels and inducing geological disasters such as water inrush and mudslides. These disasters are commonly found in tunnel excavation, coal mining, and other deep underground engineering projects, characterized by their suddenness and destructiveness, seriously threatening engineering safety and human lives.

[0003] Currently, experimental research methods for studying the dynamic evolution of such complex geological processes remain significantly insufficient. Traditional experimental setups generally employ uniaxial loading to simulate fault slippage, coupled with simplified seepage boundary conditions to approximate the water inrush process. While such methods can reflect the mechanical response of a single fault under load to some extent, they struggle to accurately reproduce the spatial correlation and sequential activation characteristics among faults in a convective fault group, thus limiting their ability to reveal the collaborative disaster-causing mechanisms of fault groups. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a test system and method for activating and displaced water and mud inrush in tunnels through goose-shaped faults, which is used to solve the problem that it is difficult to realistically simulate the spatial linkage, activation process and water and mud inrush disaster mechanism of goose-shaped fault groups under engineering disturbance in the prior art.

[0005] To achieve the above and other related objectives, this invention provides a test system for tunneling through a goose-shaped fault activation fault displacement water and mud inrush test system, comprising: a test chamber, multiple fault simulation devices, a cylindrical rigid body, a stress loading device, a water supply device, a collection device, and a detection device; the test chamber is enclosed by a bottom plate, a top plate, a left side plate, a right side plate, a front side plate, and a rear side plate, with an excavation simulation hole provided in the left side plate; multiple fault simulation devices are arranged in a goose-shaped pattern within the test chamber, and the intervals between the fault simulation devices and the left side plate, between two adjacent fault simulation devices, and between the fault simulation devices and the right side plate are used to fill the space with a rock-like material; each fault simulation device includes two spaced-apart clamping mechanisms, and the space between the two clamping mechanisms of the same fault simulation device is used to fill the space with a fault-like material; the cylindrical rigid body is removably installed in the excavation simulation hole and partially extends into the test chamber; the stress loading device includes a digital hydraulic pump station, multiple rigid jacks, and multiple side-mounted ball bearings. A pressure plate is formed by splicing rectangular plates; the joint between two adjacent rectangular plates corresponds to the bottom of the fault simulation device; some rigid jacks are set on the top plate, and other rigid jacks are set on the bottom plate, with the output end of each rigid jack set on the bottom plate connected to a rectangular plate; the water supply device includes a water tank, a water pump, a main water inlet pipe, multiple sub-water inlet pipes, multiple flow meters, and multiple water valves; the inlet of the water pump is connected to the water tank, and the outlet of the water pump is connected to the main water inlet pipe; multiple water inlets are set on the top plate, and at least one water inlet is set between two adjacent clamping plate mechanisms; one end of the sub-water inlet pipe is connected to the water inlet, and the other end is connected to the main water inlet pipe; each sub-water inlet pipe is equipped with a flow meter and a water valve; the collection device is connected to the excavation simulation hole; the detection device includes a pre-embedded strain sensor and a pore water pressure sensor embedded in the fault-similar material, an acoustic emission sensor set on the inner wall of the right side plate, and a high-speed camera device set corresponding to the excavation simulation hole.

[0006] Optionally, the clamping mechanism includes a first clamping plate, a second clamping plate, a first rotating column, a second rotating column, a first locking assembly, and a second locking assembly; the inner walls of the front and rear side plates are respectively provided with horizontally arranged first sliding grooves, and the two ends of the first rotating column are respectively slidably connected to the first sliding grooves; the first end of the first clamping plate and the first locking assembly are respectively rotatably connected to the first rotating column, and the first end of the first clamping plate abuts against the pressure plate; the second end of the first clamping plate is provided with a receiving cavity; the first end of the second clamping plate is slidably disposed in the receiving cavity, and the second end is rotatably connected to the second rotating column; the second rotating column is slidably connected to the top of the front and rear side plates; and the second locking assembly is connected to one end of the second rotating column.

[0007] Optionally, the first locking assembly includes a connector, a first adapter, and a first locking member. The connector is rotatably connected to the first rotating column. The lower side of the connector is used to abut against the upper side of the pressure plate. One end of the first adapter is fixedly connected to the connector, and the other end is provided with a U-shaped groove with its opening facing the pressure plate. The top of the rear side plate is slidably connected to the bottom of the U-shaped groove, and one side wall of the U-shaped groove is located outside the test chamber. A first threaded hole is provided on the side wall of the U-shaped groove extending outside the test chamber. The first locking member is threadedly connected to the first threaded hole, and one end of the locking member passes through the first threaded hole and abuts against the outer side wall of the rear side plate.

[0008] Optionally, the second locking assembly includes an abutment, a second adapter, and a second locking member; a second sliding groove is provided on the outer side wall of the front side plate, and the second sliding groove is parallel to the first sliding groove; the abutment is fixedly mounted on the second rotating column, and the abutment is used to abut against the inner side wall of the front side plate; the second adapter is connected to the second rotating column, and the second adapter is located outside the test chamber; a second threaded hole is provided on the second adapter, and the second locking member is threadedly connected to the second threaded hole, and one end of the second locking member passes through the second threaded hole and extends into the second sliding groove, and abuts against the bottom of the second sliding groove.

[0009] Optionally, the first clamping plate includes a first sub-clamping plate and a second sub-clamping plate. The first sub-clamping plate and the second sub-clamping plate are respectively provided with semi-circular grooves, and the two semi-circular grooves surround each other to form a clearance hole for the cylindrical rigid body to pass through.

[0010] Optionally, the cylindrical rigid body includes a first cylinder, a plurality of second cylinders and a third cylinder with the same diameter; a cylindrical segment is provided at the second end of the first cylinder and the second end of the second cylinder respectively; a receiving hole for connecting with the cylindrical segment is provided at the first end of the second cylinder and the first end of the third cylinder respectively.

[0011] Optionally, the clamping mechanism may also include a disc for sealing the clearance hole.

[0012] Optionally, the collection device includes a collection bucket and a guide channel, the guide channel being inclinedly disposed on the outer side wall of the left side plate and located below the excavation simulation hole; the collection bucket is located below the lower end of the guide channel.

[0013] Optionally, a multi-stage filter screen is detachably installed in the collection bucket along the vertical direction, with the mesh size of each filter screen decreasing from top to bottom.

[0014] On the other hand, the present invention also provides a test method for activating fault displacement and water / mud inrush in tunnels through a goose-shaped fault, including a test system for activating fault displacement and water / mud inrush in tunnels through a goose-shaped fault as described above, and further including: a test chamber preparation step: the left side plate, right side plate, front side plate and rear side plate are fixed to the bottom plate to form a test chamber; a similar material filling step: multiple fault simulation devices are arranged in a goose-shaped pattern in the test chamber, and a cylindrical rigid body is inserted into the test chamber through excavated simulation holes, and fault similar material and pre-embedded strain sensors and pore water pressure sensors are filled between the two clamping mechanisms of each fault simulation device; then the fault simulation device is removed from the test chamber, and surrounding rock similar material is filled between two adjacent fault similar materials, between the fault similar material and the left side plate, and between the fault similar material and the right side plate, and an acoustic emission sensor is set on the inner wall of the right side plate; finally, the top plate is connected to the front side plate, rear side plate, left side plate and right side plate.

[0015] The initial stress and hydraulic boundary condition application steps are as follows: Start the digital hydraulic pump station to independently control the rigid jacking on the bottom and top plates, apply a three-dimensional stress field to the model, and simulate the original ground stress in the engineering area; start the water supply device, and inject dyed water through the main inlet pipe and each sub-inlet pipe into the inlet above the fault-similar material column via the water pump; independently adjust the water pressure and flow rate injected into different fault sections through the flow meters and water valves on each sub-inlet pipe to simulate high-pressure aquifers; tunnel excavation and disaster process simulation steps: slowly extract the cylindrical rigid body at constant or variable speed to simulate the tunnel face advancement process, where strain sensors and pore water pressure sensors monitor the deformation and water pressure evolution of the fault in real time; acoustic emission sensor array captures rock micro-fracture signals to locate damage and determine the fault activation sequence; high-speed camera device fully records the crack propagation and disaster dynamics near the excavation face; collect the mixture of water and mud inrush using a collection device.

[0016] As described above, the tunnel-through-a-fault activation fault displacement water and mud inrush test system and method of the present invention has at least the following beneficial effects: 1. Improved realism and comprehensiveness of disaster simulation: The system integrates stress loading, high-pressure water injection, excavation disturbance, and multi-dimensional monitoring. Through an independently controlled water supply device, differential water pressure in different fault sections can be simulated; the extraction of the cylindrical rigid body enables progressive simulation of the tunnel excavation face. Simultaneously, strain and water pressure sensors, arrayed acoustic emission sensors, and high-speed cameras embedded in key locations constitute a three-dimensional monitoring network, capable of simultaneously capturing stress and strain within the fault, pore water pressure evolution, spatiotemporal location of micro-fractures, and macroscopic disaster morphology, providing a complete and accurate data chain for mechanism research.

[0017] 2. Realistic simulation of the entire activation process of a goose-fence group: Through a clamping mechanism with adjustable spacing and dip angle, the complex spatial geometry of a goose-fence group can be accurately constructed. Combined with the independent control of multiple rigid jacks by a digital hydraulic pump station, a non-uniform three-dimensional stress field that sequentially activates the faults can be simulated, thus realistically reproducing the chain activation and displacement process of the fault group from local slippage to overall connection, overcoming the limitation of traditional devices that can only simulate a single fault.

[0018] 3. High system integration, strong operability, and high reliability: This invention highly integrates complex geological structure simulation, loading, water supply, and monitoring systems. The ingeniously designed clamping mechanism facilitates easy assembly and disassembly, ensuring the accuracy and efficiency of model preparation. The bearing plates with ball bearings on the sides effectively reduce boundary friction, ensuring the authenticity of stress transfer. The multi-stage filter in the collection device can also perform particle classification of the water and mud mixture, facilitating subsequent physical property analysis. The entire system has a reasonable structure and good repeatability, providing an efficient and reliable experimental platform for in-depth research on the disaster mechanisms of tunnels crossing complex faults. Attached Figure Description

[0019] Figure 1 shows a schematic diagram of the overall structure of a tunnel-through-goose-fault activation fault displacement water and mud inrush test system according to the present invention.

[0020] Figure 2 shows a partial structural schematic diagram of the tunnel cross-goose-type fault activation fault displacement water and mud inrush test system of the present invention.

[0021] Figure 3 shows a partial structural schematic diagram of the tunnel cross-goose-fault activation fault displacement water and mud inrush test system of the present invention.

[0022] Figure 4 shows a partial structural schematic diagram of the tunnel cross-goose-type fault activation fault displacement water and mud inrush test system of the present invention.

[0023] Figure 5 shows a schematic diagram of the fault simulation device of the present invention.

[0024] Figure 6 shows an enlarged view of point A in Figure 2.

[0025] Figure 7 shows an enlarged view of point B in Figure 4.

[0026] Figure 8 shows an exploded view of a rigid cylindrical body.

[0027] Component labeling: 1. Test chamber body, 11. Base plate, 12. Top plate, 13. Left side plate, 131. Excavated simulated hole, 14. Right side plate, 15. Front side plate, 16. Rear side plate, 17. First slide groove, 18. Second slide groove; 2. Clamping mechanism, 21. First clamping plate, 211. Receiving cavity, 212. First sub-clamping plate, 213. Second sub-clamping plate, 214. Semi-circular groove, 22. Second clamping plate, 23. First rotating column, 24. Second rotating column, 25. First locking assembly, 251. Connecting piece, 252. First adapter piece, 2521. U-shaped groove, 253. First locking piece, 26. Second locking assembly, 261. Abutment 1. Connecting component, 262. Second adapter component, 263. Second locking component; 2. Cylindrical rigid body, 31. First cylinder, 32. Second cylinder, 33. Third cylinder, 34. Cylindrical section, 35. Receiving hole; 3. Stress loading device, 41. Digital hydraulic pump station, 42. Rigid lifting, 43. Rectangular plate, 44. Pressure plate; 4. Water supply device, 51. Water supply tank, 52. Water pump, 53. Main water inlet pipe, 54. Sub-water inlet pipe, 55. Flow meter, 56. Water valve; 6. Collection device, 61. Collection bucket, 62. Guide channel; 7. Detection device, 71. Embedded strain sensor, 72. Pore water pressure sensor, 73. Acoustic emission sensor. Detailed Implementation

[0028] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0029] Please refer to all the accompanying drawings below. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and are not intended to limit the scope of the invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed in this invention. Furthermore, the terms such as "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and are not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0030] The following embodiments are for illustrative purposes only. These embodiments can be combined and are not limited to the content shown in any single embodiment below.

[0031] Please refer to Figures 1-4. The front side plate is omitted in Figure 1, and the dashed lines in the figure represent the clamping plate mechanism. This invention provides a test system for water and mud inrush in tunnels through a goose-shaped fault activation and displacement, including a test chamber 1, multiple fault simulation devices, a cylindrical rigid body 3, a stress loading device 4, a water supply device 5, a collection device 6, and a detection device 7.

[0032] The test chamber 1 is formed by a bottom plate 11, a top plate 12, a left side plate 13, a right side plate 14, a front side plate 15, and a rear side plate 16. These plates are connected together by bolts to form the test chamber 1, which has a test cavity. A simulated excavation hole 131 is provided on the left side plate 13. The left side plate 13, front side plate 15, rear side plate 16, and right side plate 14 can be made of transparent materials, such as glass or acrylic.

[0033] Multiple fault simulation devices are arranged in a goose-like formation within the test chamber 1. The spaces between the fault simulation devices and the left side plate 13, between adjacent fault simulation devices, and between the fault simulation devices and the right side plate 14 are filled with surrounding rock similarity material. Each fault simulation device includes two spaced-apart clamping mechanisms 2, and the spaces between the two clamping mechanisms 2 of the same fault simulation device are filled with fault similarity material. Surrounding rock similarity material is a composite material artificially formulated based on similarity theory, used to simulate the physical and mechanical properties of the natural rock mass surrounding an engineering structure in physical model tests. Surrounding rock similarity material is typically composed of aggregates, binders, and modifiers mixed in specific proportions; by adjusting the proportions, different strength grades and deformation characteristics of the rock mass can be simulated. Fault similarity material is a special similarity material specifically used to simulate geological faults or large weak interlayers in physical models. Fault similarity materials commonly use clay (such as bentonite), talc powder, putty powder, silica gel, petroleum jelly, etc., in different proportions.

[0034] The cylindrical rigid body 3 is removably installed in the excavation simulation hole 131 and partially extends into the test chamber 1.

[0035] The stress loading device 4 includes a digital hydraulic pump station 41, multiple rigid jacks 42, and a pressure plate 44 composed of multiple rectangular plates 43 with ball bearings on their sides. Ball bearings on the sides of the rectangular plates 43 reduce friction between adjacent plates. The joint between two adjacent rectangular plates 43 corresponds to the bottom of the fault simulation device. Some rigid jacks 42 are mounted on the top plate 12, which are used to apply downward prestress to the surrounding rock-like material. Other rigid jacks 42 are mounted on the bottom plate 11, and the output end of each rigid jack 42 mounted on the bottom plate 11 is connected to a rectangular plate 43, which is used to apply controllable non-uniform stress to the fault simulation device and the surrounding rock-like material. The digital hydraulic pump station 41 is configured to independently control the loading pressure and loading sequence of each rigid jack 42.

[0036] The water supply device 5 includes a water supply tank 51, a water pump 52, a main inlet pipe 53, multiple sub-inlet pipes 54, multiple flow meters 55, and multiple water valves 56. The inlet of the water pump 52 is connected to the water supply tank 51, and the outlet of the water pump 52 is connected to the main inlet pipe 53. It is used to extract the dyed water from the water supply tank 51 and transmit it through the main inlet pipe 53 to the multiple sub-inlet pipes 54. Multiple inlets are provided on the top plate 12, with at least one inlet between two adjacent clamping mechanisms 2, i.e., at least one inlet is provided above the fault-like material. One end of each sub-inlet pipe 54 is connected to an inlet, and the other end is connected to the main inlet pipe 53. Each sub-inlet pipe 54 is equipped with a flow meter 55 and a water valve 56. In this embodiment, the presence of dyed water facilitates observation of the seepage path and allows for direct recording of the formation process of the fault water-conducting channel.

[0037] The collection device 6 is connected to the excavation simulation hole 131 and is used to collect the mixture of water and mud inrush.

[0038] The detection device 7 includes a pre-embedded strain sensor 71 and a pore water pressure sensor 72 embedded in a fault-like material, an acoustic emission sensor 73 set on the inner wall of the right side plate 14, and a high-speed camera device set corresponding to the excavation simulation hole 131.

[0039] Before the formal test, fault-simulating materials and surrounding rock-simulating materials were prepared according to the geological conditions of different en echelon faults. The left side plate 13, right side plate 14, front side plate 15, and rear side plate 16 were bolted to the base plate 11. Then, multiple fault simulation devices were placed on the base plate 11 in an en echelon pattern. After completing the above operations, fault-simulating materials were filled layer by layer and compacted between the two clamping mechanisms 2 of each fault simulation device to simulate an en echelon fault. During the filling process, strain sensors 71 and pore water pressure sensors 72 were pre-embedded at key locations within the fault-simulating materials. "Key locations" mainly refer to the areas where the fault is most likely to deform or fail first after engineering disturbance (excavation), or are most sensitive to changes in stress and water flow. The pre-embedded sensors at these locations aim to capture key data throughout the entire process of the fault from stabilization to activation, and finally to water inrush.

[0040] Next, the fault simulation devices are removed from the test chamber 1, and surrounding rock similar materials are filled into the spaces between each fault simulation device (fault-similar material) and between the fault simulation device (fault-similar material) and the side wall of the test chamber 1 to simulate the intact rock mass on both sides of the fault. Before filling with surrounding rock similar materials, the cylindrical rigid body 3 is inserted into the test chamber 1 through the excavated simulation hole 131, and acoustic emission sensors 73 are installed on the right side plate 14. There can be multiple acoustic emission sensors 73, which are arranged in a grid array on the inner side wall of the right side plate 14.

[0041] Then, the digital hydraulic pump station 41 is started, and a three-dimensional stress field is applied to the model by independently controlling the rigid lifting 42 on the bottom plate 11 and the top plate 12 to simulate the original rock stress in the engineering area. The ball bearings on the side of the pressure plate 44 can effectively reduce the friction between the plates, ensure that the stress is uniformly transmitted along the bottom of the preset fault and allow it to generate relative displacement.

[0042] Dyed water is injected from the water supply tank 51 into the inlet using water pump 52. The flow path is observed to see if it extends along a preset fault. The water pressure and flow rate injected into different fault sections are independently controlled by the flow meters 55 and water valves 56 on each branch to simulate a high-pressure aquifer. The detection device 7 is activated to verify the signal stability of the strain sensor, pore water pressure sensor 72, and acoustic emission sensor 73. The focal length and frame rate of the high-speed camera are adjusted to ensure clear capture of the fissure expansion and water / mud inrush dynamics at the moment of fault activation.

[0043] The tunnel face advancement process is then simulated by slowly extracting a cylindrical rigid body 3 from the simulated excavation hole 131 at a constant or variable speed. During this process, strain and pore water pressure sensors 72 monitor the deformation and pore water pressure evolution of the fault in real time.

[0044] The acoustic emission sensor array 73 captures micro-fracture signals in the rock mass to locate damage and determine the activation sequence.

[0045] High-speed camera equipment fully records the crack propagation and disaster dynamics near the excavation face.

[0046] When stress concentration exceeds the strength of materials similar to the fault, the fault undergoes activation and slippage, forming a continuous water-conducting channel, triggering a water and mud inrush disaster. The mixture of water and mud is collected by collection device 6. After the experiment, all monitoring data are comprehensively analyzed to study the disaster mechanism, providing theoretical basis and experimental support for disaster early warning and prevention in practical engineering.

[0047] Referring to Figures 1-7, in this embodiment, the clamping mechanism 2 includes a first clamping plate 21, a second clamping plate 22, a first rotating column 23, a second rotating column 24, a first locking assembly 25, and a second locking assembly 26. The inner walls of the front side plate 15 and the rear side plate 16 are respectively provided with horizontally arranged first sliding grooves 17, and both ends of the first rotating column 23 are slidably connected to the first sliding grooves 17. The first end of the first clamping plate 21 and the first locking assembly 25 are rotatably connected to the first rotating column 23. The first end of the first clamping plate 21 abuts against the pressure plate 44, and the first locking assembly 25 is used to restrict the sliding of the first rotating column 23 within the first sliding groove 17. The second end of the first clamping plate 21 is provided with a receiving cavity 211; the first end of the second clamping plate 22 is slidably disposed within the receiving cavity 211, and the second end is rotatably connected to the second rotating column 24. The second rotating column 24 is slidably connected to the top of the front side plate 15 and the rear side plate 16; the second locking assembly 26 is connected to one end of the second rotating column 24 and is used to fix the second rotating column 24 on the front side plate 15 or the rear side plate 16.

[0048] Specifically, the first locking assembly 25 includes a connector 251, a first adapter 252, and a first locking member 253. The first ends of the connector 251 and the first clamping plate 21 are respectively provided with through holes for the first rotating column 23 to pass through. After the first rotating column 23, the connector 251, and the first clamping plate 21 are connected together, they form a hinge structure. One end of the first adapter 252 is fixed to the connector 251 by welding or other means, and the other end is provided with a U-shaped groove 2521 with its opening facing the pressure plate 44. The top of the rear side plate 16 is slidably connected to the bottom of the U-shaped groove 2521, and one side wall of the U-shaped groove 2521 is located outside the test chamber 1. The U-shaped groove 2521 extends out of the side wall of the test chamber 1 and is provided with a first threaded hole. The first locking member 253 can be a screw, which is threadedly connected to the first threaded hole, and one end of it passes through the first threaded hole and abuts against the outer side wall of the rear side plate 16, thereby fixing the connecting member 251 to the pressure plate 44 to restrict the first rotating column 23 from sliding in the first slide groove 17.

[0049] The second locking assembly 26 includes an abutment 261, a second adapter 262, and a second locking member 263. A second slide groove 18, parallel to the first slide groove 17, is provided on the outer wall of the front side plate 15. The abutment 261 can be a disc-shaped structure, fixedly mounted on the second rotating column 24, and abuts against the inner wall of the front side plate 15. A through hole for the second rotating column 24 to pass through is provided on the second end of the second clamping plate 22. The second adapter 262 is connected to the second rotating column 24, specifically in a fixed connection, and is located outside the test chamber 1. A second threaded hole is provided on the second adapter 262. The second locking member 263 can be a screw, threadedly connected to the second threaded hole. One end of the second locking member 263 passes through the second threaded hole and extends into the second slide groove 18, abutting against the bottom of the second slide groove 18, thereby fixing the second rotating column 24 to the front side plate 15.

[0050] The first clamping plate 21 may include a first sub-clamping plate 212 and a second sub-clamping plate 213. The first sub-clamping plate 212 and the second sub-clamping plate 213 are respectively provided with semi-circular grooves 214. The two semi-circular grooves 214 surround to form an avoidance hole for the cylindrical rigid body 3 to pass through, so that the cylindrical rigid body 3 can not only be inserted into the surrounding rock similar material between the left side plate 13 and the fault simulation device, but also into the fault similar material.

[0051] In use, the left side plate 13, right side plate 14, and rear side plate 16 are first bolted to the base plate 11. The first rotating post 23 is then passed through the through holes of the first sub-clamp plate 212, the second sub-clamp plate 213, and the connector 251, forming a hinge structure. At this point, the two semi-circular grooves 214 of the first and second sub-clamp plates 212 and 213 enclose a clearance hole for the cylindrical rigid body 3 to pass through. Then, the first end of the second clamp plate 22 is inserted into the receiving cavity 211 of the first and second sub-clamp plates 212 and 213, and the second rotating post 24 is inserted into the through hole on the second end of the second clamp plate 22.

[0052] Then, the entire structure formed by the connector 251, the first rotating column 23, the first sub-clamp plate 212, the second sub-clamp plate 213, the second clamp plate 22, and the second rotating column 24 is placed into the test chamber. One end of the first rotating column 23 is inserted into the first sliding groove 17, and one end of the second rotating column 24 is placed on the top of the rear side plate 16. After placement, the spacing between the connectors 251 of the same fault simulation device is adjusted, that is, the spacing between the two first clamp plates 21 is adjusted. It can be understood that the spacing between the two first clamp plates 21 is the thickness of the fault-similar material, which is also the simulated thickness of the goose-eighths fault in this simulation. After adjustment, the first adapter 252 is fixed to the rear side plate 16 using the first locking member 253, that is, the connector 251 is fixed to the pressure plate.

[0053] After fixing the connector 251, adjust the length of the second clamping plate 22 extending out of the receiving cavity 211 and the inclination angle of the first clamping plate 21 relative to the pressure plate, that is, adjust the simulated inclination angle of the goose-tail fault. During the adjustment process, the second rotating column 24 is always connected to the top of the rear side plate 16.

[0054] After the tilt angle is adjusted, the front side plate 15 is fixed to the bottom plate 11 with bolts. At this time, the first rotating column 23 is inserted into the first sliding groove 17 of the front side plate 15, the second rotating column 24 is connected to the top of the front side plate 15, and the abutment member 261 is located inside the test chamber. Then, the second adapter member 262 is installed on the second rotating column 24, and the second locking member 263 is threaded onto the second adapter member 262. One end of the second locking member 263, which extends into the second threaded hole, extends into the second sliding groove 18 and abuts against the bottom of the second sliding groove 18, thereby restricting the up-down and left-right movement of the second clamping plate 22. It can be understood that when the second locking member 263 abuts against the bottom of the second sliding groove 18, the second rotating column 24 is always located at the top of the front side plate 15 and the rear side plate 16.

[0055] After the clamping mechanism 2 is installed, the cylindrical rigid body 3 is first inserted into the test chamber through the excavated simulated hole 131 and filled with a fault-like material. After filling, the locking effect of the second locking assembly 26 on the second rotating column 24 can be released first, and then the front side plate 15 can be removed from the bottom plate 11, and the second clamping plate 22 and the second sub-clamping plate 213 can be removed from the test chamber. Then the front side plate 15 is installed on the bottom plate 11, and after releasing the locking effect of the first locking assembly 25 on the connector 251, the rear side plate 16 is removed to remove the connector 251, the first rotating column 23, the first sub-clamping plate 212 and the first adapter 252.

[0056] By utilizing the locking action of the first locking assembly 25 and the second locking assembly 26 on the first clamping plate 21 and the second clamping plate 22, the relative positions between the clamping plate mechanisms 2 do not change when filling and compacting fault-like materials between the two clamping plate mechanisms 2 in the same fault simulation device. Furthermore, by setting up the clamping plate mechanism 2, the key geometric discontinuities of the en echelon fault group can be accurately reproduced, laying the foundation for subsequent mechanical and seepage simulations.

[0057] Referring to Figures 1 and 8, the cylindrical rigid body 3 may include a first cylinder 31 of the same diameter, multiple second cylinders 32, and a third cylinder 33. A cylindrical segment 34 is provided at the second end of the first cylinder 31 and the second end of the second cylinder 32, respectively. A receiving hole 35 for connecting to the cylindrical segment 34 is provided at the first end of the second cylinder 32 and the first end of the third cylinder 33, respectively. Thus, during testing, the first cylinder 31, the second cylinder 32, and the third cylinder 33 can be pulled out from the simulated excavation hole 131, accurately simulating the dynamic process of the tunnel face gradually approaching and crossing the en echelon fault zone, thereby achieving a realistic simulation of the tunnel excavation process and obtaining accurate test data. Optionally, the clamping mechanism 2 also includes a disc (not shown in the figure) for sealing the avoidance hole. During the experiment, if the cylindrical rigid body 3 does not need to be inserted into the clearance hole formed between the first sub-clamp plate 212 and the second sub-clamp plate 213, the clearance hole can be sealed by the disc to facilitate the filling of fault-like material.

[0058] The collection device 6 includes a collection bucket 61 and a guide channel 62. The guide channel 62 is inclinedly disposed on the outer side wall of the left side plate 13 and located below the excavation simulation hole 131. The collection bucket 61 is located below the lower end of the guide channel 62 to collect the mixture of water and mud flowing out from the excavation simulation hole 131.

[0059] The collection tank 61 is vertically detachable and equipped with multiple stages of filter screens. These screens can be installed onto the inner wall of the collection tank using bolts or other structural means. The mesh size of each filter screen decreases from top to bottom, used for particle classification of the water and mud mixture. For example, when there are two filter screens, the upper screen has a larger mesh size than the lower screen. The upper screen filters out the larger particles in the mixture first, and then the lower screen filters out the smaller particles.

[0060] On the other hand, the present invention also provides a test method for water and mud inrush in tunnels through a goose-shaped fault activation and displacement test system, including the above-mentioned test system for water and mud inrush in tunnels through a goose-shaped fault activation and displacement test system, and further includes the following steps: Test chamber 1 preparation step: the left side plate 13, the right side plate 14, the front side plate 15 and the rear side plate 16 are fixed to the bottom plate 11 to form the test chamber 1.

[0061] Similar material filling steps: Multiple fault simulation devices are arranged in a goose-like formation inside the test chamber 1, and a cylindrical rigid body 3 is inserted into the test chamber 1 through an excavated simulation hole 131. Fault similar material and pre-embedded strain sensor 71 and pore water pressure sensor 72 are filled between the two clamping mechanisms 2 of each fault simulation device. Then, the fault simulation device is removed from the test chamber 1, and surrounding rock similar material is filled between two adjacent fault similar materials, between the fault similar material and the left side plate 13, and between the fault similar material and the right side plate 14. Acoustic emission sensor 73 is set on the inner wall of the right side plate 14. Finally, the top plate 12 is connected to the front side plate 15, the rear side plate 16, the left side plate 13, and the right side plate 14.

[0062] Specifically, based on the fault inclination angle and spacing designed for the experiment, within the test chamber 1, the positions of all clamping mechanisms 2 are adjusted and fixed using the first locking assembly 25, the second locking assembly 26, the first sliding groove 17, and the second sliding groove 18. This results in multiple pairs of clamping mechanisms 2 being arranged in a goose-like formation within the chamber, with a predetermined thickness of fault-filling space formed between the same pair of clamping mechanisms 2. A cylindrical rigid body 3 is then inserted into the test chamber 1. If one or more clamping mechanisms 2 do not require the insertion of the cylindrical rigid body 3, they are sealed with disc clearance holes. Then, fault-similar material is filled and compacted, and during the filling process, strain sensors and pore water pressure sensors 72 are pre-embedded in key positions. After the fault-similar material is filled, the locking effect of the second locking assembly 26 on the second rotating column 24 is first released, then the front side plate 15 is removed from the bottom plate 11, and the second clamping plate 22 and the second sub-clamping plate 213 are removed from the test chamber. Then, install the front side plate 15 onto the bottom plate 11, release the locking effect of the first locking assembly 25 on the connector 251, and remove the rear side plate 16 to remove the connector 251, the first rotating column 23, the first sub-clamp plate 212, the first adapter 252, and the disc.

[0063] Finally, surrounding rock similar materials are filled between two adjacent fault-similar materials, between the fault-similar material and the left side plate 13, and between the fault-similar material and the right side plate 14. Acoustic emission sensors 73 are installed on the inner wall of the right side plate 14. The initial stress and hydraulic boundary condition application steps are as follows: The digital hydraulic pump station 41 is started, and the rigid lifting 42 on the bottom plate 11 and top plate 12 is independently controlled to apply a three-dimensional stress field to the model, simulating the original ground stress in the engineering area. The water supply device 5 is started, and the dyed water is injected through the main inlet pipe 53 and each sub-inlet pipe 54 into the inlet above the fault-similar material column via the water pump 52. The water pressure and flow rate injected into different fault sections are independently adjusted through the flow meter 55 and water valve 56 on each sub-inlet pipe 54 to simulate a high-pressure aquifer.

[0064] In addition, in this step, the signal stability of the strain sensor, pore water pressure sensor 72, and acoustic emission sensor 73 is activated and verified. The focal length and frame rate of the high-speed camera are adjusted to ensure that it can be clearly aimed at the area of ​​the excavated simulated hole 131 to capture the transient process of water and mud inrush.

[0065] Tunnel excavation and disaster process simulation steps: The cylindrical rigid body 3 is slowly pulled out at a constant or variable speed to simulate the advancement process of the tunnel excavation face.

[0066] In this step, the first cylinder 31, the second cylinder 32, and the third cylinder 33 of the cylindrical rigid body 3 are removed sequentially at predetermined time intervals. During and after removal, comprehensive data monitoring is performed simultaneously, and the water and mud mixture is collected using the collection device 6. Strain sensors and pore water pressure sensors 72 monitor the deformation and water pressure evolution of the fault in real time. An array of acoustic emission sensors 73 captures micro-fracture signals in the rock mass to locate damage and determine the fault activation sequence. A high-speed camera device fully records the crack propagation and catastrophic dynamics near the excavation face. When the fault is activated and forms a continuous water-conducting channel, the water and mud mixture will be ejected from the excavation simulation hole 131, guided by the diversion channel 62, and received by the collection bucket 61. A multi-stage filter screen inside the collection bucket 61 can classify the mixture into particles.

[0067] After the experiment, the collected strain, pore pressure, acoustic emission, and high-speed image data will be synchronously integrated into the data acquisition system to invert the evolution of stress field, displacement field, and seepage field during the fault activation process, thereby quantitatively revealing the disaster mechanism of water and mud inrush.

[0068] In summary, this invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0069] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A test system for water and mud inrush in tunnels traversing a goose-shaped fault, characterized in that, include: The test chamber comprises a test chamber, multiple fault simulation devices, a cylindrical rigid body, a stress loading device, a water supply device, a collection device, and a detection device. The test chamber is enclosed by a bottom plate, a top plate, a left side plate, a right side plate, a front side plate, and a rear side plate. The left side plate has an excavation simulation hole. Multiple fault simulation devices are arranged in a goose-like formation within the test chamber. Spaces between each fault simulation device and the left side plate, between adjacent fault simulation devices, and between each fault simulation device and the right side plate are used to fill with surrounding rock-like materials. Each fault simulation device includes two spaced-apart clamping mechanisms, and the space between the two clamping mechanisms of the same fault simulation device is used to fill with fault-like materials. The cylindrical rigid body is removably mounted in the excavation simulation hole and partially extends into the test chamber. The stress loading device includes a digital hydraulic pump station, multiple rigid jacks, and a pressure plate composed of multiple rectangular plates with ball bearings on their sides. The joints between adjacent rectangular plates correspond to the fault. The simulation device is located at the bottom; a portion of the rigid jacks are mounted on the top plate, and another portion is mounted on the bottom plate. Each rigid jack mounted on the bottom plate has its output end connected to a rectangular plate. The water supply device includes a water tank, a water pump, a main inlet pipe, multiple sub-inlet pipes, multiple flow meters, and multiple water valves. The inlet of the water pump is connected to the water tank, and the outlet of the water pump is connected to the main inlet pipe. Multiple inlets are provided on the top plate, with at least one inlet between two adjacent clamping mechanisms. One end of each sub-inlet pipe is connected to an inlet, and the other end is connected to the main inlet pipe. Each sub-inlet pipe has a flow meter and a water valve. The collection device is connected to the excavation simulation hole. The detection device includes a pre-embedded strain sensor and a pore water pressure sensor embedded in a fault-like material, an acoustic emission sensor mounted on the inner wall of the right side plate, and a high-speed camera device corresponding to the excavation simulation hole.

2. The test system for activated fault displacement, water inrush, and mud inrush in tunnels according to claim 1, characterized in that: The clamping mechanism includes a first clamping plate, a second clamping plate, a first rotating column, a second rotating column, a first locking assembly, and a second locking assembly. The inner walls of the front and rear side plates are respectively provided with horizontally arranged first sliding grooves. Both ends of the first rotating column are slidably connected to the first sliding grooves. The first end of the first clamping plate and the first locking assembly are rotatably connected to the first rotating column. The first end of the first clamping plate abuts against the pressure plate. The second end of the first clamping plate is provided with a receiving cavity. The first end of the second clamping plate is slidably disposed within the receiving cavity, and the second end is rotatably connected to the second rotating column. The second rotating column is slidably connected to the top of the front and rear side plates. The second locking assembly is connected to one end of the second rotating column.

3. The test system for activated fault displacement, water inrush, and mud inrush in tunnels according to claim 2, characterized in that: The first locking assembly includes a connector, a first adapter, and a first locking member. The connector is rotatably connected to the first rotating column. The lower side of the connector is used to abut against the upper side of the pressure plate. One end of the first adapter is fixedly connected to the connector, and the other end is provided with a U-shaped groove with its opening facing the pressure plate. The top of the rear side plate is slidably connected to the bottom of the U-shaped groove, and one side wall of the U-shaped groove is located outside the test chamber. A first threaded hole is provided on the side wall of the U-shaped groove extending outside the test chamber. The first locking member is threadedly connected to the first threaded hole, and one end of the locking member passes through the first threaded hole and abuts against the outer side wall of the rear side plate.

4. The test system for activated fault displacement, water inrush, and mud inrush in tunnels according to claim 3, characterized in that: The second locking assembly includes an abutment, a second adapter, and a second locking member; a second sliding groove is provided on the outer side wall of the front side plate, and the second sliding groove is parallel to the first sliding groove; the abutment is fixedly mounted on the second rotating column, and the abutment is used to abut against the inner side wall of the front side plate; the second adapter is connected to the second rotating column, and the second adapter is located outside the test chamber; a second threaded hole is provided on the second adapter, and the second locking member is threadedly connected to the second threaded hole, with one end of the second locking member passing through the second threaded hole and extending into the second sliding groove, abutting against the bottom of the second sliding groove.

5. The test system for activated fault displacement, water inrush, and mud inrush in tunnels according to claim 2, characterized in that: The first clamping plate includes a first sub-clamping plate and a second sub-clamping plate. The first sub-clamping plate and the second sub-clamping plate are respectively provided with semi-circular grooves. The two semi-circular grooves surround each other to form an avoidance hole for the cylindrical rigid body to pass through.

6. The test system for activated fault displacement, water inrush, and mud inrush in tunnels according to claim 5, characterized in that: The cylindrical rigid body includes a first cylinder, a plurality of second cylinders and a third cylinder of the same diameter; a cylindrical segment is provided at the second end of the first cylinder and the second end of the second cylinder; a receiving hole for connecting with the cylindrical segment is provided at the first end of the second cylinder and the first end of the third cylinder.

7. The test system for activated fault displacement, water inrush, and mud inrush in tunnels according to claim 5, characterized in that: The clamping mechanism also includes a disc for sealing the clearance hole.

8. The test system for activated fault displacement, water inrush, and mud inrush in tunnels according to claim 1, characterized in that: The collection device includes a collection bucket and a guide channel. The guide channel is inclinedly disposed on the outer side wall of the left side plate and located below the excavation simulation hole. The collection bucket is located below the lower end of the guide channel.

9. The test system for activated fault displacement, water inrush, and mud inrush in tunnels according to claim 8, characterized in that: The collection bucket is detachably equipped with multiple levels of filter screens along the vertical direction, with the mesh size of each filter screen decreasing from top to bottom.

10. A test method for water and mud inrush during tunneling through a goose-shaped fault activation and displacement, characterized in that, The test system for activating fault displacement and water / mud inrush in tunnels as described in any one of claims 1-9 further includes: a test chamber preparation step: fixing the left side plate, right side plate, front side plate, and rear side plate to the bottom plate to form a test chamber; a similar material filling step: arranging multiple fault simulation devices in a goose-like pattern inside the test chamber, inserting a cylindrical rigid body into the test chamber through excavation simulation holes, and filling the space between the two clamping mechanisms of each fault simulation device with fault similar material and pre-embedded strain sensors and pore water pressure sensors; then removing the fault simulation devices from the test chamber, and filling the space between two adjacent fault similar materials, between the fault similar material and the left side plate, and between the fault similar material and the right side plate with surrounding rock similar material, and setting an acoustic emission sensor on the inner wall of the right side plate; finally connecting the top plate to the front side plate, rear side plate, left side plate, and right side plate; initial stress Steps for applying force and hydraulic boundary conditions: Start the digital hydraulic pump station to independently control the rigid jacking on the bottom and top plates, apply a three-dimensional stress field to the model, and simulate the original ground stress in the engineering area; Start the water supply device to inject dyed water through the main inlet pipe and each sub-inlet pipe into the inlet above the fault-similar material column; Independently regulate the water pressure and flow rate injected into different fault sections through the flow meters and water valves on each sub-inlet pipe to simulate high-pressure aquifers; Tunnel excavation and disaster process simulation steps: Slowly extract the cylindrical rigid body at a constant or variable speed to simulate the tunnel face advancement process, wherein strain sensors and pore water pressure sensors monitor the deformation and water pressure evolution of the fault in real time; Acoustic emission sensor array captures rock micro-fracture signals to locate damage and determine the fault activation sequence; High-speed camera device fully records the crack propagation and disaster dynamics near the excavation face; Collect the mixture of water and mud inrush using a collection device.

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