Tunnel water-rich fault fracture zone area loading simulation test device and method

Abstract

The invention relates to the technical field of rock mass testing, in particular to a tunnel water-rich fault fracture zone area loading simulation test device and method.The tunnel water-rich fault fracture zone area loading simulation test device comprises a test box, and a partition plate is arranged in the test box; the partition plate divides the test box into a first area and a second area, and the second area is filled with a rock-soil sample; a lateral loading structure; a vertical loading structure; the simulated fault test structure comprises a mounting frame fixedly connected to the partition plate, a driving structure and a simulated fault unit, one end of the driving structure is hinged to the mounting frame, and the other end of the driving structure is connected with the simulated fault unit; the fault simulation unit is hinged to the mounting frame and used for simulating an adjustable fault, and the technical problems that an existing test device cannot dynamically adjust the fault fracture width and the dip angle according to the load effect and cannot perform real-time coupling simulation on a hydrological seepage field are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of rock mass tests, and particularly relates to a loading simulation test device and method for a water-rich fault fracture zone in a tunnel area. Background Art

[0002] In tunnel engineering construction, a water-rich fault fracture zone is an extremely complex and dangerous geological area. In such areas, the rock mass is broken, the structure is loose, and it is rich in groundwater. During the tunnel excavation process, water inrush, mud inrush, collapse and other disasters are extremely likely to occur, seriously threatening construction safety and engineering quality. Currently, the model test research on such problems mostly relies on simplified geological conditions. The existing fault model tunnel simulation experiments are too single in terms of fault fracture width, fault dip angle and hydrology, etc., and cannot truly simulate the coupled dynamic change of the surrounding rock stress field during the tunnel excavation process, resulting in a significant deviation between the fault fracture expansion mode and the engineering reality, and it is difficult to flexibly adapt to the changing engineering actual geological conditions; at the same time, most test models adopt a preset fixed dip angle fault structure, and the dip angle and fracture width cannot be changed according to the load, ignoring the self-adaptive adjustment effect on the fault fracture zone under the action of the load, and it is difficult to reveal the differential failure mechanism of the change of the fault dip angle and the dislocation of the fault fracture width; moreover, the dynamic change of the fault dip angle and fracture width will also significantly affect the migration path and seepage pressure of groundwater, leading to the reconstruction of the underground space relationship and the formation of a more permeable dominant seepage channel, thereby triggering water inrush disasters; although some test models also have a hydrological simulation link, the hydrological simulation is designed with constant pressure water injection or fixed seepage path, and a real-time coupling mechanism between the change of the fracture width and the evolution of the hydrological seepage field cannot be established, resulting in inaccurate evaluation of the formation process of the water inrush channel and the grouting water blocking effect.

[0003] Therefore, in view of this, the inventor proposes a loading simulation test device and method for a water-rich fault fracture zone in a tunnel area to solve the above technical problems. Summary of the Invention

[0004] One of the purposes of the present invention is to provide a loading simulation test device for a water-rich fault fracture zone in a tunnel area to solve the technical problems that the existing test device cannot dynamically adjust the fault fracture width and dip angle according to the load action and cannot simulate the real-time coupling of the hydrological seepage field; the second purpose is to provide a method.

[0005] In order to achieve the above purposes, the technical scheme adopted by the present invention is as follows: A loading simulation test device for a water-rich fault fracture zone in a tunnel area, comprising a test box, a partition is arranged in the test box, the partition divides the test box into a first area and a second area, and a rock and soil sample is filled in the second area; A lateral loading structure configured to apply a lateral load to the rock and soil sample in the second area; A vertical loading structure configured to apply a vertical load to a geotechnical sample within the second region; A simulated fault test structure, comprising a mounting frame fixedly connected to the partition, a driving structure, and a simulated fault unit. One end of the driving structure is hinged to the mounting frame, and the other end of the driving structure is connected to the simulated fault unit; the simulated fault unit is hinged to the mounting frame for simulating an adjustable fault; A data acquisition system distributed around the tunnel, configured to monitor in real time the impact of the geotechnical sample on the tunnel during the simulation process and collect data information generated during the test; Wherein, the lateral loading structure is connected to the driving structure, such that while applying a lateral load, the lateral loading structure drives the driving structure to act, and further drives the simulated fault unit to move relative to the mounting frame, so as to dynamically change the inclination angle and width of the simulated fault unit within the geotechnical sample.

[0006] According to the above technical solution, when the loading simulation test device for a water-rich fault fracture zone of a tunnel is working, the lateral loading structure is activated to apply a lateral load to the geotechnical sample filled in the second region of the test box. Since the lateral loading structure is connected to the driving structure, during the application of the lateral load, the driving structure will be synchronously driven to act. One end of the driving structure is hinged to the mounting frame and the other end is connected to the simulated fault unit, and its action will drive the connected simulated fault unit to move relative to the mounting frame fixedly connected to the partition. The simulated fault unit itself is hinged to the mounting frame for simulating an adjustable fault. Through this series of actions, the inclination angle and width of the simulated fault unit within the geotechnical sample can be dynamically changed. At the same time, the data acquisition system distributed around the tunnel monitors in real time the impact of the geotechnical sample on the tunnel during the simulation process and collects data information generated during the test, thereby realizing the simulation test of the loading condition of the water-rich fault fracture zone of the tunnel.

[0007] Further, the simulated fault unit comprises a plurality of simulated fault members connected end to end; Each simulated fault member comprises two symmetrically arranged parallel cross frames and two symmetrically arranged parallel hydro-expansion members. The two cross frames are symmetrically arranged on both sides of the two hydro-expansion members; each cross frame comprises a first connecting rod and a second connecting rod that are cross-hinged to each other. One of the first connecting rods is hinged to the mounting frame, and one of the second connecting rods is hinged to a third connecting rod, and the third connecting rod is hinged to the mounting frame.

[0008] Furthermore, the hydro - telescopic member includes a first telescopic plate and a second telescopic plate. An injection cavity is formed in the first telescopic plate, and the second telescopic plate is hermetically and slidably arranged in the injection cavity. The end of the second telescopic plate extends out of the injection cavity and is hinged to the first telescopic plate of the adjacent simulated fault member, and the first telescopic plate is hinged to the second telescopic plate of the adjacent simulated fault member.

[0009] Furthermore, a plurality of spray nozzles and water inlets communicating with the injection cavity are formed in the first telescopic plate. A water inlet pipe is connected to the water inlet, and a one - way valve is arranged in the water inlet pipe; A pressure water spraying structure is installed in the spray nozzle. The pressure water spraying structure includes a nozzle seat fixedly installed at the spray nozzle. A conical flow channel communicating with the injection cavity is formed in the nozzle seat. A spring and a rubber ball are arranged in the flow channel, and the spring has a tendency to block the conical flow channel with the rubber ball; When the second telescopic plate compresses the injection cavity, resulting in an increase in its internal pressure and overcoming the elastic force of the spring, the rubber ball is pushed to move, so that the liquid in the injection cavity can be sprayed out through the conical flow channel.

[0010] According to the above technical solution, when the hydro - telescopic member in the simulated fault unit works, the liquid enters through the water inlet communicating with the injection cavity of the first telescopic plate. The one - way valve in the water inlet pipe can prevent the liquid from flowing back, ensuring the one - way injection of the liquid into the injection cavity. During the process that the simulated fault unit deforms due to external force and the second telescopic plate compresses the injection cavity, the internal pressure of the injection cavity gradually increases. At this time, the pressure water spraying structure in the spray nozzle plays a role. In the conical flow channel of the nozzle seat, the spring makes the rubber ball have a tendency to block the conical flow channel, playing a sealing role. When the pressure in the injection cavity increases enough to overcome the elastic force of the spring, the rubber ball is pushed to move and no longer blocks the conical flow channel, and the liquid in the injection cavity can be sprayed out through the conical flow channel. This process realizes the linkage between the pressure change in the injection cavity and the liquid spraying, simulates the hydro - seepage change caused by the change of the fault morphology in the water - rich fault fracture zone area, provides a more realistic hydro - logical response simulation for the test, and helps to more accurately study the characteristics and variation laws of the tunnel water - rich fault fracture zone under different working conditions.

[0011] Furthermore, the simulated fault unit has a first state and a second state. The driving structure includes a driving housing hinged to the installation frame. A piston is hermetically and movably connected in the driving housing. The piston divides the driving housing into a first chamber and a second chamber, and the second chamber communicates with a first pipeline; A push rod is fixedly connected to the piston. The push rod is hermetically and slidably connected to the driving housing, and the push rod extends out of the second chamber and is hinged to the second connecting rod.

[0012] Further, the side loading structure comprises a fixed seat, a cylinder, a sliding seat and a plurality of guide rods, each of the guide rods is fixed to one side of the fixed seat, the sliding seat is slidably connected to the guide rod, a first push rod and a second push rod hinged to each other are symmetrically arranged between the sliding seat and the fixed seat, a free end of the first push rod is hinged to the fixed seat, and a free end of the second push rod is hinged to the sliding seat; A push column is fixed on one side of the sliding seat away from the fixed seat, and the push column passes through the test box and is connected to a side plate.

[0013] The cylinder is fixed on the fixed seat, and the fixed seat is symmetrically provided with an air pressure box, a push block is slidably provided between the two air pressure boxes, the piston rod of the cylinder passes through the fixed seat and is connected to the push block, and a third push rod is hinged at both ends of the push block, and the free end of the third push rod is hinged to the middle position of the first push rod.

[0014] Furthermore, a pneumatic chamber is provided in the pneumatic box, a telescopic sealing plate is provided on the pneumatic box, one end of the telescopic sealing plate is fixed on the pneumatic box, the other end of the telescopic sealing plate is connected to the push block, an air inlet is opened on the pneumatic chamber, a one-way valve is provided at the air inlet, the pneumatic chamber is connected to the first pipeline, and when the pneumatic chamber is compressed, the gas in the pneumatic chamber enters the second chamber through the first pipeline.

[0015] Furthermore, the vertical loading structure includes a hydraulic press, a hydraulic plate is connected to the hydraulic press, a hydraulic rod is connected below the hydraulic plate, and the hydraulic rod is connected to a load plate.

[0016] According to the above technical solution, when the vertical loading structure is working, the hydraulic press starts, converts hydraulic energy into mechanical energy, and pushes the hydraulic plate downward. The hydraulic plate drives the hydraulic rod connected below to move downward synchronously, and the hydraulic rod then pushes the load plate downward to apply pressure, thereby applying a vertical load to the geotechnical specimens in the second area of ​​the test box, simulating the vertical pressure environment in actual engineering.

[0017] Furthermore, the data acquisition system comprises: A high-speed camera, mounted on one side of the test chamber, is used to record the tunnel of the test chamber frame by frame; Acoustic emission sensors are distributed outside the tunnel lining to obtain acoustic signals generated by rock fracture; Distributed optical fiber sensors are buried inside the rock and soil samples to sense the strain distribution of the rock and soil bodies; A pressure sensor is arranged in the area surrounding the simulated fault unit to measure stress changes in the fault zone; A deformation sensor is installed on the inner wall of the test chamber for detecting the displacement of surrounding rock; and piezometers are distributed on the seepage path of the geotechnical specimen for monitoring the pore water pressure state; A computer controller, which is connected to the high-speed camera, the acoustic emission sensor, the distributed optical fiber sensor, the pressure sensor, the deformation sensor and the piezometer. The computer controller is connected with a data memory for storing the data of the computer controller.

[0018] When the data acquisition system works, each sensor cooperates with the high-speed camera to collect various types of data during the simulation test in real time. The high-speed camera installed on one side of the test chamber records the tunnel in the test chamber frame by frame, accurately capturing details such as the morphological changes and structural damages of the tunnel under different loading stages, providing intuitive image data for subsequent analysis; the acoustic emission sensors distributed on the outer side of the tunnel lining monitor the acoustic signals generated by rock mass fractures at all times; when there are minor fractures inside the rock mass, the acoustic emission sensors can quickly capture these signals and convert them into electrical signals and transmit them to the computer controller, so as to judge the location, degree and development trend of rock mass fractures; the distributed optical fiber sensors buried inside the geotechnical specimen sense the strain distribution of the geotechnical mass; as the loading progresses, the geotechnical mass deforms, and the distributed optical fiber sensors accurately measure the strain conditions of each part of the geotechnical mass by sensing the changes in optical signals, providing key data for studying the mechanical properties of the geotechnical mass; the pressure sensors arranged in the surrounding area of the simulated fault unit measure the stress changes in the fault zone and real-time feedback the stress state of the fault zone under different working conditions; the deformation sensors installed on the inner wall of the test chamber detect the displacement of the surrounding rock and master the deformation law of the surrounding rock during the loading process, and the piezometers distributed on the seepage path of the geotechnical specimen monitor the pore water pressure state to understand the hydrogeological response in the water-rich fault fracture zone area. The computer controller receives and processes the data of each sensor and the high-speed camera, and then stores the data in the connected data memory for subsequent in-depth analysis and research.

[0019] On the other hand, the present application also proposes a loading simulation test method for the water-rich fault fracture zone area of a tunnel. Using the loading simulation test device for the water-rich fault fracture zone area of a tunnel as described above, it includes the following steps: Test configuration: Fill the geotechnical specimen in the test chamber and bury the tunnel model, install the simulated fault unit in the initial state, and arrange the sensor array; Linkage loading and fault adjustment: Synchronously apply vertical load and lateral load, and drive the simulated fault unit to dynamically and cooperatively adjust the fault dip angle and fracture width through air pressure transmission; Hydrogeological response and data acquisition: In response to the deformation of the fault unit triggering liquid ejection to simulate the seepage effect, synchronously collect data on crack propagation, rock mass fracture, geotechnical strain, stress and pore water pressure; Analysis termination: Decrease the load, establish a mechanical coupling model of fault dip - fracture width - surrounding rock stress and a seepage coupling model of fracture width - seepage path.

[0020] Advantages of the present invention: In the present invention, the gas generated by the cylinder of the lateral loading structure driving the push block to compress the air pressure chamber is transported through the first pipeline to the second chamber of the driving structure to push the piston and the push rod; the push rod acts on the second connecting rod of the simulated fault unit, forcing the cross frame and the hydro - telescopic member to deform synergistically, and real - time changing the fault dip and fracture width; at the same time, the deformation of the fault unit compresses the second telescopic plate of the hydro - telescopic member, increasing the liquid pressure in the water injection chamber and triggering the pressure water spraying structure, realizing the mechanical real - time coupling of lateral load - dynamic adjustment of fault morphology - hydro - response.

[0021] Other advantages, objectives and features of the present application will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be learned from the practice of the present application. The objectives and other advantages of the present application can be achieved and obtained through the following specific embodiments. Brief Description of the Drawings

[0022] Figure 1 It is a schematic diagram of the overall structure of the loading simulation test device for the water - rich fault fracture zone in the tunnel of the present invention; Figure 2 It is a schematic cross - sectional view of the first state of the loading simulation test device for the water - rich fault fracture zone in the tunnel of the present invention; Figure 3 It is a schematic cross - sectional view of the second state of the loading simulation test device for the water - rich fault fracture zone in the tunnel of the present invention; Figure 4 It is a schematic diagram of the simulated fault test structure (view Figure 1 ) in the loading simulation test device for the water - rich fault fracture zone in the tunnel of the present invention; Figure 5 It is a schematic diagram of the local structure of the loading simulation test device for the water - rich fault fracture zone in the tunnel of the present invention Figure 3 ; Figure 6 It is a schematic diagram of the simulated fault test structure (view Figure 2 ) in the loading simulation test device for the water - rich fault fracture zone in the tunnel of the present invention; Figure 7 It is a schematic cross - sectional view of the simulated fault test structure in the loading simulation test device for the water - rich fault fracture zone in the tunnel of the present invention; Figure 8It is a schematic structural diagram of the first state of the simulated fault test structure in the loading simulation test device for the water-rich fault fracture zone of the tunnel of the present invention; Figure 9 It is a schematic structural diagram of the second state of the simulated fault test structure in the loading simulation test device for the water-rich fault fracture zone of the tunnel of the present invention; Figure 10 It is a partial structural schematic diagram of the lateral loading structure in the loading simulation test device for the water-rich fault fracture zone of the tunnel of the present invention; Figure 11 It is a partial sectional schematic diagram of the lateral loading structure in the loading simulation test device for the water-rich fault fracture zone of the tunnel of the present invention; Figure 12 For the loading simulation test device for the water-rich fault fracture zone of the tunnel of the present invention Figure 7 Schematic diagram of the structure of part A; Figure 13 For the loading simulation test device for the water-rich fault fracture zone of the tunnel of the present invention Figure 12 Schematic diagram of part B.

[0023] Among them, test box 1, partition 11, first area 12, second area 13, geotechnical sample 14, tunnel 15, lateral loading structure 2, fixed seat 21, cylinder 22, sliding seat 23, guide rod 24, push column 25, side plate 26, air pressure box 27, air pressure chamber 271, telescopic sealing plate 272, air inlet 273, push block 28, first push rod 281, second push rod 282, third push rod 283, vertical loading structure 3, hydraulic press 31, hydraulic plate 32, hydraulic rod 33, load plate 34, simulated fault test structure 4, installation frame 41, drive structure 42, drive housing 421, piston 422, second chamber 423, first pipe 424, push rod 425, simulated fault unit 43, cross frame 431, first connecting rod 4311, second connecting rod 4312, third connecting rod 4313, hydroscopic expansion member 432, first expansion plate 4321, second expansion plate 4322, water injection chamber 4323, water inlet pipe 4324, pressure water spraying structure 433, nozzle seat 4331, conical flow channel 4332, spring 4333, rubber ball 4334. Detailed implementation mode

[0024] The following will describe the implementation manners of the present invention with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for explaining the present invention, rather than for limiting the protection scope of the present invention.

[0025] It should be noted that the illustrations provided in the following embodiments only schematically illustrate the basic concept of the present invention. Therefore, only the components related to the present invention are shown in the drawings, rather than being drawn according to the number, shape, and size of the components in actual implementation. The types, quantities, and proportions of the components in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0026] This embodiment proposes a loading simulation test device for a water-rich fault fracture zone in a tunnel, as Figures 1 to 13 shown, which includes a test box 1, a lateral loading structure 2, a vertical loading structure 3, a simulated fault test structure 4, and a device of a data acquisition system. A partition 11 is arranged in the test box 1 to divide the test box 1 into a first area 12 and a second area 13, and a geotechnical sample 14 is filled in the second area 13; the test box 1 is a transparent structure, which is convenient for observation and research; It should be noted that in this embodiment, when studying the simulated fault, the fault dip angle and the fracture width are carried out simultaneously because the two are interrelated and jointly affect its characteristics in the actual fault zone; the change of the fault dip angle will reshape the stress distribution and deformation mode of the fault zone, thereby affecting the fracture development and width. For example, under a steep dip angle, shear stress concentration may cause the fracture to expand and the width to increase; and the change of the fracture width will also act on the fault dip angle, changing its mechanical stability. The prior art has studied with a single object and has not carried out tests on the coupling effect of the fault dip angle and the fracture width, and cannot provide an accurate basis for the stability research of underground projects such as tunnels 15.

[0027] The purpose of setting the simulated fault test structure 4 in this embodiment is to simulate the fault zone in the water-rich fault fracture zone of the tunnel 15. By dynamically changing the dip angle and the fracture width of the simulated fault test structure 4 simultaneously, the fault morphology under the conditions of the fault fracture zone can be achieved, which is used to study the mechanical response of the fault under the action of the fault dip angle and the fracture width, and clarify the influence mechanism of the fault on the stability of the tunnel 15.

[0028] The lateral loading structure 2 is configured to apply a lateral load to the geotechnical specimen 14, and the vertical loading structure 3 applies a vertical load; the simulated fault test structure 4 includes a mounting frame 41, a driving structure 42, and a simulated fault unit 43. One end of the driving structure 42 is hinged to the mounting frame 41, and the other end is connected to the simulated fault unit 43; the data acquisition system is distributed around the tunnel 15 and is used to monitor the influence of the geotechnical specimen 14 on the tunnel 15 in real time and collect test data. The lateral loading structure 2 is connected to the driving structure 42, so that while the lateral loading structure 2 applies a lateral load, it drives the driving structure 42 to act, and then drives the simulated fault unit 43 to move relative to the mounting frame 41, so as to dynamically change the inclination angle and width of the simulated fault unit 43 in the geotechnical specimen 14. When the lateral loading structure 2 applies a load, its power is transmitted to the driving structure 42, and the hinge point of the driving structure 42 undergoes displacement, driving the simulated fault unit 43 to generate a combined movement of rotation and translation relative to the mounting frame 41. This movement changes the spatial orientation of the fault unit in the geotechnical specimen 14 and realizes the synchronous adjustment of the inclination angle and the fracture width.

[0029] In this embodiment, when the loading simulation test device for the water-rich fault fracture zone area of the tunnel 15 is working, the lateral loading structure 2 is started to apply a lateral load to the geotechnical specimen 14 filled in the second area 13 of the test box 1. Since the lateral loading structure 2 is connected to the driving structure 42, during the application of the lateral load, the driving structure 42 will be driven to act synchronously. One end of the driving structure 42 is hinged to the mounting frame 41 and the other end is connected to the simulated fault unit 43. Its action will drive the connected simulated fault unit 43 to move relative to the mounting frame 41 fixedly connected to the partition 11. The simulated fault unit 43 itself is hinged to the mounting frame 41 to simulate an adjustable fault. Through this series of actions, the inclination angle and width of the simulated fault unit 43 in the geotechnical specimen 14 can be dynamically changed. At the same time, the data acquisition system distributed around the tunnel 15 monitors the influence of the geotechnical specimen 14 on the tunnel 15 during the simulation process in real time and collects the data information generated during the test process, so as to realize the simulation test of the loading condition of the water-rich fault fracture zone area of the tunnel 15. Compared with the prior art, the existing test device can only preset fixed fault parameters and cannot reflect the fault inclination angle and fracture width dislocation effects caused by the change of surrounding rock stress. Through the linkage design of the loading system and the driving structure 42, this solution realizes the dynamic adjustment of the fault inclination angle and the fracture width, and more realistically simulates the interaction between the stress field and the fault morphology in the project. At the same time, the combined data acquisition system can capture the influence of the change of fault parameters on the seepage path, overcoming the problem of the disconnection between the traditional model hydrological simulation and the mechanical response.

[0030] As a preferred embodiment, such as Figure 4As shown, the simulated fault unit 43 includes a number of simulated fault components connected end to end; the simulated fault component includes two cross frames 431 arranged symmetrically in parallel and two hydro-elastic components 432 arranged symmetrically in parallel. The two cross frames 431 are symmetrically arranged on both sides of the two hydro-elastic components 432; the cross frame 431 includes a first connecting rod 4311 and a second connecting rod 4312 that are cross-hinged to each other. Among them, the first connecting rod 4311 on the leftmost side is hinged to the mounting frame 41, and the second connecting rod 4312 on the leftmost side is hinged to a third connecting rod 4313, and the third connecting rod 4313 is hinged to the mounting frame 41. The hydro-elastic component 432 includes a first telescopic plate 4321 and a second telescopic plate 4322. The first telescopic plate 4321 is hinged to the mounting frame 41, and the second telescopic plate 4322 is hinged to the first telescopic plate 4321 on the adjacent simulated fault component; as Figure 12 As shown, a water injection cavity 4323 is formed in the first telescopic plate 4321. The left end of the second telescopic plate 4322 is hermetically slidably arranged in the water injection cavity 4323, and the right end of the second telescopic plate 4322 extends out of the water injection cavity 4323 and is hinged to the first telescopic plate 4321 of the adjacent simulated fault component.

[0031] According to the above technical solution, when the simulated fault unit 43 works, multiple simulated fault components are connected end to end and work together. In the simulated fault component, the cross frame 431 and the hydro-elastic component 432 cooperate with each other, and the two cross frames 431 are symmetrically distributed on both sides of the two hydro-elastic components 432. In the cross frame 431, the first connecting rod 4311 and the second connecting rod 4312 that are cross-hinged to each other, one first connecting rod 4311 is hinged to the mounting frame 41, and one second connecting rod 4312 is hinged to a third connecting rod 4313 connected to the mounting frame 41. This structure provides a stable support and a flexible deformation basis for the simulated fault unit 43. When the simulated fault unit 43 moves due to an external force (such as being driven by the lateral loading structure 2 and the driving structure 42), the hinged structure of the cross frame 431 changes the angles and positions between the connecting rods, thereby affecting the overall shape of the simulated fault unit 43 and realizing the dynamic adjustment of the dip angle and width.

[0032] In this embodiment, the distance between the two hydro-elastic components 432 arranged parallel to each other is used to simulate the fracture width, and the angle between the simulated fault unit 43 and the vertical direction is the fault dip angle. As Figure 8 As shown, in the initial state, the fracture width is d1 and the fault dip angle is a.

[0033] When lateral loads and vertical loads are applied, the articulated structure of the cross frame 431 changes the angles and positions between the connecting rods, causing relative movement between the first telescopic plate 4321 and the second telescopic plate 4322 in the hydro telescopic member 432. The second telescopic plate 4322 slides sealingly in the water injection cavity 4323 of the first telescopic plate 4321. As the simulated fault unit 43 deforms, the second telescopic plate 4322 expands and contracts within the water injection cavity 4323, changing the volume of the water injection cavity 4323. Since the end of the second telescopic plate 4322 is articulated with the first telescopic plate 4321 of the adjacent simulated fault member, and the first telescopic plate 4321 is articulated with the second telescopic plate 4322 of the adjacent simulated fault member, this articulated relationship ensures the connection and coordinated deformation between the simulated fault members, and at the same time causes the liquid in the water injection cavity 4323 to be squeezed or released, thus simulating the hydro response caused by fault changes in the water-rich fault fracture zone area and providing a more realistic simulation environment for the test.

[0034] As a preferred embodiment, as Figure 7 , Figure 12 and Figure 13 shown, a number of nozzles and water inlets communicating with the water injection cavity 4323 are provided on the first telescopic plate 4321. A water inlet pipe 4324 is connected to the water inlet, and a check valve is arranged in the water inlet pipe 4324; a pressure water spraying structure 433 is installed in the nozzle. The pressure water spraying structure 433 includes a nozzle seat 4331 fixedly installed at the nozzle. A conical flow channel 4332 communicating with the water injection cavity 4323 is provided in the nozzle seat 4331. A spring 4333 and a rubber ball 4334 are arranged in the flow channel. The spring 4333 has a tendency to block the conical flow channel 4332 with the rubber ball 4334; when the second telescopic plate 4322 compresses the water injection cavity 4323, causing the internal pressure to increase and overcome the elastic force of the spring 4333, the rubber ball 4334 is pushed to move, enabling the liquid in the water injection cavity 4323 to be sprayed out through the conical flow channel 4332.

[0035] It should be noted that in the underground fracture zone environment, the changes in the fault dip angle and width will directly change the opening degree and connectivity of the water conduction channels. The wider the fault width, the lower the density of the filling medium inside the fault, and the easier it is to occur water inrush and migration. The increase in the fault width will change the connectivity of the water conduction channels, making the groundwater flow more easily; secondly, from the mechanical level, when loads are applied, the redistribution of the surrounding rock stress will squeeze or expand the seepage path, driving the redistribution of groundwater and resulting in the phenomenon of hydro inrush and migration.

[0036] In this embodiment, when the hydroscopic member 432 in the simulated fault unit 43 works, liquid enters through the water inlet pipe 4324 connected to the water injection cavity 4323 of the first expansion plate 4321. The check valve in the water inlet pipe 4324 can prevent liquid backflow and ensure that the liquid is injected into the water injection cavity 4323 unidirectionally. When the simulated fault unit 43 deforms due to external force and the second expansion plate 4322 compresses the water injection cavity 4323, the internal pressure of the water injection cavity 4323 gradually increases. At this time, the pressure water spraying structure 433 in the nozzle plays a role. In the conical flow channel 4332 of the nozzle seat 4331, the spring 4333 makes the rubber ball 4334 tend to block the conical flow channel 4332, playing a sealing role. When the second expansion plate 4322 moves in the water injection cavity 4323 and the pressure of the water injection cavity 4323 increases to overcome the elastic force of the spring 4333, the rubber ball 4334 is pushed outward and no longer blocks the conical flow channel 4332. Then the liquid in the water injection cavity 4323 can spray out through the conical flow channel 4332, simulating the hydrogeological seepage change caused by the change of the fault morphology in the water-rich fault fracture zone area. This process realizes the linkage between the pressure change of the water injection cavity 4323 and the liquid spraying, provides a more realistic hydrogeological response simulation for the test, and helps to study the characteristics and variation laws of the water-rich fault fracture zone of the tunnel 15 under different working conditions more accurately. Compared with the prior art, the traditional test device uses a fixed inclination angle fault structure and the fracture width is not adjustable, and it cannot reflect the dynamic response of the fault under the action of load. This solution realizes the self-adaptive adjustment of the inclination angle through the articulated frame of the simulated fault member, coordinates the control of the fracture width with the telescopic component, and integrates the hydrogeological conditions and structural deformation in the same unit, which is more in line with the actual situation of the underground fault zone. In the prior art, the hydrogeological system is independent of the fault structure, while the hydroscopic member 432 in this solution directly changes the geometric shape of the seepage channel during the telescopic process, realizes the coordinated change of the fault inclination angle, fracture width and hydrogeology during the loading process, enables the change of the fracture width to directly drive the reconstruction of the seepage channel, and solves the problem of the disconnection between the hydrogeological conditions and the dynamic response of the fault.

[0037] As a preferred embodiment, the simulated fault unit 43 has a first state (corresponding to Figure 8 ) and a second state (corresponding to Figure 9 ). When conducting the simulation test, this embodiment focuses on studying the process of the simulated fault unit 43 transforming from the first state to the second state; as Figure 7 shown, the driving structure 42 includes a driving housing 421 hinged to the mounting frame 41. A piston 422 is hermetically and movably connected in the driving housing 421. The piston 422 divides the driving housing 421 into a first chamber and a second chamber 423. The second chamber 423 is communicated with a first pipe 424; a push rod 425 is fixedly connected to the piston 422. The push rod 425 is hermetically and slidably connected to the driving housing 421. The push rod 425 extends out of the second chamber 423 and is hinged to the second connecting rod 4312.

[0038] In this embodiment, in the initial first state, the driving structure 42 is in a relatively stationary state. The piston 422 divides the driving housing 421 into a first chamber and a second chamber 423. At this time, the second chamber 423 does not receive or only receives a small amount of pressurized gas that can maintain the current state through the first pipeline 424. When the lateral loading structure 2 acts and generates a corresponding acting force, power will be transmitted to the driving structure 42 through the connection relationship, causing the gas to enter the second chamber 423 through the first pipeline 424. As the gas pressure in the second chamber 423 increases, the piston 422 is pushed to slide sealingly within the driving housing 421. The piston 422 moves to the left, and the piston 422 pulls the push rod 425 fixedly connected thereto to move. While the push rod 425 slides sealingly within the driving housing 421, since it extends out of the second chamber 423 and is hinged to the second connecting rod 4312, the second connecting rod 4312 will be pulled. The movement of the second connecting rod 4312 further drives components such as the cross frame 431 to deform, causing the simulated fault unit 43 to gradually change from the first state to the second state, dynamically changing the inclination angle and width of the simulated fault unit 43 in the geotechnical specimen 14. Thus, the lateral load is converted into the morphological change of the simulated fault unit 43 through the driving structure 42. The inclination angle is converted from angle a to angle b, and the crack width is converted from d1 to d2.

[0039] As a preferred embodiment, as Figure 2 、 Figure 3 、 Figure 5 、 Figure 10 and Figure 11 shown, the lateral loading structure 2 includes a fixed seat 21, a cylinder 22, a sliding seat 23, and several guide rods 24. Each guide rod 24 is fixed to the left side of the fixed seat 21. The sliding seat 23 is slidably connected to the guide rods 24. A first push rod and a second push rod that are hinged to each other are symmetrically arranged between the sliding seat 23 and the fixed seat 21. The free end of the first push rod (i.e., Figure 5 the right end of the first push rod in Figure 5 ) is hinged to the fixed seat 21, and the free end of the second push rod (i.e., Figure 4 the left end of the second push rod in

[0040] ) is hinged to the sliding seat 23; a push post 25 is fixed to the side of the sliding seat 23 facing away from the fixed seat 21 (i.e., Figure 4 the left side of the sliding seat 23 in

[0040] ), and the push post 25 passes through the test box 1 and is connected to a side plate 26.

[0040] The cylinder 22 is fixed to the fixed seat 21. As Figure 5 and Figure 10 shown, two air pressure boxes 27 are symmetrically arranged on the fixed seat 21. A push block 28 is slidably arranged between the two air pressure boxes 27. The piston rod 422 of the cylinder 22 passes through the fixed seat 21 and is connected to the push block 28. The two ends of the push block 28 are hinged to third push rods, and the free ends of the third push rods are respectively hinged to the middle positions of the two first push rods.

[0041] In this embodiment, when the lateral loading structure 2 is working, the air cylinder 22 is started, and the piston rod 422 thereof pushes the push block 28 to slide between the two air pressure boxes 27. Since the two ends of the push block 28 are hinged with third push rods, and the free ends of the third push rods are hinged to the middle position of the first push rod, when the push block 28 moves, it will drive the third push rods to move, and then apply a force to the first push rod. The free end of the first push rod is hinged to the fixed seat 21. Under the action of the force, the first push rod rotates at an angle, and at the same time drives the second push rod hinged to it to move. The free end of the second push rod is hinged to the sliding seat 23, and the sliding seat 23 is also slidably connected to the guide rod 24 fixed to one side of the fixed seat 21. Under the combined action of the first push rod and the second push rod, the sliding seat 23 slides to the left along the guide rod 24; the push column 25 fixed to the side of the sliding seat 23 away from the fixed seat 21 moves accordingly, and the push column 25 passes through the connecting side plate 26 of the test box 1, so as to push the side plate 26 to apply a lateral load to the geotechnical sample 14 in the second area 13 of the test box 1.

[0042] As Figure 10 and Figure 11 shown, an air pressure chamber 271 is provided in the air pressure box 27, and a telescopic sealing plate 272 is provided on the air pressure box 27. One end of the telescopic sealing plate 272 is fixed to the air pressure box 27, and the other end of the telescopic sealing plate 272 is connected to the push block 28. It should be noted that the telescopic sealing plate 272 is a common component in the prior art. The purpose of the telescopic sealing plate 272 is to seal the air pressure chamber 271, so that the air pressure chamber 271 is an independent sealed chamber, and to prevent the air pressure chamber 271 from communicating with the outside. An air inlet 273 is opened on the air pressure chamber 271, and a one-way valve is provided at the air inlet 273. The gas can only enter unidirectionally from the air inlet 273. The air pressure chamber 271 is connected to the first pipe 424. When the air cylinder 22 pushes the push block 28 to move, not only does it push the side plate 26 to apply a lateral load to the geotechnical sample 14 in the second area 13 of the test box 1, but the push block 28 also compresses the air pressure chamber 271, and the gas in the air pressure chamber 271 enters the second chamber 423 through the first pipe 424.

[0043] In this embodiment, when the pneumatic box 27 in the lateral loading structure 2 is working, the piston rod 422 of the air cylinder 22 pushes the push block 28 to slide between the two pneumatic boxes 27. Since one end of the telescopic sealing plate 272 provided on the pneumatic box 27 is fixed to the pneumatic box 27 and the other end is connected to the push block 28, when the push block 28 moves, it will drive the telescopic sealing plate 272 to expand and contract, thereby changing the volume of the pneumatic chamber 271. During the process of the push block 28 compressing the pneumatic chamber 271, the pressure in the pneumatic chamber 271 increases. At this time, the one-way valve provided at the air inlet 273 can prevent the gas from escaping from the air inlet 273, ensuring that the gas in the pneumatic chamber 271 can only flow in one direction. As the pneumatic chamber 271 is compressed, the gas inside it enters the second chamber 423 of the driving structure 42 through the first pipe 424 connected to it. The gas entering the second chamber 423 increases the pressure in the chamber, pushing the piston 422 to move inside the driving housing 421, and then driving the analog fault unit 43 to change its shape, realizing the linkage between the lateral load and the dynamic change of the analog fault unit 43. This design cleverly utilizes the air pressure change to achieve the power transmission and coordinated operation between the lateral loading structure 2 and the driving structure 42.

[0044] Compared with the prior art, the traditional lateral loading device can only apply static loads unidirectionally and cannot form a dynamic coupling with the fault parameters of the fracture zone. Most of the prior art uses independent hydraulic systems to control loading and fault adjustment respectively, resulting in problems such as response hysteresis and energy loss. This solution combines the process of applying lateral loads with pneumatic energy storage through a mechanical linkage mechanism, uses a single power source to synchronously drive load application and fault adjustment, eliminates the timing error caused by multi-system coordinated control, realizes the real-time linkage between lateral loading and fault dynamic adjustment, and enables the fault dip angle and fracture width to be automatically adjusted with the change of the surrounding rock stress field; the mechanical linkage design avoids the high energy consumption and complex maintenance problems of the traditional electro-hydraulic control system, and the pneumatic energy storage mechanism ensures the continuous and stable supply of the fault driving force; the synchronous change of the lateral load and the fault morphology during the test process more realistically simulates the interaction relationship between the surrounding rock stress field and the fault structure during the excavation of the tunnel 15, providing high-precision test conditions for studying the disaster-causing mechanism of the water-rich fault fracture zone.

[0045] As a preferred embodiment, the hydraulic press 31 refers to a power device that generates a controllable pressure through hydraulic transmission. Specifically, it can be realized by an electric hydraulic pump cooperating with an oil cylinder, and is used to convert hydraulic energy into mechanical energy to push the load plate 34 to move. Among them, the hydraulic plate 32 refers to a rigid force-transmitting member that bears the output force of the hydraulic press 31. Specifically, it can be processed and formed by a high-strength alloy steel plate, and is used to evenly disperse the pressure applied by the hydraulic press 31. Among them, the hydraulic rod 33 refers to a linear motion actuator that connects the hydraulic plate 32 and the load plate 34. Specifically, it can be realized by a piston rod 422 made of chrome-plated steel cooperating with a sealing component, and is used to transmit the linear motion of the hydraulic plate 32 to the load plate 34. Among them, the load plate 34 refers to the load application surface that directly contacts the geotechnical specimen 14. Specifically, it can be a rectangular steel plate with anti-slip patterns on the surface, and is used to convert the concentrated force into a surface load and evenly transmit it to the specimen surface. Specifically, when the hydraulic press 31 is started, the hydraulic oil is pressed into the oil cylinder to push the piston rod 422 to extend. The piston rod 422 drives the hydraulic plate 32 to move vertically, and the hydraulic plate 32 drives the hydraulic rod 33 to move downward synchronously through a rigid connection. The load plate 34 connected to the end of the hydraulic rod 33 applies the pressure evenly on the surface of the geotechnical specimen 14 in a plane contact manner. The anti-slip patterns on the contact surface between the load plate 34 and the specimen can prevent slip errors during the loading process. By adjusting the output pressure of the hydraulic press 31, the vertical load value applied by the load plate 34 can be accurately controlled, forming a continuously adjustable stress environment, so as to apply a vertical load to the geotechnical specimen 14 in the second area 13 of the test chamber 1 and simulate the vertical pressure environment in actual engineering.

[0046] As a preferred embodiment, the data acquisition system includes: A high-speed camera, installed on one side of the test chamber 1, for frame-by-frame recording of the tunnel 15 in the test chamber 1; Acoustic emission sensors, distributed on the outer side of the lining of the tunnel 15, for obtaining the acoustic signals generated by rock mass fractures; Distributed fiber optic sensors, buried inside the geotechnical specimen 14, for sensing the strain distribution of the geotechnical mass; Pressure sensors, arranged in the surrounding area of the simulated fault unit 43, for measuring the stress changes in the fault zone; Displacement sensors, installed on the inner wall of the test chamber 1, for detecting the displacement of the surrounding rock; and piezometers distributed on the seepage path of the geotechnical specimen 14, for monitoring the pore water pressure state; A computer controller, which is connected to the high-speed camera, acoustic emission sensors, distributed fiber optic sensors, pressure sensors, displacement sensors and piezometers. The computer controller is connected to a data storage device for storing the data of the computer controller.

[0047] A high-speed camera refers to an image acquisition device with high frame rate shooting ability, which can be specifically implemented by an industrial-grade camera. By capturing an image sequence of no less than 1000 frames per second, it can capture the transient displacement caused by fault dislocation and the process of crack propagation. An acoustic emission sensor refers to a piezoelectric device that can receive high-frequency acoustic wave signals, such as a sensor with a frequency response range of 20 kHz to 1 MHz. By capturing the elastic wave signals generated by rock mass rupture, it can identify the dynamic characteristics of the initiation and expansion of microcracks inside rock and soil masses in real time. A distributed fiber optic sensor refers to a sensing optical fiber based on optical time domain reflectometry technology, such as a polyimide-coated optical fiber with a diameter of 0.9 mm. By demodulating the Brillouin scattering optical frequency shift, it can continuously sense the strain distribution at different depths of the rock and soil specimen 14. A pressure sensor refers to a piezoresistive or capacitive mechanical sensor, such as a micro pressure gauge with a range of 0 - 10 MPa, which directly measures the stress change in the area around the simulated fault unit 43. A deformation sensor refers to a high-precision displacement measurement device, such as a laser displacement meter or a displacement sensor, which is used to detect the millimeter-level displacement change of the inner wall of the test box 1. An osmometer refers to a pore water pressure monitoring device, such as a ceramic head osmometer, which reflects the influence of the change in fault fracture width on the groundwater migration path by measuring the water pressure gradient on the seepage path of the rock and soil specimen 14.

[0048] Specifically, through image sequence analysis, the high-speed camera can extract the crack propagation rate and displacement amount on the surface of the tunnel 15 caused by fault dislocation; through collecting the number, energy, and location information of acoustic emission events, the acoustic emission sensor can judge the starting position and propagation direction of rock mass rupture; through demodulating the strain distribution data along the optical fiber, the distributed fiber optic sensor can construct a three-dimensional evolution model of the surrounding rock stress field; the pressure sensor records the dynamic response of the stress in the fault zone with the change of fracture width and dip angle in real time; the deformation sensor evaluates the overall stability of the surrounding rock by monitoring the displacement of the inner wall of the test box 1; the osmometer reveals the reconstruction effect of fault activity on the groundwater seepage path through the pore water pressure data. The computer controller synchronously collects multi-source data and realizes the coupled analysis of the stress field, seepage field, and displacement field through timestamp alignment. Using the developed data synchronous acquisition software, the sampling frequencies of each sensor are unified to 10 Hz, and the data is stored in a solid-state drive.

[0049] In some specific embodiments, the high-speed camera can be configured with a ring-shaped LED fill light system, such as a cold light source array with a color temperature of 5500K, to ensure clear images are obtained in the closed environment of the test box 1; the acoustic emission sensor can adopt an array layout method, such as arranging 8 sensors in a ring outside the lining of the tunnel 15, and determining the coordinates of the acoustic emission source through the time difference location algorithm; the distributed fiber optic sensor can bury multiple sensing optical fibers along the axial direction of the rock and soil specimen 14, such as forming a grid-like distribution at a spacing of 10 cm; the osmometer can be arranged in the upstream and downstream areas of the simulated fault unit 43, such as setting 3 groups of osmometers on both sides of the fault zone to monitor the change of hydraulic gradient.

[0050] On the other hand, the present invention also provides a method for simulating the loading in the water-rich fault fracture zone of a tunnel 15, comprising the following steps: Test configuration: Fill the geotechnical sample 14 in the test box 1 and bury the tunnel 15 model, install the simulated fault unit 43 in the initial state, and arrange the sensor array; Configure the test box 1, and divide the first area 12 and the second area 13 through the partition plate 11; Fill the geotechnical sample 14 in the second area 13 and bury the tunnel 15 model; Install the simulated fault test structure 4, and adjust the simulated fault unit 43 to the first state of the initial inclination angle and crack width; Connect the water inlet pipe 4324 of the hydro-expansion member 432 to the water supply system, and inject liquid into the water injection cavity 4323 until the set pressure; Arrange the sensor array of the data acquisition system, including the acoustic emission sensors outside the tunnel 15 lining, the distributed optical fiber sensors in the geotechnical sample 14, the pressure sensors and piezometers around the simulated fault unit 43; Calibrate the communication links of each sensor with the computer controller.

[0051] Linkage loading and fault adjustment: Synchronously apply the vertical load and the lateral load, and drive the dynamic coordinated adjustment of the fault inclination angle and the crack width of the simulated fault unit 43 through air pressure transmission; Start the vertical loading structure 3, and apply a vertical load to the geotechnical sample 14 through the hydraulic press 31 driving the load plate 34; Synchronously start the cylinder 22 of the lateral loading structure 2, and push the push block 28 to compress the air pressure cavity 271; The gas in the air pressure cavity 271 is transported through the pipeline to the second chamber 423 of the driving structure 42 to drive the piston 422 to move; The piston 422 pulls the second connecting rod 4312 of the simulated fault unit 43 through the push rod 425, causing the displacement of the hinge point of the cross frame 431; The simulated fault unit 43 changes from the first state to the second state, realizing the dynamic coordinated adjustment of the fault inclination angle and the crack width; During this process, the lateral loading structure 2 synchronously applies a lateral load to the geotechnical sample 14 through the push column 25.

[0052] Hydrological response and data acquisition: In response to the deformation of the fault unit triggering the liquid ejection to simulate the seepage effect, synchronously collect the data of crack propagation, rock mass fracture, geotechnical strain, stress and pore water pressure; When the deformation of the simulated fault unit 43 causes the hydrological telescopic member 432 to act, the second telescopic plate 4322 slides in the water injection cavity 4323 to change the cavity volume; when the pressure in the water injection cavity 4323 rises to exceed the threshold value of the water spraying structure 433, the liquid is ejected through the conical flow channel 4332 to simulate the seepage effect of the fault zone; the data acquisition system synchronously captures the following parameters in real time: the high-speed camera records the process of crack propagation, the acoustic emission sensor collects the rock mass rupture signal, the distributed optical fiber sensor monitors the geotechnical strain distribution, the pressure sensor measures the stress change in the fault zone, and the piezometer tracks the evolution of pore water pressure; the computer controller integrates multi-source data and stores it.

[0053] Analysis termination: Apply a decreasing load to establish a mechanical coupling model of fault dip - crack width - surrounding rock stress and a seepage coupling model of crack width - seepage path.

[0054] When the displacement or seepage pressure of the tunnel 15 is monitored to reach the warning threshold, the vertical and lateral loads are decreased at a set rate until they stop; the water supply system is cut off and the liquid in the water injection cavity 4323 is drained; the geotechnical specimen 14 is recovered and the failure characteristics are marked; the computer controller performs time domain alignment processing on the stored data to establish a mechanical coupling model of fault dip - crack width - surrounding rock stress and a seepage coupling model of crack width - seepage path - pore water pressure; based on the acoustic emission event location and strain distribution atlas, the influence mechanism of fault activity on the stability of the tunnel 15 is determined.

[0055] The above embodiments are only the preferred embodiments given to fully illustrate the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or transformations made by those skilled in the art on the basis of the present invention are all within the protection scope of the present invention.

Claims

1. A loading simulation test device for a water-rich fault fracture zone in a tunnel, characterized in that, Comprising: A test chamber (1), within which a partition (11) is provided. The partition (11) divides the test chamber (1) into a first region (12) and a second region (13), and a geotechnical sample (14) is filled in the second region (13); A lateral loading structure (2), configured to apply a lateral load to the geotechnical sample (14) within the second region (13); A vertical loading structure (3), configured to apply a vertical load to the geotechnical sample (14) within the second region (13); A simulated fault test structure (4), including a mounting frame (41) fixedly connected to the partition (11), a driving structure (42) and a simulated fault unit (43). One end of the driving structure (42) is hinged to the mounting frame (41), and the other end of the driving structure (42) is connected to the simulated fault unit (43); the simulated fault unit (43) is hinged to the mounting frame (41) and is used to simulate an adjustable fault; A data acquisition system, which is distributed around the tunnel (15) and is used to monitor in real time the influence of the geotechnical sample (14) on the tunnel (15) during the simulation process and collect the data information generated during the test process; Wherein, the lateral loading structure (2) is connected to the driving structure (42), so that while applying a lateral load, the lateral loading structure (2) drives the driving structure (42) to act, and further drives the simulated fault unit (43) to move relative to the mounting frame (41), so as to dynamically change the inclination angle and width of the simulated fault unit (43) in the geotechnical sample (14).

2. The loading simulation test device for the water-rich fault fracture zone in the tunnel according to claim 1, wherein: The simulated fault unit (43) includes a plurality of simulated fault members connected end to end; Each simulated fault member includes two cross frames (431) arranged in parallel and symmetrically and two hydroscopic expansion members (432) arranged in parallel and symmetrically. The two cross frames (431) are symmetrically arranged on both sides of the two hydroscopic expansion members (432); each cross frame (431) includes a first connecting rod (4311) and a second connecting rod (4312) that are cross-hinged to each other. One of the first connecting rods (4311) is hinged to the mounting frame (41), and one of the second connecting rods (4312) is hinged to a third connecting rod (4313), and the third connecting rod (4313) is hinged to the mounting frame (41).

3. The loading simulation test device for the water-rich fault fracture zone in the tunnel according to claim 2, wherein: Each hydroscopic expansion member (432) includes a first expansion plate (4321) and a second expansion plate (4322). A water injection cavity (4323) is formed in the first expansion plate (4321), and the second expansion plate (4322) is hermetically and slidably arranged in the water injection cavity (4323). The end of the second expansion plate (4322) extends out of the water injection cavity (4323) and is hinged to the first expansion plate (4321) of the adjacent simulated fault member, and the first expansion plate (4321) is hinged to the second expansion plate (4322) of the adjacent simulated fault member.

4. The loading simulation test device for the water-rich fault fracture zone in the tunnel according to claim 3, characterized in that: The first telescopic plate (4321) is provided with a plurality of nozzles and a water inlet connected to the water injection chamber (4323); the water inlet is connected to a water inlet pipe (4324); a one-way valve is provided in the water inlet pipe (4324); A pressure water spray structure (433) is installed in the nozzle, and the pressure water spray structure (433) comprises a nozzle seat (4331) fixedly installed at the nozzle, and a conical flow channel (4332) connected to the water injection chamber (4323) is provided in the nozzle seat (4331), and a spring (4333) and a rubber ball (4334) are provided in the flow channel, and the spring (4333) has a tendency to cause the rubber ball (4334) to block the conical flow channel (4332); When the second telescopic plate (4322) compresses the water injection chamber (4323), causing its internal pressure to increase and overcome the elastic force of the spring (4333), the rubber ball (4334) is pushed to move, so that the liquid in the water injection chamber (4323) can be sprayed out through the conical flow channel (4332).

5. The loading simulation test device for the water-rich fault fracture zone in the tunnel according to claim 4, characterized in that: The simulated fault unit (43) has a first state and a second state; The driving structure (42) comprises a driving housing (421) hinged on the mounting frame (41), a piston (422) being sealed and movably connected inside the driving housing (421), the piston (422) dividing the driving housing (421) into a first chamber and a second chamber (423), the second chamber (423) being connected to a first pipe (424); A push rod (425) is fixedly connected to the piston (422), the push rod (425) is sealingly and slidably connected to the drive housing (421), and the push rod (425) extends out of the second chamber (423) and is hinged to the second connecting rod (4312).

6. The loading simulation test device for the water-rich fault fracture zone in the tunnel according to claim 5, wherein: The side loading structure (2) comprises a fixed seat (21), a cylinder (22), a sliding seat (23) and a plurality of guide rods (24), each of the guide rods (24) being fixed to one side of the fixed seat (21), the sliding seat (23) being slidably connected to the guide rods (24), a first push rod (281) and a second push rod (282) being symmetrically arranged between the sliding seat (23) and the fixed seat (21), the free end of the first push rod (281) being hinged to the fixed seat (21), and the free end of the second push rod (282) being hinged to the sliding seat (23); A push column (25) is fixed to a side of the sliding seat (23) facing away from the fixed seat (21), and the push column (25) passes through the test box (1) and is connected to a side plate (26); The cylinder (22) is fixed on the fixed seat (21). Symmetrically arranged on the fixed seat (21) are air pressure boxes (27). A push block (28) is slidably arranged between the two air pressure boxes (27). The piston (422) rod of the cylinder (22) penetrates through the fixed seat (21) and is connected to the push block (28). The two ends of the push block (28) are hinged with third push rods (283), and the free ends of the third push rods (283) are hinged with the middle positions of the first push rods (281).

7. The loading simulation test device for the water-rich fault fracture zone in the tunnel according to claim 6, wherein: An air pressure cavity (271) is arranged inside the air pressure box (27). An expansion and contraction sealing plate (272) is arranged on the air pressure box (27). One end of the expansion and contraction sealing plate (272) is fixed on the air pressure box (27), and the other end of the expansion and contraction sealing plate (272) is connected to the push block (28). An air inlet (273) is opened on the air pressure cavity (271), and a one-way valve is arranged at the air inlet (273). The air pressure cavity (271) is connected to the first pipeline (424). When the air pressure cavity (271) is compressed, the gas in the air pressure cavity (271) enters the second chamber (423) through the first pipeline (424).

8. The loading simulation test device for the water-rich fault fracture zone in the tunnel according to claim 1, characterized in that: The vertical loading structure (3) includes a hydraulic press (31). A hydraulic plate (32) is connected to the hydraulic press (31). A hydraulic rod (33) is connected below the hydraulic plate (32), and the hydraulic rod (33) is connected to a load plate (34).

9. The loading simulation test device for tunnel water-rich fault fracture zone area according to claim 7, wherein: The data acquisition system includes: A high-speed camera, installed on one side of the test chamber (1) for frame-by-frame recording of the tunnel (15) in the test chamber (1); Acoustic emission sensors, distributed on the outer side of the lining of the tunnel (15) for acquiring acoustic signals generated by rock mass fracture; Distributed optical fiber sensors, buried inside the geotechnical specimen (14) for sensing the strain distribution of the geotechnical mass; Pressure sensors, arranged in the surrounding area of the simulated fault unit (43) for measuring the stress change in the fault zone; Displacement sensors, installed on the inner wall of the test chamber (1) for detecting the displacement of the surrounding rock; and piezometers distributed on the seepage path of the geotechnical specimen (14) for monitoring the pore water pressure state; A computer controller, which is connected to the high-speed camera, the acoustic emission sensors, the distributed optical fiber sensors, the pressure sensors, the displacement sensors and the piezometers. The computer controller is connected to a data memory for storing the data of the computer controller.

10. A simulation test method for loading in a water-rich fault fracture zone area of a tunnel, characterized in that: Using the tunnel water-rich fault fracture zone area loading simulation test device as described in any one of claims 1-9, includes the following steps: Test configuration: Fill the geotechnical specimen (14) in the test chamber (1) and bury the tunnel (15) model, install the simulated fault unit (43) in the initial state, and arrange the sensor array; Linkage loading and fault adjustment: Synchronously apply vertical load and lateral load, and drive the simulated fault unit (43) to dynamically and coordinately adjust the fault dip angle and fracture width through air pressure transmission; Hydrological response and data acquisition: In response to the deformation of the fault unit triggering the simulated seepage effect of liquid ejection, synchronously collect data on fracture propagation, rock mass rupture, geotechnical strain, stress, and pore water pressure; Analysis termination: Decrease the load, and establish a mechanical coupling model of fault dip - fracture width - surrounding rock stress and a seepage coupling model of fracture width - seepage path.

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