Testing device for simulating rock mass shearing-seepage coupling process

Abstract

The invention relates to the related technical field of rock mass mechanics and seepage tests, in particular to a test device for simulating a rock mass shear-seepage coupling process, which comprises a master control system, a loading system, a shear seepage control unit, a seepage loading system and a data acquisition system, a groove cavity used for containing a rock sample is formed in the shear seepage control unit, the upper end and the lower end of the shear face are sealed through rubber rings capable of being extruded and deformed by normal pressure, a closed water cavity is formed to prevent seepage, the loading system is composed of a normal loading unit and an axial loading unit, and variable normal constant pressure and axial shear force are applied to the sample respectively. The seepage loading system establishes a stable seepage channel on a shear surface, and the data acquisition system is used for synchronously recording various parameters. The device realizes shear-seepage coupling simulation under the condition of controllable normal constant pressure by using equivalent confining pressure and sealing effect generated by compression expansion of the rubber ring, and can truly reflect the influence of rock shear deformation on permeability characteristics.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of rock mass mechanics and seepage test, and particularly relates to a test device for simulating a rock mass shear-seepage coupling process. BACKGROUND

[0002] Rock mass seepage characteristics are key factors affecting the stability of underground engineering, the risk of water inrush in roadways, and the analysis of surrounding rock failure modes under high water pressure conditions. In actual engineering, the seepage of rock mass mainly occurs along the structural plane, weak plane or fracture generated after stress, and the permeability will change significantly with the occurrence of shear deformation. However, most of the existing rock shear fracture seepage test devices can only simulate uniaxial stress conditions, and cannot truly reflect the mechanical behavior and seepage characteristics of rock under complex stress environment, which leads to the fact that the test results under uniaxial stress conditions are often difficult to accurately predict the performance of rock in actual engineering, thereby increasing the error and risk of engineering design and construction. Specifically, the traditional shear seepage test has problems such as lateral leakage, unstable seepage path, unstable seepage boundary, and insufficient loading coupling, which limits the accurate simulation of the shear-seepage coupling process of rock mass. Therefore, there is an urgent need for a test device and method that can effectively control the seepage path, simulate the real stress state and realize synchronous data acquisition, so as to further explore the evolution law of fracture permeability characteristics of rock in the process of shear deformation, and provide reliable technical support for the seepage mechanics research of rock mass engineering and coal mine roadway.

[0003] To address the aforementioned issues, a search revealed a patent with publication number CN118408842B disclosing a shear box and its usage method for testing the shear-seepage coupling characteristics of rock mass. The patent proposes that "by setting a first compression block in a first holding tank and a second compression block in a second holding tank, the upper and lower rock mass samples are respectively compressed. For example, the first compression block utilizes the combined action of a first adjusting bolt and a first small wedge and a second large wedge on a first inclined surface. The first adjusting bolt pulls the first small wedge in a second direction, and this movement in the second direction pushes the first large wedge through the first inclined surface, achieving movement in two directions: in the first direction, it moves towards the upper rock mass sample, thus compressing the first elastic seal on this side; and in the third direction, it moves towards the lower movable shear box, thus compressing the first elastic seal on this side. Ultimately, the first and second compression blocks respectively achieve compression and sealing of the first elastic seals on the corresponding first and second large wedges, ensuring that the upper and lower rock mass samples are sealed in both the first and third directions." The sealing effect is achieved through compression in the first direction. For the sealing of the upper and lower rock mass samples on both sides in the second direction, an elastic capsule is used. Fluid is injected into the elastic capsule, causing it to expand and deform elastically, thus sealing the contact points of the upper and lower rock mass samples and the gaps around the elastic capsule, forming multiple sealing guarantees. Furthermore, the elastic capsule is made of corrosion-resistant material, providing a certain degree of corrosion resistance to the injected fluid, ultimately providing strong sealing and corrosion resistance for the direct shear test system under seepage conditions. Further, the first limiting protrusion on the first front and rear side plates cooperates with the first limiting groove on the fixed shear pull head to achieve outward separation of the first front and rear side plates. Compared to the traditional method of connecting the first front and rear side plates to the fixed shear pull head with bolts, this method is simpler in structure and easier and more secure in installation. Its structural complexity and reliance on high-precision adjustment make it cumbersome and costly to operate in conventional rock mass shear seepage tests, and it is difficult to achieve effective sealing quickly and stably.

[0004] In light of this, in-depth research into the aforementioned issues led to the creation of this case. Summary of the Invention

[0005] The purpose of this invention is to provide a test device for simulating the shear-seepage coupling process of rock mass, in order to solve the problem that most existing rock shear fracture seepage test devices mentioned in the background art can only simulate uniaxial stress conditions and cannot truly reflect the mechanical behavior and seepage characteristics of rocks under complex stress environments. The test results under uniaxial stress conditions often cannot accurately predict the performance of rocks in actual engineering, leading to increased errors and risks in engineering design and construction.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an experimental device for simulating the shear-seepage coupling process of rock mass, comprising a total control system, a loading system, a shear-seepage control unit, a seepage loading system, and a data acquisition system;

[0007] The shear seepage control unit includes a vehicle base. A water-receiving base is located at the upper end of the vehicle base. A lower water-sealing metal base is located above the water-receiving base. A rubber gasket is placed in a groove on the upper surface of the lower water-sealing metal base. A lower metal box is located on the upper surface of the lower metal box. The lower part of a rock sample is placed in the cavity of the lower metal box. A U-shaped inclined rubber sleeve is fitted on the upper side of the outer ring of the lower part of the rock sample. A U-shaped pressure strip is fitted on the lower side of the outer ring of the lower part of the rock sample. Metal screws are installed at the four corners of the vehicle base. The device includes a metal upper box above the lower metal box, a top water-sealing metal top plate connected to the upper metal box, a test device top plate connected to the top water-sealing metal top plate, a normal pressure column in the groove of the top water-sealing metal top plate, a top plate nut connected to one end of the metal threaded column, a rock sample upper part in the groove cavity of the upper metal box, an annular rubber ring on the outer ring of the upper part of the rock sample, a metal water guide groove inserted into the water inlet side of the lower metal box, and an outlet water guide groove placed into the water outlet side of the upper metal box.

[0008] Preferably, the shear seepage control unit includes a base, a shear unit, a seepage unit, and a normal pressure unit. It functions to fix the rock to provide conditions for shearing, to close rock fissures through normal pressure, and to provide a sealing device for the seepage test, ensuring a unique seepage path. The frame of the shear seepage control unit mainly includes: a vehicle base, a water-receiving base, a lower water-sealing metal base, a lower metal box, an upper metal box, an upper water-sealing metal top plate, a device top plate, and a normal pressure column. The vehicle base facilitates test installation and debugging, and the water-receiving base is installed on it to collect wastewater overflowing during disassembly and assembly to prevent contamination of the laboratory. A lower water-sealing metal base is installed on the water base. A rubber gasket with a cross-sectional diameter of approximately 5mm is placed on the lower water-sealing metal base. Under pressure, the gasket expands, preventing water leakage from the upper surface of the lower water-sealing metal base. A lower metal box is installed on the lower water-sealing metal base. The lower metal box has a cavity inside. The rock sample, after being fitted with a U-shaped inclined rubber sleeve, a U-shaped pressure strip, and a metal water guide groove, is inserted into the cavity. An annular groove is also provided to hold the rubber gasket with a cross-sectional diameter of approximately 5mm. At this point, the metal water guide groove, the lower metal box, the sample, and the upper metal box form a water inlet chamber. The water inlet chamber is connected to the shear surface... In direct contact, when the U-shaped inclined rubber sleeve is compressed, the water flowing in from the inlet will not flow downwards to the bottom surface, but will only flow through the metal water guide groove to the water inlet chamber. The annular rubber ring is placed on the upper half of the sample, tightly against the lower metal box. The water guide groove is inserted into the side of the annular rubber ring near the outlet of the device, and the upper metal box is placed on top. The top plate nut of the device applies downward pressure to the annular rubber ring, causing it to expand and seal the water in the water inlet chamber, preventing it from flowing upwards. Simultaneously, the upper metal box has a groove to hold a rubber washer with a cross-sectional diameter of approximately 5mm. An upper sealing metal top plate is installed on the upper metal box. The top plate nut of the device... The lower metal upper box groove provides pressure to the rubber gasket. The upper water-sealing metal top plate has a normal pressure column in the middle groove. The normal pressure column contacts the upper surface of the sample, transferring the normal load of the loading system to the upper surface of the rock. The test device top plate is fitted onto the normal pressure column, and the four top plate nuts at the four corners are tightened. Pressure is applied downward through the bolt structure, causing the U-shaped inclined rubber sleeve and the annular rubber ring inside the device to be deformed under great pressure and make complete contact with the lower metal box, forming a whole on the shear plane, sealing the ineffective seepage path, so that the seepage path is kept on the shear plane and will not overflow from all sides.

[0009] The data acquisition system includes a shear displacement measuring device, which is installed on both sides of the shear seepage control unit. One end of the scale of the shear displacement measuring device is equipped with a top plate of the shear displacement measuring device. Normal displacement measuring devices are installed at the four corners of the normal pressure column, and a normal displacement measuring device base is provided at the lower end of the normal displacement measuring device.

[0010] Preferably, the data acquisition system includes a shear displacement measuring instrument, a normal displacement measuring instrument, an outlet water pressure measuring instrument, an inlet water pressure measuring instrument, and a balance. The displacement measuring instrument is installed at a fixed position in the lateral axial direction and normal direction of the shear seepage control unit. The outlet water pressure measuring instrument is installed at the outlet. The water seeping from the shear surface flows through the outlet water pressure measuring instrument into the measuring cylinder on the balance.

[0011] The loading system includes a normal pressure head module, an axial shear pressure head module, and an axial shear reaction force module. A pressure chamber is located at the center of the loading system, and a shear seepage control unit is located inside the pressure chamber.

[0012] Preferably, the loading system includes a reaction frame, a horizontal axial loading shaft, a normal vertical loading shaft, and an oil source control. The normal vertical loading shaft is set on top of the simulation device to continuously apply a stable normal constraint force to the sample during shear loading. The horizontal axial loading shaft is set in the axial direction of the simulation device to provide shear force.

[0013] The overall control system is electrically connected to the above-mentioned systems and is used to collect, process, and display shear force, normal force, displacement, and water pressure data to realize automatic control and synchronous data acquisition during the test process.

[0014] Preferably, the main controller includes a desktop computer, data cables, a loading system data cable, a balance data cable, a water pressure monitoring device data cable, and a displacement monitoring device data cable. The desktop computer is connected to each subsystem via the data cables.

[0015] Preferably, an upper part and a lower part of the rock sample are provided between the lower metal box and the upper metal box, and the upper part and the lower part of the rock sample form a water-sealing structure by a U-shaped inclined rubber sleeve and an annular rubber ring, respectively.

[0016] Preferably, the U-shaped inclined rubber sleeve and the annular rubber ring are compressed by the normal pressure column to form a sealed cavity with the lower metal box and the upper metal box, which is used to limit the water flow path to pass only through the shear surface of the sample.

[0017] Preferably, the top sealing metal top plate and the test device top plate, together with the device's own weight, form a normal load on the U-shaped inclined rubber sleeve and the annular rubber ring by tightening the top plate nut and compressing and expanding them.

[0018] Preferably, the normal pressure column is in contact with the upper part of the rock sample to transfer the normal pressure of the loading system to the sample.

[0019] Preferably, the four corners of the vehicle base are provided with bolt connection structures, and the internal rubber ring is deformed by tightening the top plate nut, thereby enhancing the sealing performance and stabilizing the confining pressure.

[0020] An experimental method for simulating the shear-seepage coupling process in rock mass includes the following steps:

[0021] S1. Sample preparation stage: including: internal rock sample: a cuboid rock column with dimensions of 100mm×100mm×200mm, which is split along the axial direction;

[0022] S2. Sample installation stage: The sample is precisely placed into the shear flow test device and installed from bottom to top according to the structure of the device.

[0023] S3. Equipment Inspection Phase: Open the oil source control system and main control console. Adjust the loading system and obtain the original shear displacement and normal displacement, which should match the device dimensions. Observe the operating status of all load and displacement sensors. If there are no abnormalities, proceed to the next step.

[0024] S4. Preload application stage: Adjust the loading system so that the normal load is slowly increased to 300kN;

[0025] S5, Shear-Seepage Stage: After the normal load stabilizes, adjust the seepage loading system to increase the seepage pressure to 2.5MPa~3MPa, record the relationship between seepage pressure and time. When the seepage displacement reaches 230mm, reduce the seepage pressure to about 0.5MPa, adjust the loading system to adjust the shear deformation to 1mm, and repeat the above operation in S5 after stabilization. Finally, shear to the target deformation and obtain seepage pressure parameters and effluent pressure parameters under different shear deformation degrees in multiple segments.

[0026] S6. Unloading phase: Gradually reduce normal load, shear load and seepage load until zero;

[0027] S7. End of test: Remove the sample, observe its morphology and fracture state, and the test is complete;

[0028] S8. Clean the test facilities and laboratory of stains, and turn off the water and electricity.

[0029] Compared with the prior art, the beneficial effects of the present invention are:

[0030] 1. By utilizing the coupling of bolt structure, multi-layer rubber, and metal outer casing, and through the physical properties of soft material deformation under pressure, this method solves the problems of lateral leakage, unstable seepage path, unstable seepage boundary, and insufficient loading coupling in traditional shear seepage tests. It simulates the conditions of rocks in actual environments through normal and axial loads, realizing visualization of the shear seepage process. It can acquire multi-dimensional data in real time, including normal displacement, normal load, normal deformation, shear displacement, shear load, shear deformation, seepage displacement, seepage pressure, and effluent pressure. It automatically plots the relationship between the above parameters and time in the central control platform, allowing test personnel to transparently understand the changes in the mechanical properties and seepage characteristics of rocks during the shear seepage process.

[0031] 2. By utilizing the equivalent confining pressure and sealing effect generated by the expansion of the rubber ring under pressure, shear-seepage coupling simulation under controllable normal constant pressure conditions is realized. It can realistically reflect the influence of rock shear deformation on permeability characteristics. The device has a compact structure, good sealing performance, and high repeatability, and is suitable for seepage mechanics research in rock engineering and coal mine roadways. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the overall structure of the experimental device for simulating the shear-seepage coupling process in rock mass according to the present invention.

[0033] Figure 2 This is a schematic diagram of the data acquisition system of the experimental device structure for simulating the coupled shear-seepage process in rock mass according to the present invention;

[0034] Figure 3 This is a side cross-sectional schematic diagram of the experimental device structure used in this invention to simulate the coupled shear-seepage process in rock mass;

[0035] Figure 4 This is a schematic diagram of the key sealing structure of the experimental device used in this invention to simulate the shear-seepage coupling process in rock mass.

[0036] Figure 5 This is a schematic diagram of the loading system and shear-seepage control unit of the experimental apparatus of the present invention used to simulate the coupled process of rock mass shear and seepage.

[0037] In the diagram: 1. Vehicle base; 2. Water receiving base; 3. Lower water-sealing metal base; 4. Shear head; 5. Lower metal box; 6. Upper metal box; 7. Upper water-sealing metal top plate; 8. Test device top plate; 9. Normal pressure column; 10. Top plate nut; 11. U-shaped inclined rubber sleeve; 12. U-shaped lower pressure strip; 13. Metal threaded column; 14. Upper part of rock sample; 15. Lower part of rock sample; 16. Annular rubber ring; 17. Metal water guide channel; 18. Water outlet guide channel; 19. Shear displacement measuring device; 20. Normal displacement measuring device base; 21. Shear displacement measuring device top plate; 22. Normal displacement measuring device; 23. Rubber gasket; 24. Loading system; 25. Pressure chamber. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] Please seeFigures 1-5 The present invention provides a technical solution: an experimental device for simulating the shear-seepage coupling process of rock mass, comprising a total control system, a loading system, a shear-seepage control unit, a seepage loading system and a data acquisition system;

[0040] The shear seepage control unit fixes a rock of a specified size inside the device. It performs shearing and seepage tests via a two-part metal box structure, corresponding to the inlet, outlet, and inlet chamber. The device includes a base 1, a water-receiving base 2 at its upper end, a lower water-sealing metal base 3 above the water-receiving base 2, a rubber gasket 23 placed in a groove on the upper surface of the lower water-sealing metal base 3, and a lower metal box 5 on its upper surface. A rock sample lower part 15 is placed inside the cavity of the lower metal box 5. A U-shaped inclined rubber sleeve 11 is fitted around the upper side of the outer ring of the rock sample lower part 15. A U-shaped pressure strip 12 is fitted on the bottom of the vehicle base 1. Metal threaded posts 13 are installed at the four corners of the base. A metal upper box 6 is set above the metal lower box 5. A water-sealing metal top plate 7 is connected above the metal upper box 6. A test device top plate 8 is connected above the water-sealing metal top plate 7. A normal pressure post 9 is set in the groove of the water-sealing metal top plate 7. A top plate nut 10 is connected to one end of the metal threaded post 13. A rock sample upper part 14 is set in the groove of the metal upper box 6. An annular rubber ring 16 is fitted around the outer ring of the rock sample upper part 14. A metal water guide groove 17 is inserted into the water inlet side of the metal lower box 5. A water outlet guide groove 18 is placed into the water outlet side of the metal upper box 6.

[0041] The data acquisition system includes a shear displacement measuring device 19, which is installed on both sides of the shear seepage control unit. A shear displacement measuring device top plate 21 is installed at one end of the scale of the shear displacement measuring device 19. Normal displacement measuring devices 22 are installed at the four corners of the normal pressure column 9, and normal displacement measuring device bases 20 are installed at the lower ends of the normal displacement measuring devices 22. Figure 2 As shown, shear displacement measuring devices 19 are arranged on both sides of the shear seepage control unit. The scale of the shear displacement measuring device 19 rests on the top plate 21 of the shear displacement measuring device. When shear deformation occurs, the scale will move a corresponding distance. The average value of the values ​​measured by the shear displacement measuring devices 19 on both sides is taken as the shear displacement. The normal displacement measuring device 22 rests on the base 20 of the normal displacement measuring device. When the device is subjected to axial load, it deforms and the scale moves a corresponding distance. The average value of the four normal displacement measuring devices 22 is taken as the normal displacement.

[0042] The loading system 24 includes a normal pressure head module, an axial shear pressure head module, and an axial shear reaction force module. A pressure chamber 25 is located at the center of the loading system, and a shear seepage control unit is installed inside the pressure chamber 25. Figure 5As shown, it includes a normal indenter module, an axial shear indenter module, and an axial shear reaction module. A pressure chamber 25 is set at the center of the loading system 24. A shear seepage control unit is set in the pressure chamber 25. The shear seepage control unit fixes a standard cuboid rock sample and simulates the rock stress state through normal load and shear load.

[0043] The loading system 24 also includes a seepage loading system, which includes a water pump and a pressurizing device connected to a shear seepage control unit. It is used to establish a stable seepage pressure on the shear surface of the sample. It includes a water filling chamber and a pressurizing pump chamber. The water filling and seepage pressure are controlled by a central control platform. At the same time, it can obtain the accurate values ​​of shear load and normal load in real time.

[0044] The main control system is electrically connected to the above systems and is used to collect, process, and display shear force, normal force, displacement, and water pressure data to realize automatic control and synchronous data acquisition during the test process. As the main control platform of the test system, the main control system can receive data transmitted from the data acquisition system and centrally display: normal displacement, normal load, normal deformation, shear displacement, shear load, shear deformation, seepage displacement, seepage pressure, and outlet pressure, and generate curves of the above parameters changing over time. At the same time, the main control platform can control the loading system and the seepage loading system.

[0045] Furthermore, a rock sample upper part 14 and a rock sample lower part 15 are provided between the lower metal box 5 and the upper metal box 6, and the upper rock sample upper part 14 and the lower rock sample lower part 15 form a water-sealing structure through a U-shaped inclined rubber sleeve 11 and an annular rubber ring 16, respectively.

[0046] Furthermore, the U-shaped inclined rubber sleeve 11 and the annular rubber ring 16 are squeezed by the normal pressure column 9 and form a sealed cavity with the lower metal box 5 and the upper metal box 6, which is used to limit the water flow path to pass only through the shear surface of the sample.

[0047] Furthermore, the top sealing metal top plate 7 and the test device top plate 8, together with the device's own weight, exert a normal load on the U-shaped inclined rubber sleeve 11 and the annular rubber ring 16 by tightening the top plate nut 10, and compress and expand them.

[0048] Furthermore, the normal pressure column 9 contacts the upper part 14 of the rock sample to transfer the normal pressure of the loading system to the sample.

[0049] Furthermore, the data acquisition system also includes two sets of shear displacement measuring instruments and four sets of normal displacement measuring instruments, which are installed on both sides of the shear seepage control unit and at fixed positions in the normal direction, respectively, for real-time monitoring of shear and normal deformation.

[0050] Furthermore, the overall control system includes a desktop computer, a data acquisition module, and multiple signal lines. The desktop computer is connected to the loading system, the seepage loading system, and the data acquisition system via data lines to achieve automatic loading and synchronous data display.

[0051] Furthermore, bolt connection structures are provided at the four corners of the base 1. By tightening the top plate nut 10, the internal rubber ring is deformed under pressure, which enhances the sealing performance and stabilizes the confining pressure.

[0052] Working principle: The base 1 is installed on the slide rail of the loading system 24, and the water receiving base 2 is installed on the base 1; the lower water sealing metal base 3 is installed on the water receiving base 2, and a rubber washer 23 with a cross-sectional diameter of about 5mm is placed in the groove of the lower water sealing metal base 3. A metal lower box 5 is set on the lower water sealing metal base 3, and a rubber washer 23 with a cross-sectional diameter of about 5mm is also placed in the groove of the metal lower box 5. The four corner screws of the metal lower box 5 are fixed to the nuts under the base 1 so that the base 1, the lower water sealing metal base 3, and the metal lower box 5 are not When subjected to load, relative displacement will occur. Take the prepared rock sample, attach the U-shaped lower pressure strip 12, attach the U-shaped inclined rubber sleeve 11, and place it into the lower metal box 5 chamber. Insert a metal water guide groove 17 into the inlet side. Inserting the metal pressure strip reduces the size of the inlet chamber, enhancing its sealing and ensuring more stable water pressure within the inlet chamber. Place sliding rails on both sides to assist in the displacement that occurs when the upper and lower metal boxes are sheared. At this point, place the annular rubber ring 16 on the upper half of the rock sample, leaving an opening on the outlet side for the outlet water guide groove. 18. Place the upper metal box 6 on top, and put a rubber washer 23 with a cross-sectional diameter of about 5mm in the groove of the upper metal box 6. Install the upper water-sealing metal top plate 7 on the upper metal box 6, and tighten the six screws on the upper water-sealing metal top plate 7 to prevent relative misalignment between the upper metal box 6 and the upper water-sealing metal top plate 7 during the shearing process. Install L-shaped shearing heads 4 on both sides, each with two rows of four screws. One side is connected to the lower water-sealing metal top plate and the lower metal box 5, and the other side is connected to the upper metal box 6 and the upper water-sealing metal top plate 7. When the loading system 24 applies a load to the device, the force is transmitted from the shear head 4 to the upper metal box 6 and the lower metal box 5 in the middle, causing shear deformation of the rock. A normal pressure column 9 is placed in the chamber inside the upper water-sealing metal top plate 7, and a metal ring is fitted onto the normal pressure column 9. The twelve screws on the metal ring are tightened. Four metal threaded posts 13 are installed at the four corners of the base plate 1. Then, the test device top plate 8 is fitted onto the four metal threaded posts 13, and the top plate nuts 10 are tightened. The screws on the test device top plate 8 are tightened, and then the data acquisition system is installed. Figure 2The shear displacement measuring device 19 is fixed to the lower metal box 5 and the lower water-sealing metal base 3. The scale of the measuring instrument rests on the top plate 21 of the shear displacement measuring device. This is done on both sides of the device. Normal displacement measuring device bases 20 are installed on both sides. After installation, ensuring there is no shaking, four normal displacement measuring devices 22 are installed on the normal pressure column 9. Figure 5 As shown, the entire shear seepage control unit is pushed into the pressure chamber 25 within the loading system 24 via a track, and the data cable of the installed data acquisition device is connected to the main control platform.

[0053] The operation of the main control platform is as follows:

[0054] P1: Turn on the power to the main control platform, load system, and percolation load system;

[0055] P2: Open the oil source control system on the main control platform. The main control platform is connected to the loading system, seepage loading system, and data acquisition system.

[0056] P3: Adjust the shear displacement and normal displacement, and observe the values ​​of shear load and normal load. When the load starts to increase steadily, the contact is complete and the shear displacement will no longer increase.

[0057] P4: Observe whether the shear displacement and normal displacement are consistent with the dimensions of the shear seepage control unit. If there is any abnormality, stop the test and investigate the problem.

[0058] P5: The subsequent adjustment normal load increases to 300kN at a rate of 5000N / s;

[0059] P6: After the normal load stabilizes, adjust the seepage loading system so that the seepage pressure increases to 2.5MPa~3MPa at a rate of 1MPa / s, and record the relationship between seepage pressure and time.

[0060] P7: When the seepage displacement reaches 230mm, reduce the seepage pressure to approximately 0.5MPa at a rate of 1MPa / s;

[0061] P8: Adjust the loading system to set the shear deformation to 1mm;

[0062] P9: After stabilization, add seepage water to the seepage loading system and adjust the seepage displacement velocity to 50 mm / min, with a target of 1 mm.

[0063] P10: Water addition is complete when the seepage displacement reaches 1mm;

[0064] P11: Adjust the shear deformation rate to 0.3 mm / min with a target of 1 mm, then repeat the above operation to increase the seepage pressure to 2.5 MPa~3 MPa at a rate of 1 MPa / s, and record the relationship between seepage pressure and time, etc., until the shear deformation reaches 7 mm;

[0065] P12: At this point, the relationship between seepage pressure and time in multiple segments is collected on the main control platform. The multiple curves represent the seepage pressure under different shear deformation conditions.

[0066] P13: Adjust the shear load and normal load to slowly reduce the load to 0~1000N. Adjust the shear displacement and normal displacement to separate the loading system from the shear seepage control unit. Turn off the oil source control system, disconnect the main control platform from each system, turn off the power, clean any stains that may exist on the test device, and end the test.

[0067] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An experimental apparatus for simulating the shear-seepage coupling process in rock mass, comprising a total control system, a loading system, a shear-seepage control unit, a seepage loading system, and a data acquisition system, characterized in that: The shear seepage control unit includes a vehicle base (1), a water receiving base (2) is provided at the upper end of the vehicle base (1), a lower water sealing metal base (3) is provided above the water receiving base (2), a rubber gasket (23) is placed in the groove on the upper surface of the lower water sealing metal base (3), a metal lower box (5) is provided on the upper surface of the lower water sealing metal base (3), a rock sample lower part (15) is placed in the groove of the metal lower box (5), a U-shaped inclined rubber sleeve (11) is fitted on the upper side of the outer ring of the rock sample lower part (15), a U-shaped lower pressure strip (12) is fitted on the lower side of the outer ring of the rock sample lower part (15), and metal threaded columns (13) are installed at the four corners of the vehicle base (1). A metal upper box (6) is provided above the lower metal box (5). A water-sealing metal top plate (7) is connected above the upper metal box (6). A test device top plate (8) is connected above the upper water-sealing metal top plate (7). A normal pressure column (9) is provided in the groove of the upper water-sealing metal top plate (7). A top plate nut (10) is connected to one end of the metal threaded column (13). A rock sample upper part (14) is provided in the groove of the upper metal box (6). An annular rubber ring (16) is fitted around the upper rock sample upper part (14). A metal water guide groove (17) is inserted into the water inlet side of the lower metal box (5). A water outlet guide groove (18) is placed into the water outlet side of the upper metal box (6). The data acquisition system includes a shear displacement measuring device (19), which is set on both sides of the shear seepage control unit. A shear displacement measuring device top plate (21) is set at one end of the scale of the shear displacement measuring device (19). A normal displacement measuring device (22) is installed at the four corners of the normal pressure column (9). A normal displacement measuring device base (20) is set at the lower end of the normal displacement measuring device (22). The loading system (24) includes a normal pressure head module, an axial shear pressure head module, and an axial shear reaction force module. A pressure chamber (25) is provided at the center of the loading system, and a shear seepage control unit is provided in the pressure chamber (25). The seepage loading system includes a water pump and a pressurizing device, which are connected to a shear seepage control unit to establish a stable seepage pressure on the shear surface of the sample. The overall control system is electrically connected to the above-mentioned systems and is used to collect, process, and display shear force, normal force, displacement, and water pressure data to realize automatic control and synchronous data acquisition during the test process.

2. The experimental apparatus for simulating the shear-seepage coupling process of rock mass according to claim 1, characterized in that: The lower metal box (5) and the upper metal box (6) are provided with an upper part (14) and a lower part (15) of the rock sample, and the upper part (14) and the lower part (15) of the rock sample are respectively formed by a U-shaped inclined rubber sleeve (11) and an annular rubber ring (16) to form a water-sealing structure.

3. The experimental apparatus for simulating the shear-seepage coupling process in rock mass according to claim 1, characterized in that: The U-shaped inclined rubber sleeve (11) and the annular rubber ring (16) are squeezed by the normal pressure column (9) and form a sealed cavity with the lower metal box (5) and the upper metal box (6) to limit the water flow path to pass only through the shear surface of the sample.

4. The experimental apparatus for simulating the shear-seepage coupling process of rock mass according to claim 1, characterized in that: The top sealing metal top plate (7) and the test device top plate (8) together with the device's own weight, through tightening the top plate nut (10), form a normal load on the U-shaped inclined rubber sleeve (11) and the annular rubber ring (16) and compress and expand.

5. The experimental apparatus for simulating the shear-seepage coupling process of rock mass according to claim 1, characterized in that: The normal pressure column (9) is in contact with the upper part (14) of the rock sample and is used to transfer the normal pressure of the loading system to the sample.

6. The experimental apparatus for simulating the shear-seepage coupling process in rock mass according to claim 1, characterized in that: The data acquisition system also includes two sets of shear displacement measuring instruments and four sets of normal displacement measuring instruments, which are installed on both sides of the shear seepage control unit and at fixed positions in the normal direction, respectively, for real-time monitoring of shear and normal deformation.

7. The experimental apparatus for simulating the shear-seepage coupling process of rock mass according to claim 1, characterized in that: The overall control system includes a desktop computer, a data acquisition module, and multiple signal lines. The desktop computer is connected to the loading system, the seepage loading system, and the data acquisition system via data lines to achieve automatic loading and synchronous data display.

8. The experimental apparatus for simulating the shear-seepage coupling process of rock mass according to claim 1, characterized in that: The base (1) is provided with bolt connection structure at the four corners. By tightening the top plate nut (10), the internal rubber ring is deformed under pressure, which enhances the sealing performance and stabilizes the confining pressure.

9. A test method for simulating the shear-seepage coupling process of rock mass is implemented using the test apparatus for simulating the shear-seepage coupling process of rock mass as described in any one of claims 1-8, characterized in that, Includes the following steps: S1. Sample preparation: Prepare a rectangular rock column with dimensions of 100mm×100mm×200mm and split it axially to form a shear surface; S2. Install the sample: Place the sample into the shear seepage control unit and install the vehicle base, lower water seal metal base, lower metal box, sample, U-shaped rubber sleeve, metal water guide groove, annular rubber sleeve, upper metal box, upper water seal metal top plate, normal pressure column and device top plate in sequence. S3. Equipment Inspection: Connect the oil source control system, loading system and data acquisition system, and confirm that the sensor values ​​are normal; S4. Apply normal preload: Adjust the normal loading system to slowly increase the normal load to 300kN and maintain constant pressure; S5. Apply seepage pressure: Adjust the seepage loading system to increase the seepage pressure to 2.5MPa~3MPa at a rate of 1MPa / s, and record the change of inlet water pressure over time. S6. Apply shear deformation: Apply shear force under normal constant pressure and steady seepage conditions to cause the sample to undergo 1 mm shear deformation, and record the shear force and seepage parameters. S7. Repeat the application of load and seepage stage to obtain seepage curves under different shear deformations; S8. Unloading phase: Gradually reduce normal load, shear load and seepage pressure until zero; S9. End of test: Remove the sample, observe the rock failure morphology, and clean the test apparatus.

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