Multifunctional rock joint full shear-seepage coupling test system containing heating module

Abstract

The invention belongs to the technical field of mechanical test devices, and provides a multifunctional rock joint full-shear-seepage coupling test system comprising a heating module, the multifunctional rock joint full-shear-seepage coupling test system comprises a constant-temperature box, the constant-temperature box is internally provided with a confining pressure generating mechanism for injecting water into the constant-temperature box; the shearing assembly comprises an upper shearing box and a lower shearing box which are arranged in the constant-temperature box, the top and the bottom of the sample are clamped in the upper shearing box and the lower shearing box respectively, loading mechanisms are arranged between the upper shearing box and the constant-temperature box and between the lower shearing box and the constant-temperature box, and the loading mechanisms are used for enabling the upper shearing box and the lower shearing box to longitudinally clamp and transversely shear the sample; the high-temperature loading assembly is arranged in the constant-temperature box and is used for heating water in the constant-temperature box; a crack is formed in the middle of the sample, and the seepage assembly is used for enabling seepage water to flow through the crack of the sample to form crack seepage. According to the invention, comprehensive simulation of a'heat-force-water 'multi-field coupling environment where underground deep rock joints are located is realized in one system.

Description

Technical Field

[0001] This invention belongs to the field of mechanical testing equipment technology, and particularly relates to a multifunctional rock joint full shear-seepage coupling test system with heating module. Background Technology

[0002] Currently, geothermal development urgently needs to clarify the key factors and indicators controlling the disaster-causing energy of hydraulically induced fracture shear slip. However, existing research rarely focuses on the disaster-causing energy (micro-earthquakes, or even strong earthquakes) of hydraulically induced fracture shear slip, and even less on the disaster-causing energy of fracture shear slip in geothermal temperature-pressure coupled environments. Therefore, precise experiments are needed to determine the energy release patterns of hydraulically induced fracture shear slip in deep geothermal reservoirs.

[0003] In deep geothermal development, the strength and deformation characteristics of rocks have a significant impact on the structural design, sealing, and hydraulic fracturing of geothermal wells. To meet these requirements, direct shear testing of rocks, as a crucial experimental method, is essential for understanding the behavior of rocks under coupled hydro-mechanical-thermal environments. However, existing coupled direct shear testing devices for rocks are rarely applied in deep geothermal research, and significant problems exist: 1. Insufficient multi-field coupling capability: Currently, most direct rock shearing devices can only conduct experiments under single physical factors, such as temperature and pressure. There is a lack of experimental devices capable of simulating geothermal temperatures, water environments, and pressures while simultaneously conducting acoustic emission experiments. This limitation means that experimental results cannot accurately reflect the actual rock responses during deep geothermal development. 2. Lack of precision in temperature and pressure control: During deep geothermal development, temperature and pressure often fluctuate drastically. However, existing experimental equipment suffers from insufficient precision in controlling high temperatures and pressures, making it difficult to meet stringent experimental requirements. This affects the repeatability and reliability of the experiments, and consequently, the interpretation and application of the experimental results. 3. Insufficient simulation capability of hydraulic fracturing process: In deep geothermal development, hydraulic fracturing is an important means to enhance resource extraction. However, traditional direct shear devices often cannot achieve precise control of fluid injection rate and pressure during hydraulic fracturing, which seriously affects the experimental results. Summary of the Invention

[0004] The purpose of this invention is to provide a multifunctional rock joint full shear-seepage coupling test system with a heating module to solve the above-mentioned problems.

[0005] To achieve the above objectives, the present invention provides the following solution: a multifunctional rock joint full shear-seepage coupling test system including a heating module, comprising: A constant temperature chamber, wherein the constant temperature chamber is equipped with a confining pressure generating mechanism for injecting water into the chamber; The shearing assembly includes an upper shear box and a lower shear box disposed inside the constant temperature chamber. The top and bottom of the sample are respectively snapped into the upper shear box and the lower shear box. A loading mechanism is provided between the upper shear box, the lower shear box and the constant temperature chamber. The loading mechanism is used to make the upper shear box and the lower shear box clamp the sample longitudinally and shear it laterally. A high-temperature loading component is disposed inside the constant temperature chamber and is used to heat the water inside the constant temperature chamber; The seepage assembly has a crack in the middle of the sample (6). The seepage assembly is used to allow seepage water to flow through the crack of the sample (6) to form crack seepage.

[0006] Preferably, the loading mechanism includes a longitudinal loading member and a horizontal loading member. The longitudinal loading member includes a vertical loading head, which is vertically fixedly connected to the top of the inner side of the constant temperature chamber. The telescopic end of the vertical loading head is fixedly connected to the top of the upper shear box. The horizontal loading component includes a first horizontal servo motor and a second horizontal servo motor. The first horizontal servo motor and the second horizontal servo motor are arranged in parallel and located on both sides of the constant temperature chamber. The telescopic ends of the first horizontal servo motor and the second horizontal servo motor respectively abut against the side walls of the upper shear box and the lower shear box through a first X-direction loading head and a second X-direction loading head.

[0007] Preferably, a ball bearing slide rail is fixedly connected to the bottom of the constant temperature chamber, and the ball bearing slide rail is arranged parallel to the extension and retraction direction of the second horizontal servo motor, and the lower shear box is placed on the ball bearing slide rail.

[0008] Preferably, the bottom of the upper shear box and the top of the lower shear box are respectively provided with placement grooves, the two placement grooves are respectively engaged with the top and bottom of the sample, and a sealing strip is abutting between the top edge and bottom edge of the sample and the two placement grooves.

[0009] Preferably, the confining pressure generating mechanism includes a third water inlet pipe, the inlet end of which is connected to the outlet end of the first plunger pump, the outlet end of which is connected to the interior of the constant temperature chamber, and a liquid collector is connected to the bottom of the constant temperature chamber through a drain outlet.

[0010] Preferably, the confining pressure generating mechanism further includes a pressure pump and a pressure gauge connected to the top of the constant temperature chamber, wherein the pressure pump is used to regulate the air pressure in the constant temperature chamber, and the pressure gauge is used to detect the air pressure value in the constant temperature chamber.

[0011] Preferably, the high-temperature loading component includes multiple electromagnetic heating modules fixedly connected to the inner wall of the constant temperature chamber, and the electromagnetic heating modules are used to heat the water in the constant temperature chamber.

[0012] Preferably, two sets of rigid sealing strips are detachably fitted on the outer wall of the sample. The two rigid sealing strips are located above and below the crack, respectively. Two sets of silicone sealing layers are fixedly connected to the two opposite wall surfaces of the two rigid sealing strips. The two silicone sealing layers are located on the two opposite side walls of the sample, respectively, to prevent water in the sample from flowing into the constant temperature chamber or water in the constant temperature chamber from flowing into the sample.

[0013] Preferably, the seepage assembly includes two sets of sealing rubber sheets. The top and bottom of the sealing rubber sheets are detachably connected between the bottom of the upper shear box and the top of the lower shear box, respectively. The two sealing rubber sheets are located on the other two sides of the sample. The two ends of the silicone sealing layer are fixedly connected to the edges of the two sealing rubber sheets. The two sealing rubber sheets form an inlet cavity and an outlet cavity between the two silicone sealing layers, the upper shear box, the lower shear box, and the two sides of the sample, respectively. The inlet cavity communicates with the outlet cavity through a crack. The upper shear box is equipped with a second water inlet pipe. One end of the second water inlet pipe is connected to the water inlet cavity, and the other end of the second water inlet pipe is connected to the water outlet of the preheating pipe. The water inlet of the preheating pipe is connected to a second plunger pump. A liquid heating tank is also provided. The liquid heating tank is equipped with heating liquid and an electric heating rod for heating the heating liquid. The preheating pipe is immersed in the heating liquid.

[0014] Preferably, the upper shear box and the lower shear box are provided with a plurality of acoustic emission position holes, and acoustic emission probes are fixedly connected to the plurality of acoustic emission position holes, and the plurality of acoustic emission probes are electrically connected to an acoustic emission acquisition and control system.

[0015] Compared with the prior art, the present invention has the following advantages and technical effects: 1. This invention integrates high-temperature loading, multi-directional stress shear, fracture seepage, and confining pressure environments to achieve a comprehensive simulation of the "thermal-mechanical-hydraulic" multi-field coupled environment of jointed rocks in deep underground within a single system. This greatly enhances the realism and complexity of the experimental environment and provides a reliable experimental platform for studying the behavior of jointed rock masses in deep geological activities.

[0016] 2. This invention can simulate the movement of groundwater along joint surfaces in different directions, forming multi-directional fracture seepage within the sample. This allows for the study of the influence of changes in fracture aperture and connectivity during shear deformation on anisotropic seepage characteristics, overcoming the limitations of traditional single-directional seepage tests and providing more comprehensive data support for revealing the seepage laws of fractured rock masses.

[0017] 3. The constant temperature chamber works in conjunction with the built-in high-temperature loading component to effectively reduce external environmental interference and internal heat loss, ensuring that the entire sample is in a uniform and stable target temperature field during long-term testing, thereby improving the accuracy of temperature control and the repeatability of the test. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the test system of the present invention; Figure 2 This is a schematic diagram of the connection of the acoustic emission probe of the present invention; Figure 3 This is a schematic diagram of the seepage component of the present invention; Figure 4 This is a schematic diagram showing the connection between the rigid sealing strip, the silicone sealing layer, and the specimen of the present invention; Figure 5 This is a schematic diagram of the liquid heating tank of the present invention; The components include: 1. First horizontal servo motor; 2. Constant temperature chamber; 3. Pressure gauge; 4. Vertical loading head; 6. Sample; 7. Upper shear box; 8. Lower shear box; 9. Second horizontal servo motor; 10. First X-direction loading head; 11. Pressure pump; 13. Ball bearing slide rail; 16. Acoustic emission probe; 18. Acoustic emission acquisition and control system; 19. Second X-direction loading head; 22. First plunger pump; 23. Sealing rubber sheet; 25. Drain outlet; 26. Third water inlet pipe; 28. Liquid collector; 29. ​​Preheating pipe; 30. Electromagnetic heating module; 31. Second plunger pump; 32. Liquid heating box; 33. Electric heating rod; 34. Rigid sealing strip; 35. Silicone sealing layer. Detailed Implementation

[0020] 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.

[0021] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] Reference Figures 1-5 This invention provides a multifunctional rock joint full shear-seepage coupling test system with a heating module, comprising: Thermostatic chamber 2 is equipped with a confining pressure generating mechanism for injecting water into the chamber. The shearing assembly includes an upper shear box 7 and a lower shear box 8 disposed inside the constant temperature chamber 2. The top and bottom of the sample 6 are respectively snapped into the upper shear box 7 and the lower shear box 8. A loading mechanism is provided between the upper shear box 7, the lower shear box 8 and the constant temperature chamber 2. The loading mechanism is used to make the upper shear box 7 and the lower shear box 8 clamp the sample 6 longitudinally and shear it laterally. High-temperature loading component, which is installed inside the constant temperature chamber 2, is used to heat the water inside the constant temperature chamber 2; The seepage component has a crack in the middle of the sample 6. The seepage component is used to allow seepage water to flow through the crack in the sample 6 to form crack seepage.

[0023] The scheme is further optimized. The loading mechanism includes a longitudinal loading component and a horizontal loading component. The longitudinal loading component includes a vertical loading head 4, which is vertically fixedly connected to the top of the inner side of the constant temperature chamber 2. The telescopic end of the vertical loading head 4 is fixedly connected to the top of the upper shear box 7. The horizontal loading component includes a first horizontal servo motor 1 and a second horizontal servo motor 9. The first horizontal servo motor 1 and the second horizontal servo motor 9 are arranged in parallel and located on both sides of the constant temperature chamber 2. The telescopic ends of the first horizontal servo motor 1 and the second horizontal servo motor 9 abut against the side walls of the upper shear box 7 and the lower shear box 8 through the first X-direction loading head 10 and the second X-direction loading head 19, respectively.

[0024] The main function of the constant temperature chamber 2 is to reduce heat exchange between the chamber and the external environment, maintain the stability of the temperature inside the chamber, and reduce the interference of temperature fluctuations on the test results. The main function of the upper shear box 7 and the lower shear box 8 is to clamp the sample 6 in the constant temperature chamber 2, so that the loading mechanism can apply shear force to the sample 6. The main function of the loading mechanism is to clamp and shear the sample 6 at the same time. The main function of the high temperature loading assembly is to heat the sample 6. The main function of the confining pressure generation mechanism is to simulate the confining pressure of the formation outside the sample 6 by injecting water into the constant temperature chamber 2. The seepage assembly is used to inject seepage water into the water inlet cavity formed on the side wall of the sample through a plunger pump and establish seepage water pressure, so that the seepage water flows through the cracks of the sample 6 to the water outlet cavity, thereby forming crack seepage. Overall, this invention integrates high-temperature loading, multi-directional stress shear, fracture seepage simulation, and confining pressure environment to achieve a comprehensive simulation of the "thermal-mechanical-hydraulic" multi-field coupled environment of jointed rocks in deep underground within a single system. This greatly enhances the realism and complexity of the experimental environment and provides a reliable experimental platform for studying the behavior of jointed rock masses in deep geological activities.

[0025] In this embodiment, the constant temperature chamber 2 is made of aluminum alloy and has a heat insulation plate on its inner wall to achieve a constant temperature effect.

[0026] The scheme is further optimized. The loading mechanism includes a longitudinal loading component and a horizontal loading component. The longitudinal loading component includes a vertical loading head 4, which is vertically fixedly connected to the top of the inner side of the constant temperature chamber 2. The telescopic end of the vertical loading head 4 is fixedly connected to the top of the upper shear box 7.

[0027] In this embodiment, a pre-drilled hole is provided on the top of the constant temperature chamber 2, and the vertical loading head 4 is fixedly connected to the constant temperature chamber 2 through the pre-drilled hole. The longitudinal loading and unloading of the sample 6 is achieved by extending and retracting the telescopic end.

[0028] The scheme is further optimized. The horizontal loading component includes a first horizontal servo motor 1 and a second horizontal servo motor 9. The first horizontal servo motor 1 and the second horizontal servo motor 9 are arranged in parallel and located on both sides of the constant temperature chamber 2. The telescopic ends of the first horizontal servo motor 1 and the second horizontal servo motor 9 abut against the side walls of the upper shear box 7 and the lower shear box 8 through the first X-direction loading head 10 and the second X-direction loading head 19, respectively.

[0029] To further optimize the design, one end of a retractable protective hose is fitted onto the first horizontal servo motor 1 and the second horizontal servo motor 9, and the other end of the protective hose is fixedly connected to the outer wall of the constant temperature chamber 2. This ensures the normal retraction and extension of the first horizontal servo motor 1 and the second horizontal servo motor 9 while maintaining the good heat preservation function of the constant temperature chamber 2.

[0030] Further optimization of the scheme: the bottom of the constant temperature box 2 is fixedly connected to a ball bearing slide rail 13, the ball bearing slide rail 13 is set parallel to the extension and retraction direction of the second horizontal servo motor 9, and the lower shear box 8 is placed on the ball bearing slide rail 13.

[0031] Through the coordinated movement of the first horizontal servo motor 1 and the second horizontal servo motor 9, the lower shear box 8 can be driven to generate relative displacement with respect to the upper shear box 7, thereby performing transverse shearing on the sample 6. The main function of the ball bearing slide rail 13 is to reduce the friction between the lower shear box 8 and the constant temperature chamber 2, maintain linear movement, and ensure the smoothness and accuracy of the lower shear box 8 when moving horizontally.

[0032] To further optimize the design, placement slots are provided at the bottom of the upper shear box 7 and the top of the lower shear box 8, respectively. The two placement slots are respectively engaged with the top and bottom of the sample 6, and sealing strips (not shown in the figure) are abutted between the top and bottom edges of the sample 6 and the two placement slots.

[0033] In this embodiment, the main function of the sealing strip is to stop water flow and prevent water from flowing out from the connection between the sample 6 and the upper shear box 7 and the lower shear box 8, so as to ensure the seepage effect on the sample 6.

[0034] The scheme is further optimized. The confining pressure generating mechanism includes a third water inlet pipe 26. The water inlet end of the third water inlet pipe 26 is connected to the water outlet end of the first plunger pump 22. The water outlet end of the third water inlet pipe 26 is connected to the inside of the constant temperature box 2. The bottom of the constant temperature box 2 is connected to a liquid collector 28 through a drain outlet 25.

[0035] In a further optimized design, the confining pressure generating mechanism also includes a pressure pump 11 and a pressure gauge 3 connected to the top of the constant temperature chamber 2. The pressure pump 11 is used to regulate the air pressure in the constant temperature chamber 2, and the pressure gauge 3 is used to detect the air pressure value in the constant temperature chamber 2.

[0036] The pressure pump 11 can adjust the air pressure inside the thermostat 2, change the boiling point of the liquid, and heat the liquid to different temperatures, thus simulating the geothermal environment more accurately.

[0037] The solution is further optimized by including multiple electromagnetic heating modules 30 fixedly connected to the inner wall of the constant temperature chamber 2. The electromagnetic heating modules 30 are used to heat the water in the constant temperature chamber 2.

[0038] To further optimize the design, a crack is provided in the middle of the sample 6. Two sets of rigid sealing strips 34 are detachably fitted on the outer wall of the sample 6. The two rigid sealing strips 34 are located above and below the crack, respectively. Two sets of silicone sealing layers 35 are fixedly connected to the two opposite walls of the two rigid sealing strips 34. The two silicone sealing layers 35 are located on the two opposite side walls of the sample 6, respectively, to prevent water in the sample 6 from flowing into the constant temperature chamber 2 or water in the constant temperature chamber 2 from flowing into the sample 6.

[0039] In this embodiment, artificial fissures are created on rock sample 6 using the Brazilian splitting method. The surface of the fissures is washed with water and relatively intact fissure samples are selected as master samples and placed in the upper shear box 7 and the lower shear box 8.

[0040] Further optimization of the scheme: the seepage component includes two sets of sealing rubber sheets 23. The top and bottom of the sealing rubber sheets 23 are detachably connected between the bottom of the upper shear box 7 and the top of the lower shear box 8, respectively. The two sealing rubber sheets 23 are located on the other two sides of the sample 6, respectively. The two ends of the silicone sealing layer 35 are fixedly connected to the edges of the two sealing rubber sheets 23, respectively. The two sealing rubber sheets 23 form a water inlet cavity and a water outlet cavity between the two silicone sealing layers 35, the upper shear box 7, the lower shear box 8, and the two sides of the sample 6, respectively. The water inlet cavity is connected to the water outlet cavity through a crack. The upper shear box 7 is equipped with a second water inlet pipe. One end of the second water inlet pipe is connected to the water inlet cavity, and the other end of the second water inlet pipe is connected to the water outlet of the preheating pipe 29. The water inlet of the preheating pipe 29 is connected to the second plunger pump 31. A liquid heating tank 32 is also provided. The liquid heating tank 32 is equipped with heating liquid and an electric heating rod 33 for heating the heating liquid. The preheating pipe 29 is immersed in the heating liquid. The water outlet cavity is connected to the liquid collector 28. A temperature sensor is connected to the second water inlet pipe to monitor the temperature of the liquid injected into the water storage cavity.

[0041] In this embodiment, before the test begins, the two ends of the silicone sealing layer 35 are glued together along the edge of the sealing rubber sheet 23 to form a sealed connection, thereby creating an inlet cavity and an outlet cavity. During the test, the water pressure in the constant temperature chamber 2 keeps the silicone sealing layer 35 tightly attached to the sealing rubber sheet 23. Even if there is relative displacement between the upper shear box 7 and the lower shear box 8, the adhesion between the silicone sealing layer 35 and the sealing rubber sheet 23 can be maintained, ensuring the seal.

[0042] After shear stress is applied, the shear stress acts on the sample 6, and the lower shear box 8 can slide left and right with the bottom ball bearing slide rail 13. The sealing rubber sheet 23 can deform freely with the shear displacement of the sample 6 without being damaged, thus ensuring the sealing during the shearing process.

[0043] The liquid enters the preheating tube 29 through the second plunger pump 31. In this embodiment, the preheating tube 29 is made of copper tube wound into a ring coil and surrounded on the outside of the electric heating rod 33. The electric heating rod 33 heats the heating liquid and heats the seepage liquid to the specified temperature through the preheating tube 29. Then it is transported to the water storage cavity through the second water inlet pipe.

[0044] In this embodiment, the water in the constant temperature chamber 2 forms a confining pressure on the sample 6 through water pressure. The water in the water storage cavity mainly serves as seepage water. After the confining pressure is formed in the constant temperature chamber 2, water is injected into the water inlet cavity through the second plunger pump 31. After water pressure is formed, the water seeps into the cracks of the sample 6 and flows towards the water outlet cavity under the push of water pressure, forming crack seepage in the sample 6. During the experiment, when the water pressure in the constant temperature chamber 2 is greater than the seepage water pressure, the silicone sealing layer 35 can be squeezed by pressing the rigid sealing strip 34 in the middle to achieve lateral sealing and prevent water in the constant temperature chamber 2 from seeping into the sample 6.

[0045] In a further optimized design, a third water inlet pipe 26 is also provided. The inlet end of the third water inlet pipe 26 is connected to the outlet end of the first plunger pump 22, and the outlet end of the third water inlet pipe 26 is connected to the inside of the constant temperature chamber 2. A second water pressure gauge is connected to the third water inlet pipe 26, and a liquid collector 28 is connected to the bottom of the constant temperature chamber 2 through a drain outlet 25.

[0046] The third water inlet pipe 26 is connected to a second control valve. By controlling the opening degree of the second control valve, a constant pressure is injected into the constant temperature chamber 2. The second water pressure gauge is used to monitor the water pressure in the constant temperature chamber 2. Pressure is maintained by injecting water into the constant temperature chamber 2 and closing the valve.

[0047] In this embodiment, the geothermal environment can be simulated by heating the confining water in the constant temperature chamber 2.

[0048] To further optimize the scheme, several acoustic emission position holes are respectively opened on the side walls of the upper shear box 7 and the lower shear box 8. Acoustic emission probes 16 are fixedly connected to the several acoustic emission position holes, and the several acoustic emission probes 16 are electrically connected to the acoustic emission acquisition and control system 18.

[0049] Acoustic emission probe 16 is used to receive acoustic emission signals generated by sample 6 during the stress-induced fracture process. All acoustic emission probes 16 are electrically connected to acoustic emission acquisition and control system 18, which is responsible for signal acquisition, amplification, processing and recording, thereby analyzing the microscopic fracture evolution process of the sample.

[0050] To further optimize the design, a vacuum insulation layer is installed on the inner wall of the constant temperature chamber 2. The vacuum insulation layer is used to reduce temperature fluctuations inside the constant temperature chamber 2.

[0051] In this embodiment, since the surrounding rock pressure and the inter-fracture water injection pressure applied to sample 6 are achieved through two separate water injection systems, the difference between rock pressure and water pressure is more effectively realized, effectively avoiding the interference of rock-water coupling on the test results in the traditional method, and significantly improving the independence between surrounding rock pressure and fracture water pressure.

[0052] The scheme has been further optimized by including a data acquisition system. The main function of the data acquisition mechanism is to record parameters such as shear stress, shear displacement, temperature, confining pressure, seepage pressure and flow rate, and acoustic emission signals during the test.

[0053] The operation procedure of this experimental system is as follows: 1. Accurately insert the prepared sample 6 into the placement slots of the upper shear box 7 and the lower shear box 8, ensuring that the sealing strip is compacted, and connect the system.

[0054] 2. Liquid is injected into the constant temperature chamber 2 by the first plunger pump 22 and adjusted to the target confining pressure. Then, the target amount of seepage water is injected into the water inlet cavity by the second plunger pump 31 and the liquid heating chamber 32, and the seepage water is driven to seep into the sample 6 through the crack.

[0055] 3. A predetermined normal stress is applied to the sample by the vertical loading head 4, and then the relative displacement between the upper shear box 7 and the lower shear box 8 is generated by the first horizontal servo motor 1 and the second horizontal servo motor 9 to perform shear loading.

[0056] 4. During the shearing process or at specific shearing stages, the acoustic emission acquisition and control system 18 continuously operates to monitor the damage to the sample. The data acquisition system records all key parameters such as shear stress, shear displacement, temperature, confining pressure, seepage pressure and flow rate, and acoustic emission signals.

[0057] Specifically, the test system of the present invention can maintain a constant shear force by fixing the extension length of the first horizontal servo motor 1 and the second horizontal servo motor 9. Under the condition of fixed shear force, the water supply pressure of the second plunger pump 31 is increased to increase the permeation pressure of the sample 6, thereby increasing the water injection pressure between the fractures to induce fracture surface shear. At the same time, the test system of the present invention can also control the first horizontal servo motor 1 and the second horizontal servo motor 9 to increase the shear force on the sample 6 by stabilizing the water supply pressure of the second plunger pump 31, thereby conducting experiments to study the shear force generated by increasing the shear force under the condition of fixed water injection pressure.

[0058] 5. After the experiment, the collected multi-physics coupling data were analyzed to study the mechanical behavior, seepage characteristics and their intrinsic relationship of rock joints under the combined action of high temperature, shear deformation and confining pressure.

[0059] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0060] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A multifunctional rock joint full shear-seepage coupling test system with heating module, characterized in that, include: The constant temperature chamber (2) is provided with a confining pressure generating mechanism for injecting water into the chamber; The shearing assembly includes an upper shear box (7) and a lower shear box (8) disposed in the constant temperature chamber (2). The top and bottom of the sample (6) are respectively clamped in the upper shear box (7) and the lower shear box (8). A loading mechanism is provided between the upper shear box (7), the lower shear box (8) and the constant temperature chamber (2). The loading mechanism is used to make the upper shear box (7) and the lower shear box (8) clamp the sample (6) longitudinally and shear it laterally. A high-temperature loading component is disposed inside the constant temperature chamber (2) and is used to heat the water inside the constant temperature chamber (2); The seepage assembly has a crack in the middle of the sample (6). The seepage assembly is used to allow seepage water to flow through the crack of the sample (6) to form crack seepage.

2. The multifunctional rock joint full shear-seepage coupling test system with heating module according to claim 1, characterized in that: The loading mechanism includes a longitudinal loading component and a horizontal loading component. The longitudinal loading component includes a vertical loading head (4). The vertical loading head (4) is vertically fixedly connected to the top of the inner side of the constant temperature chamber (2). The telescopic end of the vertical loading head (4) is fixedly connected to the top of the upper shear box (7). The horizontal loading component includes a first horizontal servo motor (1) and a second horizontal servo motor (9). The first horizontal servo motor (1) and the second horizontal servo motor (9) are arranged in parallel and located on both sides of the constant temperature chamber (2). The telescopic ends of the first horizontal servo motor (1) and the second horizontal servo motor (9) respectively abut against the side walls of the upper shear box (7) and the lower shear box (8) through the first X-direction loading head (10) and the second X-direction loading head (19).

3. The multifunctional rock joint full shear-seepage coupling test system with heating module according to claim 2, characterized in that: The bottom of the constant temperature chamber (2) is fixedly connected to a ball bearing slide rail (13). The ball bearing slide rail (13) is arranged parallel to the extension and retraction direction of the second horizontal servo motor (9). The lower shear box (8) is placed on the ball bearing slide rail (13).

4. The multifunctional rock joint full shear-seepage coupling test system with heating module according to claim 1, characterized in that: The bottom of the upper shear box (7) and the top of the lower shear box (8) are respectively provided with placement slots. The two placement slots are respectively engaged with the top and bottom of the sample (6). A sealing strip is abutted between the top edge and the bottom edge of the sample (6) and the two placement slots.

5. The multifunctional rock joint full shear-seepage coupling test system with heating module according to claim 1, characterized in that: The confining pressure generating mechanism includes a third water inlet pipe (26), the water inlet end of the third water inlet pipe (26) is connected to the water outlet end of the first plunger pump (22), the water outlet end of the third water inlet pipe (26) is connected to the inside of the constant temperature box (2), and the bottom of the constant temperature box (2) is connected to a liquid collector (28) through a drain outlet (25).

6. The multifunctional rock joint full shear-seepage coupling test system with heating module according to claim 5, characterized in that: The confining pressure generating mechanism also includes a pressure pump (11) and a pressure gauge (3) connected to the top of the constant temperature chamber (2). The pressure pump (11) is used to adjust the air pressure in the constant temperature chamber (2), and the pressure gauge (3) is used to detect the air pressure value in the constant temperature chamber (2).

7. The multifunctional rock joint full shear-seepage coupling test system with heating module according to claim 1, characterized in that: The high-temperature loading component includes multiple electromagnetic heating modules (30) fixedly connected to the inner wall of the constant temperature chamber (2), and the electromagnetic heating modules (30) are used to heat the water in the constant temperature chamber (2).

8. The multifunctional rock joint full shear-seepage coupling test system with heating module according to claim 5, characterized in that: Two sets of rigid sealing strips (34) are detachably fitted on the outer wall of the sample (6). The two rigid sealing strips (34) are located above and below the crack, respectively. Two sets of silicone sealing layers (35) are fixedly connected to the two opposite walls of the two rigid sealing strips (34). The two silicone sealing layers (35) are located on the two opposite side walls of the sample (6) to prevent water in the sample (6) from flowing into the constant temperature chamber (2) or water in the constant temperature chamber (2) from flowing into the sample (6).

9. The multifunctional rock joint full shear-seepage coupling test system with heating module according to claim 8, characterized in that: The seepage assembly includes two sets of sealing rubber sheets (23). The top and bottom of the sealing rubber sheets (23) are detachably connected between the bottom of the upper shear box (7) and the top of the lower shear box (8), respectively. The two sealing rubber sheets (23) are located on the other two sides of the sample (6). The two ends of the silicone sealing layer (35) are fixedly connected to the edges of the two sealing rubber sheets (23), respectively. The two sealing rubber sheets (23) form an inlet cavity and an outlet cavity between the two silicone sealing layers (35), the upper shear box (7), the lower shear box (8), and the two sides of the sample (6), respectively. The inlet cavity is connected to the outlet cavity through a crack. The upper shear box (7) is provided with a second water inlet pipe. One end of the second water inlet pipe is connected to the water inlet cavity, and the other end of the second water inlet pipe is connected to the water outlet of the preheating pipe (29). The water inlet of the preheating pipe (29) is connected to a second plunger pump (31). A liquid heating tank (32) is also provided. The liquid heating tank (32) is provided with heating liquid and an electric heating rod (33) for heating the heating liquid. The preheating pipe (29) is immersed in the heating liquid.

10. The multifunctional rock joint full shear-seepage coupling test system with heating module according to claim 1, characterized in that: The upper shear box (7) and the lower shear box (8) are provided with a number of acoustic emission position holes, and acoustic emission probes (16) are fixedly connected in the number of acoustic emission position holes. The number of acoustic emission probes (16) are electrically connected to the acoustic emission acquisition and control system (18).

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