Rock shear test system and method under deep complex conditions and stress state mutual feedback

Abstract

The present application belongs to the technical field of rock testing, and discloses a rock shear test system and method under deep complex conditions and stress state mutual feedback, which can be used with a device capable of providing axial pressure to simplify the structure and save cost. The test system can be combined with the pressure rod of the device capable of providing axial pressure through the pressure link, so as to drive the first rack and the second rack to move synchronously, and then drive the left and right fixed heads of the sample to rotate in opposite directions, so as to apply a torsional moment to the rock sample. Therefore, a power mechanism for providing torsional shear is not needed, the structure is simpler, and the manufacturing cost is lower. Moreover, the test system can apply axial pressure to the rock sample through the axial pressure mechanism, inject test oil into the triaxial pressure cavity to apply triaxial confining pressure to the rock sample, and inject water into the rock sample through the left and right seepage channels, so as to facilitate triaxial confining pressure-seepage-axial pressure-torsional shear coupling test of the rock sample.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of rock testing, and particularly relates to a rock shear test system and method under mutual feedback of deep complex conditions and stress states. BACKGROUND

[0002] In the construction of underground rock mass engineering, the rock mass is often subjected to the combined action of multiple complex stresses. For example, the rock mass may still be subjected to shear stress while being subjected to axial compression. Therefore, knowing the size of the shear strength parameters of the rock under axial compression is one of the guarantees for the safety and reliability of rock mass engineering construction. At present, the main methods for testing rock shear strength parameters in relevant testing specifications are as follows: direct shear test, variable angle plate shear test, triaxial compression test, etc. These methods have their own advantages and disadvantages. For the direct shear test, not only a specific two-way loading test machine with shear function is needed, but also the shear load direction is fixed, which leads to the fact that the failure can only occur along the predetermined load direction, and the result obtained may not be the failure along the minimum shear stress direction. For the variable angle plate shear test, although all material pressure test machines can perform the test, not only does it have the same problem as the direct shear test, but it also needs to correct the friction coefficient of the variable angle plate. For the triaxial compression test, not only a special triaxial pressure test machine is needed, but also the stress state of the rock and the test and analysis process are complex. For the above-mentioned different types of shear tests, although the shear strength parameters of the rock at failure can be obtained ultimately, the internal stress of the rock is complex stress state in any of the tests, and pure shear stress cannot be obtained.

[0003] In fact, pure shear stress has important value for studying the failure of rock mass engineering. Considering the laboratories of engineering construction or scientific research units, they usually have material testing systems (MTS) such as material pressure test machines that can provide axial compression. In order to solve the problem that all material pressure test machines can perform rock pure shear test, the Chinese invention patent application with publication number CN104297027A provides a rock block test piece for pure shear test and a rock pure shear test method. However, if the shear angle under pure shear is to be obtained, this method cannot achieve it.

[0004] In order to carry out pure shear test of rock, the existing rock torsion shear test device is a specially designed device capable of providing torsion shear force. However, the existing rock torsion shear test device for pure shear test at least has one of the following disadvantages: (1) only pure shear test can be carried out, and the test function is too single; (2) the rotating shaft for applying torsion force is fixed during torsion shear process, which causes the change of force arm and cannot apply linear torsion load; (3) it needs to be specially designed and produced, which not only needs a large amount of expenses, but also needs to occupy a large amount of laboratory space; (4) it cannot be directly tested on the existing test machine; (5) if the complex coupling conditions are considered, the peripheral facilities such as triaxial loading, seepage and heating coupling conditions are needed; (6) it is inconvenient to use strain method or acoustic emission positioning technology to test the state of torsion shear change; (7) the axial load cannot be constant or controllable change.

[0005] For example: the Chinese invention patent application with publication number CN107421821A discloses a rock torsion shear-pressure comprehensive experimental device, which comprises a rack, a torsion shear assembly, a loading assembly, an oil circuit system; the torsion shear assembly comprises a torsion loading oil cylinder, the end of the torsion loading oil cylinder is installed in a mounting sleeve, the bottom of the mounting sleeve is rotatably assembled with a movable partition plate through a mounting sleeve support shaft; the torsion extension shaft of the torsion loading oil cylinder is fixedly connected with the driving guide end of a torsion driving plate; a guide sliding shaft is also fixed on the driving guide end, the bottom of the guide sliding shaft is assembled with a torsion guide groove arranged on the movable partition plate; the torsion driving end of the torsion driving plate is assembled with a loading rod torsion part, specifically, a through slot is arranged on the torsion driving end and assembled with the loading rod torsion part, and the loading rod torsion part can move up and down in the through slot. In use, the torsion loading oil cylinder is pressurized, so that the torsion extension shaft rotates the driving guide end with the axis of the loading rod torsion part as the center, in this process, the mounting sleeve support shaft and the movable partition plate rotate. When the torsion driving plate rotates, a torsion force in the circumferential direction is applied to the loading rod torsion part, and the torsion force acts on the rock sample to achieve the effect of torsion shear.

[0006] Although the rock torsion-shear-pressure comprehensive experimental device can be used to apply torque to the rock sample in the rock torsion-shear test to realize the research on the deformation and damage of the rock under the torsion-shear effect, it cannot convert the axial pressure of the existing pressure testing machine into torsion-shear force, so it cannot be used with the equipment that can provide axial pressure, the torsion-shear component of the device includes a torsion loading oil cylinder specially providing torsion-shear force in addition to the necessary transmission mechanism, which undoubtedly increases the complexity and volume of the device, increases the cost of the equipment, and occupies more laboratory space. In addition, the rock torsion-shear-pressure comprehensive experimental device lacks a structure for applying seepage, and is not convenient for conducting seepage-torsion-shear coupling test, triaxial confining pressure-seepage-torsion-shear coupling test, and triaxial confining pressure-seepage-axial pressure-torsion-shear coupling test on the rock sample. SUMMARY

[0007] The rock shear test system under the mutual feedback of deep complex conditions and stress state can be used with the equipment that can provide axial pressure to simplify the structure, save costs, and facilitate triaxial confining pressure-seepage-axial pressure-torsion-shear coupling test on the rock sample.

[0008] The technical solution adopted by the rock shear test system under the mutual feedback of deep complex conditions and stress state to solve the technical problems is: the rock shear test system under the mutual feedback of deep complex conditions and stress state comprises a device main body, a sample fixing mechanism, and a triaxial pressure chamber.

[0009] The device main body comprises a device bottom plate, a device left support plate, and a device right support plate which are arranged at intervals on the device bottom plate, and a working cavity is formed between the device left support plate and the device right support plate.

[0010] The sample fixing mechanism comprises a sample left fixing head and a sample right fixing head which are arranged in the working cavity, and the sample left fixing head and the sample right fixing head are provided with sample fixing parts at positions corresponding to each other.

[0011] It also comprises a power conversion mechanism and an axial pressure mechanism.

[0012] The sample left fixing head is rotatably arranged on the device left support plate through a first horizontal shaft, the sample right fixing head is rotatably arranged on the device right support plate through a second horizontal shaft, and the first horizontal shaft or the second horizontal shaft is a telescopic shaft.

[0013] The sample left fixing head is provided with a sample left connecting column at the sample fixing part, and the sample left connecting column is provided with a left seepage channel; the first seepage liquid inlet and outlet of the left seepage channel are located at the connecting end of the sample left connecting column, and the second seepage liquid inlet and outlet are located on the side wall surface of the sample left connecting column.

[0014] The sample fixing part of the sample right fixing head is provided with a sample right connecting column, and a right seepage passage is arranged in the sample right connecting column.

[0015] The power conversion mechanism comprises a first gear, a second gear, a first rack, a second rack and a pressure receiving connecting rod.

[0016] The first gear is in transmission connection with the sample left fixing head, and the second gear is in transmission connection with the sample right fixing head.

[0017] The first rack and the second rack are vertically arranged in the working cavity, the pressure receiving connecting rod is arranged in the working cavity and connected with the first rack and the second rack respectively, and the pressure receiving connecting rod can drive the first rack and the second rack to move up and down synchronously.

[0018] The first rack is engaged with the first gear and can drive the sample left fixing head to rotate through the first gear, the second rack is engaged with the second gear and can drive the sample right fixing head to rotate through the second gear, and when the first rack and the second rack move up and down synchronously, the rotation direction of the sample left fixing head is opposite to that of the sample right fixing head.

[0019] The shaft pressing mechanism comprises a shaft pressing loading passage and a shaft pressing loading component; when the first horizontal shaft is not a telescopic shaft, the shaft pressing loading passage penetrates the device left supporting plate, the first horizontal shaft and the sample left fixing head in sequence and penetrates to the sample fixing part of the sample left fixing head; when the second horizontal shaft is not a telescopic shaft, the shaft pressing loading passage penetrates the device right supporting plate, the second horizontal shaft and the sample right fixing head in sequence and penetrates to the sample fixing part of the sample right fixing head; the shaft pressing loading component is slidably arranged in the shaft pressing loading passage, and when the inner end of the shaft pressing loading component is at the sample fixing part, the outer end of the shaft pressing loading component is at the outer side of the device main body.

[0020] The inner cavity of the three-axis pressure chamber is a three-axis pressure cavity, a pressure rod through hole is formed on the three-axis pressure chamber, the pressure rod through hole is used for allowing a pressure rod to penetrate into the three-axis pressure cavity, the device main body is arranged in the three-axis pressure cavity, and the pressure receiving connecting rod is at least partially below the pressure rod through hole.

[0021] Further, the sample fixing part is a recess with a regular polygonal structure.

[0022] Further, the device bottom plate is provided with a first limiting seat and a second limiting seat, the lower end of the first rack is provided with a first lower guide rod in sliding cooperation with the first limiting seat, and the lower end of the second rack is provided with a second lower guide rod in sliding cooperation with the second limiting seat.

[0023] Further, a compression part is arranged at the central position of the top of the compression link, and the compression part is directly below the compression rod through hole.

[0024] Further, the axial compression loading component comprises a compression shaft, a sliding groove is arranged at the outer end of the compression shaft, a piston is slidably arranged in the sliding groove, the piston and the sliding groove jointly form a compression chamber, and a compression medium inlet and outlet are arranged on the compression shaft and are in communication with the compression chamber.

[0025] Further, the test system further comprises an axial compression loading module, a confining pressure field module and a seepage field module.

[0026] The axial compression loading module is cyclically connected with the compression medium inlet and outlet of the compression chamber through a medium inlet and outlet pipeline.

[0027] The confining pressure medium outlet of the confining pressure field module is in communication with the compression port of the triaxial compression chamber, and the confining pressure medium inlet is in communication with the pressure relief port of the triaxial compression chamber.

[0028] The seepage liquid outlet of the seepage field module is in communication with the second seepage liquid inlet and outlet of the left seepage channel, and the seepage liquid inlet is in communication with the second seepage liquid inlet and outlet of the right seepage channel; or the seepage liquid outlet of the seepage field module is in communication with the second seepage liquid inlet and outlet of the right seepage channel, and the seepage liquid inlet is in communication with the second seepage liquid inlet and outlet of the left seepage channel.

[0029] Further, the device body further comprises a device cross beam, and the device cross beam is connected with the device left support plate and the device right support plate respectively.

[0030] Further, the device cross beam is two, and is arranged at the top of the working cavity.

[0031] Further, a first limiting block and a second limiting block are arranged at the top of the working cavity.

[0032] The first limiting block is connected with the device left support plate and the device cross beam on the rear side respectively, and the upper end of the first rack is provided with a first upper guide rod which is in sliding cooperation with the first limiting block.

[0033] The second limiting block is connected with the device right support plate and the device cross beam on the front side respectively, and the upper end of the second rack is provided with a second upper guide rod which is in sliding cooperation with the second limiting block.

[0034] The application further provides a rock shear test method under deep complex conditions and force state mutual feedback, which adopts a rock torsional shear test system to perform rock test, and the rock torsional shear test system is the rock shear test system under deep complex conditions and force state mutual feedback.

[0035] Step one, making rock sample, and wrapping sealing film on the rock sample, the two ends of the sealing film are tightly sealed with sealing ring, and then the rock sample is fixed between the left sample fixing head and the right sample fixing head of the rock torsion shear test system;

[0036] Step two, the rock torsion shear test system with the fixed rock sample is installed on the device capable of providing axial pressure; and the axial pressure loading module is circularly connected with the pressure medium inlet and outlet of the pressure chamber through the medium inlet and outlet pipeline; the confining pressure medium outlet of the confining pressure field module is communicated with the pressurizing port of the triaxial pressure chamber, and the confining pressure medium inlet is communicated with the pressure relief port of the triaxial pressure chamber; the seepage field module is circularly communicated with the left seepage channel and the right seepage channel to form a seepage loop;

[0037] Step three, the device providing axial pressure drives the pressure receiving connecting rod to move downward, and the first rack and the second rack are synchronously driven to move downward by the pressure receiving connecting rod, and then the first rack drives the left sample fixing head to rotate through the first gear, and the second rack drives the right sample fixing head to rotate through the second gear, and the rotating direction of the left sample fixing head is opposite to that of the right sample fixing head, so that the torsional moment is applied to the rock sample;

[0038] Meanwhile, the pre-pressure is applied to the piston, and the amount of the pressurizing medium in the pressure chamber is controlled by the axial pressure loading module, so that the constant axial pressure is applied to the rock sample, or the axial pressure applied to the rock sample meets the expected axial pressure change of the test; and the triaxial confining pressure is applied to the rock sample by injecting the test oil into the triaxial pressure chamber through the confining pressure field module; the seepage liquid is circularly flowed in the seepage loop through the seepage field module, and the water injection seepage is carried out on the rock sample;

[0039] Step four, the triaxial confining pressure-seepage-axial pressure-torsion shear coupling test is carried out on the rock sample, the deformation and damage of the rock sample in the test process are measured, and the information is collected for data analysis.

[0040] The beneficial effects of the present application are:

[0041] 1) Since the test system can drive the first rack and the second rack to move synchronously up and down through the pressure link of the power conversion mechanism, that is, the pressure link, the first rack and the second rack can all move linearly up and down, and the device capable of providing axial pressure is capable of providing axial pressure through the linear motion of the pressure rod, so it can cooperate with the pressure rod of the device capable of providing axial pressure through the pressure link to use the axial pressure provided by the device as the power to drive the first rack and the second rack to move synchronously; and since the sample left fixing head and the sample right fixing head are both rotatably arranged and respectively connected with the first gear and the second gear, the first gear and the second gear are respectively engaged with the first rack and the second rack and can drive the sample left fixing head and the sample right fixing head to rotate in opposite directions, so after the test system is used in cooperation with the device capable of providing axial pressure, under the driving of the device capable of providing axial pressure, the rock sample installed and fixed between the sample left fixing head and the sample right fixing head can be applied with a torsional moment for testing. It can be seen that the test system can convert axial pressure into torsional shear force, so rock torsional shear test can be carried out under the test condition capable of providing axial force, without the need to set a special power mechanism to provide torsional shear force. Compared with the existing rock torsional shear test device with the same function, the structure is simpler, the manufacturing cost is lower, and the laboratory space occupied is reduced.

[0042] Moreover, the axial pressure loading channel of the axial pressure mechanism successively penetrates the device left supporting plate, the first horizontal shaft which is not a telescopic shaft, and the sample left fixing head and penetrates to the sample fixing part of the sample left fixing head, or successively penetrates the device right supporting plate, the second horizontal shaft which is not a telescopic shaft, and the sample right fixing head and penetrates to the sample fixing part of the sample right fixing head, and the axial pressure loading component of the axial pressure mechanism is slidably arranged in the axial pressure loading channel, so that the rock sample is applied with axial pressure by pushing the axial pressure loading component.

[0043] In addition, the test system sets the device main body in the three-axial pressure cavity of the three-axial pressure chamber, and the pressure link is at least partially below the pressure rod through hole, so that the rock sample installed and fixed between the sample left fixing head and the sample right fixing head can be applied with three-axial confining pressure by injecting test oil into the three-axial pressure cavity; the sample left connecting column with a left seepage channel is arranged at the sample fixing part of the sample left fixing head, and the sample right connecting column with a right seepage channel is arranged at the sample fixing part of the sample right fixing head, to be connected with the rock sample respectively, and then the left and right seepage channels and the seepage liquid inlet and outlet of the seepage field module are communicated and a seepage loop is formed, so as to facilitate the seepage-torsional shear coupling test of the rock sample, or cooperate with the three-axial pressure chamber and the axial pressure mechanism to facilitate the three-axial confining pressure-seepage-axial pressure-torsional shear coupling test of the rock sample.

[0044] 2) Since the test system can be used in cooperation with a device capable of providing axial pressure, the test system as a whole can be regarded as a test piece to be tested, and the test can be carried out on an existing test machine in the laboratory, thereby expanding the test function of the existing test machine.

[0045] 3) The test system realizes the conversion of the linear motion of the rack into the relative rotary motion of the left and right fixing heads of the sample through the gear and rack cooperation transmission, so that the power can be input and output in a shorter transmission distance, the structure of the device as a whole is simple and compact, which is beneficial to reduce the volume, and a new test machine does not need to be produced, thereby saving a large amount of cost and space.

[0046] 4) The test system can make the force arm constant during the torsion and shear process through the gear and rack cooperation transmission, so as to ensure that the torsional load can be applied linearly.

[0047] 5) The test system is also convenient for synchronous testing of strain method and acoustic emission during the testing of the rock sample.

[0048] 6) The test system can carry out the torsion and shear test of the rock in the test machine without complicated disassembly and installation, and has the advantages of simple operation and convenient use, and can save manpower and material resources.

[0049] 7) The test system can directly use the peripheral facilities of the existing test machine to carry out other coupling tests, such as temperature field module, confining pressure field module, seepage field module, etc., without the need of re-design and production, which is beneficial to further reduce the cost.

[0050] 8) The amount of the pressurizing medium in the control pressure cavity is controlled to realize the constant or regular change of the pressure, which not only can realize the constant or controllable change of the axial pressure applied to the rock sample, but also has the advantages of convenient control and high precision, and is convenient for carrying out the torsion and shear test under constant pressure or the torsion and shear test under variable pressure. BRIEF DESCRIPTION OF DRAWINGS

[0051] Figure 1 is the schematic diagram of the implementation structure of the test system of the present application;

[0052] Figure 2 is the schematic diagram of the three-dimensional structure of the device main body;

[0053] Figure 3 is the schematic diagram of the top view structure of the device main body;

[0054] Figure 4 is the sectional view along the line A-A in FIG. Figure 3

[0055] Figure 5 is the sectional view along the line B-B in FIG. Figure 4

[0056] ​​Figure 6 This is a schematic diagram of a half-section of a solid rock sample;

[0057] Figure 7 This is a schematic diagram of a half-section of a hollow rock sample;

[0058] The components in the diagram are labeled as follows: device body 100, device base plate 110, first limiting seat 111, second limiting seat 112, device left support plate 120, device right support plate 130, working chamber 140, first limiting block 141, second limiting block 142, device crossbeam 150, sample fixing mechanism 200, sample left fixing head 210, sample right fixing head 220, first horizontal shaft 230, second horizontal shaft 240, sample left connecting column 250, left seepage channel 260, sample right connecting column 270, right seepage channel 280, power conversion mechanism 300, first gear 31. 0. Second gear 320, first rack 330, first lower guide rod 331, first upper guide rod 332, second rack 340, second lower guide rod 341, second upper guide rod 342, pressure-bearing connecting rod 350, pressure-bearing part 351, axial pressure mechanism 400, axial pressure loading channel 410, axial pressure loading component 420, pressure shaft 421, piston 422, pressure chamber 423, rock sample 500, sealing membrane 510, sealing ring 520, triaxial pressure chamber 600, triaxial pressure chamber 610, oil filling pipe 611, oil return pipe 612, pressure rod through hole 620, pressure rod 710. Implementation

[0059] The invention will now be further described with reference to the accompanying drawings.

[0060] In the description of this invention, it should be noted that the terms "front," "rear," "left," "right," "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the appendix. Figure 2 The orientations or positional relationships shown are for descriptive purposes only and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. When "many" indicates a quantity, it usually refers to a quantity of three or more. For example, "multiple" usually refers to three or more. The expression "mainly composed of or constituted by" can be interpreted as also including structural components not mentioned in the sentence. "And / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can indicate three situations: A alone, A and B simultaneously, and B alone. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0061] Combination Figures 1 to 7As shown, the rock shear test system under the mutual feedback of deep complex conditions and stress state includes a device main body 100, a sample fixing mechanism 200, a power conversion mechanism 300, a shaft pressing mechanism 400, and a triaxial pressure chamber 600.

[0062] The device main body 100 is the main component of the test system; the device main body 100 includes a device bottom plate 110, a device left support plate 120, and a device right support plate 130 which are arranged at intervals on the device bottom plate 110, and a working cavity 140 is formed between the device left support plate 120 and the device right support plate 130; the working cavity 140 is a space for loading the rock sample 500 and performing rock test;

[0063] The sample fixing mechanism 200 is mainly used for installing and fixing the rock sample 500 to be tested for testing; the rock sample 500 to be tested can be various, for example: Figure 6 the rock sample 500 in the form of a solid cylinder, Figure 7 the rock sample 500 in the form of a hollow cylinder, or the rock sample 500 in the form of a solid square column, the rock sample 500 in the form of a hollow square column, etc.; the sample fixing mechanism 200 includes a sample left fixing head 210 and a sample right fixing head 220 which are arranged at intervals in the working cavity 140, and the sample fixing parts are arranged at the corresponding positions of the sample left fixing head 210 and the sample right fixing head 220.

[0064] The sample left fixing head 210 is rotatably arranged on the device left support plate 120 through a first horizontal shaft 230, and the sample right fixing head 220 is rotatably arranged on the device right support plate 130 through a second horizontal shaft 240; the first horizontal shaft 230 or the second horizontal shaft 240 is a telescopic shaft; the rotatable arrangement of the sample left fixing head 210 and the sample right fixing head 220 can be various, for example, rotatable cooperation with the corresponding horizontal shaft through a shaft hole, a shaft sleeve, or a bearing, or fixed connection with the corresponding horizontal shaft and rotatable installation of the corresponding horizontal shaft and the device support plate through a shaft hole cooperation, a shaft sleeve cooperation, a bearing cooperation, etc.; the telescopic shaft of the first horizontal shaft 230 or the second horizontal shaft 240 is used to adjust the distance between the sample left fixing head 210 and the sample right fixing head 220, so as to load the rock sample 500 between the sample left fixing head 210 and the sample right fixing head 220; the telescopic shaft can be various, such as an electric push rod, an air cylinder, an oil cylinder, etc.

[0065] The sample left fixing head 210 is rotatably arranged on the device left support plate 120 through a first horizontal shaft 230, and the sample right fixing head 220 is rotatably arranged on the device right support plate 130 through a second horizontal shaft 240; the first horizontal shaft 230 or the second horizontal shaft 240 is a telescopic shaft; the rotatable arrangement of the sample left fixing head 210 and the sample right fixing head 220 can be various, for example, rotatable cooperation with the corresponding horizontal shaft through a shaft hole, a shaft sleeve, or a bearing, or fixed connection with the corresponding horizontal shaft and rotatable installation of the corresponding horizontal shaft and the device support plate through a shaft hole cooperation, a shaft sleeve cooperation, a bearing cooperation, etc.; the telescopic shaft of the first horizontal shaft 230 or the second horizontal shaft 240 is used to adjust the distance between the sample left fixing head 210 and the sample right fixing head 220, so as to load the rock sample 500 between the sample left fixing head 210 and the sample right fixing head 220; the telescopic shaft can be various, such as an electric push rod, an air cylinder, an oil cylinder, etc.

[0066] The specimen fixing part of the specimen fixing head 220 is provided with a specimen right connecting column 270, and a right seepage channel 280 is provided inside the specimen right connecting column 270; the first seepage liquid inlet and outlet of the right seepage channel 28 is located at the connecting end of the specimen right connecting column 270, and its second seepage liquid inlet and outlet is located on the side wall surface of the specimen right connecting column 270.

[0067] The specimen fixing part is connected to the end of the rock specimen 500 via the left connecting post 250 or the right connecting post 270. The specimen fixing part can have various structures, preferably a groove with a regular polygonal cross-section. The left connecting post 250 and the right connecting post 270 are typically adhesively fixed to the end of the rock specimen 500. For hollow rock specimens 500, protrusions are typically provided at the connecting ends of the left connecting post 250 and the right connecting post 270 to increase the adhesive area by nesting with the end of the inner cavity of the rock specimen 500. Figure 7 As shown in the implementation method;

[0068] The first seepage inlet and outlet of each of the left seepage channel 260 and the right seepage channel 280 can be connected to the end of the rock sample 500 to form seepage inlet and outlet points. The second seepage inlet and outlet of each of the left seepage channel 260 and the right seepage channel 280 can be circulated with the seepage inlet and outlet of the seepage field module to form a seepage loop. A sealing joint can usually be installed at the first seepage inlet and outlet to connect with the end of the rock sample 500. The sealing joint generally includes a sealing joint body, with sealing connection ends at both ends, and end sealing rings on the sealing connection ends. The sealing joint body is usually made of flexible or elastic material, preferably flexible rubber, to ensure it is not damaged when torsional differences occur. For a hollow rock sample 500, the first seepage inlet and outlet of each of the left seepage channel 260 and the right seepage channel 280 are usually connected to the inner cavity of the rock sample 500. Figure 7 As shown; in this way, not only can the rock sample 500 be permeated, but the permeate in its inner cavity can also partially or completely offset the confining pressure on the rock sample 500; usually, a water pipe with a water injection connector is set at the second permeate inlet and outlet to connect with the permeate inlet and outlet of the permeate field module. The water injection connector generally includes a water injection connector body, and the water injection connector body is provided with a tapered end, a connector shoulder and a connector connecting sleeve from front to back. The connector connecting sleeve is nested with the water injection connector body and can be threadedly connected to the second permeate inlet and outlet.

[0069] The power conversion mechanism 300 includes a first gear 310, a second gear 320, a first rack 330, a second rack 340, and a pressure-bearing connecting rod 350;

[0070] The first gear 310 is in transmission connection with the left sample fixing head 210, and the second gear 320 is in transmission connection with the right sample fixing head 220. The transmission connection mode of the gear and the sample fixing head can be various, for example, coaxial fixed connection, coaxial nested connection, and the like, and for example, the connection is realized through a shaft coupling, a transmission gear, and the like;

[0071] The first rack 330 and the second rack 340 are vertically arranged in the working cavity 140, the pressure receiving connecting rod 350 is arranged in the working cavity 140 and connected with the first rack 330 and the second rack 340 respectively, and the pressure receiving connecting rod 350 can drive the first rack 330 and the second rack 340 to move up and down synchronously. In the working cavity 140, and / or on the first rack 330 and the second rack 340, a structure for limiting is usually arranged to ensure that the rack can move up and down. The pressure receiving connecting rod 350 is mainly used for cooperating with a pressure rod of a device capable of providing axial pressure, so as to utilize the axial pressure provided by the device as the power for driving the first rack 330 and the second rack 340 to move. In order to facilitate the cooperation with the pressure rod of the device capable of providing axial pressure, a pressure receiving part 351 is usually arranged at the central position of the top of the pressure receiving connecting rod 350, and the pressure receiving part 351 is preferably located directly below the pressure rod through hole 620. The pressure receiving part 351 can be various structures. In order to realize coaxial cooperation with the pressure rod 710, the pressure receiving part 351 is preferably arranged in a cylindrical structure;

[0072] The transmission ratio of the first rack 330 and the first gear 310 and the transmission ratio of the second rack 340 and the second gear 320 can be set according to the torsional shear effect required by the test. In order to simplify the structure and facilitate use, the transmission ratio of the first rack 330 and the first gear 310 and the transmission ratio of the second rack 340 and the second gear 320 are preferably the same;

[0073] The first rack 330 is engaged with the first gear 310 and can be driven by the first gear 310 to rotate the left sample fixing head 210. The second rack 340 is engaged with the second gear 320 and can be driven by the second gear 320 to rotate the right sample fixing head 220. When the first rack 330 and the second rack 340 move up and down synchronously, the rotation direction of the left sample fixing head 210 is opposite to the rotation direction of the right sample fixing head 220. Since the moving directions of the first rack 330 and the second rack 340 are the same during the working process, in order to realize that the rotation direction of the left sample fixing head 210 is opposite to the rotation direction of the right sample fixing head 220, the front tooth surface of the first rack 330 is usually engaged with the first gear 310, and the rear tooth surface of the second rack 340 is engaged with the second gear 320, or the rear tooth surface of the first rack 330 is engaged with the first gear 310, and the front tooth surface of the second rack 340 is engaged with the second gear 320;

[0074] The power conversion mechanism 300 not only can convert the lifting linear motion of the pressure link 350 into the relative rotary motion of the sample left fixing head 210 and the sample right fixing head 220, is convenient for being used in cooperation with the equipment capable of providing axial pressure, is particularly suitable for being used in cooperation with the vertical testing machine, but also can simultaneously apply torsional shear to both ends of the rock sample 500 installed between the sample left fixing head 210 and the sample right fixing head 220, so as to better simulate the actual working condition, improve the accuracy of the test result, avoid the non-uniform stress distribution of the rock sample 400 when the single-end torsional shear is applied, can apply greater torque in the same time to reduce the time required for the test, and can make the deformation and stress distribution of the rock sample 400 more uniform to reduce the test error caused by the non-uniform deformation;

[0075] The axial pressure mechanism 400 is mainly used for applying axial pressure to the rock sample 500 installed and fixed between the sample left fixing head 210 and the sample right fixing head 220; the axial pressure mechanism 400 comprises an axial pressure loading channel 410 and an axial pressure loading component 420; the axial pressure loading channel 410 penetrates the device left support plate 120, the first horizontal shaft 230 which is not a telescopic shaft, and the sample left fixing head 210 in sequence and penetrates to the sample fixing part of the sample left fixing head 210, or penetrates the device right support plate 130, the second horizontal shaft 240 which is not a telescopic shaft, and the sample right fixing head 220 in sequence and penetrates to the sample fixing part of the sample right fixing head 220; the axial pressure loading component 420 is slidably arranged in the axial pressure loading channel 410, the inner end of which is located at the sample fixing part, and the outer end of which is located outside the device main body 100; the inner end of the axial pressure loading component 420 is mainly used for abutting against the end of the rock sample 500, and the outer end of the axial pressure loading component 420 is mainly used for cooperating with the external axial pressure equipment;

[0076] The inner cavity of the triaxial pressure chamber 600 is a triaxial pressure cavity 610, and the triaxial pressure chamber 600 is provided with a pressure rod through hole 620 through which the pressure rod 710 penetrates into the triaxial pressure cavity 610; the device main body 100 is arranged in the triaxial pressure cavity 610, and the pressure link 350 is at least partially located directly below the pressure rod through hole 620; the triaxial pressure chamber 600 is mainly used for injecting test oil into the triaxial pressure cavity 610 to apply triaxial confining pressure to the rock sample 500; the triaxial pressure chamber 600 is usually provided with a pressurizing port and a pressure relief port which are in communication with the triaxial pressure cavity 610, respectively; the pressurizing port is usually connected with a filling oil pipe 611, and the pressure relief port is usually connected with a return oil pipe 612, so as to inject and discharge the test oil.

[0077] The test system can simulate complex stress conditions in deep earth, and can at least perform triaxial confining pressure test, torsional shear test, seepage test, triaxial confining pressure-torsional shear coupling test, seepage-torsional shear coupling test, triaxial confining pressure-seepage-torsional shear coupling test, and triaxial confining pressure-seepage-axial pressure-torsional shear coupling test on the rock sample 500. The power conversion mechanism 300 transmits power through the meshing of the gear and the rack, and has the following advantages: ① The gear and the rack have high transmission accuracy, and can realize accurate conversion of linear and rotary motion. ② By designing the gear and the rack, different speed ratio transmission can be realized; this makes the speed ratio of transmission more easily adjusted and optimized. ③ The gear and the rack can provide high rigidity and can withstand large loads. ④ The gear and the rack have mature processing technology and are easy to obtain, and the assembly is simple and direct, which reduces the manufacturing difficulty and cost of parts. ⑤ The gear and the rack have high transmission efficiency, and can reduce energy loss in the process of converting input linear motion into rotary motion and output.

[0078] In order to facilitate the limiting and guiding of the rack, improve the stability of its transmission, and further improve the accuracy of the test, as shown in Figure 1 、 Figure 2 、 Figure 4 and Figure 5 , the first limiting seat 111 and the second limiting seat 112 are arranged on the device bottom plate 110, the lower end of the first rack 330 is provided with a first lower guide rod 331 which is in sliding fit with the first limiting seat 111, and the lower end of the second rack 340 is provided with a second lower guide rod 341 which is in sliding fit with the second limiting seat 112. The first limiting seat 111 and the second limiting seat 112 can have various structures, and are preferably both conical frustum structures.

[0079] As shown in Figure 1 and Figure 4As shown, as a preferred scheme of the device, the axial pressure loading component 420 comprises a pressurizing shaft 421, a sliding groove is formed at the outer end of the pressurizing shaft 421, a piston 422 is slidably arranged in the sliding groove, the piston 422 and the sliding groove jointly enclose a pressure cavity 423, and the pressurizing shaft 421 is provided with a pressurizing medium inlet and outlet which is in communication with the pressure cavity 423. The axial pressure loading component 420 of this structure can realize fine control of the axial pressure applied to the rock sample 500 by the pressurizing shaft 421 through regulating the amount of pressurizing medium in the pressure cavity 423 after pre-pressure is applied by external axial pressure equipment or a baffle, which is very convenient and has higher testing precision. The pressurizing medium inlet and outlet is used for injection and discharge of the pressurizing medium in the pressure cavity 423 to control the pressure in the pressure cavity 423, thereby facilitating the operator to control the size of the axial pressure applied to the rock sample 500 by the pressurizing shaft 421; and a clamping table for limiting and supporting the piston 422 is usually arranged in the sliding groove to avoid the piston 422 from entering the sliding groove too deeply when not working. Preferably, the test system further comprises an axial pressure loading module; the axial pressure loading module is in cyclic communication with the pressurizing medium outlet of the pressure cavity 423 to facilitate pressure control.

[0080] Preferably, the test system further comprises an axial pressure loading module, a confining pressure field module and a seepage field module; the axial pressure loading module is in cyclic connection with the pressurizing medium inlet and outlet of the pressure cavity 423 through a medium inlet and outlet pipeline; the confining pressure medium outlet of the confining pressure field module is in communication with the pressurizing port of the triaxial pressure chamber 600, and the confining pressure medium inlet thereof is in communication with the pressure relief port of the triaxial pressure chamber 600; the seepage liquid outlet of the seepage field module is in communication with the second seepage liquid inlet and outlet of the left seepage channel 260, and the seepage liquid inlet thereof is in communication with the second seepage liquid inlet and outlet of the right seepage channel 280; or, the seepage liquid outlet of the seepage field module is in communication with the second seepage liquid inlet and outlet of the right seepage channel 280, and the seepage liquid inlet thereof is in communication with the second seepage liquid inlet and outlet of the left seepage channel 260.

[0081] The axial pressure loading module described above mainly comprises a container containing pressurizing medium, a pressurizing pump, a flow meter, a control valve and the like, which can inject and / or discharge pressurizing medium into the pressure cavity 423 to control the size of the axial pressure applied to the rock sample 500 by the pressurizing shaft 421, thereby facilitating the study of the mechanical behavior of the rock sample 500 when axial pressure-torsional shear coupling acts on the rock sample 500 and obtaining the mechanical parameters of the rock, which provides test basis and data support for rock engineering investigation and design. The pressurizing medium can be various, such as gas, water, hydraulic oil and the like.

[0082] Based on the aforementioned axial compression loading module, the process and principle of conducting a torsion-shear test under constant axial pressure using this test system are as follows: After the rock sample is prepared and the test system is installed, the pressure bar 710 of a testing machine can be brought into contact with the outer end face of the piston 422, or the piston 422 can be brought into contact with the inner wall of the triaxial pressure chamber 600 to apply axial preload; then, a pressurizing medium is injected into the pressure chamber 423 through the axial compression loading module, so that the pressure reaches the expected axial pressure on the rock sample 500; then, the pressurizing medium will transmit pressure to the surroundings, and the piston 422 will tend to slide outwards, transmitting the pressure to the pressure bar 710 or the triaxial pressure chamber 600; The pressure shaft 421 tends to move inward and directly transmits the axial pressure to the end of the rock sample 500; at this point, the operation of pre-applying a constant axial pressure to the rock sample 500 is completed; during the subsequent torsion shear operation, the oil discharge of the pressure chamber 423 is controlled by the overflow valve. When the pressure generated by the pressure medium is greater than the preset axial pressure, the oil discharge threshold of the pressure chamber 423 is reached, and the pressure medium is controlled to be discharged into the oil tank so that the pressure transmitted by the pressure medium to the surroundings remains constant, thereby keeping the axial pressure applied by the pressure shaft 421 to the rock sample 500 constant; or, the amount of pressure medium in the pressure chamber 423 is controlled so that the axial pressure changes regularly according to the test requirements.

[0083] The aforementioned confining pressure field module mainly consists of a high-pressure vessel, a pressure control system, and pressure sensors. It can generate confining pressure of varying degrees on rock sample 500 to study the mechanical behavior of the rock and obtain its mechanical parameters. Alternatively, it can be coupled with torsional shear to study the triaxial confining pressure-torsional shear performance of the rock under complex environments and obtain corresponding parameters, providing experimental basis and data support for rock engineering exploration and design.

[0084] The aforementioned seepage field module mainly consists of a water tank, water pump, water pipe, orifice plate, regulating valve, flow meter, etc. It can simulate the groundwater flow field to study the seepage performance of rocks and obtain rock seepage parameters, or couple it with torsional shear to study the seepage-torsional shear performance of rocks in complex environments and obtain corresponding parameters, or couple it with triaxial confining pressure and torsional shear to study the triaxial confining pressure-seepage-torsional shear performance of rocks in complex environments and obtain corresponding parameters, providing experimental basis and data support for rock engineering exploration and design.

[0085] To improve the overall structural strength and stability of the test system, and in combination with Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the main body 100 of the device also includes a device crossbeam 150, which is connected to the left support plate 120 and the right support plate 130 of the device respectively.

[0086] Preferably, the device crossbeam 150 is two, and is arranged in the top of the working cavity 140. On this basis, in order to further limit and guide the rack, a first limiting block 141 and a second limiting block 142 are usually arranged on the top of the working cavity 140; the first limiting block 141 is connected with the device left support plate 120 and the device crossbeam 150 on the rear side respectively, and the upper end of the first rack 330 is provided with a first upper guide rod 332 which is in sliding fit with the first limiting block 141; the second limiting block 142 is connected with the device right support plate 130 and the device crossbeam 150 on the front side respectively, and the upper end of the second rack 340 is provided with a second upper guide rod 342 which is in sliding fit with the second limiting block 142. The first limiting block 141 and the second limiting block 142 can be various structures, and preferably are both "L" shaped structures.

[0087] The application further provides a rock shear test method under deep complex conditions and force state mutual feedback, which adopts a rock torsional shear test system to perform rock test, and the rock torsional shear test system is the rock shear test system under deep complex conditions and force state mutual feedback as described above; the method comprises the following steps:

[0088] The sample manufacturing and installation step: before the test starts, the sample manufacturing and installation of the rock are performed. The diameter and length of the rock sample 500 to be tested have a specified standard test size, which needs to be manufactured during rock processing; then, the sample left connecting column 250 and the sample right connecting column 270 are adhered to the two ends of the rock sample 500 respectively by means of adhesion; the sample left connecting column 250 or the sample right connecting column 270 on the end of the rock sample 500 to which an axial pressure needs to be applied can be provided with a through hole for the axial pressure loading channel 410 to pass through, or can not be provided with the through hole; then, the sealing ring 520 is sleeved on the connecting column, the rock sample 500 is wrapped with a heat shrinkable film, and the heat shrinkable film is tightly contracted to form a sealing film 510 by blowing hot air, and the two ends of the sealing film 510 are tightly sealed by the sealing ring 520 on the sample left connecting column 250 and the sample right connecting column 270; finally, the distance between the sample left fixed head 210 and the sample right fixed head 220 is adjusted by the telescopic shaft, so that the rock sample 500 with the sample left connecting column 250 and the sample right connecting column 270 adhered to the two ends is fixed between the sample left fixed head 210 and the sample right fixed head 220 of the test system, and then the telescopic shaft is adjusted to make the sample left connecting column 250 and the sample right connecting column 270 be positioned and matched with the two sample fixed parts, so that the rock sample 500 is fixed.

[0089] Preloading axial compression step: the rock torsional shear test system fixed with the rock sample 500 is installed on a device (for example, MTS) capable of providing axial compression in the laboratory, and the device bottom plate 110 is fixedly connected with the test bench; the rock sample 500 is preloaded with axial compression by the axial compression loading component 420, and the preloaded axial compression can be applied by another device capable of providing axial compression, or by abutting the piston 422 with the inner wall surface of the triaxial compression chamber 600, or by abutting the pressurizing shaft 421 or the piston 422 by other devices arranged in the triaxial compression cavity 610; then, the axial compression loading module is cyclically communicated with the pressure cavity 423, and the pressurizing medium is injected into the pressure cavity 423, so that the pressure reaches the expected axial compression of the rock sample 500; then, the pressurizing medium transmits pressure to the surrounding, the piston 422 has a tendency to slide outward and is abutted, the pressurizing shaft 421 has a tendency to move inward and directly transmits the axial compression to the end of the rock sample 500. During the application of the axial compression, the amount of the pressurizing medium in the pressure cavity 423 can be adjusted, when the pressure generated by the pressurizing medium is greater than the pre-set axial compression, the threshold for discharging the pressurizing medium is reached, the pressurizing medium is discharged to keep the pressure transmitted to the surrounding constant, so that the axial compression applied to the rock sample 500 is kept constant, or the pressurizing medium is injected and / or discharged, so that the axial compression applied to the rock sample 500 meets the expected axial compression change.

[0090] Confining pressure loading step: the triaxial compression chamber 600 generally includes a triaxial compression chamber base and a triaxial compression chamber body arranged on the triaxial compression chamber base and connected with the triaxial compression chamber base by a sealing rubber ring; in use, the entire device is fixedly positioned on the workbench of a device capable of providing axial compression, for example, MTS, by the triaxial compression chamber base; and the confining pressure medium outlet of the confining pressure field module is communicated with the pressurizing port of the triaxial compression chamber 600, and the confining pressure medium inlet is communicated with the pressure relief port of the triaxial compression chamber 600; the medium circulation pipeline of the confining pressure field module is generally threadedly connected with the pressurizing port and the pressure relief port of the triaxial compression chamber 600 through the left oil inlet joint and the right oil outlet joint, respectively, and a layer of sealing rubber ring is generally arranged in the left oil inlet joint and the right oil outlet joint to prevent leakage; the confining pressure field module, the medium circulation pipeline, the left oil inlet joint and the right oil outlet joint, etc. are generally the components of the device itself capable of providing axial compression, and are convenient to install and disassemble. After being connected, the test oil can be injected into the triaxial compression cavity 610 by the confining pressure field module, and the confining pressure field is loaded according to the type of test to be performed, the pre-determined loading scheme and the test content.

[0091] Seepage loading step: one of the seepage liquid inlets and outlets of the seepage field module is communicated with the second seepage liquid inlet and outlet of the left seepage channel 260, and the other seepage liquid inlet and outlet of the seepage field module is communicated with the second seepage liquid inlet and outlet of the right seepage channel 280 to form a seepage loop; the seepage water body is circulated in the seepage loop by the seepage field module, and the seepage field loading is performed according to the type of the test to be performed, the predetermined loading scheme and the test content.

[0092] Torque loading step: the height of the pressure rod 710 is adjusted by the axial loading module of the device, so that the bottom of the pressure rod 710 and the pressure link 350 use the axial pressure as the driving force to move the first rack 330 and the second rack 340, so that the first rack 330 and the second rack 340 move downward, and then the first gear 310 engaged with the first rack 330 drives the left sample fixing head 210 to rotate, and the second gear 320 engaged with the second rack 340 drives the right sample fixing head 220 to rotate in the opposite direction of the left sample fixing head 210, so that the rock sample 500 fixed between the left sample fixing head 210 and the right sample fixing head 220 is subjected to a torsional torque.

[0093] Test step: loading and testing are performed according to the predetermined loading scheme and test content; for example, the rock sample 500 is subjected to a triaxial confining pressure field, a seepage field, an axial pressure and a torsional shear torque at the same time, and a triaxial confining pressure-seepage-axial pressure-torsional shear coupling test is performed on the rock sample 500, and the deformation and failure of the rock sample 500 during the test are measured, and the stress and strain, the torsional angle, the torsional torque, the triaxial pressure, the axial pressure, the seepage and other information of the rock sample 500 are collected for data analysis.

[0094] During the above test process, the lower cylinder, sealing, test oil filling and other operations of the triaxial pressure chamber 600 need to be performed according to the relevant operations of rock testing, and the seepage operation needs to be performed; the instruments for collecting triaxial confining pressure, seepage flow, seepage flow rate, axial pressure, stress and strain, torsional angle and / or torque are arranged in a position and manner according to the prior art; generally, the instrument for collecting stress and strain or torsional angle can be installed between the sample fixing head and the rock sample 500, and the sample fixing head is the left sample fixing head 210 or the right sample fixing head 220; the deformation of the rock sample 500 under the load can be measured by the volume deformation test module; in order to facilitate the detection of the torque of the test loading, a torque detection sensor corresponding to the first gear 310 and / or the second gear 320, or corresponding to the left sample fixing head 210 and / or the right sample fixing head 220 can be generally arranged for detection.

Claims

1. A rock shear test system under deep complex conditions and stress state feedback, including the main body of the device (100), the sample fixing mechanism (200) and the triaxial pressure chamber (600); The main body of the device (100) includes a device base plate (110), and a device left support plate (120) and a device right support plate (130) spaced apart on the device base plate (110), wherein a working cavity (140) is formed between the device left support plate (120) and the device right support plate (130); The sample fixing mechanism (200) includes a left sample fixing head (210) and a right sample fixing head (220) arranged in the working chamber (140). The left sample fixing head (210) and the right sample fixing head (220) are provided with sample fixing parts at corresponding positions. Its features are: It also includes a power conversion mechanism (300) and a shaft compression mechanism (400); The left fixing head (210) of the sample is rotatably mounted on the left support plate (120) of the device via the first horizontal axis (230), and the right fixing head (220) of the sample is rotatably mounted on the right support plate (130) of the device via the second horizontal axis (240). The first horizontal axis (230) or the second horizontal axis (240) is a telescopic axis. The sample fixing part of the sample fixing head (210) is provided with a sample left connecting column (250), and a left seepage channel (260) is provided inside the sample left connecting column (250); the first seepage liquid inlet and outlet of the left seepage channel (260) is located at the connecting end of the sample left connecting column (250), and its second seepage liquid inlet and outlet is located on the side wall surface of the sample left connecting column (250). The specimen fixing part of the specimen fixing head (220) is provided with a specimen right connecting column (270), and a right seepage channel (280) is provided inside the specimen right connecting column (270); the first seepage liquid inlet and outlet of the right seepage channel (280) is located at the connecting end of the specimen right connecting column (270), and its second seepage liquid inlet and outlet is located on the side wall surface of the specimen right connecting column (270). The power conversion mechanism (300) includes a first gear (310), a second gear (320), a first rack (330), a second rack (340), and a pressure-bearing connecting rod (350); The first gear (310) is connected to the left fixed head (210) of the sample, and the second gear (320) is connected to the right fixed head (220) of the sample. The first rack (330) and the second rack (340) are both vertically arranged in the working chamber (140). The pressure-bearing connecting rod (350) is arranged in the working chamber (140) and connected to the first rack (330) and the second rack (340) respectively. The pressure-bearing connecting rod (350) can drive the first rack (330) and the second rack (340) to move up and down synchronously. The first rack (330) meshes with the first gear (310) and can drive the left fixed head (210) of the sample to rotate through the first gear (310); the second rack (340) meshes with the second gear (320) and can drive the right fixed head (220) of the sample to rotate through the second gear (320); when the first rack (330) and the second rack (340) move up and down synchronously, the rotation direction of the left fixed head (210) of the sample is opposite to the rotation direction of the right fixed head (220) of the sample. The axial compression mechanism (400) includes an axial compression loading channel (410) and an axial compression loading component (420); when the first horizontal shaft (230) is not a telescopic shaft, the axial compression loading channel (410) sequentially passes through the left support plate (120) of the device, the first horizontal shaft (230), and the left fixing head (210) of the sample, and extends to the sample fixing part of the left fixing head (210); when the second horizontal shaft (240) is not a telescopic shaft, the axial compression loading channel (410) sequentially passes through the right support plate (130) of the device, the second horizontal shaft (240), and the right fixing head (220) of the sample, and extends to the right fixing head (220) of the sample. At the sample fixing part of 0); the axial pressure loading component (420) is cylindrical, and the axial pressure loading component (420) is slidably disposed in the axial pressure loading channel (410). When its inner end is at the sample fixing part, its outer end is outside the device body (100); the axial pressure loading component (420) includes a pressure shaft (421), and the outer end of the pressure shaft (421) is provided with a groove. A piston (422) is slidably disposed in the groove. The piston (422) and the groove together form a pressure chamber (423). The pressure shaft (421) is provided with a pressure medium inlet and outlet that communicates with the pressure chamber (423); The inner cavity of the triaxial pressure chamber (600) is a triaxial pressure chamber (610), and the triaxial pressure chamber (600) is provided with a pressure rod through hole (620) for the pressure rod (710) to pass into the triaxial pressure chamber (610); the main body of the device (100) is arranged in the triaxial pressure chamber (610), and the pressure-bearing connecting rod (350) is at least partially located directly below the pressure rod through hole (620).

2. The rock shear test system under deep complex conditions and stress state feedback as described in claim 1, characterized in that: The sample fixing part is a groove with a regular polygonal structure.

3. The rock shear test system under deep complex conditions and stress state feedback as described in claim 1, characterized in that: The device base plate (110) is provided with a first limiting seat (111) and a second limiting seat (112). The lower end of the first rack (330) is provided with a first lower guide rod (331) that slides with the first limiting seat (111), and the lower end of the second rack (340) is provided with a second lower guide rod (341) that slides with the second limiting seat (112).

4. The rock shear test system under deep complex conditions and stress state feedback as described in claim 1, characterized in that: The pressure-bearing part (351) is provided at the center of the top of the pressure-bearing connecting rod (350), and the pressure-bearing part (351) is located directly below the pressure rod through hole (620).

5. The rock shear test system under deep complex conditions and stress state feedback as described in any one of claims 1 to 4, characterized in that: It also includes an axial compression loading module, a confining pressure field module, and a seepage field module; The axial pressure loading module is circulatedly connected to the inlet and outlet of the pressurized medium in the pressure chamber (423) through a medium inlet and outlet pipe; The confining pressure medium outlet of the confining pressure field module is connected to the pressurization port of the triaxial pressure chamber (600), and its confining pressure medium inlet is connected to the depressurization port of the triaxial pressure chamber (600). The seepage outlet of the seepage field module is connected to the second seepage inlet and outlet of the left seepage channel (260), and its seepage inlet is connected to the second seepage inlet and outlet of the right seepage channel (280); or, the seepage outlet of the seepage field module is connected to the second seepage inlet and outlet of the right seepage channel (280), and its seepage inlet is connected to the second seepage inlet and outlet of the left seepage channel (260).

6. The rock shear test system under deep complex conditions and stress state feedback as described in claim 5, characterized in that: The main body (100) of the device also includes a device crossbeam (150), which is connected to the left support plate (120) and the right support plate (130) of the device respectively.

7. The rock shear test system under deep complex conditions and stress state feedback as described in claim 6, characterized in that: The device has two crossbeams (150), which are distributed at the top front and back of the working chamber (140).

8. The rock shear test system under deep complex conditions and stress state feedback as described in claim 7, characterized in that: A first limiting block (141) and a second limiting block (142) are also provided at the top of the working cavity (140); The first limiting block (141) is connected to the left support plate (120) of the device and the device crossbeam (150) located on the rear side respectively. The upper end of the first rack (330) is provided with a first upper guide rod (332) that slides with the first limiting block (141). The second limiting block (142) is connected to the right support plate (130) of the device and the device crossbeam (150) located on the front side, respectively. The upper end of the second rack (340) is provided with a second upper guide rod (342) that slides with the second limiting block (142).

9. A rock shear test method under the mutual feedback of deep complex conditions and stress states, wherein the method uses a rock torsion-shear test system to conduct rock tests, characterized in that: The rock torsion-shear test system is the rock shear test system under deep complex conditions and stress state feedback as described in any one of claims 5 to 8; the method includes the following steps. Step 1: Prepare a rock sample (500) and wrap a sealing film (510) around the rock sample (500). Tighten and seal both ends of the sealing film (510) with sealing rings (520). Then fix the rock sample (500) between the left fixing head (210) and the right fixing head (220) of the rock torsion shear test system. Step 2: Install the rock torsion shear test system with the rock sample (500) fixed on the equipment that can provide axial pressure; and make the axial pressure loading module circulate with the pressurized medium inlet and outlet of the pressure chamber (423) through the medium inlet and outlet pipe; the confining pressure field module's confining pressure medium outlet is connected to the pressurization port of the triaxial pressure chamber (600), and the confining pressure medium inlet is connected to the pressure relief port of the triaxial pressure chamber (600); the seepage field module is circulately connected with the left seepage channel (260) and the right seepage channel (280) to form a seepage loop; Step 3: The device that provides axial pressure drives the pressure-bearing connecting rod (350) to move downward. The pressure-bearing connecting rod (350) drives the first rack (330) and the second rack (340) to move downward synchronously. Then, the first rack (330) drives the left fixed head (210) of the sample to rotate through the first gear (310), and the second rack (340) drives the right fixed head (220) of the sample to rotate through the second gear (320). The rotation direction of the left fixed head (210) of the sample is opposite to the rotation direction of the right fixed head (220) of the sample, thereby applying a torsional torque to the rock sample (500). Simultaneously, a pre-pressure is applied to the piston (422), and the amount of pressurized medium in the pressure chamber (423) is controlled by the axial pressure loading module to apply a constant axial pressure to the rock sample (500), or to make the axial pressure applied to the rock sample (500) meet the expected axial pressure change of the test; and, test oil is injected into the triaxial pressure chamber (610) through the confining pressure field module to apply triaxial confining pressure to the rock sample (500); the seepage field module makes the seepage liquid circulate in the seepage circuit to perform water injection seepage on the rock sample (500); Step 4: Triaxial confining pressure-seepage-axial pressure-torsion shear coupling test is conducted on the rock sample (500) to measure the deformation and failure of the rock sample (500) during the test and collect information for data analysis.

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