Rock compression-torsion shear test system and method under deep complex conditions

Abstract

The present application belongs to the technical field of rock testing, and discloses a rock pressure-torsion shear test system and method under deep and complex conditions, which can be used in cooperation with a device capable of providing axial pressure to simplify the structure and save costs. The test system can be connected with the pressure rod of the device capable of providing axial pressure through the pressure link, so as to use the axial pressure provided by the device as the power to drive the synchronous movement of the first main rack and the second main rack, and then drive the left and right fixed heads of the sample to rotate in opposite directions, so as to test the torsional moment of the rock sample. Therefore, it is not necessary to set a power mechanism specially providing torsional shear force, and the structure is simpler and the manufacturing cost is lower. Moreover, the test system can inject test oil into the triaxial pressure chamber to apply triaxial confining pressure to the rock sample, and can inject water into the rock sample through the left and right seepage channels, so as to facilitate the triaxial confining pressure-seepage-torsional shear coupling test of the rock sample.

Description

Technical Field

[0001] This invention belongs to the field of rock testing technology, specifically relating to a rock compression-torsion-shear testing system and method under deep and complex conditions. Background Technology

[0002] In engineering construction, the safety and reliability of the design are fundamental to ensuring the quality and quantity of the project. The shear strength of rock is one of the key parameters that must be considered in engineering construction. Currently, the main methods for testing the shear strength of rock according to relevant testing standards include direct shear tests, variable-angle plate shear tests, and triaxial compression tests. Each method has its own advantages and disadvantages. For direct shear tests, not only is a specific bidirectional loading testing machine with shear-specific capabilities required, but the direction of the shear load is also fixed, meaning failure can only occur along the predetermined load direction, and the result may not be failure along the direction of minimum shear stress. For variable-angle plate shear tests, although all material compression testing machines can perform the test, it not only faces the same problems as direct shear tests but also requires correction for the friction coefficient of the variable-angle plate. For triaxial compression tests, not only is a dedicated triaxial compression testing machine required, but the stress state of the rock and the testing and analysis process are complex. While all of these different types of shear tests can ultimately obtain the shear strength parameters at rock failure, regardless of the method, the internal stress state of the rock is complex during testing, and the pure shear stress experienced by the rock cannot be obtained.

[0003] In fact, pure shear stress is of great value for studying rock mass engineering failure. Laboratories in engineering construction or scientific research units typically possess Material Testing Systems (MTS) capable of providing axial pressure, such as material compression testing machines. To address the issue of whether all MTSs can perform pure shear tests on rocks, Chinese invention patent application CN104297027A provides a rock specimen and a method for pure shear testing; however, this method cannot achieve the required shear angle under pure shear.

[0004] For rock pure shear testing, existing rock torsion shear testing devices are all specially designed and manufactured to provide torsion shear force. However, existing rock torsion shear testing devices for pure shear testing have at least one of the following drawbacks: (1) They can only perform pure shear, and the testing function is too limited; (2) The shaft for applying torque during torsion shear is fixed, which causes the lever arm to change and cannot apply linear torsion load; (3) They need to be specially designed and manufactured, which not only requires a lot of money, but also requires a lot of laboratory space; (4) They cannot be tested directly on existing testing machines; (5) If complex coupling conditions are considered, supporting peripheral facilities are required, such as triaxial loading, seepage, heating and other coupling conditions; (6) It is inconvenient to use strain method or acoustic emission positioning and other techniques to test the state of torsion shear change.

[0005] For example, Chinese invention patent application CN107421821A discloses a rock torsion-shear-compression integrated experimental device, including a frame, a torsion-shear assembly, a loading assembly, and an oil circuit system. The torsion-shear assembly includes a torsion loading cylinder, the end of which is installed in a mounting sleeve. The bottom of the mounting sleeve is rotatably assembled with a movable partition via a mounting sleeve support shaft. The torsion telescopic shaft of the torsion loading cylinder is connected and fixed to the drive guide end of the torsion drive plate. A guide slide shaft is also fixed on the drive guide end, and the bottom of the guide slide shaft is assembled with a torsion guide groove provided on the movable partition. The torsion drive end of the torsion drive plate is assembled with the torsion part of the loading rod. Specifically, the torsion drive end is provided with a through groove for assembling the torsion part of the loading rod, and the torsion part of the loading rod can move up and down within this through groove. In use, the torsion loading cylinder is pressurized, causing the torsion telescopic shaft to rotate the drive guide end around the axis of the torsion part of the loading rod. During this process, the mounting sleeve support shaft and the movable partition rotate. When the torsion drive plate rotates, it applies a circumferential torque to the torsion part of the loading rod, and this torque acts on the rock sample to achieve a torsion shear effect.

[0006] Although the aforementioned rock torsion-shear-compression integrated experimental device, through its torsion-shear component, can apply torque to rock samples in torsion-shear tests to study the deformation and failure of rocks under torsion-shear action, it cannot convert the axial pressure of existing pressure testing machines into torsion-shear force. Therefore, it cannot be used with equipment that can provide axial pressure. In addition to the necessary transmission mechanism, its torsion-shear component also includes a dedicated torsion loading cylinder to provide torsion-shear force, which undoubtedly increases the complexity and size of the device, raises equipment costs, and occupies more laboratory space. Furthermore, the aforementioned rock torsion-shear-compression integrated experimental device lacks a seepage application structure, making it inconvenient for conducting seepage-torsion-shear coupled tests and triaxial confining pressure-seepage-torsion-shear coupled tests on rock samples. Summary of the Invention

[0007] This invention provides a rock compression-torsion-shear testing system under deep and complex conditions, which is designed to be used in conjunction with equipment that can provide axial pressure to simplify the structure, save costs, and facilitate triaxial confining pressure-seepage-torsion-shear coupled testing of rock samples.

[0008] The technical solution adopted by the present invention to solve its technical problem is: a rock compression-torsion shear test system under deep and complex conditions, including a main body of the device, a sample fixing mechanism and a triaxial pressure chamber;

[0009] The main body of the device includes a device base plate, and a device left support plate and a device right support plate spaced apart on the device base plate, with a working cavity formed between the device left support plate and the device right support plate.

[0010] The sample fixing mechanism includes a left sample fixing head and a right sample fixing head distributed on the left and right sides in the working chamber, and the left sample fixing head and the right sample fixing head are provided with sample fixing parts at corresponding positions.

[0011] It also includes a power conversion mechanism;

[0012] The left fixing head of the sample is rotatably mounted on the left support plate of the device via a first horizontal axis, and the right fixing head of the sample is rotatably mounted on the right support plate of the device via a second horizontal axis. The first horizontal axis and / or the second horizontal axis are telescopic axes.

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

[0014] The specimen fixing part of the specimen fixing head is provided with a specimen right connecting column, and a right seepage channel is provided inside the specimen right connecting column; the first seepage liquid inlet and outlet of the right seepage channel is located at the connecting end of the specimen right connecting column, and its second seepage liquid inlet and outlet are located on the side wall surface of the specimen right connecting column.

[0015] The power conversion mechanism includes a first gear, a second gear, a first main rack, a second main rack, and a pressure-bearing connecting rod;

[0016] The first gear is connected to the left fixed head of the sample, and the second gear is connected to the right fixed head of the sample.

[0017] The first and second main racks are both vertically arranged in the working cavity. The pressure-bearing connecting rod is arranged in the working cavity and is connected to the first and second main racks respectively. The pressure-bearing connecting rod can drive the first and second main racks to move up and down synchronously.

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

[0019] The inner cavity of the triaxial pressure chamber is a triaxial pressure chamber, and a pressure rod through hole is provided on the triaxial pressure chamber for the pressure rod to pass through the triaxial pressure chamber; the main body of the device is set in the triaxial pressure chamber, and the pressure-bearing connecting rod is at least partially located directly below the pressure rod through hole.

[0020] Furthermore, the sample fixing part is a groove with a regular polygonal structure.

[0021] Furthermore, a pressure-receiving part is provided at the center of the top of the pressure-receiving connecting rod, and the pressure-receiving part is located directly below the pressure rod through hole.

[0022] Furthermore, the power conversion mechanism also includes a reset element capable of driving the compressed connecting rod to reset.

[0023] Furthermore, the test system also includes a confining pressure field module and a seepage field module;

[0024] The confining pressure medium outlet of the confining pressure field module is connected to the pressurization port of the triaxial pressure chamber, and its confining pressure medium inlet is connected to the depressurization port of the triaxial pressure chamber.

[0025] The seepage outlet of the seepage field module is connected to the second seepage inlet and outlet of the left seepage channel, and its seepage inlet is connected to the second seepage inlet and outlet of the right seepage channel; or, the seepage outlet of the seepage field module is connected to the second seepage inlet and outlet of the right seepage channel, and its seepage inlet is connected to the second seepage inlet and outlet of the left seepage channel.

[0026] Furthermore, the power conversion mechanism also includes a first rack, a second rack, and a rack-and-pinion linkage;

[0027] The first and second auxiliary racks are both vertically arranged in the working cavity, and the auxiliary rack connecting rod is arranged in the working cavity and connected to the first and second auxiliary racks respectively.

[0028] The first auxiliary rack meshes with the first gear. The first main rack and the first auxiliary rack are located on both sides of the first gear. The first main rack can also drive the first auxiliary rack to move up and down through the first gear.

[0029] The second auxiliary rack meshes with the second gear. The second main rack and the second auxiliary rack are located on both sides of the second gear, and the second main rack can also drive the second auxiliary rack to move up and down through the second gear.

[0030] Furthermore, the device base plate is provided with a first main limiting seat, a second main limiting seat, a first auxiliary limiting seat, and a second auxiliary limiting seat;

[0031] The lower end of the first main rack is provided with a first lower guide rod that slides in cooperation with the first main limiting seat;

[0032] The lower end of the second main rack is provided with a second lower guide rod that slides in cooperation with the second main limiting seat;

[0033] The lower end of the first rack is provided with a first rack lower guide rod that slides in cooperation with the first rack limiting seat;

[0034] The lower end of the second rack is provided with a lower guide rod of the second rack that slides in cooperation with the second limit seat.

[0035] Furthermore, the main body of the device also includes a device crossbeam, which is connected to the left support plate and the right support plate of the device respectively.

[0036] Furthermore, the device has two crossbeams, which are distributed front and back at the top of the working chamber;

[0037] A first main limiting block, a second main limiting block, a first secondary limiting block, and a second secondary limiting block are also provided at the top of the working chamber;

[0038] The first main limiting block is connected to the left support plate of the device and one of the device crossbeams respectively. The upper end of the first main rack is provided with a first upper guide rod that slides with the first main limiting block.

[0039] The second main limiting block is connected to the right support plate of the device and another device crossbeam respectively. The upper end of the second main rack is provided with a second upper guide rod that slides with the second main limiting block.

[0040] The first set of limiting blocks are connected to the left support plate of the device and another device crossbeam respectively. The upper end of the first set of racks is provided with a guide rod of the first set of racks that slides with the first set of limiting blocks.

[0041] The second set of limiting blocks are connected to the right support plate of the device and one of the device crossbeams respectively. The upper end of the second set of racks is provided with a guide rod of the second set of racks that slides in cooperation with the second set of limiting blocks.

[0042] This invention also provides a method for testing rock compression-torsional shear under deep and complex conditions. This method employs a rock torsion-shear testing system, which is the aforementioned rock compression-torsional shear testing system for deep and complex conditions. The method includes the following steps:

[0043] Step 1: Prepare a rock sample and wrap a sealing film around it. Seal both ends of the sealing film with sealing rings. Then fix the rock sample between the left and right fixed heads of the rock torsion shear test system.

[0044] Step 2: Install the rock torsion shear test system with the rock sample fixed on it onto a device that can provide axial pressure; and connect the confining pressure medium outlet of the confining pressure field module to the pressurization port of the triaxial pressure chamber, and connect the confining pressure medium inlet to the pressure relief port of the triaxial pressure chamber; the seepage field module is circulated with the left seepage channel and the right seepage channel to form a seepage loop;

[0045] Step 3: The pressure rod of the device providing axial pressure is inserted into the triaxial pressure chamber through the pressure rod through hole, and the pressure-bearing connecting rod is driven to move downward. The pressure-bearing connecting rod drives the first main rack and the second main rack to move downward synchronously. Then, the first main rack drives the left fixed head of the sample to rotate through the first gear, and the second main rack drives the right fixed head of the sample to rotate through the second gear. The rotation direction of the left fixed head of the sample is opposite to the rotation direction of the right fixed head of the sample, thereby applying a torsional torque to the rock sample.

[0046] Simultaneously, test oil is injected into the triaxial pressure chamber through the confining pressure field module to apply triaxial confining pressure to the rock sample; and the seepage field module makes the seepage fluid circulate in the seepage circuit to perform water injection seepage on the rock sample.

[0047] Step four: Conduct triaxial confining pressure-seepage-torsion shear coupling tests on the rock samples, measure the deformation and failure of the rock samples during the test, and collect information for data analysis.

[0048] The beneficial effects of this invention are:

[0049] 1) Because the test system can drive the first main rack and the second main rack to move up and down synchronously through the pressure-bearing connecting rod of the power conversion mechanism, that is, the pressure-bearing connecting rod, the first main rack and the second main rack can all move up and down linearly, and the device that provides axial pressure provides axial pressure through the linear movement of the pressure rod, it can cooperate with the pressure rod of the device that provides axial pressure to use the axial pressure provided by the device as the power to drive the first main rack and the second main rack to move synchronously. Furthermore, because the left and right fixed heads of the sample can be rotatably set and respectively connected to the first gear and the second gear, and the first gear and the second gear mesh with the first main rack and the second main rack respectively, and can drive the left and right fixed heads of the sample to rotate in opposite directions, the test system, when used in conjunction with the device that provides axial pressure, can apply a torsional torque to the rock sample installed and fixed between the left and right fixed heads of the sample for testing under the drive of the device that provides axial pressure. It is evident that this testing system can convert axial pressure into torsional shear force. Therefore, rock torsional shear tests can be conducted under test conditions that can provide axial force, without the need for a dedicated power mechanism to provide torsional shear force. Compared with existing rock torsional shear testing devices with the same function, it has a simpler structure, lower manufacturing cost, and helps to reduce the laboratory space occupied.

[0050] Furthermore, by placing the main body of the device in the triaxial pressure chamber of the triaxial pressure chamber, and with the pressure-bearing connecting rod at least partially located directly below the pressure rod through hole, test oil can be injected into the triaxial pressure chamber to apply triaxial confining pressure to the rock sample installed and fixed between the left and right fixed heads of the sample. Moreover, by setting a left connecting column with a left seepage channel at the sample fixing part of the left fixed head of the sample, and a right connecting column with a right seepage channel at the sample fixing part of the right fixed head of the sample, and connecting them to the rock sample respectively, the seepage liquid inlet and outlet of the seepage field module can be connected through the left and right seepage channels to form a seepage loop, thereby facilitating seepage-torsion-shear coupling test on the rock sample, or cooperating with the triaxial pressure chamber to facilitate triaxial confining pressure-seepage-torsion-shear coupling test on the rock sample.

[0051] 2) By using a first auxiliary rack that is opposite to the first main rack and meshes with the first gear, and a second auxiliary rack that is opposite to the second main rack and meshes with the second gear, the transmission stability of the power conversion mechanism can be improved, and it is easier to cooperate with the pressure rod of the device that can provide axial pressure, thus ensuring the accuracy of the test. The auxiliary rack connecting rod can strengthen the structural strength of the power conversion mechanism by connecting the first and second auxiliary racks, so that the test system can be used to load greater axial pressure for testing.

[0052] 3) Since the test system can be used with equipment that can provide axial pressure, the entire test system can be regarded as the test specimen and tested on the existing test machine in the laboratory, thus expanding the testing function of the existing test machine.

[0053] 4) The test system uses a gear and rack transmission to convert the linear motion of the rack into the relative rotational motion of the left and right fixed heads of the specimen. This allows the power to be input and output within a shorter transmission distance, making the overall structure of the device simple and compact, which is conducive to reducing the size and eliminating the need to produce new testing machines, thus saving a lot of costs and space.

[0054] 5) The test system uses a gear and rack transmission to keep the lever arm constant during the torsion and shear process, ensuring that the torsional load can be applied linearly.

[0055] 6) This test system also facilitates simultaneous strain method and acoustic emission testing of rock samples during the testing process.

[0056] 7) This test system can directly utilize the peripheral facilities of existing test machines to conduct other coupled tests, such as temperature field module, confining pressure field module, seepage field module, etc., without the need for redesign and production, which helps to further reduce costs.

[0057] 8) This test system can be placed inside the test machine to carry out rock torsion shear tests under triaxial confining pressure without the need for complicated disassembly and installation. It also has the advantages of simple operation and convenient use, which can save manpower and material resources. Attached Figure Description

[0058] Figure 1 This is a schematic diagram of one embodiment of the test system of the present invention;

[0059] Figure 2 yes Figure 1 A three-dimensional structural diagram of the main body of the device in the implementation method;

[0060] Figure 3 yes Figure 1 A top view of the main body of the device in the implementation embodiment;

[0061] Figure 4 It is along Figure 3 Sectional view of line AA in the middle;

[0062] Figure 5 It is along Figure 4 Sectional view of the middle BB line;

[0063] Figure 6 This is a schematic diagram of another embodiment of the test system of the present invention;

[0064] Figure 7yes Figure 6 A three-dimensional structural diagram of the main body of the device in the implementation method;

[0065] Figure 8 yes Figure 6 A top view of the main body of the device in the implementation embodiment;

[0066] Figure 9 It is along Figure 8 A cross-sectional view of the CC line;

[0067] Figure 10 It is along Figure 9 Sectional view of the DD line;

[0068] Figure 11 This is a schematic diagram of a half-section of a solid rock sample;

[0069] Figure 12 This is a schematic diagram of a half-section of a hollow rock sample;

[0070] The components in the diagram are labeled as follows: device body 100, device base plate 110, first main limiting seat 111, second main limiting seat 112, first auxiliary limiting seat 113, second auxiliary limiting seat 114, device left support plate 120, device right support plate 130, working chamber 140, first main limiting block 141, second main limiting block 142, first auxiliary limiting block 143, second auxiliary limiting block 144, device crossbeam 150, sample fixing mechanism 200, sample left fixing head 210, sample right fixing head 220, first horizontal axis 230, second horizontal axis 240, sample left connecting column 250, left seepage channel 260, sample right connecting column 270, right seepage channel 280, power source. The system includes a conversion mechanism 300, a first gear 310, a second gear 320, a first main rack 330, a first lower guide rod 331, a first upper guide rod 332, a second main rack 340, a second lower guide rod 341, a second upper guide rod 342, a pressure-bearing connecting rod 350, a pressure-bearing part 351, a first auxiliary rack 360, a first auxiliary rack lower guide rod 361, a second auxiliary rack 370, a second auxiliary rack lower guide rod 371, a second auxiliary rack upper guide rod 372, an auxiliary rack connecting rod 380, a rock sample 400, a sealing membrane 410, a sealing ring 420, a pressure rod 510, a triaxial pressure chamber 600, a triaxial pressure cavity 610, an oil filling pipe 611, an oil return pipe 612, and a pressure rod through hole 620. Detailed Implementation

[0071] The invention will now be further described with reference to the accompanying drawings.

[0072] 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 and 7The 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.

[0073] Combination Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, a rock compression-torsion-shear test system under deep and complex conditions includes a main body 100, a sample fixing mechanism 200, a power conversion mechanism 300, and a triaxial pressure chamber 600.

[0074] The main body 100 is the main component of the test system; the main body 100 includes a base plate 110, and a left support plate 120 and a right support plate 130 spaced apart on the base plate 110. A working cavity 140 is formed between the left support plate 120 and the right support plate 130; the working cavity 140 is a space for placing the rock sample 400 and conducting rock tests.

[0075] The sample fixing mechanism 200 is mainly used to install and fix the rock sample 400 to be tested for testing; the rock sample 400 to be tested can be of various types, such as: Figure 11 The rock sample 400, shown is a solid cylindrical structure. Figure 12 The rock sample 400 shown can be in the form of a hollow cylindrical structure, a solid square column structure, or a hollow square column structure, etc.; the sample fixing mechanism 200 includes a left sample fixing head 210 and a right sample fixing head 220 distributed on the left and right sides of the working chamber 140, and sample fixing parts are provided at corresponding positions of the left sample fixing head 210 and the right sample fixing head 220.

[0076] The left fixing head 210 of the sample is rotatably mounted on the left support plate 120 of the device via the first horizontal shaft 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 shaft 240. The first horizontal shaft 230 and / or the second horizontal shaft 240 are telescopic shafts. The left fixing head 210 and the right fixing head 220 of the sample can be rotatably mounted in various ways, such as: rotatably engaging with the corresponding horizontal shaft through shaft holes, bushings, or bearings, or fixedly connected to the corresponding horizontal shaft, and the corresponding horizontal shaft is rotatably installed with the device support plate through shaft hole engagement, bushing engagement, bearing engagement, etc. The purpose of making the first horizontal shaft 230 and / or the second horizontal shaft 240 a telescopic shaft is to adjust the distance between the left fixing head 210 and the right fixing head 220 of the sample so that a rock sample 400 can be inserted between the left fixing head 210 and the right fixing head 220 of the sample. The telescopic shaft can be an electric push rod, a cylinder, a hydraulic cylinder, etc.

[0077] The left fixed head 210 of the sample is provided with a left connecting column 250 of the sample, and a left seepage channel 260 is provided inside the left connecting column 250. The first seepage inlet and outlet of the left seepage channel 260 is located at the connecting end of the left connecting column 250 of the sample, and the second seepage inlet and outlet is located on the side wall surface of the left connecting column 250 of the sample.

[0078] 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.

[0079] The specimen fixing part is connected to the end of the rock specimen 400 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 400. For hollow rock specimens 400, 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 400. Figure 12 As shown in the implementation method;

[0080] The first seepage inlets and outlets of the left seepage channel 260 and the right seepage channel 280 are connected to the end of the rock sample 400 to form seepage inlet and outlet points. The second seepage inlets and outlets of the left seepage channel 260 and the right seepage channel 280 are circulated with the seepage inlet and outlet of the seepage field module to form a seepage loop. A sealing joint is typically installed at the first seepage inlet and outlet to connect with the end of the rock sample 400. 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 in the event of torsional differences. For a hollow rock sample 400, the first seepage inlets and outlets of the left seepage channel 260 and the right seepage channel 280 are typically connected to the inner cavity of the rock sample 400. Figure 12 As shown; in this way, not only can the rock sample 400 be permeated, but the permeate in its inner cavity can also partially or completely offset the confining pressure on the rock sample 400; 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.

[0081] The power conversion mechanism 300 includes a first gear 310, a second gear 320, a first main rack 330, a second main rack 340, and a pressure-bearing connecting rod 350;

[0082] 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 gears can be connected to the sample fixed head in various ways, such as coaxial fixed connection, coaxial nested connection, etc., or the connection can be achieved through couplings, transmission gears, etc.

[0083] The first main rack 330 and the second main rack 340 are both vertically arranged in the working cavity 140. The pressure-bearing connecting rod 350 is arranged in the working cavity 140 and connected to the first main rack 330 and the second main rack 340 respectively. The pressure-bearing connecting rod 350 can drive the first main rack 330 and the second main rack 340 to move up and down synchronously. In the working cavity 140, and / or the first main rack 330 and the second main rack 340 are usually provided with a limiting structure to ensure that each rack can move up and down. The pressure-bearing link 350 is mainly used to cooperate with the pressure rod 510 of the device that can provide axial pressure, so as to use the axial pressure provided by the device as the power to drive the first main rack 330 and the second main rack 340 to move. In order to facilitate cooperation with the pressure rod 510 of the device that provides axial pressure, a pressure-bearing part 351 is usually provided at the center of the top of the pressure-bearing link 350. The pressure-bearing part 351 can have various structures. In order to achieve coaxial cooperation with the pressure rod 510, the pressure-bearing part 351 is preferably set as a cylindrical structure.

[0084] The first main 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 main 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 main rack 330 and the second main 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; due to the operation, the first main rack The first main rack 330 and the second main rack 340 move in the same direction. In order to make the rotation direction of the left fixed head 210 of the sample opposite to the rotation direction of the right fixed head 220 of the sample, the first main rack 330 is usually made to mesh with the front tooth surface of the first gear 310 and the second main rack 340 is made to mesh with the rear tooth surface of the second gear 320, or the first main rack 330 is made to mesh with the rear tooth surface of the first gear 310 and the second main rack 340 is made to mesh with the front tooth surface of the second gear 320.

[0085] The transmission ratio between the first main rack 330 and the first gear 310, and the transmission ratio between the second main 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, it is preferable to make the transmission ratio between the first main rack 330 and the first gear 310 the same as the transmission ratio between the second main rack 340 and the second gear 320.

[0086] The inner cavity of the triaxial pressure chamber 600 is a triaxial pressure chamber 610. The triaxial pressure chamber 600 has a pressure rod through hole 620 for the pressure rod 510 to pass through into the triaxial pressure chamber 610. The main body 100 of the device is disposed 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, preferably the pressure-bearing part 351 is located directly below the pressure rod through hole 620. The triaxial pressure chamber 600 is mainly used to inject test oil into the triaxial pressure chamber 610 to apply triaxial confining pressure to the rock sample 400. The triaxial pressure chamber 600 is usually provided with a pressure inlet and a pressure outlet that are respectively connected to the triaxial pressure chamber 610. The pressure inlet is usually connected to an oil filling pipe 611 and the pressure outlet is usually connected to an oil return pipe 612 for injecting and discharging test oil.

[0087] This testing system can simulate complex deep-earth conditions and perform at least three-axis confining pressure tests, torsion-shear tests, seepage tests, triaxial confining pressure-torsion-shear coupled tests, seepage-torsion-shear coupled tests, and triaxial confining pressure-seepage-torsion-shear coupled tests on rock samples 400. Its power conversion mechanism 300 transmits power through a gear and rack meshing method, offering the following advantages: ① The gear and rack combination provides high transmission accuracy, enabling precise conversion between linear and rotary motion. ② By designing the gear and rack tooth ratio, different speed ratios can be achieved, making the transmission speed ratio easier to adjust and optimize. ③ The gear and rack combination provides high rigidity, capable of withstanding large loads. ④ Gear surface machining technology is mature and readily available, and assembly is relatively simple and direct, reducing the manufacturing difficulty and cost of components. ⑤ The gear and rack combination provides high transmission efficiency, reducing energy loss during the conversion of input linear motion into rotary motion and output.

[0088] In addition, the power conversion mechanism 300 of the test system can not only convert the linear motion of the compression link 350 into the relative rotational motion of the left fixed head 210 and the right fixed head 220 of the specimen, making it easy to use with equipment that can provide axial pressure, especially suitable for use with vertical testing machines, but also can simultaneously apply torsional shear to both ends of the rock specimen 400 installed between the left fixed head 210 and the right fixed head 220 of the specimen to better simulate actual working conditions, improve the accuracy of test results, avoid non-uniform stress distribution when the rock specimen 400 is torsionally sheared at one end, and apply a larger torque at the same time to reduce the time required for the test, but also make the deformation and stress distribution of the rock specimen 400 more uniform to reduce test errors caused by non-uniform deformation.

[0089] Preferably, the power conversion mechanism 300 also includes a reset element capable of driving the pressure-bearing connecting rod 350 to reset, so that the next set of tests can be performed after one set of rock samples 400 has been tested. The reset element can be of various types, such as: spring, elastic sheet, rubber band, etc. Preferably, a reset spring is sleeved on the first lower guide rod 331 and / or the second lower guide rod 341 as the reset element.

[0090] In a preferred embodiment of the present invention, the test system further includes a confining pressure field module and a seepage field module; the confining pressure field module's confining pressure medium outlet is connected to the pressurization port of the triaxial pressure chamber 600, and its confining pressure medium inlet is connected to the pressure relief port of the triaxial pressure chamber 600; the seepage liquid outlet of the seepage field module is connected to the second seepage liquid inlet and outlet of the left seepage channel 260, and its seepage liquid inlet is connected to the second seepage liquid inlet and outlet of the right seepage channel 280; or, the seepage liquid outlet of the seepage field module is connected to the second seepage liquid inlet and outlet of the right seepage channel 280, and its seepage liquid inlet is connected to the second seepage liquid inlet and outlet of the left seepage channel 260.

[0091] 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 400 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.

[0092] 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.

[0093] As another preferred embodiment of the present invention, combined with Figure 6 , Figure 7 , Figure 8 , Figure 9 and Figure 10As shown, the power conversion mechanism 300 of the test system also includes a first rack 360, a second rack 370, and a rack connecting rod 380. Both the first rack 360 and the second rack 370 are vertically arranged in the working chamber 140. The rack connecting rod 380 is arranged in the working chamber 140 and connected to the first rack 360 and the second rack 370 respectively. The first rack 360 meshes with the first gear 310. The first main rack 330 and the first rack 360 are located on opposite sides of the first gear 310. The first main rack 330 can also drive the first rack 360 to move up and down through the first gear 310. The second rack 370 meshes with the second gear 320. The second main rack 340 and the second rack 370 are located on opposite sides of the second gear 320. The second main rack 340 can also drive the second rack 370 to move up and down through the second gear 320. In the working chamber 140, and / or on the first rack 360 and the second rack 370, there are usually limiting structures to ensure that each rack can move up and down.

[0094] By using a first auxiliary rack 360 that is opposite to the first main rack 330 and meshes with the first gear 310, and a second auxiliary rack 370 that is opposite to the second main rack 340 and meshes with the second gear 320, the transmission stability of the power conversion mechanism 300 can be improved, further facilitating its cooperation with the pressure bar of a device that can provide axial pressure, thus ensuring the accuracy of the test. Connecting the first auxiliary rack 360 and the second auxiliary rack 370 through the auxiliary rack connecting rod 380 can strengthen the structural strength of the power conversion mechanism 300, enabling the test system to be used for testing under greater axial pressure.

[0095] To facilitate the limiting and guiding of the rack and pinion, thereby improving its transmission stability and further enhancing the accuracy of the test, for example... Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, preferably, a first main limiting seat 111, a second main limiting seat 112, a first auxiliary limiting seat 113, and a second auxiliary limiting seat 114 are provided on the device base plate 110; the lower end of the first main rack 330 is provided with a first lower guide rod 331 that slides with the first main limiting seat 111; the lower end of the second main rack 340 is provided with a second lower guide rod 341 that slides with the second main limiting seat 112; the lower end of the first auxiliary rack 360 is provided with a first auxiliary rack lower guide rod 361 that slides with the first auxiliary limiting seat 113; and the lower end of the second auxiliary rack 370 is provided with a second auxiliary rack lower guide rod 371 that slides with the second auxiliary limiting seat 114.

[0096] To improve the overall structural strength and stability of the test system, and in combination with Figure 1 , Figure 2 and Figure 3As 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.

[0097] Preferably, the device has two crossbeams 150, which are distributed front and rear at the top of the working chamber 140. Furthermore, to further limit and guide the rack, a first main limiting block 141, a second main limiting block 142, a first auxiliary limiting block 143, and a second auxiliary limiting block 144 are typically provided at the top of the working chamber 140. The first main limiting block 141 is connected to the left support plate 120 and one of the device crossbeams 150, respectively. The upper end of the first main rack 330 is provided with a first upper guide rod 332 that slides with the first main limiting block 141. The second main limiting block 142 is connected to the right support plate 130, respectively. The device is connected to another crossbeam 150. The upper end of the second main rack 340 is provided with a second upper guide rod 342 that slides with the second main limiting block 142. The first auxiliary limiting block 143 is connected to the left support plate 120 and another crossbeam 150 respectively. The upper end of the first auxiliary rack 360 is provided with a first auxiliary rack upper guide rod that slides with the first auxiliary limiting block 143. The second auxiliary limiting block 144 is connected to the right support plate 130 and one of the crossbeams 150 respectively. The upper end of the second auxiliary rack 370 is provided with a second auxiliary rack upper guide rod 372 that slides with the second auxiliary limiting block 144. The first main limiting block 141, the second main limiting block 142, the first auxiliary limiting block 143 and the second auxiliary limiting block 144 can have various structures, preferably all of which are "L" shaped structures.

[0098] This invention also provides a method for testing rock compression-torsional shear under deep and complex conditions. This method employs a rock torsion-shear testing system, which is the aforementioned rock compression-torsional shear testing system for deep and complex conditions. The method includes the following steps:

[0099] Sample preparation and installation steps: Before the test begins, the rock sample is prepared and installed. The diameter and length of the rock sample 400 to be tested have specified standard test dimensions, which must be met during rock processing. Then, the left connecting column 250 and the right connecting column 270 are glued to both ends of the rock sample 400. Next, sealing rings 420 are fitted onto the connecting columns, and the rock sample 400 is wrapped with heat-shrink film. The heat-shrink film is then blown with hot air to shrink it into a sealing film 410. The two ends of the sealing film 410 are connected by the left connecting column 250 and the right connecting column. The sealing rings 420 on 270 are tightened and sealed respectively; finally, the distance between the left fixing head 210 and the right fixing head 220 of the sample is adjusted by the telescopic shaft so that the rock sample 400, with the left connecting column 250 and the right connecting column 270 of the sample glued to both ends, is fixed between the left fixing head 210 and the right fixing head 220 of the sample in the test system. Then, the telescopic shaft is adjusted so that the left connecting column 250 and the right connecting column 270 of the sample are respectively positioned and engaged with the two sample fixing parts to fix the rock sample 400.

[0100] Confining pressure loading steps: The triaxial pressure chamber 600 generally includes a triaxial pressure chamber base, and a triaxial pressure chamber body mounted on the base and connected to it via a sealing rubber ring. In use, the entire device is fixed to the workbench of an equipment capable of providing axial pressure (e.g., MTS) via the triaxial pressure chamber base. The confining pressure medium outlet of the confining pressure field module 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 medium circulation pipeline of the confining pressure field module is generally threaded to the pressurization port and pressure relief port of the triaxial pressure chamber 600 via a left inlet connector and a right outlet connector, respectively. A sealing rubber ring is usually installed inside the left inlet connector and the right outlet connector to prevent leakage. The confining pressure field module, medium circulation pipeline, left inlet connector, and right outlet connector are usually components within the equipment providing axial pressure, making installation and disassembly convenient. Once connected, test oil can be injected into the triaxial pressure chamber 610 through the confining pressure field module, and the confining pressure field can be loaded according to the type of test to be performed and the predetermined loading scheme and test content.

[0101] Seepage loading steps: Connect one of the seepage inlet / outlet of the seepage field module to the second seepage inlet / outlet of the left seepage channel 260, and connect the other seepage inlet / outlet of the seepage field module to the second seepage inlet / outlet of the right seepage channel 280 to form a seepage loop; the seepage water is circulated in the seepage loop through the seepage field module, and the seepage field loading can be carried out according to the type of test to be carried out, according to the predetermined loading scheme and test content.

[0102] Torque loading step: The height of the pressure rod 510 is adjusted using the axial loading module of the equipment, so that the bottom of the pressure rod 510 and the pressure-bearing connecting rod 350 use axial pressure as the power to drive the first main rack 330 and the second main rack 340 to move downwards. This causes the left fixed head 210 of the sample to rotate through the first gear 31 meshing with the first main rack 330, and the right fixed head 220 of the sample to rotate in the opposite direction of the rotation of the left fixed head 210 through the second gear 320 meshing with the second main rack 340. This applies a torsional torque to the rock sample 400 installed and fixed between the left fixed head 210 and the right fixed head 220 of the sample. If the power conversion mechanism 300 has a first auxiliary rack 360, a second auxiliary rack 370 and an auxiliary rack connecting rod 380, the first auxiliary rack 360, the second auxiliary rack 370 and the auxiliary rack connecting rod 380 will move upwards synchronously to improve the stability of the power conversion mechanism 300 and provide the test load.

[0103] Finally, triaxial confining pressure, seepage field and torsional moment were applied simultaneously to conduct a triaxial confining pressure-seepage-torsion-shear coupling test on rock specimen 400. The deformation and failure of rock specimen 400 during the test were measured, and information such as stress-strain, torsion angle, torsional moment and triaxial pressure of rock specimen 400 were collected for data analysis.

[0104] During the above tests, it is necessary to perform operations such as lowering the triaxial pressure chamber 600, sealing it, filling it with test oil, and adding seepage flow according to the relevant procedures for rock testing. The instruments for collecting parameters such as triaxial confining pressure, seepage flow rate, seepage velocity, stress and strain, torsion angle, and / or torque are arranged in the existing technology. Typically, the instruments for collecting stress and strain or torsion angle can be installed between the specimen fixing head and the rock specimen 400, with the specimen fixing head being the left fixing head 210 or the right fixing head 220. The rock specimen 400 deforms under load, and the deformation can be measured by the volume deformation test module. To facilitate the detection of the torque applied in the test, a torque detection sensor corresponding to the first gear 310 and / or the second gear 320, or corresponding to the left fixing head 210 and / or the right fixing head 220, can be set up for detection.

Claims

1. A rock compression-torsion-shear test system under deep and complex conditions, comprising a main body (100), a specimen fixing mechanism (200), and a 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), with a working cavity (140) 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), a confining pressure field module, and a seepage field module; 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) and / or the second horizontal axis (240) are telescopic axes. The left fixing head (210) of the sample is provided with a left connecting column (250) for the sample, and a left seepage channel (260) is provided inside the left connecting column (250); the first seepage inlet and outlet of the left seepage channel (260) is located at the connecting end of the left connecting column (250) for the sample, and the second seepage inlet and outlet is located on the side wall surface of the left connecting column (250) for the sample. 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 main rack (330), a second main 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 main rack (330) and the second main rack (340) are both vertically arranged in the working cavity (140). The pressure-bearing connecting rod (350) is arranged in the working cavity (140) and connected to the first main rack (330) and the second main rack (340) respectively. The pressure-bearing connecting rod (350) can drive the first main rack (330) and the second main rack (340) to move up and down synchronously. The first main 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 main 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 main rack (330) and the second main 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 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 (510) to pass through 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); 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 pressure relief 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).

2. The rock compression-torsion shear testing system under deep and complex conditions according to claim 1, characterized in that: The sample fixing part is a groove with a regular polygonal structure.

3. The rock compression-torsion shear testing system under deep and complex conditions according to 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).

4. The rock compression-torsion shear testing system under deep and complex conditions according to claim 1, characterized in that: The power conversion mechanism (300) also includes a reset member capable of driving the pressure link (350) to reset.

5. The rock compression-torsional shear testing system under deep complex conditions according to any one of claims 1 to 4, characterized in that: The power conversion mechanism (300) also includes a first rack (360), a second rack (370), and a rack linkage (380). The first auxiliary rack (360) and the second auxiliary rack (370) are both vertically arranged in the working cavity (140), and the auxiliary rack connecting rod (380) is arranged in the working cavity (140) and connected to the first auxiliary rack (360) and the second auxiliary rack (370) respectively. The first auxiliary rack (360) meshes with the first gear (310). The first main rack (330) and the first auxiliary rack (360) are located on both sides of the first gear (310). The first main rack (330) can also drive the first auxiliary rack (360) to move up and down through the first gear (310). The second auxiliary rack (370) meshes with the second gear (320). The second main rack (340) and the second auxiliary rack (370) are located on both sides of the second gear (320). The second main rack (340) can also drive the second auxiliary rack (370) to move up and down through the second gear (320).

6. The rock compression-torsion shear testing system under deep and complex conditions according to claim 5, characterized in that: The device base plate (110) is provided with a first main limiting seat (111), a second main limiting seat (112), a first auxiliary limiting seat (113), and a second auxiliary limiting seat (114). The lower end of the first main rack (330) is provided with a first lower guide rod (331) that slides with the first main limiting seat (111). The lower end of the second main rack (340) is provided with a second lower guide rod (341) that slides with the second main limit seat (112). The lower end of the first rack (360) is provided with a first rack lower guide rod (361) that slides with the first limit seat (113). The lower end of the second rack (370) is provided with a second rack lower guide rod (371) that slides with the second limit seat (114).

7. The rock compression-torsion shear testing system under deep and complex conditions according to claim 6, characterized in that: The main body of the device (100) 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.

8. The rock compression-torsion shear testing system under deep and complex conditions according to claim 7, characterized in that: The device has two crossbeams (150), which are distributed front and back on the top of the working chamber (140); A first main limiting block (141), a second main limiting block (142), a first secondary limiting block (143), and a second secondary limiting block (144) are also provided at the top of the working cavity (140). The first main limiting block (141) is connected to the left support plate (120) of the device and one of the device crossbeams (150) respectively. The upper end of the first main rack (330) is provided with a first upper guide rod (332) that slides with the first main limiting block (141). The second main limiting block (142) is connected to the right support plate (130) of the device and another device crossbeam (150) respectively. The upper end of the second main rack (340) is provided with a second upper guide rod (342) that slides with the second main limiting block (142). The first auxiliary limiting block (143) is connected to the left support plate (120) of the device and another device crossbeam (150) respectively. The upper end of the first auxiliary rack (360) is provided with a first auxiliary rack upper guide rod that slides with the first auxiliary limiting block (143). The second auxiliary limiting block (144) is connected to the right support plate (130) of the device and one of the device crossbeams (150) respectively. The upper end of the second auxiliary rack (370) is provided with a second auxiliary rack upper guide rod (372) that slides with the second auxiliary limiting block (144).

9. A method for testing rock compression-torsional shear under deep and complex conditions, wherein the method employs a rock torsion-shear testing system for rock testing, characterized in that: The rock torsion-shear testing system is the rock compression-torsion-shear testing system under deep and complex conditions as described in any one of claims 1 to 8; the method includes the following steps. Step 1: Prepare a rock sample (400) and wrap a sealing film (410) around the rock sample (400). Tighten and seal both ends of the sealing film (410) with sealing rings (420). Then fix the rock sample (400) 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 (400) fixed on it onto a device that can provide axial pressure; and make the confining pressure medium outlet of the confining pressure field module connected to the pressurization port of the triaxial pressure chamber (600), and the confining pressure medium inlet connected to the pressure relief port of the triaxial pressure chamber (600); the seepage field module is circulatedly connected to the left seepage channel (260) and the right seepage channel (280) to form a seepage loop; Step 3: The pressure rod (510) of the device providing axial pressure is inserted into the triaxial pressure chamber (610) through the pressure rod through hole (620), and the pressure-bearing connecting rod (350) is driven to move downward. The pressure-bearing connecting rod (350) drives the first main rack (330) and the second main rack (340) to move downward synchronously. Then, the first main rack (330) drives the left fixed head (210) of the sample to rotate through the first gear (310), and the second main 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 (400). Simultaneously, 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 (400); and the seepage field module is used to make the seepage liquid circulate in the seepage circuit to perform water injection seepage on the rock sample (400). Step 4: Triaxial confining pressure-seepage-torsion shear coupling test is performed on the rock sample (400) to measure the deformation and failure of the rock sample (400) during the test and collect information for data analysis.

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