A mobile in-situ true triaxial testing device and method for large size specimens

Abstract

The application provides a mobile in-situ true triaxial testing device and method for large-size samples, and belongs to the technical field of rock mechanics testing.The testing device comprises a mobile machine, a hydraulic servo module, a pressurizing module and a testing module, the mobile machine comprises a machine top plate, a machine vertical plate is fixed to the side of the machine top plate, and the bottom surface of the machine top plate is provided with the hydraulic servo module and the pressurizing module; the testing module comprises an X-axis testing module, a Y-axis testing module and a Z-axis testing module, and the X-axis testing module, the Y-axis testing module and the Z-axis testing module are all provided with a displacement measuring module.In the above scheme, the testing device can provide true triaxial pressure for the sample, test the deformation and damage parameters of the sample, and obtain the elastic-plastic parameters and damage characteristics of the fractured rock mass by arranging the pressurizing module and the testing module on the mobile machine.

Description

Technical Field

[0001] This invention relates to the field of rock mechanics testing technology, and in particular to a mobile in-situ true triaxial testing device and method for large-size specimens. Background Technology

[0002] Accurate acquisition of rock mass mechanical parameters is fundamental for deep rock mass engineering excavation and design. The mechanical parameters of rock mass differ under different stress paths, and accurately reproducing the three-dimensional stress state of the original rock is a prerequisite for obtaining accurate mechanical parameters. Laboratory tests often use small-sized specimens with good integrity to conduct triaxial compression tests, which are insufficient to encompass joints and fissures in the rock mass. These specimens exhibit locality and lack representativeness on an engineering scale, leading to biased test data. In-situ testing, conducted at the geotechnical engineering site with minimal disturbance to the rock mass, is a method to obtain the mechanical properties and other indicators of the rock mass in its in-situ state. In-situ testing allows for loading and unloading tests on large-sized specimens, which can encompass joints and fissures present in the rock mass, more realistically reflecting the actual state and mechanical properties of the rock mass, and avoiding the disturbance to the specimens caused by sampling and preparation processes in laboratory tests.

[0003] Chinese invention patent CN110132714B discloses a device for testing the deformation parameters of irregular rock mass samples. The device includes a rock mass sample with a central through-hole, an axial pressure device for the rock mass sample, a force transmission device, surrounding rock, and a measuring device. The pressure device and the force transmission device are sequentially arranged above the rock mass sample, and the top of the force transmission device is fixedly connected to the top surrounding rock via a connector. The measuring device includes a dial gauge for measuring the deformation of the upper surface of the rock mass sample, a lateral deformation monitoring device for the rock mass sample, and a multi-point displacement meter located in the central through-hole of the rock mass sample. Although this device can be used with irregular rock mass samples, facilitating sample processing and ensuring the accuracy of deformation parameter testing, thus providing convenience for on-site testing of rock mass sample mechanical parameters, it still has certain drawbacks: First, the device only performs tests in one direction on the rock mass, which means it cannot meet the requirements of triaxial loading tests. First, it cannot reproduce the true three-dimensional stress state of the rock mass, and the amount of data that can be obtained by unidirectional test measurements is small. Second, although the above-mentioned device is designed in a "smaller at the top and larger at the bottom" manner to test irregular rock masses, the device is designed to meet the overall irregularity of the rock mass, but ignores the fact that the cross-sectional area of ​​the rock mass is different from top to bottom. The irregularity leads to the randomness of the cross-sectional area, resulting in different stresses in each cross-section, making it difficult to calculate the rock mass parameters. Third, in-situ testing is often carried out at a location close to the excavation face, and the support process is often delayed. If the above-mentioned device is used near the unsupported working face, the tester may be seriously injured by falling debris due to insufficient safety protection in the cave, causing a safety accident. Fourth, the above-mentioned device cannot achieve rapid movement in the cave or automatic installation of the pressurization module and testing module. When conducting a large number of tests, there are problems with the time-consuming and labor-intensive manual assembly of the equipment. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a mobile in-situ true triaxial testing device and method for large-size specimens, so as to solve the problems of significant small-size effect of indoor specimens and difficulty in taking into account rock mass joints and fractures when obtaining rock mass parameters by rock mechanics test.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0006] A mobile in-situ true triaxial testing device for large-size specimens includes a mobile machine, a hydraulic servo module, a pressurization module, and a testing module. The mobile machine includes a top plate, a vertical plate fixed to the side of the top plate, and a hydraulic servo module and a pressurization module mounted on the bottom surface of the top plate. The testing module includes an X-axis testing module, a Y-axis testing module, and a Z-axis testing module. Each of the X-axis, Y-axis, and Z-axis testing modules has a fitting module at its end near the specimen. Each of the X-axis, Y-axis, and Z-axis testing modules also has a displacement measurement module.

[0007] Optionally, the machine's vertical plate has pulley grooves on both its front and back sides, with an X-axis testing module slidably connected to the inner wall of the pulley grooves. The machine's vertical plate also has side grooves on its sides, a Y-axis testing module on its inner wall, and a Z-axis testing module at the bottom of its top plate. Pull hooks are fixedly connected to both the front and back sides of the machine's vertical plate. A pulley module is installed at the bottom of the machine's vertical plate. A ladder module is fixedly connected to one side of the machine's vertical plate. A triangular fixing frame is fixedly connected to the back of the machine's vertical plate. An extension plate is fixedly connected to the top of the triangular fixing frame. An operating compartment is fixedly connected to the top of the extension plate. A top support module is provided at the top of both the machine's top plate and the extension plate.

[0008] Optionally, the pressurization module includes a hydraulic cushion, a reaction frame, a pressurization jack, a displacement jack, a pad, a universal ball joint, and a ball bearing assembly; the hydraulic cushion is used to provide two independent confining pressures to the sample; the reaction frame is used to provide a reaction force to the hydraulic cushion; the pressurization jack is used to provide axial pressure to the sample; the bottom end of the displacement jack is connected to the reaction frame for raising and lowering the reaction frame; the pad is placed on the upper surface of the sample; the universal ball joint can rotate in any direction, so that the reaction force of the ball bearing assembly on the pressurization jack is always axial; the hydraulic servo module can independently supply oil to the hydraulic cushion, the pressurization jack, and the displacement jack.

[0009] Optionally, the ball bearing assembly is fixedly connected to the bottom of the machine top plate, the pressure jack is installed at the middle position of the bottom of the ball bearing assembly, and a displacement jack is installed on each side of the bottom of the ball bearing assembly; the ball bearing assembly is composed of an upper steel plate, a lower steel plate, steel balls and springs, and springs are arranged around the upper steel plate and the lower steel plate to connect them so that the upper steel plate and the lower steel plate clamp the steel balls.

[0010] Optionally, the top support module includes a top support hydraulic motor, a top support hydraulic rod is provided on the top of the top support hydraulic motor, a top support hydraulic sleeve is threadedly connected to the top of the top support hydraulic rod, a top support plate is fixedly connected to the top of the top support hydraulic sleeve, a soft pad is provided on the top of the top support plate, a top support hydraulic motor is fixedly connected to the top of the machine top plate and the extension plate, and a top support signal receiver is fixedly connected to the front of the top support hydraulic motor.

[0011] Optionally, the X-axis testing module includes an X-axis electric drive mother car, with mother car sliding tenons fixedly connected to both sides of the mother car, the mother car sliding tenons and the side sliding grooves being mutually adapted to each other, a mother car signal receiver provided on the back of the X-axis electric drive mother car, and a mother car connecting wire hole slot and an X-axis electric drive daughter car sliding groove sequentially opened from front to back on the top of the X-axis electric drive mother car, a mother car connecting wire inserted into the inner wall of the mother car connecting wire hole slot, a mother car electrically controlled strong magnet installed on the X-axis electric drive mother car through the mother car connecting wire, a mother car strong magnetic spring fixedly connected to the back of the mother car electrically controlled strong magnet, and one end of the mother car strong magnetic spring fixedly connected to the X-axis electric drive mother car.

[0012] The X-axis electric drive mother car has an X-axis electric drive daughter car movement slot on its front side. An X-axis electric drive daughter car slides along the inner wall of the X-axis electric drive daughter car movement slot. The top of the X-axis electric drive daughter car has a daughter car sliding tenon, a daughter car signal receiver, and a daughter car monitor arranged sequentially from left to right. The X-axis electric drive daughter car sliding slot and the daughter car sliding tenon are mutually compatible. The side of the X-axis electric drive daughter car has a daughter car connection cable hole slot. A daughter car connection cable is inserted into the inner wall of the daughter car connection cable hole slot. A daughter car electrically controlled strong magnet is installed on the X-axis electric drive daughter car through the daughter car connection cable. A daughter car strong magnetic spring is fixedly connected to the front of the daughter car electrically controlled strong magnet. One end of the daughter car strong magnetic spring is fixedly connected to the X-axis electric drive daughter car.

[0013] The X-axis electric drive sub-car has a threaded hole on its front side. A sub-car bolt is threaded onto the inner wall of the threaded hole. An X-axis hydraulic motor is threaded onto the threaded hole through the sub-car bolt. An X-axis hydraulic motor signal receiver is fixedly connected to one side of the X-axis hydraulic motor. An X-axis hydraulic rod is provided on the front side of the X-axis hydraulic motor. An X-axis extrusion plate is threaded onto the surface of the X-axis hydraulic rod. A bonding module is fixedly connected to one end of the X-axis extrusion plate. A displacement measurement module is also provided on the front side of the X-axis hydraulic motor.

[0014] Optionally, the bonding module includes a spring base, one end of which has a spring placement hole. A telescopic spring is fixedly connected to the inner wall of the spring placement hole. An electromagnetic plate cylinder is mounted on the spring base through the telescopic spring. One end of the electromagnetic plate cylinder has a cylindrical hole, which is compatible with the telescopic spring. The other end of the electromagnetic plate cylinder is provided with an acoustic rebound electromagnetic plate.

[0015] Optionally, the displacement measurement module includes a telescopic rod sleeve, a rod sleeve column is fixedly connected to the surface of the telescopic rod sleeve, a telescopic main rod is installed on the inner wall of the telescopic rod sleeve, a telescopic rod hole is opened at one end of the telescopic main rod, a telescopic secondary rod is installed on the inner wall of the telescopic rod hole, displacement scales are provided on the upper surfaces of the telescopic main rod and the telescopic secondary rod, a connecting block is fixedly connected to the surface of the telescopic secondary rod, one end of the connecting block is fixed to the telescopic secondary rod, and the other end is fixedly connected to the X-axis hydraulic rod.

[0016] This invention also provides a mobile in-situ true triaxial testing method for large-size specimens. The testing method utilizes the aforementioned mobile in-situ true triaxial testing device for large-size specimens for on-site testing, and includes the following steps:

[0017] S1. Select the bottom of the cavern in the predetermined area of ​​the underground project, and make isolated cuboid specimens and grooves for placing the test device by manual chiseling or mechanical cutting. The length and width of the specimen are equal and not less than 30cm, the height of the specimen is twice the length, and the bottom surface of the specimen is connected to the original rock parent body.

[0018] S2. Move the testing device to the predetermined position, install the pressurization module, and then install the X-axis testing module, Y-axis testing module and Z-axis testing module;

[0019] S3. Determine the stress path and obtain the elastic parameters of the specimen, specifically including:

[0020] Apply equal pressure in three directions until the initial pressure value is reached. After stabilizing for 5 minutes, maintain lateral pressure. Constant, axial pressure The sample was loaded at a rate of 0.1 MPa / s until failure, and the axial and lateral strains were recorded throughout the process, resulting in a set of lateral pressure values. The stress-strain curve of the specimen during compression under the given conditions is shown. Based on the stress-strain curve, the elastic parameters of the specimen are obtained as follows:

[0021] Elastic modulus:

[0022] Poisson's ratio:

[0023] in, This represents the change in stress under a certain load gradient in the stress-strain curve. This represents the change in strain in the stress-strain curve corresponding to the load gradient. Let be the change in axial strain of the specimen under a certain load gradient. This represents the change in lateral strain of the specimen corresponding to the load gradient.

[0024] Compared with the prior art, the present invention has at least the following beneficial effects:

[0025] The above-described testing device, by setting up a pressurization module and a testing module on a mobile machine, achieves triaxial independent loading of large-sized fractured specimens, simulating the real stress environment of engineering rock masses. By setting up X-axis, Y-axis, and Z-axis testing modules, three surfaces of the test specimen can be tested simultaneously, improving testing efficiency. By setting up a bonding module and a displacement measurement module, the bonding module can fully adhere to the rock mass surface during testing, making the test data more accurate. Attached Figure Description

[0026] The accompanying drawings, which are incorporated herein and form part of the specification, illustrate embodiments of the invention and, together with the specification, further serve to explain the principles of the invention and enable those skilled in the art to practice and use the invention.

[0027] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0028] Figure 2 This is a three-dimensional assembly schematic diagram of the pressurization module of the present invention;

[0029] Figure 3 This is a schematic diagram of the assembly of the extended plate and the triangular fixing frame of the present invention;

[0030] Figure 4 This is a schematic diagram of the pulley module structure of the present invention;

[0031] Figure 5 This is a schematic diagram of the ladder module structure of the present invention;

[0032] Figure 6 This is a schematic diagram of the top support module structure of the present invention;

[0033] Figure 7 This is a schematic diagram of the X-axis testing module structure of the present invention;

[0034] Figure 8 This is a schematic diagram of the bonding module structure of the present invention;

[0035] Figure 9 This is a schematic diagram of the displacement measurement module structure of the present invention;

[0036] Figure 10 This is a flowchart illustrating the testing process for the elastic parameters of the present invention.

[0037] Figure 11 This is a flowchart of the test process for damage parameters under cyclic loading and unloading according to the present invention.

[0038] [Figure Labels]

[0039] 1. Machine top plate; 2. Machine vertical plate; 3. Pulley module; 301. Vertical plate base; 302. Threaded fastening ring; 303. Pulley base; 304. Pulley; 305. Stop wedge; 4. Ladder module; 401. Top ladder ring; 402. Ladder; 403. Ladder ring connecting column; 404. Bottom ladder ring; 405. Standing plate; 5. Triangular fixing frame; 6. Extension plate; 7. Operating compartment; 8. Top support module; 801. Top support hydraulic motor; 802. 803. Hydraulic strut for top support; 804. Hydraulic sleeve for top support; 805. Top support plate; 806. Soft pad; 807. Signal receiver for top support; 9. Pull hook; 10. X-axis test module; 1001. X-axis electric drive mother car; 1002. Mother car sliding tenon; 1003. Mother car signal receiver; 1004. Mother car connecting cable; 1005. Mother car electric control strong magnet; 1006. Mother car strong magnetic spring; 1007. X-axis electric drive daughter car; 1008. Daughter car sliding tenon; 10 09. Sub-vehicle signal receiver; 1010. Sub-vehicle monitor; 1011. Sub-vehicle connecting cable; 1012. Sub-vehicle electrically controlled strong magnet; 1013. Sub-vehicle strong magnetic spring; 1014. X-axis hydraulic motor; 1015. X-axis hydraulic motor signal receiver; 1016. X-axis hydraulic rod; 1017. X-axis extrusion plate; 11. Bonding module; 1101. Spring base; 1102. Telescopic spring; 1103. Electromagnetic plate cylinder; 1104. Acoustic wave rebound electric... Magnetic sheet; 12. Displacement measurement module; 1201. Telescopic rod sleeve; 1202. Rod sleeve column; 1203. Telescopic main rod; 1204. Telescopic secondary rod; 1205. Displacement scale; 1206. Connecting block; 13. Pressurization module; 1301. Reaction frame; 1302. Hydraulic pillow; 1303. Pad plate; 1304. Pressurization jack; 1305. Universal ball; 1306. Ball bearing row; 1307. Displacement jack; 14. Sample; 15. Hydraulic servo module.

[0040] As shown in the figure, specific structures and devices are marked in the figure to clearly illustrate the structure of the embodiments of the present invention. However, this is only for illustrative purposes and is not intended to limit the present invention to this specific structure, device and environment. Those skilled in the art can adjust or modify these devices and environments according to specific needs. Detailed Implementation

[0041] The present invention provides a mobile in-situ true triaxial testing device and method for large-size specimens, with reference to the accompanying drawings and specific embodiments. It should be noted that, to make the embodiments more detailed, the following embodiments are the best and preferred embodiments; those skilled in the art can also use other alternative methods to implement some known technologies; and the accompanying drawings are only for more specific description of the embodiments and are not intended to specifically limit the present invention.

[0042] It should be noted that the use of terms such as "an embodiment," "an embodiment," "an exemplary embodiment," and "some embodiments" in the specification indicates that the described embodiment may include a specific feature, structure, or characteristic, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments (whether explicitly described or not) should be within the knowledge of those skilled in the art.

[0043] Generally, terms can be understood at least partly from their use in context. For example, depending at least partly on the context, the term "one or more" as used herein can be used to describe any feature, structure, or characteristic in a singular sense, or a combination of features, structures, or characteristics in a plural sense. Additionally, the term "based on" can be understood not necessarily to convey an exclusive set of factors, but rather, alternatively, depending at least partly on the context, to allow for the presence of other factors that are not necessarily explicitly described.

[0044] It is understood that the meanings of “on”, “above”, and “above” in this invention should be interpreted in the broadest manner, such that “on” means not only “directly on” something, but also includes the meaning of being “on” something with an intervening feature or layer, and that “above” or “above” means not only “on” something, but also includes the meaning of being “on” something without an intervening feature or layer.

[0045] Furthermore, spatially related terms such as “below,” “under,” “lower,” “above,” and “upper” are used herein for convenience to describe the relationship of one element or feature to one or more other elements or features, as illustrated in the accompanying drawings. Spatially related terms are intended to cover different orientations in the use or operation of the device other than those depicted in the accompanying drawings. The device may be oriented in other ways, and the spatially related descriptive terms used herein can be interpreted similarly.

[0046] like Figures 1 to 9As shown, an embodiment of the present invention provides a mobile in-situ true triaxial testing device for large-size specimens, including a mobile machine, a hydraulic servo module 15, a pressurization module 13, and a testing module. The mobile machine includes a machine top plate 1, a machine vertical plate 2 fixedly connected to the side of the machine top plate 1, and a pressurization module 13 fixedly connected to the bottom of the machine top plate 1. The pressurization module 13 is connected to the hydraulic servo module 15. The testing module includes an X-axis testing module 10, a Y-axis testing module, and a Z-axis testing module. Each of the X-axis testing module 10, the Y-axis testing module, and the Z-axis testing module has a bonding module 11 at one end near the specimen. A displacement measurement module 12 is provided on one side of each of the X-axis testing module 10, the Y-axis testing module, and the Z-axis testing module.

[0047] The machine vertical plate 2 has pulley grooves on both the front and back sides, and an X-axis test module 10 is slidably connected to the inner wall of the pulley grooves. The machine vertical plate 2 has side sliding grooves on its side sides, and a Y-axis test module is provided on the inner wall of the machine vertical plate 2. A Z-axis test module is provided at the bottom of the machine top plate 1. Pull hooks 9 are fixedly connected to both the front and back sides of the machine vertical plate 2. A pulley module 3 is installed at the bottom of the machine vertical plate 2. A ladder module 4 is fixedly connected to the left side of the machine vertical plate 2. A triangular fixing frame 5 is fixedly connected to the back of the machine vertical plate 2. An extension plate 6 is fixedly connected to the top of the triangular fixing frame 5. An operating compartment 7 is fixedly connected to the top of the extension plate 6. A top support module 8 is provided at the top of both the machine top plate 1 and the extension plate 6.

[0048] The vertical plate 2 of the machine is welded to both sides of the top plate 1 of the machine. The pulley module 3 is installed on the vertical plate 2 of the machine. The ladder module 4 is welded to the left side of the vertical plate 2 of the machine. The triangular fixing frame 5 is first welded to the bottom of the extension plate 6. Then, the welded and assembled triangular fixing frame 5 and extension plate 6 are aligned with the back of the top plate 1 of the machine. Then, the gap between the extension plate 6 and the top plate 1 is welded. Then, the gap between the triangular fixing frame 5 and the vertical plate 2 of the machine is welded. The operating compartment 7 is welded to the top of the extension plate 6. The top support module 8 is installed on the machine top plate 1 and the extension plate 6. The traction hook 9 is welded to the front and back of the machine vertical plate 2. The pulley groove and the side slide groove are integrally formed with the machine vertical plate 2. The X-axis test module 10 is placed in the pulley groove and the side slide groove. The Y-axis test module and the Z-axis test module are also installed on the machine vertical plate 2. Finally, the bonding module 11 and the displacement measurement module 12 are also installed on the X-axis test module 10, the Y-axis test module and the Z-axis test module. The pressure module 13 is fixed to the bottom of the machine top plate 1.

[0049] In use, the tractor needs to be driven to the direction of movement of the testing device. One end of the traction rope is attached to the traction hook 9, and the other end is attached to the tractor. The tractor then pulls the testing device to move as a whole. When the testing device is pulled by the tractor, the pulley module 3 starts to move, thereby driving the testing device to move. After the testing device enters the cave and reaches the predetermined position, the stop wedge 305 is placed at the bottom of the pulley 304 to prevent the testing device from sliding. Then, the test personnel can climb the ladder module 4 to the top plate 1 of the machine and enter the operating chamber 7. The pressurization module 13 is automatically installed on the outside of the sample 14. Then, according to the actual position of the reserved hole, commands are issued to the X-axis testing module 10, the Y-axis testing module, and the Z-axis testing module to adjust each testing module to the ideal position. Then, the test personnel operate the top support module 8 to support the top of the cave and prevent the top rock fragments from falling. After the X-axis test module 10, Y-axis test module, and Z-axis test module reach their ideal positions, the test command can be issued to begin applying pressure to the sample 14 in three directions. The bonding module 11 and displacement measurement module 12 will record relevant data and provide real-time feedback to the tester in the operating chamber 7, completing the operation. By setting up the operating chamber 7, test personnel can perform the test within it, avoiding injury from falling rocks.

[0050] The pressurization module 13 includes a hydraulic pillow 1302, a reaction frame 1301, a pressurization jack 1304, a displacement jack 1307, a pad 1303, a universal ball joint 1305, and a ball bearing assembly 1306. The hydraulic pillow 1302 provides two independent confining pressures to the sample. The reaction frame 1301 provides a reaction force to the hydraulic pillow 1302. The pressurization jack 1304 provides axial pressure to the sample. The bottom end of the displacement jack 1307 is connected to the reaction frame 1301 for raising and lowering the reaction frame 1301. The pad 1303... Plate 1303 is arranged on the upper surface of the sample; the universal ball 1305 can rotate in any direction, so that the reaction force of the ball bearing 1306 on the pressure jack 1304 is always along the axial direction; the hydraulic servo module 15 can independently supply oil to the hydraulic pillow 1302, the pressure jack 1304 and the displacement jack 1307; the pressure module 13 can independently load the sample 14 in three directions, and the reaction frame 1301 and the pad 1303 are both reserved with holes so that the displacement measurement module 12 can pass through and contact the surface of the sample 14.

[0051] The hydraulic cushion 1302 is distributed on the four sides of the sample and can be loaded independently in the X and Y directions. The hydraulic cushion 1302 is made of two iron plates overlapped and welded around the perimeter, with a hole in the middle for the sensor to pass through. The hole is sealed by welding, and an oil inlet is reserved on one side. The hydraulic cushion 1302 can expand laterally under oil pressure to generate pressure on the sample. When there is no oil pressure, the two iron plates shrink to a close state. The hydraulic pillow 1302 is closely attached to the inner side of the reaction frame 1301, which is installed on the outside of the sample 14. The reaction frame 1301 is connected to the ball bearing 1306 via the displacement jack 1307. The pad 1303 is placed on the upper surface of the sample 14. The lower end of the pressure jack 1304 applies pressure to the pad 1303. The ball bearing 1306 is fixedly connected to the bottom of the machine top plate 1. The displacement jack 1307 is installed on both sides of the bottom of the ball bearing 1306, and the pressure jack 1304 is installed in the middle of the bottom of the ball bearing 1306. The ball bearing 1306 is used to make minor adjustments to the position of the pressure jack 1304 in the X and Y axis directions so that the pressure jack 1304 can be aligned with the top surface of the sample. The ball bearing 1306 consists of an upper steel plate, a lower steel plate, steel balls, and springs. The upper and lower steel plates are connected by springs around their perimeter to clamp the steel balls.

[0052] like Figures 3 to 6 As shown, the pulley module 3 includes a vertical plate base 301. A vertical plate base threaded hole is provided on the side of the vertical plate base 301. A vertical plate base bolt is threadedly connected to the inner wall of the vertical plate base threaded hole. A machine vertical plate 2 is threadedly connected to the vertical plate base threaded hole through the vertical plate base bolt. A vertical plate groove is provided on the top of the vertical plate base 301. The vertical plate groove and the machine vertical plate 2 are mutually adapted. A threaded fastening ring 302 is threadedly connected to the surface of the vertical plate base bolt. A pulley base 303 is fixedly connected to the bottom of the vertical plate base 301. A pulley 304 is provided at the bottom of the pulley base 303.

[0053] The vertical plate groove and the vertical plate base 301 are integrally formed. The pulley base 303 is welded to the bottom of the vertical plate base 301, and then the pulley 304 is installed on the bottom of the pulley base 303. Then, the assembled machine vertical plate 2 is hoisted into the vertical plate groove of the vertical plate base 301. Then, the vertical plate base bolt is screwed into the threaded hole of the vertical plate base and continues to rotate until it passes through the machine vertical plate 2 and is screwed out from the threaded hole of the vertical plate base 301 on the other side. Finally, the threaded fastening ring 302 is screwed into the vertical plate base bolt to complete the assembly.

[0054] Once the entire device is pulled to the ideal position by the tractor, the test personnel must immediately insert the stop wedges 305 into the front and back of the pulley 304 after confirming that the pulley 304 has stopped moving. This will completely stabilize the pulley 304 and prevent the entire device from moving due to the movement of other modules during the test operation, thus avoiding test accidents.

[0055] The ladder module 4 includes a top ladder ring 401, a ladder 402 fixedly connected to the inner wall of the top ladder ring 401, a ladder ring connecting post 403 fixedly connected to the surface of the top ladder ring 401, a bottom ladder ring 404 fixedly connected to the top ladder ring 401 through the ladder ring connecting post 403, a ladder 402 fixedly connected to the inner wall of the bottom ladder ring 404, and a standing plate 405 fixedly connected to the bottom of the ladder 402.

[0056] Weld one end of the ladder ring connecting post 403 to the surface of the top ladder ring 401, and weld the other end of the ladder ring connecting post 403 to the surface of the bottom ladder ring 404. Then weld the upper end of one side of the ladder 402 to the inner wall of the top ladder ring 401, and weld the lower end of one side of the ladder 402 to the inner wall of the bottom ladder ring 404. Then weld the standing plate 405 to the bottom of the ladder 402. Finally, align the assembled ladder module 4 with the machine vertical plate 2 and weld it to the left side of the machine vertical plate 2 to complete the assembly.

[0057] When in use, the test personnel need to bend down and enter the bottom climbing ladder ring 404. Then the test personnel can stand up straight and stand on the standing plate 405. Then the test personnel can climb up the climbing ladder 402 until they reach the top and can go up to the machine top plate 1 and enter the operating chamber 7.

[0058] The top support module 8 includes a top support hydraulic motor 801, a top support hydraulic rod 802 on the top of the top support hydraulic motor 801, a top support hydraulic sleeve 803 threadedly connected to the top of the top support hydraulic rod 802, a top support plate 804 fixedly connected to the top of the top support hydraulic sleeve 803, a soft pad 805 on the top of the top support plate 804, threaded holes for the top support hydraulic motor on the top of the machine top plate 1 and the extension plate 6, threaded connections for the top support hydraulic motor bolts to the inner walls of the threaded holes for the top support hydraulic motor, and the top support hydraulic motor 801 threadedly connected to the threaded holes for the top support hydraulic motor through the threaded bolts. A top support signal receiver 806 is fixedly connected to the front of the top support hydraulic motor 801.

[0059] The top support hydraulic rod 802 is integrally connected to the top support hydraulic motor 801. The top support hydraulic sleeve 803 is screwed onto the top support hydraulic rod 802, and the top support plate 804 is welded to the top of the top support hydraulic sleeve 803. Then, the soft pad 805 is attached to the top support plate 804 with adhesive. The top support signal receiver 806 is integrally connected to the top support hydraulic motor 801. Finally, the top support hydraulic motor bolt is passed through the top support hydraulic motor 801 and rotated until it is screwed into the threaded holes of the top support hydraulic motor in the machine top plate 1 and the extension plate 6, thus completing the assembly.

[0060] During use, the test personnel send a command to start the top support hydraulic motor 801 from the operation chamber 7. After receiving the command, the top support signal receiver 806 drives the top support hydraulic motor 801 to start. After the top support hydraulic motor 801 starts, it drives the top support hydraulic rod 802 to move towards the top of the cavern, thereby driving the top support plate 804 and the soft pad 805 to move towards the top until the top support plate 804 and the soft pad 805 are pressed against the top of the cavern. The soft pad 805 is made of soft material, which can better adapt to the rugged rock surface of the top rock mass, thus supporting the rock mass more tightly. After confirming that the top support plate 804 and the soft pad 805 are pressed against the rock at the top of the cavern, the test personnel send a pause command to keep the module movement in place. This can prevent large pieces of broken rock from falling off the top of the cavern to a certain extent.

[0061] like Figure 7 As shown, the X-axis test module 10 includes an X-axis electric drive mother car 1001. Mother car sliding tenons 1002 are fixedly connected to both sides of the X-axis electric drive mother car 1001. The mother car sliding tenons 1002 and the side sliding grooves are mutually adapted. A mother car signal receiver 1003 is provided on the back of the X-axis electric drive mother car 1001. A mother car connecting wire hole slot and an X-axis electric drive daughter car sliding groove are sequentially opened from front to back on the top of the X-axis electric drive mother car 1001. A mother car connecting wire 1004 is inserted into the inner wall of the mother car connecting wire hole slot. A mother car electrically controlled strong magnet 1005 is installed on the X-axis electric drive mother car 1001 through the mother car connecting wire 1004. A mother car strong magnetic spring 1006 is fixedly connected to the back of the mother car electrically controlled strong magnet 1005. One end of the mother car strong magnetic spring 1006 is fixedly connected to the X-axis electric drive mother car 1001.

[0062] The front of the X-axis electric drive mother car 1001 has an X-axis electric drive daughter car movement slot. An X-axis electric drive daughter car 1007 is slidably attached to the inner wall of the X-axis electric drive daughter car movement slot. From left to right, the top of the X-axis electric drive daughter car 1007 has a daughter car sliding tenon 1008, a daughter car signal receiver 1009, and a daughter car monitor 1010. The X-axis electric drive daughter car sliding slot and the daughter car sliding tenon 1008 are mutually compatible. The side of the vehicle 1007 has a slot for connecting the sub-vehicle cable. The inner wall of the slot is into which the sub-vehicle cable 1011 is inserted. The X-axis electric drive sub-vehicle 1007 is equipped with a sub-vehicle electric control magnet 1012 through the sub-vehicle cable 1011. The front of the sub-vehicle electric control magnet 1012 is fixedly connected to a sub-vehicle electric magnet spring 1013. One end of the sub-vehicle electric magnet spring 1013 is fixedly connected to the X-axis electric drive sub-vehicle 1007.

[0063] The X-axis electric drive sub-car 1007 has a threaded hole on its front side. A sub-car bolt is threaded into the inner wall of the threaded hole. An X-axis hydraulic motor 1014 is threaded into the threaded hole through the sub-car bolt. An X-axis hydraulic motor signal receiver 1015 is fixedly connected to one side of the X-axis hydraulic motor 1014. An X-axis hydraulic rod 1016 is provided on the front side of the X-axis hydraulic motor 1014. An X-axis extrusion plate 1017 is threaded into the surface of the X-axis hydraulic rod 1016. A bonding module 11 is fixedly connected to one end of the X-axis extrusion plate 1017. A displacement measurement module 12 is also provided on the front side of the X-axis hydraulic motor 1014. The test personnel observe and record the data of the displacement measurement module 12 through the sub-car monitor 1010.

[0064] The mother car sliding tenon 1002 is welded to the X-axis electric drive mother car 1001. The mother car connecting wire hole slot and the X-axis electric drive daughter car sliding groove are both integrally formed with the X-axis electric drive mother car 1001. One end of the mother car strong magnetic spring 1006 is welded to the mother car electric control strong magnet 1005, and the other end is welded to the X-axis electric drive mother car 1001. The mother car connecting wire 1004 is inserted into the mother car connecting wire hole slot of the X-axis electric drive mother car 1001, and the other end is inserted into the mother car electric control strong magnet 1005. Finally, the X-axis electric drive mother car 1001 is placed in the pulley groove of the machine vertical plate 2, and the mother car sliding tenon 1002 on the X-axis electric drive mother car 1001 is inserted into the side sliding groove of the machine vertical plate 2. The X-axis electric drive daughter car movement groove is also integrally formed with the X-axis electric drive mother car 1001.

[0065] The sliding tenon 1008 of the sub-car is welded to the X-axis electric drive sub-car 1007. The sub-car connecting wire hole and slot and the X-axis electric drive sub-car 1007 are integrally formed. One end of the sub-car strong magnetic spring 1013 is welded to the sub-car electronically controlled strong magnet 1012, and the other end is welded to the X-axis electric drive sub-car 1007. Then, one end of the sub-car connecting wire 1011 is inserted into the sub-car connecting wire hole and slot, and the other end is inserted into the sub-car electronically controlled strong magnet 1012. Then, the X-axis electric drive sub-car 1007 is placed in the X-axis electric drive sub-car motion slot on the X-axis electric drive mother car 1001, and the sliding tenon 1008 of the sub-car is snapped into the X-axis electric drive sub-car sliding slot. The X-axis hydraulic motor signal receiver 1015 and the X-axis hydraulic rod 1016 are both integrally connected to the X-axis hydraulic motor 1014. The X-axis extrusion plate 1017 is screwed onto the X-axis hydraulic rod 1016, and the bonding module 11 is integrally connected to the X-axis extrusion plate 1017.

[0066] During operation, the test personnel observe the positional differences between the X-axis electric drive mother car 1001 and X-axis electric drive daughter car 1007 and the reserved holes on the reaction frame 1301 through the daughter car monitor 1010 in the operating compartment 7. Based on the determined positional differences, motion commands are sent to the X-axis electric drive mother car 1001 and X-axis electric drive daughter car 1007 respectively. After receiving the motion signals, the mother car signal receiver 1003 and the daughter car signal receiver 1009 will respectively... The X-axis electric drive mother car 1001 and X-axis electric drive daughter car 1007 move in the pulley groove of the vertical plate 2 of the machine and in the X-axis electric drive daughter car movement groove of the X-axis electric drive mother car 1001, respectively. The mother car sliding tenon 1002 and daughter car sliding tenon 1008, which are stuck in the side sliding groove and the X-axis electric drive daughter car sliding groove, will also move along with it. The mother car sliding tenon 1002 and daughter car sliding tenon 1008 will ensure that the electric drive car will not fall out of the groove and overturn during operation.

[0067] After the X-axis electric drive mother car 1001 and X-axis electric drive daughter car 1007 move to the ideal position, the mother car 1001 and daughter car 1007 respectively energize the mother car's electrically controlled strong magnet 1005 and the daughter car's electrically controlled strong magnet 1012 through the mother car connecting line 1004 and the daughter car connecting line 1011. This causes the mother car's electrically controlled strong magnet 1005 and the daughter car's electrically controlled strong magnet 1012 to release their strong magnets, thereby causing the X-axis electric drive mother car 1001 and X-axis electric drive daughter car 1007 to move to the ideal position. 7 can hover. After hovering, a command to start the X-axis hydraulic motor 1014 can be sent. After receiving the command to start the X-axis hydraulic motor 1014, the X-axis hydraulic motor signal receiver 1015 drives the X-axis hydraulic motor 1014 to move, thereby driving the X-axis hydraulic rod 1016 to move towards the test sample 14, and causing the X-axis extrusion plate 1017 and the bonding module 11 to move in unison until the bonding module 11 passes through the reserved hole on the reaction frame 1301 and bonds to the surface of the test sample 14.

[0068] like Figure 8 and Figure 9 As shown, the bonding module 11 includes a spring base 1101. One end of the spring base 1101 has a spring placement hole, and a telescopic spring 1102 is fixedly connected to the inner wall of the spring placement hole. An electromagnetic plate cylinder 1103 is mounted on the spring base 1101 via the telescopic spring 1102. One end of the electromagnetic plate cylinder 1103 has a cylindrical hole that is compatible with the telescopic spring 1102. The other end of the electromagnetic plate cylinder 1103 has a sound wave rebound electromagnetic plate 1104. The electromagnetic plate cylinder 1103 has a wire harness hole, and correspondingly, the spring base 1101 has a base wire harness hole. One end of the telescopic spring 1102 is welded into the spring placement hole, and the other end of the telescopic spring 1102 is welded into the cylindrical hole. The sound wave rebound electromagnetic plate 1104 is adhered to the electromagnetic plate cylinder 1103 using adhesive.

[0069] In use, when the bonding module 11 is bonded to the test sample 14, the electromagnetic plate cylinder 1103 and the telescopic spring 1102 will cooperate with each other. When the surface of the test sample 14 is uneven, the protruding rock surface will cause the electromagnetic plate cylinder 1103 to squeeze the telescopic spring 1102, so that the module can bond to the surface of the test sample 14. After the acoustic rebound electromagnetic plate 1104 is bonded to the rock, it will record relevant data and transmit it to the X-axis hydraulic motor signal receiver 1015 through the wiring harness, and then the X-axis hydraulic motor signal receiver 1015 will transmit it to the operating chamber 7.

[0070] The displacement measurement module 12 includes a telescopic rod sleeve 1201. A rod sleeve column 1202 is fixedly connected to the surface of the telescopic rod sleeve 1201. A telescopic female rod 1203 is installed on the inner wall of the telescopic rod sleeve 1201. One end of the telescopic female rod 1203 has a telescopic rod hole, and a telescopic male rod 1204 is installed on the inner wall of the telescopic rod hole. The upper surfaces of the telescopic female rod 1203 and the telescopic male rod 1204 are provided with displacement scales 1205. A connecting block 1206 is fixedly connected to the surface of the telescopic male rod 1204. The rod sleeve column 1202 is welded to the surface of the telescopic rod sleeve 1201. The rod sleeve column 1202 and the telescopic female rod 1203 are welded to the X-axis hydraulic motor 1014. One end of the connecting block 1206 is welded to the telescopic male rod 1204, and the other end is welded to the X-axis hydraulic rod 1016. When the X-axis hydraulic rod 1016 moves, the telescopic sub-rod 1204 will also move synchronously, and the displacement scale 1205 on the telescopic sub-rod 1204 will change accordingly. The data of the change of the displacement scale 1205 will be captured in real time by the sub-vehicle monitor 1010 and transmitted back to the operation compartment 7.

[0071] This device, by setting up a bonding module 11 and a displacement measurement module 12, allows the bonding module 11 to fully adhere to the rock surface during the test of the test sample 14, enabling more accurate acquisition of test data. At the same time, the displacement measurement module 12 can fully record relevant displacement data during the test. Compared with existing devices that use multiple dial gauges to control the accuracy of the data, this device, through the combined use of the bonding module 11 and the displacement measurement module 12, makes the test data more accurate and increases the reliability of the test data.

[0072] Embodiments of the present invention provide a mobile in-situ true triaxial testing method for large-size specimens. The testing method utilizes the aforementioned mobile in-situ true triaxial testing device for large-size specimens for on-site testing. The testing method includes the following steps:

[0073] S1. Select the bottom of the cavern in the predetermined area of ​​the underground project, and make isolated cuboid specimens and grooves for placing the test device by manual chiseling or mechanical cutting. The length and width of the specimen are equal and not less than 30cm, the height of the specimen is twice the length, and the bottom surface of the specimen is connected to the original rock parent body.

[0074] S2. Move the testing device to the predetermined position, install the pressurization module, and then install the X-axis testing module, Y-axis testing module and Z-axis testing module;

[0075] S3. Determine the stress path and obtain the elastic parameters of the specimen, specifically including:

[0076] Apply equal pressure in three directions until the initial pressure value is reached. After stabilizing for 5 minutes, maintain lateral pressure. Constant, axial pressure The sample was loaded at a rate of 0.1 MPa / s until failure, and the axial and lateral strains were recorded throughout the process, resulting in a set of lateral pressure values. The stress-strain curve of the specimen during compression under the given conditions is shown. Based on the stress-strain curve, the elastic parameters of the specimen are obtained as follows:

[0077] Elastic modulus:

[0078] Poisson's ratio:

[0079] in, This represents the change in stress under a certain load gradient in the stress-strain curve. This represents the change in strain in the stress-strain curve corresponding to the load gradient. Let be the change in axial strain of the specimen under a certain load gradient. This represents the change in lateral strain of the specimen corresponding to the load gradient.

[0080] In step S2, the installation of the pressurization module specifically includes the following steps:

[0081] The hydraulic pillow 1302 is fixed tightly against the inside of the reaction frame 1301. The reaction frame 1301 is lowered and placed over the outside of the sample 14 using the displacement jack 1307. The hydraulic pillow 1302 generates pre-pressure around the sample 14. The ball bearings 1306 are slightly adjusted in the X and Y directions so that the pressure jack 1304 is aligned with the top of the sample 14. A pad 1303 is placed on the top of the sample 14 so that the pressure jack 1304 pre-presses the pad 1303.

[0082] The installation of the X-axis test module includes the following steps:

[0083] Based on the position of the sample 14, the testers sent motion commands to the X-axis electric drive mother car 1001 and the X-axis electric drive daughter car 1007 respectively. After receiving the corresponding motion signals, the mother car signal receiver 1003 and the daughter car signal receiver 1009 respectively drove the X-axis electric drive mother car 1001 and the X-axis electric drive daughter car 1007 to the positions aligned with the reserved holes of the reaction force frame 1301 and the hydraulic pillow 1302. The X-axis electric drive mother car 1001 and the X-axis electric drive daughter car 1007 respectively energized the mother car electric control strong magnet 1005 and the daughter car electric control strong magnet 1012 through the mother car connecting line 1004 and the daughter car connecting line 1011, so that the X-axis electric drive mother car 1001 and the X-axis electric drive daughter car 1007 were suspended.

[0084] The X-axis test module, the Y-axis test module, and the Z-axis test module are also equipped with an acoustic emission measurement module. Embodiments of the present invention also provide a mobile in-situ true triaxial testing method for large-size specimens. By conducting loading and unloading tests on the test specimen under different stress paths, damage parameters under cyclic loading and unloading can be obtained, including the following steps:

[0085] S1. Prepare a rectangular sample and a groove for placing the testing device, wherein the length and width of the sample are equal and not less than 30cm, the height of the sample is twice the length, and the bottom surface of the sample is connected to the original rock parent body.

[0086] S2. Move the testing device to the predetermined position, install the pressurization module, and then install the X-axis testing module, Y-axis testing module, and Z-axis testing module;

[0087] S3. Determine the stress path and obtain the damage parameters of the specimen under cyclic loading and unloading, specifically including:

[0088] (1) Apply equal pressure in three directions until the initial pressure value is reached. Acoustic emission (AE) was used to monitor the temporal characteristic parameters of the specimens during the experiment; axial pressure was maintained during the experiment. Constant, in the same cycle test, the lateral pressure Gradually unload and load according to axial strain control, and plot the curves of deviatoric stress and lateral stress changes; at the same time, determine whether the deviatoric stress-strain curve shows yielding, that is, whether the deviatoric stress has reached the failure strength. ;

[0089] (2) During the unloading process, it is necessary to determine whether the deviatoric stress has reached the failure strength. The judgment is based on the sudden changes in the noise (dB) amplitude and energy (Energy) amplitude in the time-series characteristic parameter graph of the signal collected by the acoustic emission (AE) monitoring system under different stress conditions;

[0090] (3) If the destructive strength is not reached Unload lateral pressure to a predetermined value After stabilizing for 5 minutes, apply lateral pressure to the initial value according to the axial strain control. Complete the first The cyclical unloading and loading process makes Execute the next iteration of the loop;

[0091] (4) If the destructive strength is reached ,make ,in When the destructive strength is reached during the unloading process The corresponding lateral pressure value at that time; then loading begins. Continue executing the loop of unloading and loading, making Execute the next iteration of the loop;

[0092] (5) The lateral pressure cycle unloading and loading process is performed according to step (3) or (4). In each cycle, the noise (dB) amplitude and energy (Energy) amplitude in the time-series characteristic parameter diagram monitored by AE are recorded, and the evolution law of noise (dB) amplitude and energy (Energy) amplitude in different cycles is plotted.

[0093] This invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of this invention. To provide the public with a thorough understanding of this invention, specific details are described in detail in the preferred embodiments, while those skilled in the art will fully understand the invention even without these details. Furthermore, to avoid unnecessary misunderstanding of the essence of this invention, well-known methods, processes, procedures, components, and circuits are not described in detail.

[0094] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A mobile in-situ true triaxial testing device for large-size specimens, characterized in that, It includes a mobile machine, a hydraulic servo module, a pressurization module, and a testing module. The mobile machine includes a machine top plate, a machine vertical plate is fixed to the side of the machine top plate, and a hydraulic servo module and a pressurization module are installed on the bottom surface of the machine top plate. The testing module includes an X-axis testing module, a Y-axis testing module, and a Z-axis testing module. Each of the X-axis testing module, the Y-axis testing module, and the Z-axis testing module is provided with a bonding module at one end near the sample. Each of the X-axis testing module, the Y-axis testing module, and the Z-axis testing module is provided with a displacement measurement module. The bonding module includes a spring base, one end of which has a spring placement hole. A telescopic spring is fixedly connected to the inner wall of the spring placement hole. An electromagnetic plate cylinder is mounted on the spring base through the telescopic spring. One end of the electromagnetic plate cylinder has a cylindrical hole, which is compatible with the telescopic spring. The other end of the electromagnetic plate cylinder is provided with an acoustic rebound electromagnetic plate.

2. The mobile in-situ true triaxial testing device for large-size specimens according to claim 1, characterized in that, The machine's vertical plate has pulley grooves on both the front and back sides, with an X-axis test module slidably connected to the inner wall of the pulley grooves. The machine's vertical plate has side sliding grooves on its sides, a Y-axis test module is provided on the inner wall of the machine's vertical plate, and a Z-axis test module is provided at the bottom of the machine's top plate. The machine's vertical plate has pull hooks fixedly connected to both the front and back sides. A pulley module is installed at the bottom of the machine's vertical plate. A ladder module is fixedly connected to one side of the machine's vertical plate. A triangular fixing frame is fixedly connected to the back of the machine's vertical plate. An extension plate is fixedly connected to the top of the triangular fixing frame. An operating compartment is fixedly connected to the top of the extension plate. Both the top plate of the machine and the top of the extension plate are equipped with top support modules.

3. The mobile in-situ true triaxial testing device for large-size specimens according to claim 1, characterized in that, The pressurization module includes a hydraulic cushion, a reaction frame, a pressurization jack, a displacement jack, a pad, a universal ball joint, and a ball bearing assembly. The hydraulic cushion provides two independent confining pressures to the sample. The reaction frame provides a reaction force to the hydraulic cushion. The pressurization jack provides axial pressure to the sample. The bottom end of the displacement jack is connected to the reaction frame for raising and lowering the reaction frame. The pad is placed on the upper surface of the sample. The universal ball joint can rotate in any direction, ensuring that the reaction force of the ball bearing assembly on the pressurization jack is always axial. The hydraulic servo module can independently supply oil to the hydraulic cushion, the pressurization jack, and the displacement jack.

4. The mobile in-situ true triaxial testing device for large-size specimens according to claim 3, characterized in that, The ball bearing assembly is fixedly connected to the bottom of the machine top plate. The pressure jack is installed at the middle position of the bottom of the ball bearing assembly, and a displacement jack is installed on each side of the bottom of the ball bearing assembly. The ball bearing assembly consists of an upper steel plate, a lower steel plate, steel balls, and springs. Springs are arranged around the upper steel plate and the lower steel plate to connect them so that the upper steel plate and the lower steel plate clamp the steel balls.

5. The mobile in-situ true triaxial testing device for large-size specimens according to claim 2, characterized in that, The top support module includes a top support hydraulic motor, a top support hydraulic rod is provided on the top of the top support hydraulic motor, a top support hydraulic sleeve is threadedly connected to the top of the top support hydraulic rod, a top support plate is fixedly connected to the top of the top support hydraulic sleeve, a soft pad is provided on the top of the top support plate, a top support hydraulic motor is fixedly connected to the top of the machine top plate and the extension plate, and a top support signal receiver is fixedly connected to the front of the top support hydraulic motor.

6. The mobile in-situ true triaxial testing device for large-size specimens according to claim 1, characterized in that, The X-axis test module includes an X-axis electric drive mother car. Mother car sliding tenons are fixedly connected to both sides of the X-axis electric drive mother car, and the mother car sliding tenons and side sliding grooves are mutually compatible. A mother car signal receiver is provided on the back of the X-axis electric drive mother car. From front to back, the top of the X-axis electric drive mother car has a mother car connection cable slot and an X-axis electric drive daughter car sliding groove sequentially formed. A mother car connection cable is inserted into the inner wall of the mother car connection cable slot. A mother car electrically controlled strong magnet is installed on the X-axis electric drive mother car through the mother car connection cable. A mother car strong magnetic spring is fixedly connected to the back of the mother car electrically controlled strong magnet, and one end of the mother car strong magnetic spring is fixedly connected to the X-axis electric drive mother car. The X-axis electric drive mother car has an X-axis electric drive daughter car movement slot on its front side. The X-axis electric drive daughter car slides along the inner wall of the X-axis electric drive daughter car movement slot. The top of the X-axis electric drive daughter car has a daughter car sliding tenon, a daughter car signal receiver, and a daughter car monitor arranged sequentially from left to right. The X-axis electric drive daughter car sliding slot and the daughter car sliding tenon are mutually compatible. The side of the X-axis electric drive daughter car has a daughter car connection cable hole slot. A daughter car connection cable is inserted into the inner wall of the daughter car connection cable hole slot. The X-axis electric drive daughter car is equipped with a daughter car electric control magnet through the daughter car connection cable. A daughter car electric control magnet spring is fixedly connected to the front of the daughter car electric control magnet. One end of the daughter car electric magnet spring is fixedly connected to the X-axis electric drive daughter car. The X-axis electric drive sub-car has a threaded hole on its front side. A sub-car bolt is threaded onto the inner wall of the threaded hole. An X-axis hydraulic motor is threaded onto the threaded hole through the sub-car bolt. An X-axis hydraulic motor signal receiver is fixedly connected to one side of the X-axis hydraulic motor. An X-axis hydraulic rod is provided on the front side of the X-axis hydraulic motor. An X-axis extrusion plate is threaded onto the surface of the X-axis hydraulic rod. A bonding module is fixedly connected to one end of the X-axis extrusion plate. A displacement measurement module is also provided on the front side of the X-axis hydraulic motor.

7. The mobile in-situ true triaxial testing device for large-size specimens according to claim 6, characterized in that, The displacement measurement module includes a telescopic rod sleeve, a rod sleeve column is fixedly connected to the surface of the telescopic rod sleeve, a telescopic main rod is installed on the inner wall of the telescopic rod sleeve, a telescopic rod hole is opened at one end of the telescopic main rod, a telescopic secondary rod is installed on the inner wall of the telescopic rod hole, displacement scales are provided on the upper surfaces of the telescopic main rod and the telescopic secondary rod, a connecting block is fixedly connected to the surface of the telescopic secondary rod, one end of the connecting block is fixed to the telescopic secondary rod, and the other end is fixedly connected to the X-axis hydraulic rod.

8. A mobile in-situ true triaxial testing method for large-size specimens, characterized in that, The testing method utilizes the mobile in-situ true triaxial testing device for large-size specimens as described in any one of claims 1 to 7, and the testing method includes the following steps: S1. Prepare a rectangular sample and a groove for placing the testing device, wherein the length and width of the sample are equal and not less than 30cm, the height of the sample is twice the length, and the bottom surface of the sample is connected to the original rock parent body. S2. Move the testing device to the predetermined position, install the pressurization module, and then install the X-axis testing module, Y-axis testing module and Z-axis testing module; S3. Determine the stress path and obtain the elastic parameters of the specimen, specifically including: Apply equal pressure in three directions to the initial pressure value, stabilize for 5 minutes, and then maintain lateral pressure. Constant, axial pressure The sample was loaded at a rate of 0.1 MPa / s until failure, and the axial and lateral strains were recorded throughout the process, resulting in a set of lateral pressure values. The stress-strain curve of the specimen during compression under the given conditions is shown. Based on the stress-strain curve, the elastic parameters of the specimen are obtained as follows: Elastic modulus: ; Poisson's ratio: ; in, This represents the change in stress under a certain load gradient in the stress-strain curve. This represents the change in strain in the stress-strain curve corresponding to the load gradient. Let be the change in axial strain of the specimen under a certain load gradient. This represents the change in lateral strain of the specimen corresponding to the load gradient.

Images