Two-rigid and one-flexible power disturbance true triaxial testing machine and use method thereof

Abstract

The invention provides a two-rigidity and one-flexibility dynamic disturbance true triaxial testing machine and a use method thereof, and relates to the technical field of rock mass mechanical tests, the two-rigidity and one-flexibility dynamic disturbance true triaxial testing machine comprises a pressure chamber, a pressure sensor, a control system and a control system, the pressure chamber is internally provided with a cavity, and the top is provided with a through hole; one end part of the disturbance loading test device passes through a sealing structure, penetrates through the through hole, is connected with the pressure chamber and is positioned in the cavity of the pressure chamber, and one end part, positioned in the cavity of the pressure chamber, of the disturbance loading test device is provided with a rock sample clamp. Through the oil pressure sealing technology and the accurate loading device, the minimum stress loading direction of the rock sample is converted from the original oil pressure flexible loading to the rigid loading direction, so that the minimum stress loading direction is not influenced by the oil pressure any more, the rigid loading can be applied, and the rigid power disturbance application can be carried out; therefore, the true triaxial testing machine can more truly reflect the dynamic mechanical response of the rock in the minimum principal stress direction, and a more reliable and flexible experimental means is provided for the research of rock mechanics.

Description

Technical Field

[0001] The invention relates to the technical field of rock mass mechanics testing, and in particular to a two-rigid-one-flexible dynamic disturbance true triaxial testing machine and a use method thereof. Background Art

[0002] Currently, all the hard rock true triaxial dynamic disturbance testing machines on the market use three rigid loading methods, that is, the excavation stress and dynamic disturbance are loaded by rigid loading pistons in three directions. This discards the "two rigid and one flexible" loading method used by static true triaxial testing machines. The "two rigid and one flexible" loading method does not have the influence of stress gaps during the loading process, which makes the experimental results more accurate and can obtain the true peak strength of the rock and the correct fracture mode. However, in the "two rigid and one flexible" test in the prior art, the oil pressure loading must be the minimum stress loading direction. This is because after the oil pressure is added to the pressure chamber, the oil pressure will fill the entire pressure chamber, making the stress of the rock specimen the same in three directions. , on this basis, rigid loading is continued to be applied in two of the directions, which is "two rigid", and oil pressure is "one flexible". Therefore, if you want to load dynamic disturbance stress on the "two rigid and one flexible" testing machine, you can only apply it in the rigid loading direction, but not in the minimum stress loading direction, because oil pressure cannot perform precise rigid loading disturbance. Because it cannot apply rigid dynamic disturbance in the minimum principal stress loading direction, this limits the application prospects of the "two rigid and one flexible" true triaxial loading method, which is obviously more excellent, in dynamic disturbance testing machines. Summary of the invention

[0003] The purpose of the present invention is to provide a two-rigid and one-flexible dynamic disturbance true triaxial testing machine and a method of using the same to improve the above problems. In order to achieve the above purpose, the technical solution adopted by the present invention is as follows: In a first aspect, the present application provides a two-rigid and one-flexible dynamic disturbance true three-axis testing machine, comprising: A pressure chamber, wherein a cavity is provided inside the pressure chamber, the cavity of the pressure chamber is used to be filled with oil, and a through hole is provided on the top of the pressure chamber; A disturbance loading test device, one end of which is connected to the pressure chamber through a sealing structure and through the through hole and is located in the cavity of the pressure chamber, and one end of the disturbance loading test device located in the cavity of the pressure chamber is provided with a rock sample clamp, and the rock sample clamped on the rock sample clamp has two surfaces exposed in the pressure chamber.

[0004] Furthermore, the rock sample fixture includes a first stress loading fixture, a second stress loading fixture, a third stress loading fixture and a fourth stress loading fixture, the third stress loading fixture and the fourth stress loading fixture are arranged on both sides of the rock sample along the maximum principal stress loading direction, the first stress loading fixture and the second stress loading fixture are arranged on both sides of the rock sample along the intermediate principal stress loading direction, and the four stress loading fixtures are interlockingly slidably connected.

[0005] Furthermore, the disturbance loading test device includes a dynamic disturbance loading actuator and an excavation stress loading actuator. The axes of the dynamic disturbance loading actuator and the excavation stress loading actuator are coaxially distributed, the dynamic disturbance loading actuator is fixedly connected to the top of the excavation stress loading actuator, one end of the excavation stress loading actuator is fixed to the outside of the upper end of the pressure chamber through a connecting device, and the other end of the excavation stress loading actuator is located inside the pressure chamber.

[0006] Furthermore, the disturbance loading test device also includes a power disturbance rod, which passes through the axes of the power disturbance loading actuator and the excavation stress loading actuator in sequence and is fixed thereto, the loading points of the power disturbance loading actuator and the excavation stress loading actuator coincide with the central axis of the power disturbance rod, and a disturbance sensor is provided on the end of the power disturbance rod close to the excavation stress loading actuator.

[0007] Furthermore, the disturbance loading test device also includes an oil pressure balance compound force sensor, which is a hollow cylinder. A through hole is opened at the center position of the upper and lower end surfaces of the oil pressure balance compound force sensor, and a plurality of oil pressure balance windows are opened on the side of the oil pressure balance compound force sensor. The oil pressure balance compound force sensor is fixedly connected to one end of the excavation stress loading actuator away from the dynamic disturbance loading actuator, and the dynamic disturbance rod passes through the through hole on the oil pressure balance compound force sensor.

[0008] Furthermore, the disturbance loading test device also includes a piston pressure head, one end of the piston pressure head is fixedly connected to the oil pressure balance composite force sensor through a sealing ring, and the other end of the piston pressure head is fixedly connected to the third stress loading fixture through a sealing ring. A through hole is provided in the piston pressure head, and the dynamic disturbance rod passes through the through hole of the piston pressure head and abuts against the upper end of the third stress loading fixture.

[0009] Furthermore, the disturbance loading test device also includes an atmospheric detection device, which is composed of a gas sampling pipeline. One end of the gas sampling pipeline passes through the axis of the excavation stress loading actuator, the through hole of the oil pressure balance composite force sensor and the through hole of the piston pressure head in sequence. The gas sampling pipeline is bent at ninety degrees and passes through the detection hole opened on the side of the excavation stress loading actuator.

[0010] Furthermore, a first flange is provided at the bottom of the dynamic disturbance loading actuator, and a second flange is provided at the top of the stress path loading actuator, and the first flange is fixedly connected to the second flange by bolts.

[0011] Furthermore, the first stress loading fixture and the second stress loading fixture are both provided with a first displacement sensor, and a plurality of the first displacement sensors are located in the same plane and are connected to each other through a connecting device; The third stress loading fixture and the fourth stress loading fixture are both provided with second displacement sensors, and a plurality of the second displacement sensors are located in the same plane and are connected to each other through a connecting device.

[0012] In a second aspect, the present application also provides a method for using a two-rigid and one-flexible dynamic disturbance true three-axis testing machine, including: Obtain rock samples; Fixing the rock sample on a rock sample fixture; The rock sample fixture having the rock sample fixed thereon is elastically fixedly connected to the disturbance loading test device, and the connected whole is elastically fixedly connected to the pressure chamber; Adding oil into the cavity of the pressure chamber and compressing it to apply oil pressure to the rock sample; Adjusting the first stress loading fixture, the second stress loading fixture, the third stress loading fixture and the fourth stress loading fixture on the rock sample fixture to ensure that the stress on the rock sample in the vertical direction and along the axial direction is zero, and the stress on the rock sample in the transverse direction is oil pressure; Applying initial stress to the rock sample based on the third stress loading fixture and the fourth stress loading fixture, taking the vertical direction as the minimum stress loading direction, wherein the initial stress is less than the oil pressure; Based on the disturbance loading test device, vertical dynamic disturbance loading is performed on the rock sample, and the vertical direction is the minimum principal stress direction, until the rock sample is destroyed, and the disturbance test result is obtained.

[0013] The beneficial effects of the present invention are: The present invention uses oil pressure sealing technology and precise loading devices to convert the minimum stress loading direction of the rock sample from the original oil pressure flexible loading to a direction capable of rigid loading, so that the minimum stress loading direction is no longer affected by the oil pressure, rigid loading can be applied and rigid dynamic disturbance can be applied, so that the true triaxial testing machine can more realistically (without stress blank angle) reflect the dynamic mechanical response of the rock in the minimum principal stress direction, providing a more reliable and flexible experimental means for rock mechanics research.

[0014] Other features and advantages of the present invention will be set forth in the following description, and in part will become apparent from the description, or may be understood by practicing embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0016] Figure 1 It is a structural schematic diagram of a true triaxial testing machine for two rigid and one flexible dynamic disturbances described in an embodiment of the present invention; Figure 2 It is a schematic diagram of one side structure of the disturbance loading test device and the rock sample fixture described in the embodiment of the present invention; Figure 3 It is a schematic diagram of the other side structure of the disturbance loading test device and the rock sample fixture described in the embodiment of the present invention; Figure 4 It is a schematic diagram of the position of the power disturbance rod described in an embodiment of the present invention; Figure 5 It is a schematic diagram of the structure of the oil pressure balance composite force sensor described in an embodiment of the present invention; Figure 6 It is a schematic flow chart of the method for using the two-rigid-one-flexible dynamic disturbance true triaxial testing machine described in an embodiment of the present invention.

[0017] Markings in the figure: 1. Pressure chamber; 2. Disturbance loading device; 3. Rock and sample fixture; 21. Dynamic disturbance loading actuator; 23. Excavation stress loading actuator; 24. Dynamic disturbance rod; 25. Oil pressure balance composite force sensor; 26. Piston pressure head; 27. Atmospheric detection device; 28. Disturbance sensor; 31. Rock sample; 32. First stress loading fixture; 33. Second stress loading fixture; 34. Third stress loading fixture; 35. Fourth stress loading fixture; 36. First displacement sensor; 37. Second displacement sensor; 38. Third displacement sensor; 231. Detection hole; 251. First section; 252. Second section. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0019] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. At the same time, in the description of the present invention, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0020] Embodiment 1: See also Figure 1 This embodiment provides a two-rigid and one-flexible dynamic disturbance true three-axis testing machine, including: A pressure chamber 1, wherein a cavity is provided inside the pressure chamber 1, the cavity of the pressure chamber 1 is used to be filled with oil, and a through hole is provided on the top of the pressure chamber 1; A disturbance loading test device 2, one end of which is connected to the pressure chamber 1 through a sealing structure and a through-hole and is located in the cavity of the pressure chamber 1, and a rock sample clamp 3 is provided at one end of the disturbance loading test device 2 located in the cavity of the pressure chamber 1, and a rock sample 31 clamped on the rock sample clamp 3 has two surfaces exposed in the pressure chamber 1.

[0021] Specifically, the rock sample 31 is placed in the rock sample fixture 3 at one end of the disturbance loading test device 2 to ensure that the sample is firmly clamped and the two faces of the rock sample 31 are exposed to the outside; one end of the disturbance loading test device 2 is connected to the pressure chamber 1 through the through hole at the top of the pressure chamber through the sealing structure, and the oil pressure system is started. The oil begins to flow into the cavity of the pressure chamber 1 and gradually increases the oil pressure to a predetermined value. At this time, the two exposed faces of the rock sample 31 are subjected to oil pressure, while the other four faces of the rock sample 31 are not subjected to oil pressure.

[0022] Furthermore, the rock sample fixture 3 includes a first stress loading fixture 32, a second stress loading fixture 33, a third stress loading fixture 34 and a fourth stress loading fixture 35. The third stress loading fixture 34 and the fourth stress loading fixture 35 are arranged on both sides of the rock sample 31 along the maximum principal stress loading direction, and the first stress loading fixture 32 and the second stress loading fixture 33 are arranged on both sides of the rock sample 31 along the intermediate principal stress loading direction. The four stress loading fixtures are interlocked and slidably connected.

[0023] Specifically, Figure 2 As shown, the third stress loading fixture 34 and the fourth stress loading fixture 35 are arranged along the maximum principal stress loading direction, and the first stress loading fixture 32 and the second stress loading fixture 33 are arranged along the intermediate principal stress loading direction. The maximum principal stress loading direction is the axial disturbance direction, the intermediate principal stress loading direction is the radial disturbance direction, and the third stress loading direction is the lateral disturbance direction. Under the simultaneous action of the stress loading fixture and the oil pressure, the rock sample 31 is subjected to zero force in the maximum principal stress loading direction and the intermediate principal stress loading direction, and the force in the third stress loading direction is equal to the current oil pressure.

[0024] One side of the stress loading fixture is provided with a boss, and the other side is provided with a recessed slot, the boss and the slot match each other, and multiple stress loading fixtures are slidably connected with adjacent stress loading fixtures in a clockwise or counterclockwise direction. Figure 2 and Figure 3 As shown, the boss of the third stress loading fixture 34 is inserted into the slot of the first stress loading fixture 32, and the boss of the first stress loading fixture 32 is inserted into the slot of the fourth stress loading fixture 35, and so on, which will not be repeated here. After the boss is inserted into the slot, the structure of the slot keeps the boss in the slot and can only slide relatively along the opening direction of the slot, and the slot and the boss are locked or unlocked by the plugging and pulling action of the boss, ensuring that rock samples 31 of different sizes can be effectively fixed under the action of the stress loading fixture. The arrangement of the above-mentioned multiple stress loading fixtures and the mutual configuration between the components can be flexibly designed, and there is no special restriction here.

[0025] Furthermore, the disturbance loading test device 2 includes a dynamic disturbance loading actuator 21 and an excavation stress loading actuator 23. The axes of the dynamic disturbance loading actuator 21 and the excavation stress loading actuator 23 are coaxially distributed. The dynamic disturbance loading actuator 21 is fixedly connected to the top of the excavation stress loading actuator 23. One end of the excavation stress loading actuator 23 is fixed to the outside of the upper end of the pressure chamber 1 through a connecting device, and the other end of the excavation stress loading actuator 23 is located inside the pressure chamber 1.

[0026] Specifically, the dynamic disturbance loading actuator 21 is located at the top and is responsible for applying dynamic disturbance loading to simulate the impact of earthquakes or other external disturbances on the rock sample 31; the excavation stress loading actuator 23 is used to control the stress path loading, accurately adjust the stress state of the rock sample 31 in different loading directions, and simulate the stress disturbance of the rock during the excavation process. The coaxial distribution design of the above two actuators can provide a more accurate and stable disturbance source for studying complex mechanical behaviors, rock fracture, deformation, etc. A flange is provided at the bottom of the dynamic disturbance loading actuator 21, and a flange is provided at the top of the excavation stress loading actuator 23. The dynamic disturbance loading actuator 21 and the excavation stress loading actuator 23 can be fixedly connected by bolts and flanges.

[0027] Furthermore, the disturbance loading test device 2 also includes a power disturbance rod 24, which passes through the axes of the power disturbance loading actuator 21 and the excavation stress loading actuator 23 in sequence and is fixed thereto. The loading points of the power disturbance loading actuator 21 and the excavation stress loading actuator 23 coincide with the central axis of the power disturbance rod 24, and a disturbance sensor 28 is provided on the end of the power disturbance rod 24 close to the excavation stress loading actuator 23.

[0028] like Figure 4 The dynamic disturbance rod 24 passes through the axes of the dynamic disturbance loading actuator 21 and the excavation stress loading actuator 23 in sequence, and the action points of multiple actuators coincide with the axis of the dynamic disturbance rod 24, ensuring that when the disturbance loading test device 2 applies dynamic disturbance, each loading actuator can act synchronously, thereby achieving more accurate multi-directional dynamic loading of the rock sample 31.

[0029] Furthermore, the disturbance loading test device 2 also includes an oil pressure balance compound force sensor 25, which is a hollow cylinder. A through hole is opened at the center position of the upper and lower end surfaces of the oil pressure balance compound force sensor 25, and a plurality of oil pressure balance windows are opened on the side of the oil pressure balance compound force sensor 25. The oil pressure balance compound force sensor 25 is fixedly connected to one end of the excavation stress loading actuator 23 away from the dynamic disturbance loading actuator 21, and the dynamic disturbance rod 24 passes through the through hole on the oil pressure balance compound force sensor 25.

[0030] Specifically, Figure 5 As shown, it is an oil pressure balanced composite force sensor 25, which can monitor the magnitude of the force applied by the excavation stress loading actuator 23 in real time. By passing the power disturbance rod 24 through the monitoring device and arranging a force sensor on the power disturbance rod, the force sensor is not affected by the oil pressure and only detects the current excavation stress magnitude, thereby effectively avoiding the influence of oil pressure fluctuations on the test results.

[0031] Furthermore, the disturbance loading test device 2 also includes a piston pressure head 26, one end of the piston pressure head 26 is fixedly connected to the oil pressure balance composite force sensor 25 through a sealing ring, and the other end of the piston pressure head 26 is fixedly connected to the third stress loading fixture 34 through a sealing ring. A through hole is provided in the piston pressure head 26, and the dynamic disturbance rod 24 passes through the through hole of the piston pressure head 26 and abuts against the upper end of the third stress loading fixture 34.

[0032] like Figure 3 As shown, the piston pressure head 26 balances the oil pressure between the first section 251 and the second section 252 in the figure, so that the oil pressure has no effect on the maximum principal stress loading direction and the intermediate principal stress loading direction. The piston pressure head 26 is fixedly connected to the oil pressure balance composite force sensor 25 and the third stress loading fixture 34 through a sealing ring, ensuring the sealing and stability of the loading system. The through hole set in the piston pressure head allows the power disturbance rod 24 to pass through the device smoothly and abut against the upper end of the third stress loading fixture 34. A power disturbance sensor 28 is set on one end of the power disturbance rod 24 close to the third stress loading fixture 34. The sensor is used to monitor the currently applied power disturbance, thereby realizing the effective transmission and precise monitoring of the disturbance loading force.

[0033] Furthermore, the disturbance loading test device 2 also includes an atmospheric detection device 27, which is composed of a gas sampling pipeline. One end of the gas sampling pipeline passes through the axis of the excavation stress loading actuator 23, the through hole of the oil pressure balance composite force sensor 25 and the through hole of the piston pressure head 26 in sequence. The gas sampling pipeline is bent at ninety degrees and passes through the detection hole 231 opened on the side of the excavation stress loading actuator 23.

[0034] Specifically, one end of the gas sampling pipeline is arranged in the piston pressure head 26 and abuts against the third stress loading fixture 34. During the oil pressure compression process, when oil flows out of the detection hole 231, it means that the oil pressure sealing of this test has failed and the sealing operation needs to be performed again; if no oil flows out of the detection hole 231 during the experiment, it means that the oil pressure sealing is successful and the subsequent disturbance test can continue.

[0035] Furthermore, the first stress loading fixture 32 and the second stress loading fixture 33 are both provided with a first displacement sensor 36, and a plurality of first displacement sensors 36 are located in the same plane and are connected to each other through a connecting device; The third stress loading fixture 34 and the fourth stress loading fixture 35 are both provided with a second displacement sensor 37 . The plurality of second displacement sensors 37 are located in the same plane and are connected to each other through a connecting device.

[0036] Specifically, the first stress loading fixture 32 and the second stress loading fixture 33 are both provided with a first displacement sensor 36, and the two first displacement sensors 36 are connected to each other through a connecting device, and the third stress loading fixture 34 and the fourth stress loading fixture 35 are both provided with a second displacement sensor 37, and the two second displacement sensors 37 are connected to each other through a connecting device, thereby ensuring the synchronous collection and sharing of displacement data, and the arrangement of multiple sensors not only enhances the stability of displacement detection, but also effectively avoids the influence of a single sensor failure on the test results, and improves the reliability and accuracy of the system. The third displacement sensor 38 arranged in the transverse direction is used to monitor the displacement data of the rock sample 31 in the transverse direction, i.e., under the action of oil pressure.

[0037] Embodiment 2: like Figure 6 As shown, this embodiment provides a method for using a two-rigid and one-flexible dynamic disturbance true triaxial testing machine, including: Step S10. Obtaining a rock sample 31; Step S20. Fixing the rock sample 31 on the rock sample fixture 3; Step S30. The rock sample fixture 3 having the rock sample 31 fixed thereon is elastically fixedly connected to the disturbance loading test device 2, and the connected whole is elastically fixedly connected to the pressure chamber 1; Step S40. Add oil into the cavity of the pressure chamber 1 and compress it to apply oil pressure to the rock sample 31; Step S50. Adjust the first stress loading fixture 32, the second stress loading fixture 33, the third stress loading fixture 34 and the fourth stress loading fixture 35 on the rock sample fixture to ensure that the stress on the rock sample 31 in the vertical direction and along the axial direction is zero, and the stress on the rock sample 31 in the transverse direction is oil pressure; Step S60. Apply initial stress to the rock sample 31 based on the third stress loading fixture 34 and the fourth stress loading fixture 35, and use the vertical direction as the minimum stress loading direction, wherein the initial stress is less than the oil pressure; Step S70: Perform disturbance loading on the rock sample 31 based on the disturbance loading test device 2 until the rock sample 31 is destroyed, and obtain the disturbance test result.

[0038] In the perturbation loading test process of the present invention, firstly obtain the rock sample 31 and fix it on the rock sample fixture 3, then fix the rock sample fixture with the rock sample 31 to the perturbation loading test device 2, and then fix the entire device to the pressure chamber 1. Then, add the oil into the cavity of the pressure chamber 1 and compress it, apply oil pressure to the rock sample 31, and ensure that the stress on the rock sample 31 in the radial and axial directions is zero by adjusting the first stress loading fixture 32, the second stress loading fixture 33, the third stress loading fixture 34 and the fourth stress loading fixture 35, and the corresponding oil pressure is applied to the rock sample 31 in the lateral direction. The above-mentioned multiple stress loading fixtures can apply initial stress in the radial and axial directions of the rock sample 31. When the initial stress is less than the oil pressure, the minimum stress loading direction becomes the radial and axial directions, that is, the minimum stress loading direction is converted to the direction that can perform a rigid perturbation test. Finally, the perturbation loading test device is used to perform perturbation loading on the rock sample 31 until the rock sample 31 is destroyed, and the perturbation test results are obtained.

[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0040] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A two-rigid and one-flexible dynamic disturbance true triaxial testing machine, characterized in that: include: A pressure chamber (1), wherein a cavity is provided inside the pressure chamber (1), the cavity of the pressure chamber (1) is used to be filled with oil, and a through hole is provided at the top of the pressure chamber (1); A disturbance loading test device (2), one end of the disturbance loading test device (2) is connected to the pressure chamber (1) through a sealing structure and through the through hole and is located in the cavity of the pressure chamber (1); a rock sample clamp (3) is provided at one end of the disturbance loading test device (2) located in the cavity of the pressure chamber (1); and a rock sample (31) clamped by the rock sample clamp (3) has two surfaces exposed in the pressure chamber (1).

2. The two-rigid-one-flexible dynamic disturbance true triaxial testing machine according to claim 1 is characterized in that: The rock sample fixture (3) comprises a first stress loading fixture (32), a second stress loading fixture (33), a third stress loading fixture (34) and a fourth stress loading fixture (35); the third stress loading fixture (34) and the fourth stress loading fixture (35) are arranged on both sides of the rock sample (31) along the maximum principal stress loading direction; the first stress loading fixture (32) and the second stress loading fixture (33) are arranged on both sides of the rock sample (31) along the intermediate principal stress loading direction; and the four stress loading fixtures are interlocked and slidably connected.

3. The two-rigid-one-flexible dynamic disturbance true triaxial testing machine according to claim 2 is characterized in that: The disturbance loading test device (2) comprises a dynamic disturbance loading actuator (21) and an excavation stress loading actuator (23). The axes of the dynamic disturbance loading actuator (21) and the excavation stress loading actuator (23) are coaxially distributed; the dynamic disturbance loading actuator (21) is fixedly connected to the top of the excavation stress loading actuator (23); one end of the excavation stress loading actuator (23) is fixed to the outside of the upper end of the pressure chamber (1) through a connecting device; and the other end of the excavation stress loading actuator (23) is located inside the pressure chamber (1).

4. The two-rigid-one-flexible dynamic disturbance true triaxial testing machine according to claim 3 is characterized in that: The disturbance loading test device (2) further comprises a power disturbance rod (24), wherein the power disturbance rod (24) passes through the axes of the power disturbance loading actuator (21) and the excavation stress loading actuator (23) in sequence and is fixed thereto, wherein the loading points of the power disturbance loading actuator (21) and the excavation stress loading actuator (23) coincide with the central axis of the power disturbance rod (24), and a disturbance sensor (28) is provided on the end of the power disturbance rod (24) close to the excavation stress loading actuator (23).

5. The two-rigid-one-flexible dynamic disturbance true triaxial testing machine according to claim 4 is characterized in that: The disturbance loading test device (2) also includes an oil pressure balance compound force sensor (25), which is a hollow cylinder. A through hole is provided at the center of the upper and lower end surfaces of the oil pressure balance compound force sensor (25), and a plurality of oil pressure balance windows are provided on the side of the oil pressure balance compound force sensor (25). The oil pressure balance compound force sensor (25) is fixedly connected to one end of the excavation stress loading actuator (23) away from the dynamic disturbance loading actuator (21), and the dynamic disturbance rod (24) passes through the through hole on the oil pressure balance compound force sensor (25).

6. The two-rigid-one-flexible dynamic disturbance true triaxial testing machine according to claim 5, characterized in that: The disturbance loading test device (2) further comprises a piston pressure head (26), one end of the piston pressure head (26) being fixedly connected to the oil pressure balance composite force sensor (25) via a sealing ring, and the other end of the piston pressure head (26) being fixedly connected to the third stress loading fixture (34) via a sealing ring, a through hole being provided in the piston pressure head (26), and the dynamic disturbance rod (24) passing through the through hole of the piston pressure head (26) abuts against the upper end of the third stress loading fixture (34).

7. The two-rigid-one-flexible dynamic disturbance true triaxial testing machine according to claim 6, characterized in that: The disturbance loading test device (2) also includes an atmospheric detection device (27), which is composed of a gas sampling pipeline. One end of the gas sampling pipeline passes through the axis of the excavation stress loading actuator (23), the through hole of the oil pressure balance composite force sensor (25) and the through hole of the piston pressure head (26) in sequence. The gas sampling pipeline is bent at ninety degrees and passes through a detection hole (231) opened on the side of the excavation stress loading actuator (23).

8. The two-rigid-one-flexible dynamic disturbance true triaxial testing machine according to claim 3 is characterized in that: A first flange is provided at the bottom of the dynamic disturbance loading actuator (21), and a second flange is provided at the top of the excavation stress loading actuator (23), and the first flange is fixedly connected to the second flange by bolts.

9. The two-rigid-one-flexible dynamic disturbance true triaxial testing machine according to claim 2, characterized in that: The first stress loading fixture (32) and the second stress loading fixture (33) are both provided with a first displacement sensor (36), and a plurality of the first displacement sensors (36) are located on the same plane and are connected to each other via a connecting device; The third stress loading fixture (34) and the fourth stress loading fixture (35) are both provided with a second displacement sensor (37), and a plurality of the second displacement sensors (37) are located on the same plane and are connected to each other via a connecting device.

10. A method for using a two-rigid-one-flexible dynamic disturbance true triaxial testing machine, applicable to the two-rigid-one-flexible dynamic disturbance true triaxial testing machine described in claims 1 to 9, characterized in that: include: Obtain rock samples (31); Fixing the rock sample (31) on a rock sample fixture (3); The rock sample fixture (3) on which the rock sample (31) is fixed is elastically fixedly connected to the disturbance loading test device (2), and the entire connected device is elastically fixedly connected to the pressure chamber (1); Adding oil into the cavity of the pressure chamber (1) and compressing it to apply oil pressure to the rock sample (31); Adjusting the first stress loading fixture (32), the second stress loading fixture (33), the third stress loading fixture (34) and the fourth stress loading fixture (35) on the rock sample fixture to ensure that the stress on the rock sample (31) in the vertical direction and along the axial direction is zero and the stress on the rock sample (31) in the transverse direction is oil pressure; Applying initial stress to the rock sample (31) based on the third stress loading fixture (34) and the fourth stress loading fixture (35), taking the vertical direction as the minimum stress loading direction, wherein the initial stress is less than the oil pressure; Based on the disturbance loading test device (2), vertical dynamic disturbance loading is performed on the rock sample (31), wherein the vertical direction is the minimum principal stress direction, until the rock sample (31) is destroyed, thereby obtaining a disturbance test result.

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