True triaxial aging disturbance test device for deep-buried hard rock

Abstract

The present invention relates to the technical field of deep-seated rock mechanics tests, and in particular to a true triaxial aging disturbance test device for a deep-buried hard rock. The device comprises rigid static load loading assemblies and rigid dynamic load loading assemblies; the rigid static load loading assemblies apply static loads to a rock sample, and the rigid dynamic load loading assemblies apply disturbance stresses to the rock sample; coupling application control of the long-time aging static force and disturbance stress of rocks in a true triaxial disturbance stress state is realized; and disturbance rods are arranged in the rigid dynamic load loading direction, and a point disturbance mode is switched to a surface disturbance mode by means of the disturbance rods, disturbance holes, and sample fixtures, so that a disturbance mode better fitting the actual working condition of the site is provided while power consumption is reduced and aging disturbance is achieved.

Description

A true triaxial time-dependent disturbance test device for deep-buried hard rock Technical Field

[0001] The present invention relates to the technical field of deep rock mechanics testing, and in particular to a deep-buried hard rock true triaxial time-dependent disturbance testing device. Background Art

[0002] During the excavation of deep tunnels, the use of TBMs (Tunnel Boring Machines) and blasting has revealed that surrounding rock, before support is provided, can experience time-delayed fractures due to disturbance stresses, posing a serious threat to life and property during construction. Research on deep rock mechanics has also gradually shifted from studying uniaxial and biaxial stress states to studying the physical and mechanical properties of rock under true triaxial stress. Furthermore, due to the highly disturbed stress environment at depth, the perspective of rock mechanics research has shifted from macroscopic statics to microscopic rock dynamics, thus embarking on a new path for the discipline.

[0003] Rock mechanics research relies on high-performance rock mechanics testing machines. Currently, many deep surrounding rock true triaxial stress testing machines can apply perturbation stresses based on static forces, allowing for the study of rock mechanical properties under dynamic perturbation. However, existing perturbation rock mechanics testing machines are limited by power consumption and performance, and can only apply high-frequency perturbation for 5-10 minutes. At deep engineering sites, perturbation stresses persist at the face during tunneling and propagate further along the tunnel axis, acting on the deep tunnel surrounding rock. This perturbation lasts far longer than the 5-10 minute threshold of existing testing machines. This time-dependent perturbation can cause high-frequency fatigue opening and closing of internal rock fractures, affecting the storage and release of energy within the hard rock, altering the ductility and brittleness characteristics of the rock mass, and ultimately leading to brittle fracture with a time effect. Time-delayed rockbursts are likely related to these long-lasting, high-frequency, low-amplitude perturbations.

[0004] In order to solve the above scientific problems, it is necessary to obtain the mechanical behavior of deep hard rock under the action of time-dependent disturbance stress. The present invention provides a deep-buried hard rock true triaxial time-dependent disturbance test device, which conducts relevant experimental research on the mechanical behavior of surrounding rock under the disturbance stress state during the excavation of deep hard rock tunnels, providing effective assistance for the construction of major engineering infrastructure in my country. Summary of the Invention

[0005] In response to the shortcomings of the existing technology, the present invention provides a deep-buried hard rock true triaxial aging disturbance test device, which includes a sample base platform. The sample base platform is provided with a hydrostatic pressure chamber. The hydrostatic pressure chamber is composed of a pressure chamber top cover, pressure chamber side walls and pressure chamber bottom to form a closed cavity structure. The hydrostatic pressure chamber is provided with a flexible static load loading assembly, a sample placement platform and an interlocking rigid clamp assembly.

[0006] A rigid loading system is provided on the outside of the sample base platform, and the rigid loading system includes two rigid static load loading components and two rigid dynamic load loading components; the rigid static load loading component is arranged along the main stress loading direction, and applies a directional static load to the rock sample, and a reaction support is provided on the side wall of the pressure chamber along the main stress loading direction, and the reaction support provides a reaction force of the directional static load; the rigid static load loading component is arranged along the main stress loading direction and applies a directional static load to the rock sample, and a reaction support is provided on the top cover of the pressure chamber along the main stress loading direction, and the reaction support provides a reaction force of the directional static load; the rigid dynamic load loading component is arranged on the opposite side of the rigid static load loading component, and applies a directional disturbance stress to the rock sample; the rigid dynamic load loading component is arranged on the opposite side of the rigid static load loading component, and applies a directional disturbance stress to the rock sample.

[0007] The interlocking rigid fixture assembly includes four sample fixtures, wherein the sample fixture and the sample fixture are arranged relatively on both sides of the rock sample along the main stress loading direction, and the sample fixture and the sample fixture are arranged relatively on both sides of the rock sample along the main stress loading direction, and the four sample fixtures are interlocked and slidably connected to each other; a loading piston is provided at a position corresponding to the side wall of the pressure chamber and the sample fixture, the loading piston is embedded in the side wall of the pressure chamber and slidably connected, and the loading piston is in contact with the sample fixture; a loading piston is provided at a position corresponding to the bottom of the pressure chamber and the sample fixture, the loading piston is embedded in the bottom of the pressure chamber and slidably connected, and the loading piston is in contact with the sample fixture; a reaction force support is fixedly provided at a position corresponding to the side wall of the pressure chamber and the sample fixture, the reaction force support is fixedly connected to the side wall of the pressure chamber, and the reaction force support is in contact with the sample fixture; a reaction force support is fixedly provided at a position corresponding to the top cover of the pressure chamber and the sample fixture, the reaction force support is fixedly connected to the top cover of the pressure chamber, and the reaction force support is in contact with the sample fixture.

[0008] The rigid dynamic load loading assembly includes a dynamic actuator and a self-balancing piston. The sample fixture and the reaction force support are provided with a disturbance hole along the σ2 direction. The sample fixture and the reaction force support are provided with a disturbance hole along the direction. A disturbance rod is provided in the disturbance hole. The dynamic actuator, the self-balancing piston and the disturbance rod are in contact with each other in sequence. When the dynamic actuator is working, point disturbances in the σ2 and σ1 directions are applied to the rock sample through the disturbance rod.

[0009] The rigid static load loading assembly includes a static actuator and a self-balancing piston. The rigid static load loading assembly is in contact with the loading piston, and the static load in the σ2 direction is applied to the rock sample in sequence through the loading piston and the sample fixture; the rigid static load loading assembly is in contact with the loading piston, and the static load in the σ2 direction is applied to the rock sample in sequence through the loading piston and the sample fixture.

[0010] The four sample clamps are connected to each other in an interlocking and sliding manner, which can prevent the sample clamps from being squeezed against each other when a rigid load is applied.

[0011] The interlocking rigid clamp assembly is also provided with a deformation sensor and a deformation sensor support. The deformation sensor in the σ2 and σ1 loading directions includes a stylus, a disc-type spring telescopic rod and an LVDT sensor body, and adopts a sliding orthogonal deformation LVDT sensor measurement structure; the deformation sensor in the σ3 loading direction includes a metal rod, a positioning block, and an LVDT sensor, and adopts a fixed double-span beam LVDT sensor measurement structure; the loading piston and the loading piston are respectively provided with force sensors for real-time stress and strain monitoring during static loading in the σ2 and σ1 directions; the interlocking rigid clamp assembly is also provided with an acoustic emission receiver, which can detect the sound emitted when the rock sample breaks.

[0012] Furthermore, the device also includes a disturbance mode controller, and the dynamic actuator is controlled by the disturbance mode controller. The disturbance mode controller can select the disturbance mode according to the oil temperature and power consumption, and can realize the application of disturbance stress in the long-term rheological test; the disturbance mode controller includes an intelligent oil source monitoring device and a rheological experiment process recording device; the intelligent oil source monitoring device is arranged in the disturbance rod, and is used to detect the oil temperature and send the oil temperature information to the disturbance mode controller, so as to perform an emergency stop on the disturbance loading control of the warning temperature, so as to deal with the situation where the disturbance rod temperature is too high and out of control under special circumstances, thereby improving the success rate of the rheological experiment; the rheological test process recording device is used to record information such as the duration of the rheological experiment, the duration of the disturbance stress application, the power consumption of the testing machine, and the real-time stress-strain curve of the rock sample.

[0013] Furthermore, the device also includes an intelligent information control and fracture perception system, which adopts a closed-loop servo control working mode. The intelligent information control and fracture perception system includes a σ2 system, a σ1 system, a σ3 system and a time-dependent disturbance intelligent control center;

[0014] The σ2 system is provided with a disturbance mode controller 1 to monitor and control the static actuator 21 and the dynamic actuator 31 in the direction of the σ2 principal stress loading; the σ1 system is provided with a disturbance mode controller 2 to monitor and control the static actuator 21 and the dynamic actuator 31 in the direction of the σ1 principal stress loading; the σ3 system is provided with a disturbance mode controller 3 to monitor and control the flexible static load loading component in the direction of the σ3 principal stress loading. The disturbance mode controller 1, the disturbance mode controller 2, and the disturbance mode controller 3 can monitor the oil temperature and power consumption of the servo oil source device, and select the disturbance mode according to the oil temperature and power consumption, so as to realize the application of disturbance stress in long-term rheological tests, and can also perform emergency braking of the disturbance loading control of the warning temperature;

[0015] The aging disturbance intelligent control center includes a computer and rheological experiment operation software, which can intelligently monitor the stress, strain and fracture information of the rock sample 13 throughout the aging disturbance process, and can control the static stress loading and unloading levels, disturbance stress application conditions and other functions in real time; it can also display the disturbance duration, rheological loading duration, real-time power consumption, and disturbance load-keeping intelligent switching information during the aging disturbance process in real time. The stress, strain and fracture information are respectively monitored in real time by the force sensor 5, displacement sensor 6 and acoustic emission receiver 7 arranged in each direction and fed back to the computer.

[0016] The computer includes a large-capacity storage function, an intelligent switching sampling interval function during the experiment, an intelligent switching of disturbance load, an intelligent data filtering function, and a rheological test process recording function; the large-capacity storage function provides storage space for long-term disturbance data; the intelligent switching sampling interval function during the experiment can reduce the collection of useless data; the intelligent data filtering function filters out meaningless disturbance stress records during the disturbance rheological process; the rheological test process recording function is used to record the duration of the rheological experiment, the duration of the disturbance stress application, temperature, power consumption, and real-time stress-strain curve information of the rock sample;

[0017] The rheological experiment operation software first loads the rock sample 13 to the initial stress level. At this time, the oil source power consumption monitoring and intelligent switching cooperate with each other to complete the first-level disturbance load holding and static load holding processes. In the event of excessive power consumption or excessive oil source temperature during the disturbance process, which leads to emergency braking of the test, the disturbance is intelligently stopped when the disturbance stress is applied close to the power consumption limit. The software includes the following steps:

[0018] Step 1: Preset the total rheological time of the loading level;

[0019] Step 2: Perform disturbance load protection. The oil source temperature is monitored according to the power consumption to switch to static load protection. After the oil source temperature drops, the power consumption monitoring feeds back the information to the dynamic actuator 31 to continue the disturbance load protection. This process is repeated.

[0020] Step 3: Determine the state of the rock sample 13 based on stress, strain, and fracture information. If damage occurs, stop loading and the experiment ends.

[0021] Step 4: If the rock sample 13 does not fail in step 3, continue increasing the stress in the direction of the maximum principal stress to the second level;

[0022] Step 5: Repeat steps 1 to 4 until the rock sample 13 is destroyed, then stop loading immediately and the experiment ends.

[0023] Furthermore, the device also includes a rigid loading system frame, and the rigid static load loading assembly and the rigid dynamic load loading assembly are connected to the sample base platform through the rigid loading system frame. The rigid loading system frame is mounted on the outside of the sample base platform and is slidably connected to the sample base platform. A hydraulic lifting mechanism is provided at the lower end of the sample base platform; the hydrostatic pressure chamber is a semi-closed cavity structure, and after the sample base platform descends, the hydrostatic pressure chamber is in an open state; after the sample base platform rises, the rigid loading system frame closes the hydrostatic pressure chamber, the rigid dynamic load loading assembly contacts the disturbance rod, and the static load loading assembly contacts the loading piston.

[0024] The static actuator and the dynamic actuator are both connected to a stroke measurement sensor, which is used to monitor the displacement of the static actuator and the dynamic actuator 31 when a load is applied.

[0025] The beneficial effects brought about by the technical solution provided by the present invention include at least:

[0026] (1) Using rigid static load components and rigid dynamic load components, wide-band frequency dynamic perturbation stress is applied in different principal stress directions of true triaxial test to simulate the real perturbation stress state of deep engineering rock mass, and the long-term static and perturbation stress coupling control of rock is realized under the true triaxial perturbation stress state. It is suitable for deep mining rock mass and deep buried tunnel engineering surrounding rock as test objects. According to the different dynamic perturbation frequencies and amplitudes detected on site, the physical and mechanical behaviors such as peak performance, brittle failure mode, energy storage conditions, and deformation properties of rock mass under the true triaxial perturbation stress state are studied. It is capable of conducting dynamic tests on surrounding rocks of different properties, such as jointed rock mass, brittle rock mass, and altered rock mass, and the three-dimensional stress state can be freely adjusted during the rheological process. The rock compression deformation, fracture information, and dynamic perturbation dynamic behavior can be observed in real time, and a true triaxial dynamic constitutive model of hard rock under the action of true triaxial perturbation stress with time effect is established.

[0027] (2) A three-dimensional stress loading system is adopted, which is loaded by a combination of a flexible static load loading component, a rigid dynamic load loading component, and a rigid static load loading component. A disturbance rod is provided in the direction of the rigid dynamic load loading, which realizes coaxial disturbance loading and unloading in different principal stress directions under different initial static stress conditions. The "point" disturbance is converted into a "surface" disturbance through the disturbance rod, disturbance hole, and sample fixture, which reduces power consumption and realizes time-dependent disturbance while providing a disturbance method that is more in line with the actual working conditions on site.

[0028] (3) A closed-loop servo control system is used to dynamically control the disturbance process, reasonably control and distribute the power consumption of the testing machine, and realize the rheological dynamics test of loading and unloading disturbance. It is suitable for deep engineering surrounding rocks that are subjected to disturbance stress for a long time. It can simulate the dynamic rheological mechanics of rocks related to time effect under different surrounding rock stresses, different dynamic disturbance high and low frequencies, and high and low amplitude conditions.

[0029] (4) The "two rigid and one flexible" loading method is adopted to reduce the influence of stress blank angle shear under time-dependent perturbation true triaxial stress. It can be applied to small-sized specimens, which are convenient for ultra-deep drilling core rock specimen tests. At the same time, it also reduces the influence of random results caused by rock homogeneity. The specimens are rich in variety and can be used for true triaxial time-dependent perturbation physical and mechanical tests on deep hard rock, soft rock, altered rock, jointed rock, rock-like specimens, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a schematic cross-sectional view of the deep-buried hard rock true triaxial time-dependent disturbance test apparatus;

[0031] Figure 2 Schematic diagram of the three-dimensional structure of the deep-buried hard rock true triaxial time-dependent disturbance test device;

[0032] Figure 3 is a schematic diagram of the cross-sectional structure of the sample base platform in the descending state;

[0033] Figure 4 is a schematic diagram of the three-dimensional structure of the sample base platform in the descending state;

[0034] Figure 5 is a schematic diagram of the structure of the interlocking rigid clamp assembly;

[0035] Figure 6 is a schematic diagram of the closed-loop servo control working mode of the intelligent information control and fracture sensing system;

[0036] Figure 7 Schematic diagram of the time-dependent disturbance intelligent control center;

[0037] Figure 8 Flowchart of rheological experiment operation software.

[0038] Figure numerals: 1-sample base platform; 11-hydrostatic pressure chamber; 12-sample fixture; 13 rock sample; 14 loading piston; 15 reaction support; 2-rigid static load loading assembly; 21-static actuator; 22-static self-balancing piston; 3-rigid dynamic load loading assembly; 31-dynamic actuator; 32-dynamic self-balancing piston; 33-disturbance rod; 4-rigid loading system frame; 5-force sensor; 6-deformation sensor; 61-deformation sensor support; 7-acoustic emission receiver; 8-stroke measurement sensor; X-σ2 principal stress loading direction; Y-σ1 principal stress loading direction; Z-σ3 principal stress loading direction. DETAILED DESCRIPTION

[0039] The present invention will be further described in detail with reference to the accompanying drawings and specific embodiments.

[0040] Example 1

[0041] Referring to Figures 1, 2, and 5, a deep-buried hard rock true triaxial aging disturbance test device includes a sample base platform 1, which is provided with a hydrostatic pressure chamber 11. The hydrostatic pressure chamber 11 is composed of a pressure chamber top cover, pressure chamber side walls, and pressure chamber bottom to form a closed cavity structure. The pressure chamber top cover is made of high-strength alloy by one-time molding and is equipped with a high-pressure sealing ring; a sample placement platform and an interlocking rigid clamp assembly are provided in the hydrostatic pressure chamber 11, and the sample placement platform is constructed of a large area of ​​hollow metal and has reserved holes for sample fixing; the interlocking rigid clamp assembly includes four sample clamps 12, wherein the sample clamps 12a and the sample clamps 12c are arranged on both sides of the rock sample 13 relative to each other along the σ2 principal stress loading direction, and the sample clamps 12b and the sample clamps 12d are arranged on both sides of the rock sample 13 relative to each other along the σ1 principal stress loading direction. The four sample clamps 12 are interlocked and slidably connected to each other, which can prevent the sample clamps 12 from squeezing each other when rigid loading is applied. A loading piston 14a is provided at a position corresponding to the sample fixture 12a on the side wall of the pressure chamber. The loading piston 14a is embedded in the side wall of the pressure chamber and is slidably connected. The loading piston 14a contacts the sample fixture 12a and can transmit external stress to the rock sample 13. A loading piston 14b is provided at a position corresponding to the sample fixture 12d on the bottom of the pressure chamber. The loading piston 14b is embedded in the bottom of the pressure chamber and is slidably connected. The loading piston 14b contacts the sample fixture 12d and can transmit external stress to the rock sample 13. The side wall of the pressure chamber A reaction force support 15a is fixedly provided at a position corresponding to the sample fixture 12c, and the reaction force support 15a is fixedly connected to the side wall of the pressure chamber. The reaction force support 15a is in contact with the sample fixture 12c and can provide a reaction force to the static load in the direction of the σ2 principal stress loading; a reaction force support 15b is fixedly provided at a position corresponding to the sample fixture 12b on the top cover of the pressure chamber, and the reaction force support 15b is fixedly connected to the top cover of the pressure chamber, and the reaction force support 15b is in contact with the sample fixture 12b and can provide a reaction force to the static load in the direction of the σ1 principal stress loading.

[0042] A rigid loading system is provided on the outside of the sample base platform 1, and the rigid loading system includes two rigid static load loading components 2 and two rigid dynamic load loading components 3; the rigid static load loading components 2 include a static actuator 21 and a self-balancing piston 22. The static actuator 21 adopts the existing technical structure, is powered by a servo oil source device, and can apply static loads. The rigid static load loading assembly 2a is arranged along the σ2 principal stress loading direction and is in contact with the loading piston 14a. During operation, the static load of the rigid static load loading assembly 2a is sequentially applied to the rock sample 13 through the loading piston 14a and the sample fixture 12a, applying a static load in the σ2 direction to the rock sample 13, and the reaction support 15a provides a reaction force to the static load in the σ2 direction. The maximum load of the rigid static load loading assembly 2a used is 400 kN (640 MPa); the rigid static load loading assembly 2b is arranged along the σ1 principal stress loading direction and is in contact with the loading piston 14b. During operation, the static load of the rigid static load loading assembly 2b) is sequentially applied to the rock sample 13 through the loading piston 14b and the sample fixture 12d, applying a static load in the σ1 direction to the rock sample 13, and the reaction support 15b provides a reaction force to the static load in the σ1 direction. The maximum load of the rigid static load loading assembly 2b is 50 kN (40 MPa).

[0043] The rigid dynamic load loading assembly 3 includes a dynamic actuator 31 and a self-balancing piston 32. The dynamic actuator 31 adopts a conventional structure and is powered by a servo oil source device, capable of applying disturbance stress. The sample fixture 12c and the reaction support 15a are provided with a disturbance hole along the σ2 direction, and the sample fixture 12b and the reaction support 15b are provided with a disturbance hole along the σ1 direction. The disturbance hole serves as a channel for applying disturbance stress. A disturbance rod 33 is disposed within the disturbance hole. The dynamic actuator 31, the self-balancing piston 32, and the disturbance rod 33 sequentially contact each other. When the dynamic actuator 31 is in operation, it applies point disturbances in the σ2 and σ1 directions to the sample fixture 12 through the disturbance rod 33, with a maximum amplitude of 10 MPa and a maximum disturbance frequency of 80 Hz. The sample fixture 12 transmits the disturbance to the rock sample 13, transforming the disturbance mode from point disturbance to surface disturbance. Due to the stable static loading and the stable position of the disturbance hole, dynamic disturbance loading can also be stably applied during the rheological process.

[0044] A flexible static load loading assembly is also provided in the hydrostatic pressure chamber 11. In this embodiment, the flexible static load loading assembly adopts the confining pressure loading method in the prior art, including a needle valve, a high-pressure oil pipe, and a hydraulic piston, and is powered by a servo oil source device. When working, the flexible static load loading assembly can apply a confining pressure type static load to the rock sample 13, with a maximum confining pressure of 40 MPa.

[0045] When the device is working, a "two rigid and one flexible" static load loading mode is implemented on the rock sample 13 through the rigid static load loading component 2 and the flexible static load loading component, ensuring true triaxial stress application without stress blank angles. The "two rigid" are rigid loading in the σ2 and σ1 directions, which are applied by the rigid static load loading component 2; the "one flexible" is flexible loading in the σ3 direction, which is applied by the flexible static load loading component. The dynamic load loading component 3 applies disturbance stress in the σ2 and σ1 directions, realizing the long-term static and disturbance stress coupling application of the rock under the true triaxial disturbance stress state. It is particularly suitable for deep engineering surrounding rocks subjected to disturbance stress for a long period of time, and can simulate the dynamic rheological mechanics of rocks related to time-effect under different surrounding rock stresses, different dynamic disturbance high and low frequencies, and high and low amplitude conditions.

[0046] The loading pistons 14a and 14b are respectively provided with force sensors 5 for real-time stress and strain monitoring during static loading in the σ2 and σ1 directions. The real-time oil inlet amount is determined by the servo valve, which saves power consumption while ensuring stable stress and strain control of the testing machine.

[0047] 5, the interlocking rigid fixture assembly is further provided with a deformation sensor 6 and a deformation sensor support 61. The deformation sensor 6a is provided in the sample fixture 12a, the deformation sensor support 61a is provided in the sample fixture 12c, the deformation sensor 6b is provided in the sample fixture 12d, and the deformation sensor support 61b is provided in the sample fixture 12b. The deformation sensor 6c and the deformation sensor support 61c are provided in the σ3 loading direction. The deformation sensor 6 adopts the existing technical structure, which is composed of a disc-type spring telescopic rod and an LVDT sensor body, and is composed of the corresponding For the stylus contact measurement on one side, a sliding orthogonal deformation LVDT sensor measurement structure is used in the σ2 and σ1 loading directions. When the rock specimen 4 is deformed, the stylus drives the telescopic rod of the LVDT sensor forward and backward to realize the deformation measurement in the σ2 and σ1 directions. A fixed double-span beam LVDT sensor measurement structure is used in the σ3 loading direction. This structure consists of a metal rod, a positioning block, and an LVDT sensor. When deformation occurs in the σ3 direction, the position of the positioning block on the rock specimen 4 changes, and the telescopic rod of the LVDT sensor moves accordingly to realize the deformation measurement in the σ3 direction.

[0048] The interlocking rigid clamp assembly is further provided with an acoustic emission receiver 7, which can detect the sound emitted when the rock sample 13 breaks, and monitor the rock sample 13 in real time during the rheological experiment and feed back the sound to the computer.

[0049] Referring to Figure 6 , the device also includes an intelligent information control and fracture sensing system, which adopts a closed-loop servo control working mode and includes a σ2 system, a σ1 system, a σ3 system, and a time-dependent disturbance intelligent control center;

[0050] The σ2 system is provided with a disturbance mode controller 1 to monitor and control the static actuator 21 and the dynamic actuator 31 in the direction of the σ2 principal stress loading; the σ1 system is provided with a disturbance mode controller 2 to monitor and control the static actuator 21 and the dynamic actuator 31 in the direction of the σ1 principal stress loading; the σ3 system is provided with a disturbance mode controller 3 to monitor and control the flexible static load loading component in the direction of the σ3 principal stress loading. The disturbance mode controller 1, the disturbance mode controller 2, and the disturbance mode controller 3 all adopt existing technologies, can monitor the oil temperature and power consumption of the servo oil source device, and select the disturbance mode according to the oil temperature and power consumption, can realize the application of disturbance stress in long-term rheological tests, and can also perform emergency braking on the disturbance loading control of the warning temperature to deal with the situation of excessive temperature out of control in special circumstances, thereby improving the success rate of rheological experiments.

[0051] Referring to Figure 7, the aging perturbation intelligent control center includes a computer and rheological experiment operation software. It can intelligently monitor the stress, strain, and fracture information of the rock specimen 13 throughout the aging perturbation process, enabling real-time control of static stress loading and unloading levels, perturbation stress application conditions, and other functions. It can also display real-time information during the aging perturbation process, such as perturbation duration, rheological loading duration, real-time power consumption, and intelligent switching of perturbation load protection. It can globally monitor important information during the true triaxial perturbation aging test to ensure the smooth progress of the test. The stress, strain, and fracture information are respectively monitored in real time by the load cell 5, displacement sensor 6, and acoustic emission receiver 7 arranged in each direction and fed back to the computer for real-time monitoring during the rheological experiment.

[0052] The computer includes a large-capacity storage function, an intelligent sampling interval switching function during the experiment, an intelligent switching of disturbance load, an intelligent data filtering function, and a rheological test process recording function. The large-capacity storage function provides storage space for long-term disturbance data, preserving data integrity. The intelligent sampling interval switching function during the experiment can minimize the collection of useless data, ensuring data integrity while facilitating application in rheological experiments, provided that the acquisition density allows. The intelligent data filtering function filters out meaningless disturbance stress records during the disturbance rheological process, reducing the amount of test data and ensuring the smooth progress of long-term rheological testing. The rheological test process recording function is used to record information such as the duration of the rheological experiment, the duration of the disturbance stress application, temperature, power consumption, and the real-time stress-strain curve of the rock sample.

[0053] Referring to FIG8 , the rheological experiment operation software optimizes and improves existing true triaxial experimental operations for long-term rheological testing. The rock specimen 13 is first loaded to an initial stress level. At this point, oil source power consumption monitoring and intelligent switching work together to complete the first-stage perturbation and static load-holding processes. To address the emergency braking of the test caused by excessive power consumption or excessive oil source temperature during the perturbation process, an intelligent perturbation function is implemented when the perturbation stress approaches the power consumption limit, ensuring that the perturbation rheological test can exceed the power consumption limit. The specific implementation method is as follows: the total rheological duration for the loading stage is preset and the rheological experiment for that loading stage is initiated. Perturbation load-holding is first performed, and then the power consumption monitoring of the oil source temperature determines the switch to static load-holding. After the oil source temperature cools down, the power consumption monitoring feeds this information back to the dynamic actuator 31, and the perturbation load-holding continues, repeating this process. During this process, the state of the rock sample 13 is judged by stress, strain and fracture information. If damage occurs, loading is stopped immediately and the experiment ends. If the rock sample 13 does not fail during this process, that is, after reaching the preset rheological time, the rock sample can still withstand the stress level of this level, that is, after continuing to increase the stress in the direction of the maximum principal stress to the second level, the first-level disturbance, static load holding process and loading to the next level process are repeated until the rock sample 13 fails, that is, the strain data shows a very large change and the ringing number of the acoustic emission receiver 7 increases rapidly exponentially, then loading is stopped immediately to prevent damage to the equipment and the state of the rock sample 13 after failure.

[0054] Example 2

[0055] 3 and 4, the other configurations of this embodiment are the same as those of embodiment 1, except that this device further comprises a rigid loading system frame 4, the rigid static load loading component 2a and the rigid dynamic load loading component 3b are connected to the sample base platform 1 through the rigid loading system frame 4, the rigid loading system frame 4 is sleeved on the outside of the sample base platform 1 and is slidably connected to the sample base platform 1, and a hydraulic lifting mechanism is provided at the lower end of the sample base platform 1, the hydraulic lifting mechanism adopts the existing technical structure, and when the hydraulic lifting mechanism is working, it can drive the sample base platform 1 to rise and fall in the rigid loading system frame 4; the hydrostatic pressure The force chamber 11 is a semi-closed cavity structure. After the sample base platform 1 descends, the hydrostatic pressure chamber 11 is in an open state, which is convenient for the installation operation of the rock sample 13 and the interlocking rigid clamp assembly; after the sample base platform 1 rises, the rigid loading system frame 4 closes the hydrostatic pressure chamber 11, so that the flexible static load loading assembly can apply a static load in the σ3 direction to the rock sample 13; after the sample base platform 1 rises, the rigid dynamic load loading assembly 3b contacts the disturbance rod 33, and the static load loading assembly 2a contacts the loading piston 14a, so as to realize the application of static load and disturbance stress in the σ2 direction to the rock sample 13.

[0056] Example 3

[0057] The other configurations of this embodiment are the same as those of embodiment 1, except that the static actuator 21 and the dynamic actuator 31 are both connected to a stroke measurement sensor 8 for monitoring the displacement of the static actuator 21 and the dynamic actuator 31 when applying a load, to prevent the applied load from exceeding a limit.

[0058] The usage and principle of this device are as follows:

[0059] Rock specimen 13 is prepared using the deeply buried surrounding rock. Because this device utilizes a "two rigid, one flexible" static loading method, true triaxial stress application is ensured without stress-free corners. Therefore, small-sized rock specimens 13 can be used. The rock specimen 13 selected in this embodiment measures 25 mm × 25 mm × 50 mm. The specimen base platform 1 is lowered, and the interlocking rigid fixture assembly is installed. After installation, glue is applied in the σ3 direction to isolate the oil. Once the glue dries, the fixture screws are removed and displacement sensors 6 are installed in sequence to measure the specimen's deformation during true triaxial stress testing in real time. The assembled fixture is placed on the specimen platform, and the sensor circuitry is connected to the controller. The specimen platform is raised, completing preparations for the true triaxial stress testing. The computer is turned on, and confining pressure is applied in the three principal stress directions within the hydrostatic pressure chamber 11. After applying a static prestress of 2 MPa to 3 MPa via the static actuator 21, the displacement sensor 6 is reset to zero. Static actuators 21 in the σ2 and σ1 directions then apply static stress to the desired level and maintain it constant. Dynamic perturbation stress is applied at the static stress level via a dynamic actuator 31. The time-dependent perturbation intelligent control center determines parameters such as perturbation direction, perturbation frequency, perturbation amplitude, dynamic-static switching interval, and single-stage perturbation duration to control the perturbation stress application method. Force sensors 5 and displacement sensors 6 are used to monitor the stress and strain of rock specimen 13. The sampling interval of displacement sensor 6 is automatically adjusted using intelligent filtering. After the perturbation stress application at this stress level is completed, if rock specimen 13 does not fail, the static stress level is increased to the second level via static actuator 21, and the perturbation stress application process is repeated. After repeating these steps several times, the specimen will experience a transient fracture before failure. At this point, the acoustic emission receiver 7 sends a pre-failure warning to the computer, automatically adjusting the sampling interval to identify the stress and strain level and fracture conditions immediately before failure. Throughout the entire time-dependent perturbation process, the time-dependent perturbation intelligent control center coordinates intelligent power consumption control, electro-hydraulic servo actuators, and a heat dissipation system to complete experimental control of the deep-buried surrounding rock time-dependent perturbation process. The experimental data will be exported and transmitted to the experimenters through a computer. The information includes stress and strain in the σ2, σ1, and σ3 directions, fracture information, sample disturbance time, total test time, and other data.

Claims

1. A deep-buried hard rock true triaxial aging disturbance test device, comprising a sample base platform (1), wherein the sample base platform (1) is provided with a hydrostatic pressure chamber (11), wherein the hydrostatic pressure chamber (11) is composed of a pressure chamber top cover, a pressure chamber side wall and a pressure chamber bottom to form a closed cavity structure, and wherein a flexible static load loading assembly, a sample placement platform and an interlocking rigid fixture assembly are provided in the hydrostatic pressure chamber (11), characterized in that: The flexible static load loading component applies a flexible static load in the σ3 direction to the rock sample (13), and can apply a confining pressure type static load to the rock sample (13) during operation; a rigid loading system is provided on the outside of the sample base platform (1), and the rigid loading system includes two rigid static load loading components (2) and two rigid dynamic load loading components (3); the rigid static load loading component (2) includes a static actuator (21), and the rigid dynamic load loading component (3) includes a dynamic actuator (31); the first rigid static load loading component (2a) is arranged along the σ2 principal stress loading direction, and applies a σ2 direction static load to the rock sample (13); a first reaction force support (15a) is provided on the side wall of the pressure chamber along the σ2 principal stress loading direction , the first reaction support (15a) provides a reaction force of the static load in the σ2 direction; the second rigid static load loading component (2b) is arranged along the σ1 principal stress loading direction, and applies a static load in the σ1 direction to the rock sample (13); the pressure chamber top cover is provided with a second reaction support (15b) along the σ1 principal stress loading direction, and the second reaction support (15b) provides a reaction force of the static load in the σ1 direction; the first rigid dynamic load loading component (3a) is arranged on the opposite side of the second rigid static load loading component (2b), and applies a disturbance stress in the σ1 direction to the rock sample (13); the second rigid dynamic load loading component (3b) is arranged on the opposite side of the first rigid static load loading component (2a), and applies a disturbance stress in the σ2 direction to the rock sample (13); The device also includes an intelligent information control and fracture perception system, which adopts a closed-loop servo control working mode. The intelligent information control and fracture perception system includes a σ2 system, a σ1 system, a σ3 system and a time-sensitive disturbance intelligent control center; The σ2 system is provided with a disturbance mode controller 1, which monitors and controls the static actuator (21) and the dynamic actuator (31) in the σ2 principal stress loading direction; the σ1 system is provided with a disturbance mode controller 2, which monitors and controls the static actuator (21) and the dynamic actuator (31) in the σ1 principal stress loading direction; the σ3 system is provided with a disturbance mode controller 3, which monitors and controls the flexible static load loading component in the σ3 principal stress loading direction; the disturbance mode controller 1, the disturbance mode controller 2, and the disturbance mode controller 3 can monitor the oil temperature and power consumption of the servo oil source device, and select the disturbance mode according to the oil temperature and power consumption, so as to realize the application of disturbance stress in the long-term rheological test, and also realize the emergency stop braking of the disturbance loading control of the warning temperature; according to the oil source temperature, the disturbance load holding is switched to the static load holding, and after the oil source temperature drops, the disturbance load holding is continued, and this process is repeated to realize the application of long-term disturbance stress; The aging disturbance intelligent control center includes a computer and rheological experiment operation software, which can intelligently monitor the stress, strain and fracture information of the rock sample (13) throughout the aging disturbance process, and can control the static stress loading and unloading level, disturbance stress application conditions and other functions in real time; it can also display the disturbance duration, rheological loading duration, real-time power consumption and disturbance load-keeping intelligent switching information in real time during the aging disturbance process. The stress, strain and fracture information are respectively monitored in real time by a force sensor (5), a deformation sensor (6) and an acoustic emission receiver (7) arranged in each direction and fed back to the computer.

2. The deep-buried hard rock true triaxial aging disturbance test device according to claim 1, characterized in that: The interlocking rigid fixture assembly comprises four sample fixtures (12), wherein the first sample fixture (12a) and the third sample fixture (12c) are arranged on both sides of the rock sample (13) along the σ2 principal stress loading direction, and the second sample fixture (12b) and the fourth sample fixture (12d) are arranged on both sides of the rock sample (13) along the σ1 principal stress loading direction, and the four sample fixtures (12) are interlocked and slidably connected to each other; a first loading piston (14a) is provided at a position of the pressure chamber side wall corresponding to the first sample fixture (12a), the first loading piston (14a) is embedded in the pressure chamber side wall and slidably connected, and the first loading piston (14a) is in contact with the first sample fixture (12a); the bottom of the pressure chamber is in contact with the fourth sample fixture ( A second loading piston (14b) is provided at a position corresponding to the pressure chamber (12d), the second loading piston (14b) is embedded in the bottom of the pressure chamber and is slidably connected, and the second loading piston (14b) is in contact with the fourth sample fixture (12d); a first reaction force support (15a) is fixedly provided at a position corresponding to the side wall of the pressure chamber and the third sample fixture (12c), the first reaction force support (15a) is fixedly connected to the side wall of the pressure chamber, and the first reaction force support (15a) is in contact with the third sample fixture (12c); a second reaction force support (15b) is fixedly provided at a position corresponding to the top cover of the pressure chamber and the second sample fixture (12b), the second reaction force support (15b) is fixedly connected to the top cover of the pressure chamber, and the second reaction force support (15b) is in contact with the second sample fixture (12b).

3. The deep-buried hard rock true triaxial aging disturbance test device according to claim 2, characterized in that: The rigid dynamic load loading assembly (3) further comprises a dynamic self-balancing piston (32); the third sample fixture (12c) and the first reaction force support (15a) are provided with a disturbance hole along the σ2 direction; the second sample fixture (12b) and the second reaction force support (15b) are provided with a disturbance hole along the σ1 direction; a disturbance rod (33) is provided in the disturbance hole; the dynamic actuator (31), the dynamic self-balancing piston (32), and the disturbance rod (33) are in contact with each other in sequence; when the dynamic actuator (31) is in operation, point disturbances in the σ2 and σ1 directions are applied to the rock sample (13) through the disturbance rod (33).

4. The deep-buried hard rock true triaxial aging disturbance test device according to claim 3, characterized in that: The rigid static load loading assembly (2) further comprises a static self-balancing piston (22); a first rigid static load loading assembly (2a) contacts a first loading piston (14a); a static load in the σ2 direction is sequentially applied to the rock sample (13) via the first loading piston (14a) and the first sample fixture (12a); and a second rigid static load loading assembly (2b) contacts a second loading piston (14b); a static load in the σ1 direction is sequentially applied to the rock sample (13) via the second loading piston (14b) and the fourth sample fixture (12d).

5. The deep-buried hard rock true triaxial aging disturbance test device according to claim 2, characterized in that: The four sample clamps (12) are connected to each other in an interlocking and sliding manner, which can prevent the sample clamps (12) from being squeezed against each other when a rigid load is applied.

6. The deep-buried hard rock true triaxial aging disturbance test device according to claim 4, characterized in that: The interlocking rigid fixture assembly is further provided with a deformation sensor (6) and a deformation sensor support (61); the first deformation sensor (6a) is provided in the first sample fixture (12a); the first deformation sensor support (61a) is provided in the third sample fixture (12c); the second deformation sensor (6b) is provided in the fourth sample fixture (12d); the second deformation sensor support (61b) is provided in the second sample fixture (12b); the third deformation sensor (6c) and the third deformation sensor support (61c) are provided in the σ3 loading direction; the first deformation sensor (6a) and the second deformation sensor (6b) in the σ2 and σ1 loading directions are provided. ) include a stylus, a disc-type spring telescopic rod and an LVDT sensor body, and adopt a sliding orthogonal deformation LVDT sensor measurement structure; the third deformation sensor (6c) in the σ3 loading direction includes a metal rod, a positioning block, and an LVDT sensor, and adopts a fixed double-span beam LVDT sensor measurement structure; the first loading piston (14a) and the second loading piston (14b) are respectively provided with a force sensor (5) for real-time stress and strain monitoring during static loading in the σ2 and σ1 directions; the interlocking rigid clamp assembly is also provided with an acoustic emission receiver (7) capable of detecting the sound emitted when the rock sample (13) breaks.

7. The deep-buried hard rock true triaxial aging disturbance test device according to claim 6, characterized in that: The computer includes a large-capacity storage function, an intelligent switching sampling interval function during the experiment, an intelligent switching of disturbance load protection, an intelligent data filtering function, and a rheological test process recording function; the large-capacity storage function provides storage space for long-term disturbance data; The intelligent switching sampling interval function of the experimental process can reduce the collection of useless data; the data intelligent filtering function filters out meaningless disturbance stress records during the disturbance rheological process; the rheological test process recording function is used to record the duration of the rheological experiment, the duration of the disturbance stress application, temperature, power consumption, and real-time stress-strain curve information of the rock sample (13); The rheological experiment operation software first loads the rock sample (13) to the initial stress level, at which time the oil source power consumption monitoring and intelligent switching cooperate with each other to complete the first level disturbance load holding and static load holding process, and for the test emergency braking caused by excessive power consumption and excessive oil source temperature during the disturbance process, the disturbance is intelligently stopped when the disturbance stress is applied to a level close to the power consumption limit, including the following steps: Step 1: preset the total rheological time of the loading stage; Step 2: Perform disturbance load protection. Switch to static load protection according to the monitored oil source temperature. After the oil source temperature drops, the oil source power consumption monitoring feedback information to the dynamic actuator (31), and continue to perform disturbance load protection. Repeat this process. Step 3: judging the state of the rock sample (13) through stress, strain and fracture information; if damage occurs, the loading is stopped immediately and the experiment ends; Step 4: If the rock sample (13) does not fail in step 3, continue increasing the stress in the direction of the maximum principal stress to the second level; Step 5: Repeat steps 1 to 4 until the rock sample (13) is destroyed, then stop loading immediately and the experiment ends.

8. The deep-buried hard rock true triaxial aging disturbance test device according to claim 2, characterized in that: The invention also includes a rigid loading system frame (4), wherein the first rigid static load loading component (2a) and the second rigid dynamic load loading component (3b) are connected to the sample base platform (1) through the rigid loading system frame (4), the rigid loading system frame (4) is sleeved on the outside of the sample base platform (1) and is slidably connected to the sample base platform (1), and a hydraulic lifting mechanism is provided at the lower end of the sample base platform (1); the hydrostatic pressure chamber (11) is a semi-closed cavity structure, and after the sample base platform (1) descends, the hydrostatic pressure chamber (11) is in an open state; after the sample base platform (1) rises, the rigid loading system frame (4) closes the hydrostatic pressure chamber (11), the second rigid dynamic load loading component (3b) contacts the disturbance rod (33), and the static load loading component (2a) contacts the first loading piston (14a).

9. The deep-buried hard rock true triaxial aging disturbance test device according to claim 4, characterized in that: The static actuator (21) and the dynamic actuator (31) are both connected to a stroke measurement sensor (8), and the stroke measurement sensor (8) is used to monitor the displacement of the static actuator (21) and the dynamic actuator (31) when a load is applied.

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