Simulation system and test method for fault movement under true three-dimensional stress

Abstract

The invention provides a fault dislocation simulation system under true three-dimensional stress and a test method.The fault dislocation simulation system comprises a loading simulation device, a control device and a water hydraulic device and is used for providing loading for a test model in real time in the fault dislocation test process and monitoring real-time stress, strain and displacement data of the test model in the real-time loading process; the loading simulation device comprises a bottom plate, four side plates, a top plate, an antifriction plate, a plurality of loading water bags and a plurality of telescopic rods; the water hydraulic system is connected with the loading water bag, flexible loading is provided for the test model by injecting water into the loading water bag and pressurizing the loading water bag, and differential pressurization is carried out on the loading water bag in different areas so as to realize true three-dimensional stress and dislocation functions. According to the invention, true three-direction loading can be carried out on the test model, and vertical and lateral high stress and fault dislocation simulation of the test model can be realized by independently controlling the water pressure of the circular loading water bags at different positions, so that the purpose of simulating fault dislocation is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of underground engineering test instruments, and in particular relates to a physical simulation device and test technology for fault dislocation under true triaxial stress. Background Art

[0002] With the continuous advancement of the "Deep Underground" strategy, the development and utilization of kilometer-level deep resources has become normalized, and a large number of deep underground engineering structures, characterized by deep burial depths, complex stresses, and variable rock strata, have emerged. Deep underground projects planned in Southwest my country, particularly large, high-stress deep underground projects (clusters), inevitably traverse complex, unfavorable geological zones located in the southwest, approaching or crossing seismically active fault zones, and are therefore subject to severe active fault dislocation threats. During ground dislocation, the stress and deformation states of underground engineering structures at fault zones differ from those at other locations, necessitating the study and analysis of tunnel structural failure under these special conditions. Analyzing the dislocation patterns and failure mechanisms of surrounding rock under true triaxial stress conditions will help improve the theoretical level of anti-dislocation design for major underground projects in western my country and is a crucial prerequisite for ensuring the safe operation and lifecycle of major national lifeline projects. Existing methods for analyzing the deformation and failure processes of surrounding rock dislocation in underground projects often rely on experimental simulation and numerical analysis due to the lack of actual observational data. Compared with numerical simulation and other means, model tests are more vivid and intuitive, and can directly reflect the fault movement characteristics of underground engineering projects.

[0003] Currently, the existing method of simulating true triaxial stress by loading the model boundary with a jack has a problem: rigid loading makes it difficult to eliminate the influence of the jack's natural frequency on the test model during vibration. Zhao Xu and others invented and developed a model test device to simulate the tunnel excavation process. The airbag in the device only simulates vertical pressure loading and fails to take into account the lateral pressure loading of the tunnel. In fact, deep underground projects crossing fault zones are subject to both high stress and fault dislocation. However, existing anti-dislocation test technology cannot simulate the mechanical behavior of underground engineering under the coupling of multiple influences. As a result, there is no reliable test data to explore the structural behavior and damage of underground engineering in the fault zone area, nor can it propose reasonable disaster reduction measures.

[0004] Therefore, how to provide a physical simulation device and testing technology that can simultaneously simulate the high stress and fault dislocation of deep underground engineering, simulate the actual stress state of the dislocation of deep underground engineering in the fault zone area, and realize the true simulation of the high stress and dislocation coupling effect of deep underground engineering crossing the fault zone is a technical problem that technical personnel in this field urgently need to solve. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a fault dislocation simulation system and test method under true triaxial stress, so as to solve at least one of the above technical problems.

[0006] To solve the above technical problems, in a first aspect, the present invention provides a fault dislocation simulation system under true triaxial stress, the fault dislocation simulation system under true triaxial stress comprising:

[0007] The loading simulation device comprises a bottom plate, four side plates and a top plate, the four side plates are vertically mounted on the bottom plate, the four side plates are vertically connected to each other in pairs, the top plate is mounted on the top of the four side plates, the bottom plate, the four side plates and the top plate together form a test space, and the test model is placed in the test space; the six surfaces of the test model are all provided with anti-friction plates, and the outer sides of the anti-friction plates on the four peripheral sides and the top surface of the test model are all provided with a plurality of telescopic rods and loading water bags, and the plurality of loading water bags are provided. The capsules are evenly distributed between the plurality of telescopic rods; one end of each of the telescopic rods is connected to the corresponding anti-friction plate, the other ends of each of the telescopic rods located on the four circumferential sides of the test model are connected to the corresponding side plates, and the other ends of each of the telescopic rods located on the top surface of the test model are connected to the top plate; a plurality of LVDT displacement sensors are also evenly arranged on the anti-friction plate located on one circumferential side of the test model, and the two ends of each of the LVDT displacement sensors are respectively connected to the outer side surface of the anti-friction plate and the corresponding side plate;

[0008] A control device and a water hydraulic device, a stress sensor and a strain sensor are embedded in the test model, and the stress sensor and the strain sensor are electrically connected to the control device; each loading water bag is connected to the water hydraulic device through a water inlet pipe.

[0009] In the first aspect, optionally, reserved holes are provided on the four side panels, the stress sensor and the LVDT displacement sensor are connected to the control device through the corresponding reserved holes, and several water inlet pipes are connected to the water hydraulic device through the corresponding reserved holes.

[0010] In the first aspect, optionally, the friction-reducing plates each include two adjacently arranged friction-reducing support plates, and several of the telescopic rods and the loading water bags on the same side are evenly arranged on the two adjacently arranged friction-reducing support plates; and the friction-reducing support plates in the two relatively arranged friction-reducing plates in the six faces of the test model are arranged in the same manner.

[0011] In the first aspect, optionally, each of the anti-friction support plates includes two steel plates and a roller row, and the roller row is arranged between the two steel plates so that the anti-friction support plate slides in a direction parallel to the surface of the test model when loaded.

[0012] In the first aspect, optionally, the outer side surfaces of the top plate and the four side plates are vertically provided with reinforcing ribs that are staggered in horizontal and vertical directions.

[0013] In the first aspect, optionally, a support spring is provided inside the water loading bag.

[0014] In the first aspect, optionally, a plurality of bolt holes are opened on the bottom plate, so that the four side plates can be mounted on the bottom plate through the bolt holes, and the bottom plate can be mounted on the test site.

[0015] In the first aspect, optionally, the number of loaded water bags located on the four peripheral sides and the top surface of the test model is four, and the four loaded water bags are arranged in a matrix of two rows and two columns; a plurality of the telescopic rods are evenly distributed around the four loaded water bags.

[0016] In a second aspect, the present invention provides a test method for the fault dislocation simulation system under true triaxial stress described in Example 1, the test method comprising:

[0017] Cast and manufacture the test model, bury the stress sensor in the test model, and maintain the test model until it meets the test standards;

[0018] Installing a loading simulation device in the fault dislocation simulation system under true triaxial stress at a test site, and placing a test model in the loading simulation device;

[0019] Connect the air intake pipe to the water hydraulic device, and electrically connect the LVDT displacement sensor, the stress sensor, and the water hydraulic device to the control device;

[0020] Inputting loading control information into the control device, which converts the loading control information into a pressure value and outputs it to the water hydraulic device;

[0021] The water hydraulic device injects water into the loading water bag through the water inlet pipe based on the obtained pressure value, and adjusts the pressure value in the loading water bag according to the test requirements through the pressure reducing valve. At this time, the telescopic rod expands and contracts in response to the volume change of the loading water bag, driving the friction-reducing plate to move along the expansion and contraction direction to apply stress to the test model, simulating a true triaxial stress loading process.

[0022] When the true triaxial stress loading process reaches a stable state, water is injected or released into a specific loading water bag through a water hydraulic device to simulate the fault dislocation process;

[0023] The stress sensor and the strain sensor obtain the stress value and strain value of the test model during the true triaxial stress loading process and the fault dislocation process, and transmit the stress value and strain value to the control device;

[0024] The LVDT displacement sensor obtains displacement data during the true three-dimensional stress loading process and the fault dislocation process, and transmits the displacement data to the control device;

[0025] The stress value, the strain value and the displacement data are recorded for subsequent fault slip test research.

[0026] In the second aspect, optionally, after the true triaxial stress loading reaches a stable state, water is injected or pumped out of a specific loading water bag by a water hydraulic device to simulate the fault movement process, including:

[0027] The number of the water loading bags located on the four sides and the top surface of the test model is four, and the four water loading bags are arranged in a matrix of two rows and two columns;

[0028] With the Y-axis as the central axis, the ten water-loading bladders located on one half of the test model are labeled as water-loading bladders A to J, and the ten water-loading bladders located on the other half of the test model are labeled as water-loading bladders a to j. Water-loading bladders a and b are arranged on one side of the test model, and water-loading bladders e and f are arranged on the side of the test model opposite to water-loading bladder a. Water-loading bladders a and e are aligned with each other, and water-loading bladders b and e are aligned with each other.

[0029] When the true triaxial stress loading process reaches a stable state, water is injected into loading water bags a and b through the water hydraulic device to increase the water pressure in loading water bags a and b. Water is pumped into loading water bags e and f through the water hydraulic device to reduce the water pressure in loading water bags e and f. The water pressure from loading water bags A to J, from loading water bags c to d, and from loading water bags g to j is kept constant. The test model is caused to shift along the Y-axis to simulate the fault shift process.

[0030] Beneficial effects:

[0031] The present invention provides a fault dislocation simulation system and test method under true triaxial stress, comprising a loading simulation device, a control device and a water hydraulic device, for providing real-time loading for a test model during a fault dislocation test, and monitoring real-time stress, strain and displacement data of the test model during the real-time loading process; the loading simulation device comprises a bottom plate, four side plates, a top plate and a friction reducing plate, the bottom plate, the four side plates and the top plate together form a test space, the test model is placed in the test space for testing, the top plate is located at the top of the test model, and provides a reaction force for the loading water bag on the top of the test model, the four side plates are respectively located on the four peripheral sides of the test model, and provide a reaction force for the circular loading water bag on the side; the six surfaces of the test model are all provided with friction reducing plates, the function of the friction reducing plates is to reduce the friction between the test model and the loading water bag when the test model is subjected to force dislocation; the top surface and the four peripheral sides of the test model are all provided with a plurality of loading water bags, and the plurality of loading water bags are evenly distributed between a plurality of telescopic rods. During the dislocation test, As the volume of the loaded water bag expands after being filled with water, the telescopic rod can be extended or shortened accordingly; several telescopic rods are symmetrically and evenly arranged along the surface of the anti-friction plate, which can assist in fixing the loaded water bag on the one hand, and provide support for the anti-friction plate on the other hand, so that the stress applied to the surface of the test model after the loaded water bag is pressurized and expanded is uniform; wherein, several LVDT displacement sensors are also evenly arranged on the anti-friction plate located on one of the circumferential sides of the test model, for measuring the displacement changes of the surface of the test model during the displacement process; at the same time, the test model is pre-embedded with pressure sensors and strain sensors, and the pressure sensors, strain sensors and several LVDT displacement sensors are all electrically connected to the control device; a precision pressure reducing valve is provided in the water hydraulic device, which can monitor the hydraulic pressure of each loaded water bag, and each loaded water bag can be individually filled and discharged with water to adjust the water pressure, so as to realize accurate monitoring and control of the pressure of each water bag through the water hydraulic device, and realize the simulation of vertical and lateral high stress and fault displacement of the test model;

[0032] In this way, a physical simulation device and test technology that can simultaneously simulate high stress and fault dislocation in deep underground engineering is constructed. During the test, high stress is applied to the test model by adjusting the internal pressure of a part of the loaded water bags, and at the same time, a dislocation load is applied to the test model by adjusting the internal pressure of another part of the loaded water bags to simulate the actual stress state of the dislocation of the deep underground engineering in the fault zone area, thereby realizing a true simulation of the high stress and dislocation coupling effect of the deep underground engineering crossing the fault zone, and providing an effective device and test method for the anti-dislocation test of the deep underground engineering crossing the fault zone.

[0033] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are specifically listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0035] Figure 1 A schematic structural diagram of a fault dislocation simulation system under true triaxial stress provided in an embodiment of the present application;

[0036] Figure 2 A cross-sectional view along the Y-axis of a fault dislocation simulation system under true triaxial stress provided in an embodiment of the present application;

[0037] Figure 3 A schematic diagram of partial structural distribution of a fault dislocation simulation system under true triaxial stress provided in an embodiment of the present application;

[0038] Figure 4 A cross-sectional view along the Y-axis of a fault dislocation simulation system under true triaxial stress provided in an embodiment of the present application;

[0039] Figure 5 A schematic diagram of the arrangement and numbering of loading water bags for a fault dislocation simulation system under true triaxial stress provided in an embodiment of the present application;

[0040] Reference numerals:

[0041] 1—Load the simulation device;

[0042] 11—base plate; 111—bolt hole;

[0043] 12—side panel; 121—reserved hole;

[0044] 13—top plate;

[0045] 14—friction-reducing plate; 141—friction-reducing support plate;

[0046] 15—telescopic rod;

[0047] 16—Loading water bag; 16A—Loading water bag A; 16B—Loading water bag B; 16C—Loading water bag C; 16D—Loading water bag D; 16E—Loading water bag E; 16F—Loading water bag F; 16G—Loading water bag G; 16H—Loading water bag H; 16I—Loading water bag I; 16J—Loading water bag J; 16a—Loading water bag a; 16b—Loading water bag b; 16c—Loading water bag c; 16d—Loading water bag d; 16e—Loading water bag e; 16f—Loading water bag f; 16g—Loading water bag g; 16h—Loading water bag h; 16i—Loading water bag i; 16j—Loading water bag;

[0048] 17—LVDT displacement sensor;

[0049] 18—reinforced ribs;

[0050] 2—control device;

[0051] 3—water hydraulic device;

[0052] 4—Test model; DETAILED DESCRIPTION

[0053] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0054] At the same time, in the embodiments of this specification, when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may also be a central component. When a component is considered to be "connected" to another component, it may be directly connected to the other component or there may also be a central component. When a component is considered to be "set on" another component, it may be directly set on the other component or there may also be a central component. The terms "vertical", "horizontal", "left", "right" and similar expressions used in the embodiments of this specification are for illustrative purposes only and are not intended to limit the present invention.

[0055] Example 1:

[0056] See also Figure 1-3, the present embodiment 1 provides a fault dislocation simulation system under true triaxial stress, the fault dislocation simulation system under true triaxial stress includes: a loading simulation device 1, the loading simulation device 1 includes a bottom plate 11, four side plates 12 and a top plate 13, the four side plates 12 are vertically installed on the bottom plate 11, the four side plates 12 are vertically connected to each other in pairs, the top plate 13 is installed on the top of the four side plates 12, the bottom plate 11, the four side plates 12 and the top plate 13 together form a test space, and the test model 4 is placed in the test space; the six surfaces of the test model 4 are all provided with anti-friction plates 14, and the outer sides of the anti-friction plates 14 located on the four peripheral sides and the top surface of the test model 4 are all provided with a plurality of telescopic rods 15 and loading water bags 16, and the plurality of loading water bags 16 are evenly distributed between the plurality of telescopic rods 15 One end of a plurality of telescopic rods 15 is connected to the corresponding anti-friction plate 14, the other ends of the plurality of telescopic rods 15 located on the four circumferential sides of the test model 4 are connected to the corresponding side plates 12, and the other ends of the plurality of telescopic rods 15 located on the top surface of the test model 4 are connected to the top plate 13; a plurality of LVDT displacement sensors 17 are also evenly arranged on the anti-friction plate 14 located on one circumferential side of the test model 4, and the two ends of the plurality of LVDT displacement sensors 17 are respectively connected to the outer side surface of the anti-friction plate 14 and the corresponding side plate 12; a control device 2 and a water hydraulic device 3, a stress sensor and a strain sensor are embedded in the test model 4, and the stress sensor and the strain sensor are electrically connected to the control device 2; each loading water bag 16 is connected to the water hydraulic device 3 through a water inlet pipe.

[0057] Specifically, the present invention provides a fault dislocation simulation system under true triaxial stress, including a loading simulation device 1, a control device 2 and a water hydraulic device 3, which are used to provide real-time loading for a test model 4 during a fault dislocation test, and monitor the real-time stress, strain and displacement data of the test model during the real-time loading process; the loading simulation device 1 includes a bottom plate 11, four side plates 12, a top plate 13 and six friction-reducing plates 14, the bottom plate 11 is fixed to the test site, the four side plates 12 are vertically installed on the bottom plate 11, and the four side plates 12 are vertically connected to each other in pairs, and the top plate 13 is fixed on the four side plates 12, so that the loading simulation device 1 is constructed as a whole to form a shape as shown in FIG. Figure 1The square structure shown; the bottom plate 11, four side plates 12 and the top plate 13 are enclosed to form a test space, and the test model 4 is placed in the test space for testing. The top plate 13 is located at the top of the test model 4, providing a reaction force for the loading water bag 16 on the top of the test model 4, and the four side plates 12 are respectively located on the four sides of the test model 4, providing a reaction force for the circular loading water bag 16 on the side; the six surfaces of the test model 4 are provided with anti-friction plates 14, and the function of the anti-friction plates 14 is to reduce the friction between the test model 4 and the loading water bag 16 when the force is displaced, and the anti-friction plates 14 and the side plates 12 or the top plate 13 are welded and fixed by a number of telescopic rods 15; the top surface and four sides of the test model 4 are provided with a number of loading water bags 16, and the number of loading water bags 16 are evenly distributed between the number of telescopic rods 15; as a feasible way, the present invention adopts a circular loading water bag 16 for loading. Since the loading water bag 16 is made of flexible material and has a light weight, its own natural vibration frequency has little effect on the test model 4, generating The stress boundary effect is more in line with the actual geomechanical principles; both ends of several telescopic rods 15 are welded and fixed to the anti-friction plate and the corresponding side plate 12 or top plate 13. During the displacement test, as the volume of the loaded water bag 16 is expanded by water, the telescopic rods 15 can be extended or shortened accordingly; several telescopic rods 15 are symmetrically and evenly arranged along the surface of the anti-friction plate. On the one hand, they can assist in fixing the loaded water bag 16, and on the other hand, they can also provide support for the anti-friction plate 14, so that the stress applied to the surface of the test model 4 after the loaded water bag 16 is pressurized and expanded is uniform; wherein, several LVDT displacement sensors 17 are also evenly arranged on the anti-friction plate 14 on one side of the test model 4. The LVDT displacement sensor 17 is composed of a 9.5mm lightweight iron core and a stainless steel shell, and its range is 0.5mm to 50mm. After the displacement accuracy is calibrated, the LVDT displacement sensor 17 is fixed to the set design position of the side plate 12 by industrial glue to measure the displacement change of the surface of the test model 4 during the displacement process;

[0058] At the same time, the test model 4 is pre-embedded with pressure sensors and strain sensors, and the pressure sensors, strain sensors and several LVDT displacement sensors are all electrically connected to the control device 2; several loaded water bags 16 are connected to the water hydraulic device 3 through the water inlet pipe; the water hydraulic device 3 is provided with a precision pressure reducing valve, which can monitor the hydraulic pressure of each loaded water bag 16. Each loaded water bag 16 can be individually filled and discharged with water to adjust the water pressure, so as to achieve accurate monitoring and control of the pressure of each water bag through the water hydraulic device 3. Under the control of the precision pressure reducing valve, a water bag pressure of 0.01-1.5MPa can be provided, which can realize the simulation of vertical and lateral high stress and fault dislocation of the test model.

[0059] In some possible embodiments, reserved holes 121 are provided on the four side panels 12, and the stress sensor and the LVDT displacement sensor 17 are connected to the control device 2 through the corresponding reserved holes 121, and several water inlet pipes are connected to the water hydraulic device 3 through the corresponding reserved holes 121.

[0060] Specifically, if Figure 3 As shown, the reserved hole 121 is provided to facilitate wiring of the water inlet pipe, the stress sensor and several LVDT displacement sensors through the reserved hole provided on the side panel.

[0061] In some possible embodiments, the friction-reducing plates 14 each include two adjacent friction-reducing support plates 141, and several telescopic rods 15 and loading water bags 16 on the same side are evenly arranged on the two adjacent friction-reducing support plates 141; and the friction-reducing support plates 141 in the two relatively arranged friction-reducing plates 14 on the six surfaces of the test model 4 are arranged in the same manner; the friction-reducing support plates 141 each include two steel plates and a roller row, and the roller row is arranged between the two steel plates so that the friction-reducing support plates 141 slide in a direction parallel to the surface of the test model 4 when loaded.

[0062] Specifically, if Figure 3 As shown, the friction-reducing plates 141 located on the six surfaces of the test model 4 each include two adjacently arranged friction-reducing support plates 141, and the friction-reducing support plates 141 in the two opposite friction-reducing plates 14 are arranged in the same manner, so that the rolling directions of the roller rows in the two opposite friction-reducing support plates 141 are consistent, thereby ensuring that the directions of the staggered stresses on the opposite surfaces of the test model 4 are consistent; wherein, the friction-reducing support plates 141 each include two steel plates and a roller row arranged between the two steel plates. When loaded, the friction-reducing support plates 141 can slide in a direction parallel to the surface of the test model 4, so as to reduce the friction generated by the loaded water bag 16 on the test model 4 during the pressurized expansion process.

[0063] In some possible implementations, the outer sides of the top plate 13 and the four side plates 12 are vertically provided with reinforcing ribs 18 that are staggered in both horizontal and vertical directions.

[0064] Specifically, the top plate 13 and the four side plates 12 are vertically welded with crisscross reinforcing ribs 18 to strengthen the overall strength of the top plate 13 and the four side plates 12, and provide reaction force for the loading water bags 16 on the top and surrounding sides of the test model 4, ensuring that the top plate 13 and the four side plates 12 do not deform during the loading process, reducing test errors, and thus improving the accuracy of the test.

[0065] In some possible implementations, a support spring is provided inside the water loading bag 16 .

[0066] Specifically, a support spring is provided inside each loading water bag 16. Since water needs to be repeatedly injected and discharged into the loading water bag 16 during the test to simulate different fault displacement conditions, the support spring can assist the loading water bag 16 to reach a stable and uniform state within the water filling and expansion stroke through the pre-compressed elastic force, so that the loading water bag 16 maintains uniform contact with the side panel 12 after being expanded, avoiding excessive local pressure and inconsistent height on the left and right sides.

[0067] In some possible implementations, a plurality of bolt holes 111 are provided on the bottom plate 11 , so that the four side plates 12 can be mounted on the bottom plate 11 through the bolt holes 111 , and the bottom plate 11 can be mounted on the test site.

[0068] Specifically, a plurality of bolt holes 111 are prefabricated on the bottom plate 11 for integrating the four side plates 12 , the bottom plate 11 and the test site, thereby stably fixing the loading simulation device 1 to the test site.

[0069] In some possible embodiments, there are four water loading bags 16 located on the four sides and the top surface of the test model 4 , and the four water loading bags 16 are arranged in a matrix of two rows and two columns; a plurality of telescopic rods 15 are evenly distributed around the four water loading bags 16 .

[0070] Specifically, there are four loading water bags 16 located on the four sides and the top surface of the test model 4; the four loading water bags 16 located on the same side are arranged in a matrix of two rows and two columns (that is, they are stacked in a 2×2 arrangement); as a feasible method, an elastic connecting belt is bonded to the outer side of the loading water bag 16, and the loading water bag 16 is fixed to the telescopic rod 15 adjacent to the loading water bag 16 through the elastic connecting belt.

[0071] Example 2:

[0072] The present invention provides a test method for the fault dislocation simulation system under true triaxial stress in the first embodiment, the test method comprising:

[0073] Cast and manufacture the test model, bury the stress sensor in the test model, and maintain the test model until it meets the test standards;

[0074] The loading simulation device in the fault dislocation simulation system under true triaxial stress is installed at the test site, and the test model is placed in the loading simulation device;

[0075] Connect the air intake pipe to the water hydraulic device, and electrically connect the LVDT displacement sensor, the stress sensor, and the water hydraulic device to the control device;

[0076] Inputting loading control information into the control device, the control device converts the loading control information into a pressure value and outputs it to the water hydraulic device;

[0077] The water hydraulic device injects water into the loading water bag through the water inlet pipe based on the obtained pressure value, and adjusts the pressure value in the loading water bag according to the test requirements through the pressure reducing valve. At this time, the telescopic rod expands and contracts in response to the volume change of the loading water bag, driving the friction-reducing plate to move along the expansion and contraction direction to apply stress to the test model, simulating a true triaxial stress loading process.

[0078] When the true triaxial stress loading process reaches a stable state, water is injected or released into a specific loading water bag through a water hydraulic device to simulate the fault dislocation process;

[0079] The stress sensor and the strain sensor obtain the stress value and strain value of the test model during the true triaxial stress loading process and the fault dislocation process, and transmit the stress value and strain value to the control device;

[0080] The LVDT displacement sensor obtains displacement data during the true three-dimensional stress loading process and the fault dislocation process, and transmits the displacement data to the control device;

[0081] Record stress values, strain values and displacement data for subsequent fault slip test research.

[0082] Specifically, this embodiment provides a test method for the fault dislocation simulation system under true triaxial stress in Example 1. Before the test, similar materials and various sensors required for the test are prepared, and the required instruments and equipment are checked to see if they are normal; a test model sample mold is made, stress sensors and strain sensors are embedded, the test model is cast, and the test model is maintained to ensure that the test model meets the test standards; after the test model 15 is made, the bottom plate and the test model are hoisted to the designed position of the test site, the bottom plate is connected to the test site, the four side plates and the anti-friction plate are assembled accordingly, and the test model is hoisted onto the anti-friction plate; anti-friction plates, several telescopic rods, and a loading water bag are installed on the four sides of the test model and between the four side plates; the LVDT displacement is measured. The displacement accuracy of the sensor is calibrated, and one end of several LVDT displacement sensors is fixed to the preset position on the anti-friction plate on one of the sides of the test model using industrial glue, and the other end of several LVDT displacement sensors is connected to the corresponding side plate; the water inlet pipe, stress sensor and the lines of several LVDT displacement sensors are passed through the reserved holes opened on the side plate; the anti-friction plate, several telescopic rods and loading water bags are installed between the top surface of the test model and the top plate; vaseline is applied to the surface of all loading water bags to reduce the friction between adjacent loading water bags after the water volume increases; the top plate is installed to the top of the four side plates; the air inlet pipe is connected to the water hydraulic device, and the LVDT displacement sensor, stress sensor and water bag are installed. The hydraulic device is electrically connected to the control device and debugged until it meets the test standards; after the counter-loading simulation device is assembled and fixed, the control system needs to be debugged and checked before the formal test; the formal test needs to be loaded step by step through the control system in strict accordance with the working conditions, and the control system is loaded with control information according to the input. The control device converts the loading control information into a pressure value and outputs it to the water hydraulic device, and then fills and drains the loading water bag through the water hydraulic system. According to the test requirements, the pressure value in the corresponding loading water bag is adjusted through the precision pressure reducing valve, thereby driving the friction reduction plate to move along the direction of the telescopic rod and act on the test model, providing initial stress for the test model, and simulating the true three-dimensional stress loading process; when the true three-dimensional stress loading process reaches a stable state After the state is established, water is injected or released into a specific loading water bag through a water hydraulic device to simulate the fault dislocation process; when conducting the fault dislocation test, the control system controls the water hydraulic system to keep the water pressure of the loading water bag on one side unchanged to simulate the initial ground stress, and to change the water pressure of the different loading water bags on the other side to simulate the fault dislocation; during the true triaxial stress loading process and the fault dislocation process, stress sensors, strain sensors and LVDT displacement sensors are used to collect the stress, strain and displacement data of the test model during the loading process, and transmit them to the control device for recording, so that researchers can conduct subsequent research based on this data, and provide data support for the true triaxial rock mechanical behavior, failure mechanism and dynamic response analysis in actual engineering projects in the fault zone area.

[0083] In some possible implementations, after the true triaxial stress loading reaches a stable state, water is injected or pumped out of a specific loading water bag by a water hydraulic device to simulate the fault movement process, including:

[0084] There are four water-loading bags on each of the four sides and top of the test model, and they are arranged in a matrix of two rows and two columns.

[0085] With the Y-axis as the central axis, the ten water-loading bladders on one half of the test model are labeled as water-loading bladders A to J, and the ten water-loading bladders on the other half of the test model are labeled as water-loading bladders a to j. Water-loading bladders a and b are located on one side of the test model, and water-loading bladders e and f are located on the side of the test model opposite water-loading bladder a. Water-loading bladders a and e are aligned with each other, and water-loading bladders b and e are aligned with each other.

[0086] When the true triaxial stress loading process reaches a stable state, water is injected into loading water bags a and b through the water hydraulic device to increase the water pressure in loading water bags a and b. Water is pumped into loading water bags e and f through the water hydraulic device to reduce the water pressure in loading water bags e and f. The water pressure from loading water bags A to J, from loading water bags c to d, and from loading water bags g to j is kept constant. The test model is caused to shift along the Y-axis to simulate the fault shift process.

[0087] Specifically, if Figure 5 As shown, the number of loading water bags located on the four sides and the top surface of the test model is four, and there are 20 loading water bags 16 in total. In order to facilitate the description of the control process of the loading water bags 16 during the simulated fault movement, they are marked as 16A~J and 16a~j respectively; wherein, with the Y axis as the central axis, the 10 loading water bags 16 located on one half side of the test model 4 are marked as 16A~J, and the 10 loading water bags 16 located on the other half side of the test model 4 are marked as 16a~j; the water hydraulic device 3 includes a hydraulic controller ① and a hydraulic controller ②, and each hydraulic controller Each device can independently control the water pressure of the 10 loading water bags 16. When the true triaxial stress loading reaches a stable state, the water pressure of loading water bags A to J is controlled to remain constant through hydraulic controller ① to simulate the initial stress. The water pressure of loading water bags a and b is increased through hydraulic controller ②, while the water pressure of loading water bags e and f is reduced. The water pressure of loading water bags A to J, loading water bags c to d, and loading water bags g to j is controlled to remain constant, so that the test model produces displacement along the Y-axis to achieve the effect of simulating fault displacement.

[0088] Finally, it should be noted that the above embodiments are only specific implementations of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that any person skilled in the art can modify or easily conceive of changes to the technical solutions described in the above embodiments within the technical scope disclosed by the present invention, or replace some of the technical features therein with equivalents. However, such modifications, changes, or replacements do not deviate from the essence of the corresponding technical solutions within the scope of the technical solutions of the embodiments of the present invention. They should all be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

[0089] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A fault dislocation simulation system under true triaxial stress, characterized in that: The fault dislocation simulation system under true triaxial stress includes: A loading simulation device (1) includes a bottom plate (11), four side plates (12) and a top plate (13), wherein the four side plates (12) are vertically mounted on the bottom plate (11), and the four side plates (12) are vertically connected to each other in pairs, and the top plate (13) is mounted on the top of the four side plates (12). The bottom plate (11), the four side plates (12) and the top plate (13) together form a test space, and the test model (4) is placed in the test space; the six surfaces of the test model (4) are all provided with anti-friction plates (14), and the outer side surfaces of the anti-friction plates (14) located on the four peripheral sides and the top surface of the test model (4) are all provided with a plurality of telescopic rods (15) and a loading water bag (16). If The plurality of loading water bags (16) are evenly arranged between the plurality of telescopic rods (15); one end of the plurality of telescopic rods (15) is connected to the corresponding anti-friction plate (14); the other ends of the plurality of telescopic rods (15) located on the four peripheral sides of the test model (4) are connected to the corresponding side plates (12); the other ends of the plurality of telescopic rods (15) located on the top surface of the test model (4) are connected to the top plate (13); a plurality of LVDT displacement sensors (17) are also evenly arranged on the anti-friction plate (14) located on one peripheral side of the test model (4); the two ends of the plurality of LVDT displacement sensors (17) are respectively connected to the outer side surface of the anti-friction plate (14) and the corresponding side plate (12); A control device (2) and a water hydraulic device (3); a stress sensor and a strain sensor are embedded in the test model (4); the stress sensor and the strain sensor are electrically connected to the control device (2); and each loading water bag (16) is connected to the water hydraulic device (3) via a water inlet pipe.

2. The fault dislocation simulation system under true triaxial stress according to claim 1, characterized in that: The four side plates (12) are each provided with a reserved hole (121); the stress sensor and the LVDT displacement sensor (17) are each passed through the corresponding reserved holes (121) to be connected to the control device (2); and a plurality of water inlet pipes are each passed through the corresponding reserved holes (121) to be connected to the water hydraulic device (3).

3. The fault dislocation simulation system under true triaxial stress according to claim 2, characterized in that: The outer side surfaces of the top plate (13) and the four side plates (12) are vertically provided with reinforcing ribs (18) that are staggered in both horizontal and vertical directions.

4. The fault dislocation simulation system under true triaxial stress according to claim 3, characterized in that: The friction-reducing plates (14) each include two adjacently arranged friction-reducing support plates (141), and a plurality of the telescopic rods (15) and the loading water bags (16) on the same side are evenly arranged on the two adjacently arranged friction-reducing support plates (141); and the friction-reducing support plates (141) in the two relatively arranged friction-reducing plates (14) on the six surfaces of the test model (4) are arranged in the same manner.

5. The fault dislocation simulation system under true triaxial stress according to claim 4, characterized in that: The anti-friction support plate (141) comprises two steel plates and a roller row, wherein the roller row is arranged between the two steel plates so that the anti-friction support plate (141) slides in a direction parallel to the surface of the test model (4) when loaded.

6. The fault dislocation simulation system under true triaxial stress according to claim 5, characterized in that: A supporting spring is provided inside the water loading bag (16).

7. The fault dislocation simulation system under true triaxial stress according to claim 6, characterized in that: The bottom plate (11) is provided with a plurality of bolt holes (111), so that the four side plates (12) can be mounted on the bottom plate (11) through the bolt holes (111), and the bottom plate (11) can be mounted on a test site.

8. The fault dislocation simulation system under true triaxial stress according to claim 7, characterized in that: The number of the water loading bags (16) located on the four peripheral sides and the top surface of the test model (4) is four, and the four water loading bags (16) are arranged in a matrix of two rows and two columns; a plurality of telescopic rods (15) are evenly arranged around the four water loading bags (16).

9. A test method for a fault dislocation simulation system under true triaxial stress according to any one of claims 1 to 8, characterized in that: The test method includes: Cast and manufacture the test model, bury the stress sensor in the test model, and maintain the test model until it meets the test standards; Installing a loading simulation device in the fault dislocation simulation system under true triaxial stress at a test site, and placing a test model in the loading simulation device; Connect the air intake pipe to the water hydraulic device, and electrically connect the LVDT displacement sensor, stress sensor, strain sensor, and water hydraulic device to the control device; Inputting loading control information into the control device, which converts the loading control information into a pressure value and outputs it to the water hydraulic device; The water hydraulic device injects water into the loading water bag through the water inlet pipe based on the obtained pressure value, and adjusts the pressure value in the loading water bag according to the test requirements through the pressure reducing valve. At this time, the telescopic rod expands and contracts in response to the volume change of the loading water bag, driving the friction-reducing plate to move along the expansion and contraction direction to apply stress to the test model, simulating a true triaxial stress loading process. When the true triaxial stress loading process reaches a stable state, water is injected or released into a specific loading water bag through a water hydraulic device to simulate the fault dislocation process; The stress sensor and the strain sensor obtain the stress value and strain value of the test model during the true triaxial stress loading process and the fault dislocation process, and transmit the stress value and strain value to the control device; The LVDT displacement sensor obtains displacement data during the true three-dimensional stress loading process and the fault dislocation process, and transmits the displacement data to the control device; The stress value, the strain value and the displacement data are recorded for subsequent fault slip test research.

10. The test method of the fault dislocation simulation system under true triaxial stress according to claim 9, characterized in that: After the true triaxial stress loading reaches a stable state, water is injected or pumped out of a specific loading water bag through a water hydraulic device to simulate the fault movement process, including: The number of the water loading bags located on the four sides and the top surface of the test model is four, and the four water loading bags are arranged in a matrix of two rows and two columns; With the Y-axis as the central axis, the ten water-loading bladders located on one half of the test model are labeled as water-loading bladders A to J, and the ten water-loading bladders located on the other half of the test model are labeled as water-loading bladders a to j. Water-loading bladders a and b are arranged on one side of the test model, and water-loading bladders e and f are arranged on the side of the test model opposite to water-loading bladder a. Water-loading bladders a and e are aligned with each other, and water-loading bladders b and e are aligned with each other. When the true triaxial stress loading process reaches a stable state, water is injected into loading water bags a and b through the water hydraulic device to increase the water pressure in loading water bags a and b. Water is pumped into loading water bags e and f through the water hydraulic device to reduce the water pressure in loading water bags e and f. The water pressure from loading water bags A to J, from loading water bags c to d, and from loading water bags g to j is kept constant. The test model is caused to shift along the Y-axis to simulate the fault shift process.

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