A fault simulation test device and method satisfying strong earthquake dislocation coupling loading

Abstract

The application relates to a fault simulation test device and method satisfying strong earthquake dislocation coupling loading, which comprises a rigid model box, a module assembly type component, a layered shear component, a shaking table loading device and a bracket. The bracket is arranged between the two shaking table loading devices, one end of the module assembly type component is connected with the rigid model box, the other end of the module assembly type component is connected with the layered shear component, and the bottom of the layered shear component is slidably connected with the bracket. The soil body and the tunnel model are arranged in the rigid model box and the module assembly type component and pass through the layered shear component. The rigid model box and the module assembly type component are controlled to move along the vibration direction of the shaking table loading device by inputting the seismic wave of the shaking table loading device, so that the layered shear component is driven to dislocate. Compared with the prior art, the application can effectively simulate the influence of the displacement of the fault fracture zone on the tunnel structure under the strong earthquake dislocation coupling condition, is easy to operate and has high universality.

Description

Technical Field

[0001] This invention relates to the field of geotechnical engineering technology, and in particular to a fault simulation test device and method that meets the requirements of strong earthquake dislocation coupling loading. Background Technology

[0002] my country is the country with the most frequent earthquakes and the most severe earthquake disasters on the continent, especially in the Sichuan-Yunnan region, where long active fault zones are widely distributed. With the in-depth implementation of the "14th Five-Year Plan" for the development of a modern comprehensive transportation system, more and more tunnel projects inevitably cross strong active fault zones, and the engineering disaster risks they face are also increasing. At present, earthquake resistance of cross-fault engineering has become a research hotspot and challenge in the international earthquake engineering field. However, research still faces problems such as unclear fault displacement modes during earthquakes and unclear disaster mechanisms of tunnels crossing active faults. Current domestic and international regulations and standards are mainly based on avoiding faults in engineering construction, and a systematic design guide has not yet been formed. In order to clarify the earthquake damage mechanism of tunnels crossing faults, physical model tests based on shaking tables are undoubtedly an important research method to help us objectively understand the theoretical mechanisms. The key to physical models lies in how to design fault simulation test devices that can meet the requirements of strong earthquake dislocation coupling loading.

[0003] In recent years, scholars both domestically and internationally have conducted numerous studies on the characteristics of near-fault ground motion and the damage to engineering facilities crossing faults. They have also developed a series of fault simulation test devices. However, most existing test devices are fabricated for specific projects or experiments, lacking universality and potentially affecting the scientific validity of the results. Furthermore, the loading methods of existing fault simulation test devices are mostly static loading, which involves dividing the fault into a fixed disk and a fault-prone disk, simulating fault movement by applying a load to the fault-prone disk. However, this device design cannot effectively simulate the displacement distribution patterns within the fault fracture zone, nor can this static loading method simulate the actual stress field combination of strong earthquakes and fault dislocation coupling during an earthquake. Therefore, it is necessary to develop a more universal fault simulation test device to study the impact of the coupling effect of strong ground motion and fault dislocation on underground structures during earthquakes. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the existing technology by providing a fault simulation test device and method that meets the requirements of strong earthquake dislocation coupling loading. The test device and method provided by this invention can effectively simulate the impact of fault fracture zone displacement on tunnel structures under strong earthquake dislocation coupling. The use of a multi-layered frame structure to simulate the fault fracture zone better reflects the actual displacement of the fault fracture zone compared to the previous method of applying the displacement to a single fault surface. The use of modular assembly components allows test personnel to assemble the components according to specific test requirements, meeting the test needs under different fault parameter conditions and facilitating reuse. It is highly versatile; the fault displacement process can be simulated by changing the combination of modular assembly components and layered shear components, demonstrating good versatility.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] This invention investigates the effects of strong earthquake-dislocation coupled loading on tunnel structures. A segmented structural design is used to simulate the fault structure. Fault parameters are altered through the combination of modular prefabricated components, and a frame-type layered shear assembly is used to simulate actual fault displacement. The experimental setup is easy to operate, highly versatile, and the experimental method is scientifically sound.

[0007] This invention provides a fault simulation test device that meets the requirements of strong earthquake dislocation coupling loading, comprising: a rigid model box, a modular assembly component, a layered shear assembly component, a shaking table loading device, and a bracket;

[0008] The bracket is located between two vibration table loading devices. One end of the modular assembly component is connected to the rigid model box, and the other end of the modular assembly component is connected to the layered shear component. The bottoms of the rigid model box and the modular assembly component are connected to the vibration table loading device, and the bottom of the layered shear component is slidably connected to the bracket.

[0009] The modular assembly components and the rigid model box together form an upper and lower plate structure to simulate different test conditions. The modular assembly components are designed according to the fault parameters simulated in the test. The fault parameters include the fault dip angle and the angle between the fault and the tunnel. The shape of the open surface connecting the modular assembly components and the layered shear components is the same as the fault plane. The open surface connecting the modular assembly components and the rigid model box has the same side dimensions as the rigid model box.

[0010] The soil and tunnel models are set up inside the rigid model box and modular assembly components and pass through the layered shear components. By controlling the seismic wave input of the shaking table loading device, the rigid model box and modular assembly components move along the vibration direction of the shaking table loading device, thereby causing the layered shear components to shift.

[0011] Furthermore, the rigid model box's frame includes H-beams and channel steel. The rigid model box's body includes four closed surfaces and two open surfaces. The bottom, one side end, and the front and rear surfaces of the rigid model box's body are closed surfaces. The open surfaces at the ends of the rigid model box are located at the connection surfaces between the rigid model box and the modular assembly components. The open surfaces at the top of the rigid model box are located at the top of the rigid model box.

[0012] Furthermore, modular assembly components are prefabricated structures designed for single tests. These components consist of welded steel plates connected to a rigid model box via bolts. They can only meet one processing condition and require complete replacement for subsequent tests.

[0013] Furthermore, the modular assembly is a detachable structure suitable for different fault parameters. It comprises multiple substructures, and the combination of these substructures is modified during testing to meet different fault parameters. These substructures are interconnected by bolts. Testing requirements can be met through disassembly and reassembly.

[0014] Furthermore, the substructure of the modular assembly includes interconnected block steel plates. One sidewall of the modular assembly includes multiple fault dip control components of different shapes, and the other side includes multiple fault strike control components of different shapes. The fault dip control components control the change in fault dip angle, and the fault strike control components control the change in fault strike. The fault dip angles of the two sidewalls of the modular assembly correspond one-to-one. During the experiment, the fault dip control components of the two sidewalls can be selected first according to the fault parameters to simulate the fault dip angle. Then, the fault strike can be changed by combining the fault strike control components.

[0015] Furthermore, the layered shearing assembly is connected to the bracket via guide rails or ball bearings, allowing the layered shearing assembly to slide freely on the bracket.

[0016] Furthermore, the layered shear assembly simulates the fault fracture zone. The total length of the frame assembly of the layered shear assembly is set according to the width of the fault fracture zone. The layered shear assembly includes an outer layered shear frame, an inner layered shear frame, internal connectors of the layered shear frame, and a bottom connector of the layered shear frame. The layered shear assembly is connected to the bracket through the bottom connector of the layered shear frame. The outer layered shear frame and the inner layered shear frame are connected through the internal connector of the layered shear frame. The internal connector of the layered shear frame is used to generate displacement. The modular assembly drives the layered shear assembly to generate displacement along the vibration direction of the vibration table loading device. The bottom connector of the layered shear frame can guide and limit displacement. The displacement at any location in the fault fracture zone is calculated based on the displacement curve when the fault fracture zone is displaced. Then, the fault fracture zone is divided into segments to determine the optimal size of each frame. Furthermore, the curved displacement within each frame is equivalent to a uniform linear displacement using mathematical methods, thereby determining the stroke of the bottom limiting device of each frame.

[0017] Furthermore, the internal connecting parts of the layered shear frame are bearings or springs, and the width of the outer layer layered shear frame and the inner layer layered shear frame gradually decreases towards the middle position along the modular assembly to meet the changing trend of the "S"-shaped displacement of the fault fracture zone during loading.

[0018] Furthermore, the layered shear assembly includes four open steel pipes welded together, the shape of the opening face of the steel pipes being the same as the cross-section.

[0019] This invention also provides a fault simulation test method that satisfies strong earthquake dislocation coupling loading, comprising the following steps:

[0020] S. Based on the fault to be simulated in the experiment, determine the fault parameters, including the dip angle, the width of the fault fracture zone, and the angle between the fault and the tunnel. Design according to the similarity ratio of the experiment, select the model rock material according to the surrounding rock parameters, and make the tunnel model.

[0021] S. Fabricate corresponding modular assembly components according to the fault parameters, connect the modular assembly components to the rigid model box, and fix the modular assembly components and the rigid model box to the vibration table loading device.

[0022] S. Fabricate the corresponding layered shear components according to the fault parameters, connect the layered shear components to the modular assembly components, and place the layered shear components on the bracket.

[0023] S. Lay soil at the bottom of the rigid model box, modular assembly components, and layered shear components up to the height of the tunnel model. After installing the tunnel model inside the rigid model box, modular assembly components, and layered shear components, install the corresponding sensors at the locations where data needs to be acquired, and then add the top cover soil.

[0024] S. By controlling the vibration table, the rigid model box and modular assembly components are controlled to move, thereby causing the layered shear components to move along the bottom guide rail or the arrangement direction of the balls, thus realizing the modular assembly fault simulation test that meets the requirements of strong earthquake dislocation coupling loading.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] (1) The test device and test method described in this invention can effectively simulate the impact of displacement of fault fracture zone on tunnel structure under strong earthquake dislocation coupling.

[0027] (2) The experimental device uses a multi-layer frame structure to simulate the fault fracture zone. Compared with the previous method of applying the displacement to a single displacement surface, it can better reflect the actual displacement of the fault fracture zone.

[0028] (3) This test device adopts modular assembly components. Test personnel can assemble the components according to specific test requirements to meet the test requirements under different fault parameter conditions and facilitate reuse.

[0029] (4) The power input of this test device is a shaking table. Compared with the quasi-static input used in previous tests, the shaking table power input can better simulate the input process of seismic waves. Furthermore, the model boxes simulating the hanging wall and footwall of the fault are fixed on two shaking tables respectively, and the strong earthquake-dislocation coupling input is realized by differential input of the ground motion.

[0030] (5) The test device is highly versatile. It can simulate the fault displacement process by changing the combination of modular assembly components and layered shear components. The device has good versatility. Attached Figure Description

[0031] Figure 1 A schematic diagram of a fault simulation test device designed to meet the requirements of strong earthquake dislocation coupling loading.

[0032] Figure 2 This is a schematic diagram of the modular assembly component of Example 1.

[0033] Figure 3 This is a schematic diagram of the modular assembly component of Example 2.

[0034] Figure 4 This is a schematic diagram of a layered shear assembly.

[0035] Reference numerals: 1. Rigid model box; 2. Modular assembly component; 21. Fault strike control component; 22. Fault dip control component; 31. Outer layered shear frame; 32. Inner layered shear frame; 33. Internal connector of layered shear frame; 34. Bottom connector of layered shear frame; 4. Vibration table loading device; 5. Bracket. Detailed Implementation

[0036] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. Component models, material names, connection structures, control methods, algorithms, and other features not explicitly described in this technical solution are considered common technical features disclosed in the prior art.

[0037] Example 1

[0038] This embodiment provides a fault simulation test device that meets the requirements of strong earthquake dislocation coupling loading, such as... Figure 1 As shown, it includes: a rigid model box 1, a modular assembly component 2, a layered shear component, a vibration table loading device 4, and a bracket 5;

[0039] The bracket 5 is located between the two vibration table loading devices 4. One end of the modular assembly component 2 is connected to the rigid model box 1, and the other end of the modular assembly component 2 is connected to the layered shear component. The bottoms of the rigid model box 1 and the modular assembly component 2 are both connected to the vibration table loading device 4, and the bottom of the layered shear component is slidably connected to the bracket 5.

[0040] The modular assembly component 2 and the rigid model box 1 together form an upper and lower plate structure to simulate different test conditions. The modular assembly component 2 is designed according to the fault parameters simulated in the test. The fault parameters include the fault dip angle and the angle between the fault and the tunnel. The shape of the open surface connecting the modular assembly component 2 and the layered shear component is the same as the fault plane. The open surface connecting the modular assembly component 2 and the rigid model box 1 has the same side dimensions as the rigid model box 1.

[0041] The soil and tunnel models are set inside the rigid model box 1 and the modular assembly 2 and pass through the layered shear assembly. By controlling the seismic wave input of the shaking table loading device 4, the rigid model box 1 and the modular assembly 2 move along the vibration direction of the shaking table loading device 4, thereby causing the layered shear assembly to shift.

[0042] In a specific embodiment, the frame of the rigid model box 1 includes H-beams and channel steel. The rigid model box 1 has four closed surfaces and two open surfaces. The bottom, one side end, and the front and rear surfaces of the rigid model box 1 are closed surfaces. The open surface at the end of the rigid model box 1 is located at the connection surface between the rigid model box 1 and the modular assembly component 2. The open surface at the top of the rigid model box 1 is located at the top of the rigid model box 1.

[0043] like Figure 2 As shown, in a specific embodiment, the modular assembly component 2 is a prefabricated structure for a single test. The modular assembly component 2 includes steel plates welded together and is connected to the rigid model box 1 by bolts. It can only meet one processing condition; a complete replacement is required for the next set of tests.

[0044] In a specific embodiment, the layered shearing component is connected to the bracket 5 via a guide rail or ball bearings, and the layered shearing component can slide freely on the bracket 5.

[0045] like Figure 4 As shown, in a specific embodiment, the layered shear assembly simulates the fault fracture zone. The total length of the frame assembly of the layered shear assembly is set according to the width of the fault fracture zone. The layered shear assembly includes an outer layered shear frame 31, an inner layered shear frame 32, an internal connector 33 of the layered shear frame, and a bottom connector 34 of the layered shear frame. The layered shear assembly is connected to the bracket 5 through the bottom connector 34 of the layered shear frame. The outer layered shear frame 31 and the inner layered shear frame 32 are connected through the internal connector 33 of the layered shear frame. The internal connector 33 of the layered shear frame is used to generate displacement. The layered shear assembly is driven by the modular assembly 2 to generate displacement along the vibration direction of the vibration table loading device 4. The bottom connector 34 of the layered shear frame can play a guiding and limiting role in displacement.

[0046] In this embodiment, the layered shear assembly is composed of multiple rectangular frames. Each frame is welded from four rectangular steel pipes. The cross-sectional shape of the frame is the same as the fault section taken in the test. That is, the size of the frame needs to be determined according to the specific fault parameters. Specialized design and prefabrication are required for different tests.

[0047] The displacement at any location within the fault fracture zone is calculated based on the displacement curve during fault fracture zone displacement. The fault fracture zone is then segmented to determine the optimal dimensions of each frame. Furthermore, the curved displacement within each frame is mathematically converted into a uniform linear displacement, thereby determining the stroke of the bottom limiting device for each frame. In this embodiment, a certain spacing exists between each frame to prevent collisions during lateral vibrations. An internal rubber pad prevents soil leakage and also eliminates boundary effects.

[0048] In this embodiment, to ensure the stability of the connection between each frame, considering both longitudinal vibration and lateral misalignment, an elastic coupling is used to connect adjacent frames. The connection point in the longitudinal direction is mainly subjected to the vibration load of the shaking table, resulting in a small displacement during loading and subsequent repositioning after the test. In the lateral direction, the connection point is mainly subjected to the load generated by lateral dislocation of the shaking table. As the test load increases, the lateral displacement at the connection point gradually increases, reaching its maximum displacement after the test. That is, after the test, the longitudinal relative displacement between two adjacent frames is zero, while lateral misalignment occurs.

[0049] The layered shear assembly is connected to the rigid model box 1 through connectors to ensure that the two remain synchronized during movement and form a rigid body together. During the test, the soil covering inside the box will generate soil pressure on the side walls. Therefore, in order to ensure the overall and local stability of the box, it is necessary to strengthen the lateral stiffness of the modular assembly. Thus, the two side walls can be connected by lateral connectors to improve the stability during movement.

[0050] In a specific implementation, the internal connector 33 of the layered shear frame is a bearing or a spring. The width of the outer layered shear frame 31 and the inner layered shear frame 32 gradually decreases along the modular assembly 2 towards the middle position to meet the changing trend of the "S"-shaped displacement of the fault fracture zone during loading.

[0051] In a specific embodiment, the layered shearing assembly includes four open steel pipes welded together, the shape of the opening surface of the steel pipes being the same as the cross-section.

[0052] This embodiment also provides a fault simulation test method that satisfies strong earthquake dislocation coupling loading, including the following steps:

[0053] S1. Based on the fault to be simulated in the experiment, determine the fault parameters, including dip angle, fault fracture zone width, and the angle between the fault and the tunnel. Based on the similarity ratio design, select the model rock material according to the surrounding rock parameters and construct the tunnel model. In this embodiment, the fault parameters are determined based on the geometric characteristics of the fault fracture zone to be simulated in the specific project. The required simulated fault dip angle is 88°, the angle between the tunnel and the fault is 70°, the fault fracture zone width is approximately 95~170m, and the calculated geometric similarity ratio is 1:40. Therefore, it is necessary to combine the modular assembly components 2 to simulate the fault parameters. Select a combination with a dip angle of 70° and an angle of 90° for the experiment.

[0054] S2. According to the fault parameters, the corresponding modular assembly component 2 is made, and the modular assembly component 2 is connected to the rigid model box 1. The modular assembly component 2 and the rigid model box 1 are fixed on the vibration table loading device 4. The width of the fracture zone after the similarity ratio conversion is calculated, and the total length of the layered shear component in the test is obtained. The frame in the two areas of the fracture zone core and the fracture zone influence zone is designed in a specialized manner, and the adjacent frames are connected by bearings or springs.

[0055] S3. According to the fault parameters, make the corresponding layered shear components, connect the layered shear components to the modular assembly components 2, and place the layered shear components on the bracket 5.

[0056] S4. According to the soil parameters and similarity ratio design required for the test, the test soil is mixed. The soil is laid at the bottom of the rigid model box 1, modular assembly component 2, and layered shear component up to the height of the tunnel model. After the tunnel model is installed in the rigid model box 1, modular assembly component 2, and layered shear component, the corresponding sensors are installed at the locations where data needs to be acquired, and then the upper cover soil is added.

[0057] S5. By controlling the vibration table, the rigid model box 1 and the modular assembly component 2 are controlled to move, thereby causing the layered shear component to move along the arrangement direction of the bottom guide rail or ball bearings, thus realizing the modular assembly fault simulation test that meets the requirements of strong earthquake dislocation coupling loading. Before the test begins, the rigid model box 1, the modular assembly component 2, and the layered shear component must be kept on the same horizontal plane.

[0058] Example 2

[0059] This embodiment provides a fault simulation test device that meets the requirements of strong earthquake dislocation coupling loading, such as... Figure 1 As shown, it includes: a rigid model box 1, a modular assembly component 2, a layered shear component, a vibration table loading device 4, and a bracket 5;

[0060] The bracket 5 is located between the two vibration table loading devices 4. One end of the modular assembly component 2 is connected to the rigid model box 1, and the other end of the modular assembly component 2 is connected to the layered shear component. The bottoms of the rigid model box 1 and the modular assembly component 2 are both connected to the vibration table loading device 4, and the bottom of the layered shear component is slidably connected to the bracket 5.

[0061] The modular assembly component 2 and the rigid model box 1 together form an upper and lower plate structure to simulate different test conditions. The modular assembly component 2 is designed according to the fault parameters simulated in the test. The fault parameters include the fault dip angle and the angle between the fault and the tunnel. The shape of the open surface connecting the modular assembly component 2 and the layered shear component is the same as the fault plane. The open surface connecting the modular assembly component 2 and the rigid model box 1 has the same side dimensions as the rigid model box 1.

[0062] The soil and tunnel models are set inside the rigid model box 1 and the modular assembly 2 and pass through the layered shear assembly. By controlling the seismic wave input of the shaking table loading device 4, the rigid model box 1 and the modular assembly 2 move along the vibration direction of the shaking table loading device 4, thereby causing the layered shear assembly to shift.

[0063] In a specific embodiment, the frame of the rigid model box 1 includes H-beams and channel steel. The rigid model box 1 has four closed surfaces and two open surfaces. The bottom, one side end, and the front and rear surfaces of the rigid model box 1 are closed surfaces. The open surface at the end of the rigid model box 1 is located at the connection surface between the rigid model box 1 and the modular assembly component 2. The open surface at the top of the rigid model box 1 is located at the top of the rigid model box 1.

[0064] like Figure 3 As shown, in a specific embodiment, the modular assembly component 2 is a detachable structure suitable for different fault parameters. The modular assembly component 2 includes multiple substructures. During the test, the combination of these substructures is changed to meet different fault parameters. The multiple substructures are interconnected by bolts. The test requirements can be met through disassembly and reassembly.

[0065] In a specific implementation, the substructure of the modular assembly component 2 includes interconnected block steel plates. One sidewall of the modular assembly component 2 includes multiple fault dip control components 22 of different shapes, and the other side includes multiple fault strike control components 21 of different shapes. The fault dip control components 22 control the change of fault dip angle, and the fault strike control components 21 control the change of fault strike. The fault dip angles of the two sidewalls of the modular assembly component 2 correspond one-to-one. During testing, the fault dip control components 22 of the two sidewalls can be selected first according to the fault parameters to simulate the fault dip angle. Then, the fault strike can be changed by combining the fault strike control components 21. The fault strike control component 21 includes multiple rectangular block steel plates, and the fault dip control component 22 includes multiple triangular block steel plates.

[0066] like Figure 3As shown, one sidewall of the modular assembly component 2 is composed of four fault dip control components 22, which can be disassembled to form dip angles of 60°, 70°, 80°, and 90°; the other sidewall is composed of four fault dip control components 22 and four detachable fault direction control components 21. The fault dip control components 22 on this side can be disassembled to form dip angles of 60°, 70°, 80°, and 90°, forming a fault plane together with the opposite sidewall. Furthermore, the fault direction of this sidewall can be changed by disassembling the fault direction control components 21, forming angles of 90°, 80°, 70°, and 60° between the fault direction and the tunnel direction.

[0067] In a specific embodiment, the layered shearing component is connected to the bracket 5 via a guide rail or ball bearings, and the layered shearing component can slide freely on the bracket 5.

[0068] like Figure 4 As shown, in a specific embodiment, the layered shear assembly simulates the fault fracture zone. The total length of the frame assembly of the layered shear assembly is set according to the width of the fault fracture zone. The layered shear assembly includes an outer layered shear frame 31, an inner layered shear frame 32, an internal connector 33 of the layered shear frame, and a bottom connector 34 of the layered shear frame. The layered shear assembly is connected to the bracket 5 through the bottom connector 34 of the layered shear frame. The outer layered shear frame 31 and the inner layered shear frame 32 are connected through the internal connector 33 of the layered shear frame. The internal connector 33 of the layered shear frame is used to generate displacement. The layered shear assembly is driven by the modular assembly 2 to generate displacement along the vibration direction of the vibration table loading device 4. The bottom connector 34 of the layered shear frame can play a guiding and limiting role in displacement.

[0069] In this embodiment, the layered shear assembly is composed of multiple rectangular frames. Each frame is welded from four rectangular steel pipes. The cross-sectional shape of the frame is the same as the fault section taken in the test. That is, the size of the frame needs to be determined according to the specific fault parameters. Specialized design and prefabrication are required for different tests.

[0070] The displacement at any location within the fault fracture zone is calculated based on the displacement curve during fault fracture zone displacement. The fault fracture zone is then segmented to determine the optimal dimensions of each frame. Furthermore, the curved displacement within each frame is mathematically converted into a uniform linear displacement, thereby determining the stroke of the bottom limiting device for each frame. In this embodiment, a certain spacing exists between each frame to prevent collisions during lateral vibrations. An internal rubber pad prevents soil leakage and also eliminates boundary effects.

[0071] In this embodiment, to ensure the stability of the connection between each frame, considering both longitudinal vibration and lateral misalignment, an elastic coupling is used to connect adjacent frames. The connection point in the longitudinal direction is mainly subjected to the vibration load of the shaking table, resulting in a small displacement during loading and subsequent repositioning after the test. In the lateral direction, the connection point is mainly subjected to the load generated by lateral dislocation of the shaking table. As the test load increases, the lateral displacement at the connection point gradually increases, reaching its maximum displacement after the test. That is, after the test, the longitudinal relative displacement between two adjacent frames is zero, while lateral misalignment occurs.

[0072] The layered shear assembly is connected to the rigid model box 1 through connectors to ensure that the two remain synchronized during movement and form a rigid body together. During the test, the soil covering inside the box will generate soil pressure on the side walls. Therefore, in order to ensure the overall and local stability of the box, it is necessary to strengthen the lateral stiffness of the modular assembly. Thus, the two side walls can be connected by lateral connectors to improve the stability during movement.

[0073] In a specific implementation, the internal connector 33 of the layered shear frame is a bearing or a spring. The width of the outer layered shear frame 31 and the inner layered shear frame 32 gradually decreases along the modular assembly 2 towards the middle position to meet the changing trend of the "S"-shaped displacement of the fault fracture zone during loading.

[0074] In a specific embodiment, the layered shearing assembly includes four open steel pipes welded together, the shape of the opening surface of the steel pipes being the same as the cross-section.

[0075] This embodiment also provides a fault simulation test method that satisfies strong earthquake dislocation coupling loading, including the following steps:

[0076] S1. Based on the fault to be simulated in the experiment, determine the fault parameters, including dip angle, fault fracture zone width, and the angle between the fault and the tunnel. Based on the similarity ratio design, select the model rock material according to the surrounding rock parameters and construct the tunnel model. In this embodiment, the fault parameters are determined based on the geometric characteristics of the fault fracture zone to be simulated in the specific project. The required simulated fault dip angle is 88°, the angle between the tunnel and the fault is 70°, the fault fracture zone width is approximately 95~170m, and the calculated geometric similarity ratio is 1:40. Therefore, it is necessary to combine the modular assembly components 2 to simulate the fault parameters. Select a combination with a dip angle of 70° and an angle of 90° for the experiment.

[0077] S2. According to the fault parameters, the corresponding modular assembly component 2 is made, and the modular assembly component 2 is connected to the rigid model box 1. The modular assembly component 2 and the rigid model box 1 are fixed on the vibration table loading device 4. The width of the fracture zone after the similarity ratio conversion is calculated, and the total length of the layered shear component in the test is obtained. The frame in the two areas of the fracture zone core and the fracture zone influence zone is designed in a specialized manner, and the adjacent frames are connected by bearings or springs.

[0078] S3. According to the fault parameters, make the corresponding layered shear components, connect the layered shear components to the modular assembly components 2, and place the layered shear components on the bracket 5.

[0079] S4. According to the soil parameters and similarity ratio design required for the test, the test soil is mixed. The soil is laid at the bottom of the rigid model box 1, modular assembly component 2, and layered shear component up to the height of the tunnel model. After the tunnel model is installed in the rigid model box 1, modular assembly component 2, and layered shear component, the corresponding sensors are installed at the locations where data needs to be acquired, and then the upper cover soil is added.

[0080] S5. By controlling the vibration table, the rigid model box 1 and the modular assembly component 2 are controlled to move, thereby causing the layered shear component to move along the arrangement direction of the bottom guide rail or ball bearings, thus realizing the modular assembly fault simulation test that meets the requirements of strong earthquake dislocation coupling loading. Before the test begins, the rigid model box 1, the modular assembly component 2, and the layered shear component must be kept on the same horizontal plane.

[0081] Components not described in detail in this embodiment are all existing components that can be purchased through public channels.

[0082] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A fault simulation test device that meets the requirements of strong earthquake dislocation coupling loading, characterized in that, include: Rigid model box (1), modular assembly component (2), layered shear component, vibration table loading device (4), bracket (5); The bracket (5) is located between the two vibration table loading devices (4). One end of the modular assembly component (2) is connected to the rigid model box (1), and the other end of the modular assembly component (2) is connected to the layered shear component. The bottoms of the rigid model box (1) and the modular assembly component (2) are both connected to the vibration table loading device (4). The bottom of the layered shear component is slidably connected to the bracket (5). The modular assembly component (2) and the rigid model box (1) together form an upper and lower plate structure to simulate different test conditions. The modular assembly component (2) is designed according to the fault parameters simulated in the test. The shape of the open surface connecting the modular assembly component (2) and the layered shear component is the same as the fault plane. The open surface connecting the modular assembly component (2) and the rigid model box (1) has the same side dimension as the rigid model box (1). The soil and tunnel models are set inside the rigid model box (1) and the modular assembly (2) and pass through the layered shear assembly; by controlling the seismic wave input of the shaking table loading device (4), the rigid model box (1) and the modular assembly (2) move along the vibration direction of the shaking table loading device (4), thereby causing the layered shear assembly to shift. The modular assembly component (2) is a detachable structure suitable for different fault parameters. The modular assembly component (2) includes multiple substructures. During the test, the combination of the substructures is changed to meet different fault parameters. The multiple substructures are connected to each other by bolts. The substructure of the modular assembly component (2) includes interconnected block steel plates. One side wall of the modular assembly component (2) includes multiple fault dip control components (22) of different shapes. The other side of the modular assembly component (2) includes multiple fault strike control components (21) of different shapes. The fault dip control component (22) controls the change of fault dip angle, and the fault strike control component (21) controls the change of fault strike. The fault dip angles of the two side walls of the modular assembly component (2) correspond one-to-one. The layered shear assembly simulates the fault fracture zone. The total length of the frame assembly of the layered shear assembly is set according to the width of the fault fracture zone. The layered shear assembly includes an outer layered shear frame (31), an inner layered shear frame (32), an internal connector (33) of the layered shear frame, and a bottom connector (34) of the layered shear frame. The layered shear assembly is connected to the bracket (5) through the bottom connector (34) of the layered shear frame. The outer layered shear frame (31) and the inner layered shear frame (32) are connected through the internal connector (33) of the layered shear frame. The internal connector (33) of the layered shear frame is used to generate displacement. The layered shear assembly is driven by the modular assembly assembly (2) to generate displacement along the vibration direction of the vibration table loading device (4). The bottom connector (34) of the layered shear frame can play a guiding and limiting role in displacement. The internal connector (33) of the layered shear frame is a bearing or a spring. The width of the outer layered shear frame (31) and the inner layered shear frame (32) gradually decreases towards the middle position along the modular assembly (2) to meet the changing trend of the "S"-shaped displacement of the fault fracture zone during loading.

2. The fault simulation test device for strong earthquake dislocation coupling loading as described in claim 1, characterized in that, The rigid model box (1) has a frame consisting of H-beams and channel steel. The rigid model box (1) has four closed surfaces and two open surfaces. The bottom, one side end, and the front and rear sides of the rigid model box (1) are closed surfaces. The open surface at the end of the rigid model box (1) is located at the connection surface between the rigid model box (1) and the modular assembly component (2). The open surface at the top of the rigid model box (1) is located at the top of the rigid model box (1).

3. The fault simulation test device for strong earthquake dislocation coupling loading according to claim 1, characterized in that, The modular assembly (2) is a prefabricated structure for a single test. The modular assembly (2) includes steel plates welded together and is connected to the rigid model box (1) by bolts.

4. The fault simulation test device for strong earthquake dislocation coupling loading as described in claim 1, characterized in that, The layered shearing assembly is connected to the bracket (5) via a guide rail or ball bearing, and the layered shearing assembly can slide freely on the bracket (5).

5. The fault simulation test device for strong earthquake dislocation coupling loading according to claim 1, characterized in that, The layered shear assembly (3) includes four open steel pipes welded together, the shape of the opening face of the steel pipes being the same as the cross-section.

6. A fault simulation test method for strong earthquake dislocation coupling loading, characterized in that, The fault simulation test apparatus for strong earthquake dislocation coupling loading as described in any one of claims 1-5 includes the following steps: S1. Based on the fault to be simulated in the experiment, determine the fault parameters, including the dip angle, the width of the fault fracture zone, and the angle between the fault and the tunnel. Design according to the similarity ratio of the experiment, select the model rock mass material according to the surrounding rock parameters, and make the tunnel model. S2. According to the fault parameters, make the corresponding modular assembly component (2), connect the modular assembly component (2) to the rigid model box (1), and fix the modular assembly component (2) and the rigid model box (1) on the vibration table loading device (4). S3. According to the fault parameters, make the corresponding layered shear components, connect the layered shear components to the modular assembly components (2), and place the layered shear components on the bracket (5); S4. Lay soil at the bottom of the rigid model box (1), modular assembly component (2), and layered shear component up to the height of the tunnel model. After installing the tunnel model inside the rigid model box (1), modular assembly component (2), and layered shear component, install the corresponding sensors at the locations where data needs to be acquired, and then add the top cover soil. S5. By controlling the vibration table, the rigid model box (1) and the modular assembly component (2) are controlled to move, thereby causing the layered shear component to move along the bottom guide rail or the arrangement direction of the ball, thus realizing the modular assembly fault simulation test that meets the strong earthquake dislocation coupling loading.

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