A tunnel co-seismic stick-slip faulting test device and method

Abstract

The application discloses a tunnel co-seismic stick-slip faulting test device and method, which comprises a profile steel outer frame, a model box arranged in the profile steel outer frame, an elastic energy storage device and a trigger-energy release device connecting the upper part of the model box and the profile steel outer frame, a model box base supporting the model box, a vibration table connected with the profile steel outer frame and the bottom of the model box base, and an actuator arranged at the bottom of the model box and supported by the model box base. The model box comprises an upper disc box and a lower disc box, and the upper disc box and the lower disc box are arranged in left-right adhesion, and the adhesion surface is a faulting surface. The elastic energy storage device, the trigger-energy release device and the actuator are arranged on the same side of the faulting surface. The application can simulate the tunnel co-seismic stick-slip faulting test considering the impact effect and a large number of stick-slip rates, restore the whole process of the tunnel earthquake and the stick-slip faulting in the earthquake, and thus reveal the earthquake-stick-slip faulting response damage mechanism, so as to provide support for the anti-fault and shock resistance of the tunnel crossing the active fault.

Description

Technical Field

[0001] This invention relates to a test device and method for coseismic stick-slip displacement of tunnels, belonging to the field of tunnel model test technology. Background Technology

[0002] Active faults of various sizes are widely distributed in western and southwestern China. A growing number of long, linear engineering projects under construction or planned cannot avoid these active faults, leading to an increasing number of tunnel projects directly traversing them. Due to frequent fault activity, tunnels crossing active faults are particularly vulnerable to seismic activity and fault slippage damage. Especially in the case of tunnels experiencing both earthquake and stick-slip slippage during strong earthquakes, the combined effects of the earthquake and slippage often cause extremely severe structural damage. Therefore, fault resistance and seismic mitigation for tunnels crossing active faults have become a key research focus.

[0003] Based on the mechanism of active fault slippage, it can be divided into seismic creep slippage and coseismic stick-slip slippage. Creep slippage occurs when the hanging wall and footwall of a fault zone move relative to each other at extremely low rates (on the order of mm / year) under tectonic activity. The slippage process is relatively slow, with displacement gradually applied to the lining, equivalent to a quasi-static loading process. Stick-slip slippage, on the other hand, is characterized by rapid slippage, with a slippage rate close to the peak velocity of rock mass vibration, reaching the order of m / s. Displacement is applied to the lining instantaneously, equivalent to a dynamic loading process, exhibiting a significant impact effect.

[0004] Currently, research methods for coseismic stick-slip faulting in tunnels mainly include theoretical analysis, numerical simulation, and laboratory experiments. However, both theoretical analysis and numerical calculations have limitations. Without experimental verification, it is difficult to determine the scientific validity of the theory and the effectiveness of the calculation results. Therefore, laboratory experiments are a crucial research tool for revealing the faulting response mechanism of tunnels. To this end, scholars both domestically and internationally have developed various model test devices and methods. However, the fastest faulting rate that existing test equipment can simulate is 6 mm / s, with other rates mostly in the mm / min range. Existing test methods simulate quasi-static faulting, which is suitable for creep faulting but cannot reflect the dynamic characteristics of stick-slip faulting, nor can they simulate the stress characteristics of tunnels during coseismic faulting. Furthermore, for the coupling effect of earthquake and faulting, existing experimental methods mostly adopt a faulting-first-earthquake simulation approach, where the faulting simulation still uses a low-rate quasi-static loading method, and the seismic motion simulation is achieved using a shaking table simulation device. Because the issues of faulting rates of different magnitudes and the timing of faulting simulation have not been resolved, the above simulation methods cannot actually consider the transient faulting problems that occur during strong earthquakes. It is evident that designing a test method for tunnel coseismic stick-slip faulting that can take into account the impact effect and a large number of stick-slip rates is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] This invention provides a test device and method for coseismic stick-slip faulting in tunnels, which can simulate coseismic stick-slip faulting tests in tunnels considering impact effects and large-scale stick-slip rates, reconstruct the entire process of tunnel earthquakes and stick-slip faulting during earthquakes, thereby revealing the earthquake-faulting response failure mechanism and providing support for fault-resistant and seismic mitigation design for tunnels crossing active faults.

[0006] The technical solution of this invention is:

[0007] According to one aspect of the present invention, a tunnel coseismic stick-slip fault testing device is provided, comprising a steel outer frame, a model box disposed within the steel outer frame, an elastic energy storage device and a trigger-release device 12 connecting the upper part of the model box to the steel outer frame, a model box base supporting the model box, a vibration table 31 connected to the bottom of the steel outer frame and the model box base, and an actuator 35 disposed at the bottom of the model box and supported by the model box base. The model box includes an upper plate box 27 and a lower plate box 34, which are arranged side-by-side, with the contact surface being the fault surface. At least one elastic energy storage device, trigger-release device 12, and actuator 35 are installed on the same side of the fault surface.

[0008] The model box base includes a base plate 30, multiple H-beam crossbeams 33, a first H-beam longitudinal beam 32-1, and a second H-beam longitudinal beam 32-2. The H-beam crossbeams 33 are segmented. The upper flange of the first segment supports the upper plate box 27, and the upper flange of the second segment supports the lower plate box 34. The lower flange of the first segment connects to the upper flange of the first H-beam longitudinal beam 32-1, and the lower flange of the second segment connects to the upper flange of the second H-beam longitudinal beam 32-2. The lower flanges of the first H-beam longitudinal beam 32-1 and the second H-beam longitudinal beam 32-2 are fixed to the base plate 30. An actuator 35 is installed between the base plate 30 and the upper plate box 27 / lower plate box 34.

[0009] It also includes a displacement limiting device 28, which is used to place the actuator 35 when it is unloaded and descends to a preset displacement amount.

[0010] The elastic energy storage device is either a first elastic energy storage device 1 or a second elastic energy storage device 9.

[0011] The first elastic energy storage device 1 includes a spring upper plate 2 assembled with the outer frame of the steel profile and a spring lower plate 3 connected to the model box. A connecting groove 7 is opened on the side of the spring upper plate 2 near the spring lower plate 3. The connecting groove 7 is used to install a spring 6, which is connected to the first sleeve 5 through the spring 6.

[0012] The second elastic energy storage device 9 is basically the same as the first elastic energy storage device 1, except that the working surface of the second sleeve 10 is provided with a hook, and the upper end surface of the lower spring plate 3 is provided with a connecting ring 11 for cooperating with the hook.

[0013] The trigger-release device 12 includes an upper connecting plate 13 and a lower connecting plate 14. The upper connecting plate 13 is assembled and connected to the outer steel frame and is located between two sets of elastic energy storage devices. The lower connecting plate 14, installed at the lower end of the upper connecting plate 13, is equipped with a fixed pulley 16, a roller groove 17, a limiting roller 18, a limiting block 19, and a hook 20. The movement of the rope on the fixed pulley 16 drives the limiting roller 18 to move in the roller groove 17 in a preset direction. The limiting roller 18 cooperates with the limiting block 19 to switch the state of the hook 20 installed between the limiting roller 18 and the limiting block 19. The hook 20 is used to hook the model box.

[0014] According to another aspect of the present invention, a method for testing tunnel coseismic stick-slip faults is provided, comprising:

[0015] Based on regression analysis, an expression for earthquake magnitude and fault displacement is established to determine the fault displacement. Based on the fault displacement and the selected maximum fault displacement velocity, the elastic energy storage device in the tunnel coseismic stick-slip fault test device is determined.

[0016] Seismic excitation is applied through the shaking table 31 in the tunnel coseismic stick-slip fault test device to simulate the vibration effect of an earthquake;

[0017] The elastic energy storage device and the trigger-release device 12 work together to realize slippage: according to the set earthquake time, the trigger-release device 12 is activated to simulate the stick-slip slippage velocity and slippage amount under vibration.

[0018] The expression for the earthquake magnitude and displacement is:

[0019] lnS = aM + b;

[0020] In the formula, S is the fault displacement, M is the earthquake magnitude, and a and b are empirical fitting parameters.

[0021] The expression for the maximum slip velocity v is:

[0022]

[0023] Where k is the stiffness coefficient of spring 6; n is the number of springs 6; S is the displacement; α is the displacement angle; m is the total mass of the surrounding rock in the upper box 27, or the total mass of the surrounding rock in the lower box 34; g is the gravitational acceleration.

[0024] The beneficial effects of this invention are as follows: On the one hand, by utilizing the self-weight of the box and the elastic energy storage device, the slip rate can reach the m / s level, and the magnitude of the slip rate can be adjusted according to the experimental needs. On the other hand, by employing a trigger-release device, the model box can achieve instantaneous slip at a typical moment before, at, or after the peak of the earthquake. Attached Figure Description

[0025] Figure 1 This is a front view of the present invention;

[0026] Figure 2 This is a side view of the present invention;

[0027] Figure 3 This is a schematic diagram of the first elastic energy storage device.

[0028] Figure 4 This is a schematic diagram of the second elastic energy storage device.

[0029] Figure 5 This is a schematic diagram of the trigger-release device structure;

[0030] Figure 6 This is a schematic diagram of the overall steel frame structure;

[0031] Figure 7 This is a schematic diagram of the installation of the elastic energy storage device and the trigger-release device on the steel outer frame;

[0032] The labels in the diagram are as follows: 1-First elastic energy storage device, 2-Upper spring plate, 3-Lower spring plate, 4-First screw hole, 5-First sleeve, 6-Spring, 7-Connecting groove, 8-Second screw hole, 9-Second elastic energy storage device, 10-Second sleeve, 11-Connecting ring, 12-Trigger-Release device, 13-Upper connecting plate, 14-Lower connecting plate, 15-Third screw hole, 16-Fixed pulley, 17-Roller groove, 18-Limiting roller, 19-Limiting roller 20-Hook, 21-Vertical H-beam, 22-Longitudinal H-beam, 23-Transverse H-beam, 24-Trigger-Release Zone, 25-Elastic Energy Storage Zone, 27-Upper Plate Box, 28-Displacement Limiting Device, 29-Fourth Screw Hole, 30-Base Plate, 31-Vibration Table, 32-1-First H-beam Longitudinal Beam, 32-2-Second H-beam Longitudinal Beam, 33-H-beam Crossbeam, 34-Lower Plate Box, 35-Actuator, 36-Fifth Screw Hole. Detailed Implementation

[0033] The invention will be further described below with reference to the accompanying drawings and embodiments, but the scope of the invention is not limited to the description.

[0034] Example 1: As Figure 1-7As shown, according to one aspect of the present invention, a tunnel coseismic stick-slip fault test device is provided, comprising a steel outer frame, a model box disposed within the steel outer frame, an elastic energy storage device and a trigger-release device 12 connecting the upper part of the model box to the steel outer frame, a model box base supporting the model box, a vibration table 31 connected to the bottom of the steel outer frame and the model box base, and an actuator 35 disposed at the bottom of the model box and supported by the model box base. The model box includes an upper plate box 27 and a lower plate box 34, which are arranged side-by-side, with the contact surface being the fault surface. At least one elastic energy storage device, trigger-release device 12, and actuator 35 are installed on the same side of the fault surface.

[0035] Specifically, the model box is used to house the lining model structure with embedded test elements. It is a topless model box formed by connecting the upper box 27 and the lower box 34. The upper box 27 and the lower box 34 have the same structure, both consisting of a base plate and three side plates fixedly connected, and both are installed on the model box base. A steel frame is formed by fixing multiple vertical H-beams 21, longitudinal H-beams 22, and transverse H-beams 23.

[0036] Furthermore, the model box base includes a base plate 30, multiple H-beam crossbeams 33, a first H-beam longitudinal beam 32-1, and a second H-beam longitudinal beam 32-2; wherein, the H-beam crossbeams 33 adopt a segmented design, the upper flange of the first segment of the H-beam crossbeam 33 supports the upper plate box 27, the upper flange of the second segment of the H-beam crossbeam 33 supports the lower plate box 34, the lower flange of the first segment of the H-beam crossbeam 33 is connected to the upper flange of the first H-beam longitudinal beam 32-1, and the lower flange of the second segment of the H-beam crossbeam 33 is connected to the upper flange of the second H-beam longitudinal beam 32-2. The first H-beam longitudinal beam 32-1 and the second H-beam longitudinal beam 32-2... The lower flange is fixed to the base plate 30. The base plate 30 and the upper / lower box 27 are used to install the actuator 35 (depending on the experimental requirements, the actuator 35 can be installed between the base plate 30 and the upper box 27, or between the base plate 30 and the lower box 34. Taking the upper box 27 as the side for loading, the side for loading can be equipped with a chute system for guidance and stabilization. The H-beam 33 section on the side for loading supports the base plate of the upper box, and the other H-beam 33 section is fixed to the base plate of the lower box with bolts). To realize the simulation test function under the combined action of earthquake and fault, a fourth screw hole 29 is reserved on the base plate 30 of the box base for connection with the vibration table 31, and a fifth screw hole 36 is reserved on the outer steel frame for connection with the vibration table 31, so as to realize the connection between the outer steel frame and the bottom of the model box base and the vibration table 31. In the above, the H-beam 33 is segmented with the misalignment surface as the break point.

[0037] Furthermore, it also includes a displacement limiting device 28, which is placed when the actuator 35 is unloaded and descends to a preset displacement amount. It is used to cooperate with the model box base to mitigate the impact of displacement.

[0038] Furthermore, there are two types of elastic energy storage devices, namely a first elastic energy storage device 1 or a second elastic energy storage device 9, which can realize the function of adjusting the slip rate.

[0039] Furthermore, the first elastic energy storage device 1 includes a spring upper plate 2 assembled with the outer frame of the steel profile and a spring lower plate 3 connected to the model box. A connecting groove 7 is formed on the side of the spring upper plate 2 near the spring lower plate 3, and a spring 6 is installed in the connecting groove 7. The spring 6 is connected to the first sleeve 5. The spring 6 and the sleeve 5 are coaxial and their axes are parallel to the misalignment surface. The working surface of the sleeve 5 is parallel to the upper end surface of the spring lower plate 3.

[0040] Furthermore, the second elastic energy storage device 9 is basically the same as the first elastic energy storage device 1, except that the working surface of the second sleeve 10 is provided with a hook, and the upper end surface of the lower spring plate 3 is provided with a connecting ring 11 for cooperating with the hook.

[0041] Different functions can be achieved by employing different elastic energy storage devices: to achieve the function of increasing the slip rate, the first elastic energy storage device 1 can be used. To achieve the function of decreasing the slip rate, the second elastic energy storage device 9 can be used.

[0042] Furthermore, the trigger-release device 12 includes an upper connecting plate 13 and a lower connecting plate 14. The upper connecting plate 13 is assembled and connected to the outer steel frame and is located between the two sets of elastic energy storage devices. The lower connecting plate 14, installed at the lower end of the upper connecting plate 13, is equipped with a fixed pulley 16, a roller groove 17, a limiting roller 18, a limiting block 19, and a hook 20. The movement of the rope on the fixed pulley 16 drives the limiting roller 18 to move in the roller groove 17 along a preset direction. The limiting roller 18 cooperates with the limiting block 19 to switch the state of the hook 20 installed between the limiting roller 18 and the limiting block 19. The hook 20 is used to hook the model box.

[0043] like Figure 3 , 4As shown in Figures 5 and 6, the lower spring plate 3 has a first screw hole 4 for assembly with the model box, which is used to assemble the lower spring plate 3 onto the model box and is located below the upper spring plate 2. The upper spring plate 2 has a second screw hole 8 for assembly with the outer steel frame, which is used to assemble the upper spring plate 2 into the elastic energy storage area 25. The connecting upper plate 13 has a third screw hole 15 for assembly with the outer steel frame, which is used to assemble the connecting upper plate 13 into the trigger-release area 24. There are two fixed pulleys 16, one in front and one behind the connecting lower plate 14. The limiting roller 18 is dumbbell-shaped with disc-shaped ends and is formed by a central cylinder. In use, the worker can use the rope on the fixed pulley 16 to pull the limiting roller 18 in the roller groove 17 along a preset direction to release the restriction on the hook 20, thereby unloading the model box. After the rope is released, the limiting roller 18 moves in the roller groove 17 along a preset direction to cooperate with the limiting block 19, thereby limiting the hook 20. The hook opening faces the side of the limiting roller, and the limiting block 19 can be used to prevent the hook 20 from rotating too much and damaging the trigger-release device 12.

[0044] According to another aspect of the present invention, a method for testing tunnel coseismic stick-slip faults is provided, comprising:

[0045] Based on regression analysis, an expression for earthquake magnitude and fault displacement is established to determine the fault displacement. Based on the fault displacement and the selected maximum fault displacement velocity, the elastic energy storage device in the tunnel coseismic stick-slip fault test device is determined.

[0046] Seismic excitation is applied through the shaking table 31 in the tunnel coseismic stick-slip fault test device to simulate the vibration effect of an earthquake;

[0047] The elastic energy storage device and the trigger-release device 12 work together to realize slippage: according to the set earthquake time, the trigger-release device 12 is activated to simulate the stick-slip slippage velocity and slippage amount under vibration.

[0048] Furthermore, the expressions for the earthquake magnitude and fault displacement are as follows:

[0049] lnS = aM + b;

[0050] In the formula, S is the fault displacement, M is the earthquake magnitude, and a and b are empirical fitting parameters.

[0051] Furthermore, the expression for the maximum slip velocity v is:

[0052]

[0053] Where k is the stiffness coefficient of spring 6; n is the number of springs 6; S is the displacement; α is the displacement angle; m is the total mass of the upper box 27 and the surrounding rock in the upper box 27, or represents the total mass of the lower box 34 and the surrounding rock in the lower box 34 (if the upper box is loaded and unloaded, then m is the total mass of the upper box and the surrounding rock in the upper box); g is the acceleration due to gravity.

[0054] Based on the aforementioned tunnel coseismic stick-slip slip test method, to simulate different maximum slip velocities, the initial states of three tunnel coseismic stick-slip slip test devices are assumed as follows:

[0055] ① For the test of the tunnel coseismic stick-slip slip test device without elastic energy storage device (i.e., without elastic energy storage device under the tunnel coseismic stick-slip slip test device of the present invention as described above), the initial state is: with the upper plate box 27 and the lower plate box 34 in a non-slip state, the upper plate box 27 is raised to the set slip amount in advance as the first initial state.

[0056] ② For the test of the elastic energy storage device in the tunnel coseismic stick-slip fault test device, the first elastic energy storage device 1 is used. Compared with the first method, the fault speed is increased. The initial state is: the upper plate box 27 and the lower plate box 34 are in a non-fault state. The first elastic energy storage device 1 is pre-installed. On this basis, the upper plate box 27 is raised to the set fault amount, so that the first elastic energy storage device 1 is in a compressed state, which is the second initial state.

[0057] ③ For the test of the elastic energy storage device in the tunnel coseismic stick-slip fault test device, the second elastic energy storage device 9 is used. Compared with the first method, the fault speed is reduced. The initial state is: when the upper plate box 27 and the lower plate box 34 are in a non-fault state, the upper plate box 27 is raised to the set fault amount in advance, and then the second elastic energy storage device 9 is installed to make it in a natural extension state, which is the third initial state.

[0058] The analysis of the maximum slip velocity is as follows:

[0059] The formula for calculating the stiffness coefficient k of the spring 6 is as follows:

[0060] k = G × d 4 / 8×N c ×D m 3 N / mm(1)

[0061] Where G = the stiffness modulus of spring 6, in N / mm. 2 That is, shear modulus, d = spring 6 wire diameter (mm), D0 = spring 6 outer diameter (mm), D m =Mean diameter of spring 6 = D0 - dmm, N = Total number of coils in spring 6, N c =Effective number of spring coils = N-2.

[0062] When the elastic energy storage device is not installed (initial state ① is adopted), the displacement S and maximum displacement velocity v of the model test can be expressed as:

[0063]

[0064]

[0065] In the formula, S is the displacement; α is the displacement angle; ν0 is the initial velocity, taken as ν0=0; a is the acceleration; t is the time of action; v represents the maximum displacement velocity; g is the gravitational acceleration, taken as 10N / kg.

[0066] When the first elastic energy storage device 1 is installed (initial state ②), the system energy conservation law expression for the model test is Equation 4, and its maximum slip velocity v can be expressed as Equation 5:

[0067]

[0068]

[0069] In the formula, x is the compression of spring 6; k is the stiffness coefficient of spring 6; n is the number of springs 6; S is the displacement; h is the height of the model box from the initial position, h = s; ν0 is the initial velocity, taken as ν0 = 0; α is the displacement angle; m is the total mass of the upper box 27 and the surrounding rock; g is the gravitational acceleration, taken as 10 N / kg.

[0070] When the second elastic energy storage device 9 is installed (initially using ③), its maximum slip velocity v can be expressed as formula 6:

[0071]

[0072]

[0073] In the formula, k is the stiffness coefficient of spring 6; n is the number of springs 6; S is the displacement; h is the height of the model box from the initial position, h = s; ν0 is the initial velocity, taken as ν0 = 0; α is the displacement angle; m is the total mass of the upper box 25 and the surrounding rock; g is the gravitational acceleration, taken as 10 N / kg.

[0074] Start the shaking table, input seismic waves, and apply seismic excitation to the model box to simulate earthquake action;

[0075] Based on a predetermined moment in the test plan: initially set as a typical moment before, at, or after the peak ground acceleration, for example, inputting a Parkfield seismic wave, the trigger-release device 12 can be activated at any moment—5 seconds before, at, or after the peak acceleration—to implement instantaneous slippage. This addresses the issue of controlling the timing of slippage simulation during coseismic stick-slip simulation. Utilizing the self-weight of the enclosure and adjusting the elastic energy storage device, the problem of simulating slippage rates of different magnitudes is solved, while also considering the impact effects of stick-slip slippage. Below, comparative data from optional embodiments using different installation methods are provided for different slippage angles:

[0076] Example 2: The goal is to achieve a 6cm displacement of the model box at a 45° displacement angle. Assuming the total mass of the upper box 27 and the surrounding rock is 15000kg, and using the first initial state (i.e., pre-raising the upper box to the set displacement amount), without installing an elastic energy storage device, relying solely on its own weight and activating the trigger-release device, the maximum displacement speed is:

[0077]

[0078] The elastic energy storage device and the trigger-release device are combined to achieve displacement: The model box is to be displaced by 6cm at a displacement angle of 45°. Assuming the total mass of the upper box 27 and the surrounding rock is 15000kg, the second initial state is adopted, i.e., with one set (8) of the first elastic energy storage devices 1 installed (using manganese steel spring columns, with k = 130kN / m), and the first elastic energy storage devices 1 in a natural state without compression or tension. Then, the upper box 27 is raised to the set displacement amount, so that the first elastic energy storage devices 1 are in a compressed state. Based on this state, the maximum displacement speed is:

[0079]

[0080] The elastic energy storage device and the trigger-release device are combined to achieve displacement: The model box is to be displaced by 6cm at a displacement angle of 45°. Assuming the total mass of the upper box 27 and the surrounding rock is 15000kg, the third initial state is adopted, i.e., the upper box is pre-raised to the set displacement amount. Then, a set (8 units) of the second elastic energy storage device 9 (using manganese steel spring columns, with k = 130kN / m) are installed, so that the second elastic energy storage device 9 is in a naturally extended state. Based on this state, the maximum displacement speed is:

[0081]

[0082] In the example, the slip velocity of the model box can be controlled between 0.837 and 1.304 m / s.

[0083] Example 3: The plan is to achieve a 10cm displacement of the model box at a 60° displacement angle. Assuming the total mass of the upper box 27 and the surrounding rock is 15000kg, and using the first initial state (i.e., pre-raising the upper box to the set displacement amount), without installing an elastic energy storage device, relying solely on its own weight and activating the trigger-release device, the maximum displacement speed is:

[0084]

[0085] The elastic energy storage device and the trigger-release device are combined to achieve displacement: The model box is to be displaced 10cm at a displacement angle of 60°. Assuming the total mass of the upper box 27 and the surrounding rock is 15000kg, the second initial state is adopted, i.e., with one set (8) of the first elastic energy storage devices 1 installed (using manganese steel spring columns, with k = 130kN / m), and the first elastic energy storage devices 1 in a natural state without compression or tension. Then, the upper box 27 is raised to the set displacement amount, so that the first elastic energy storage devices 1 are in a compressed state. Based on this state, the maximum displacement speed is:

[0086]

[0087] The elastic energy storage device and the trigger-release device are combined to achieve displacement: The model box is to be displaced by 10cm at a displacement angle of 60°. Assuming the total mass of the upper box 27 and the surrounding rock is 15000kg, the third initial state is adopted, i.e., the upper box is pre-raised to the set displacement amount. Then, a set (8 units) of the second elastic energy storage device 9 (using manganese steel spring columns, with k = 130kN / m) are installed, so that the second elastic energy storage device 9 is in a naturally extended state. Based on this state, the maximum displacement speed is:

[0088]

[0089] In the example, the slip velocity of the model box can be controlled between 1.037 and 1.710 m / s.

[0090] Similarly, the elastic energy storage device and the trigger-release device 12 can be assembled on the other side of the steel outer frame, that is, above the lower plate box 34, and then the lower plate box 34 can be lifted by the actuator 35 to achieve its simulation.

[0091] The specific embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A tunnel co-seismic stick-slip fault testing device, characterized in that, The system includes a steel outer frame, a model box housed within the steel outer frame, an elastic energy storage device and a trigger-release device (12) connecting the upper part of the model box house to the steel outer frame, a model box base supporting the model box house, a vibration table (31) connected to the bottom of the steel outer frame and the model box base, and an actuator (35) located at the bottom of the model box house and supported by the model box base. The model box house includes an upper plate box (27) and a lower plate box (34), which are arranged side to side and are attached together. The attachment surface is a misaligned surface. At least one elastic energy storage device, a trigger-release device (12), and an actuator (35) are installed on the same side of the misaligned surface. The elastic energy storage device is either a first elastic energy storage device (1) or a second elastic energy storage device (9). The first elastic energy storage device (1) includes a spring upper plate (2) assembled with the steel outer frame and a spring lower plate (3) connected to the model box. The spring upper plate (2) has a connecting groove (7) on the side near the spring lower plate (3). The connecting groove (7) is used to install a spring (6) and is connected to the first sleeve (5) through the spring (6). The second elastic energy storage device (9) is basically the same as the first elastic energy storage device (1), except that the working surface of the second sleeve (10) is provided with a hook, and the upper end surface of the lower spring plate (3) is provided with a connecting ring (11) for cooperating with the hook. The trigger-release device (12) includes an upper connecting plate (13) and a lower connecting plate (14). The upper connecting plate (13) and the outer steel frame are assembled and connected and located between two sets of elastic energy storage devices. The lower connecting plate (14) installed at the lower end of the upper connecting plate (13) is equipped with a fixed pulley (16), a roller groove (17), a limiting roller (18), a limiting block (19), and a hook (20). The rope on the fixed pulley (16) moves to drive the limiting roller (18) to move in the roller groove (17) along a preset direction. The limiting roller (18) cooperates with the limiting block (19) to switch the state of the hook (20) installed between the limiting roller (18) and the limiting block (19). The hook (20) is used to hook the model box.

2. The tunnel coseismic stick-slip fault test device according to claim 1, characterized in that, The model box base includes a base plate (30), multiple H-beam crossbeams (33), a first H-beam longitudinal beam (32-1), and a second H-beam longitudinal beam (32-2); wherein, the H-beam crossbeams (33) adopt a segmented design, the upper flange of the first segment of the H-beam crossbeam (33) supports the upper plate box (27), the upper flange of the second segment of the H-beam crossbeam (33) supports the lower plate box (34), and the first segment of the H-beam crossbeam (33)... The lower flange is connected to the upper flange of the first H-shaped steel longitudinal beam (32-1), and the lower flange of the second H-shaped steel crossbeam (33) is connected to the upper flange of the second H-shaped steel longitudinal beam (32-2). The lower flanges of the first H-shaped steel longitudinal beam (32-1) and the second H-shaped steel longitudinal beam (32-2) are fixed on the base plate (30). The base plate (30) and the space between the upper plate box (27) and the lower plate box (34) are used to install the actuator (35).

3. The tunnel co-seismic stick-slip fault test device according to claim 1, characterized in that, It also includes a displacement limiting device (28) for placing when the actuator (35) is unloaded and descends to a preset displacement amount.

4. A method for testing the coseismic stick-slip faulting of tunnels, characterized in that, The test is conducted using the tunnel coseismic stick-slip fault testing device as described in claim 1, comprising: Based on regression analysis, an expression for earthquake magnitude and fault displacement is established to determine the fault displacement. Based on the fault displacement and the selected maximum fault displacement velocity, the elastic energy storage device in the tunnel coseismic stick-slip fault test device is determined. The seismic excitation was applied by the shaking table (31) in the tunnel coseismic stick-slip fault test device to simulate the vibration effect of an earthquake; The elastic energy storage device and the trigger-release device (12) are combined to realize the slip motion: according to the set earthquake time, the trigger-release device (12) is activated to simulate the slip motion velocity and slip motion amount under vibration.

5. The tunnel co-seismic stick-slip fault test method according to claim 4, characterized in that, The expression for the earthquake magnitude and displacement is: lnS = aM + b; In the formula, S is the fault displacement, M is the earthquake magnitude, and a and b are empirical fitting parameters.

6. The tunnel co-seismic stick-slip fault test method according to claim 4, characterized in that, The expression for the maximum slip velocity v is: ； Where k is the stiffness coefficient of spring (6); n is the number of springs (6); and S is the displacement. is the angle of displacement; m is the total mass of the surrounding rock in the upper box (27) and the upper box (27), or represents the total mass of the surrounding rock in the lower box (34) and the lower box (34); g is the acceleration due to gravity.

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