Earthquake / creep induced tunnel complex fault activation centrifuge test equipment and method

Abstract

The invention discloses an earthquake / creep induced water-rich tunnel complex fault activation centrifuge experimental device and method. The device is characterized by comprising an overweight loading system, a seismic wave loading system and a true triaxial loading device; the overweight loading system comprises a centrifugal machine main body, a test hanging basket and a balancing weight; the seismic wave loading system is composed of two same vibration tables, and each vibration table comprises a vibration table base, a vibration exciter, a vibration table linear guide rail sliding rail, a vibration table linear guide rail sliding block and a vibration table top; the true triaxial loading device comprises an external frame, an internal sealing frame and an earthquake / creep simulation test body; the invention provides activation research equipment for inducing different occurrence faults such as forward, reverse, horizontal and the like of a water-rich tunnel under the action of earthquake / overweight and three-dimensional ground stress changing along with depth, and an activation physical test of different occurrence faults under true three-dimensional stress-water-rich-earthquake / creep-overweight conditions is realized; and catastrophe process simulation of positive, inverse and horizontal faults can be realized.

Description

Technical Field

[0001] The invention relates to the technical field of geotechnical engineering and test equipment, and in particular to centrifuge test equipment and method for earthquake / creep-induced tunnel complex fault activation. Background Art

[0002] In recent years, the focus of my country's infrastructure construction has gradually shifted to the western and southwestern regions. The geological conditions in these areas are complex and changeable. In the process of building tunnels, some geologically active areas will be crossed, and some will also need to pass through faults with seismic activity. For example, a large number of major national projects such as the Pinglu Canal are distributed in mountainous areas with active structures and developed faults. The routes often have to cross active faults and have a large burial depth. Fault creep refers to the slow-moving, aseismic sliding of natural tectonic faults. Therefore, studying earthquake / creep-induced activation of complex faults in water-rich tunnels has become an important scientific topic. During an earthquake, the stress state in the earth's crust will change dramatically, leading to fault sliding and creep, which in turn affects the stability and safety of the tunnel. Especially in water-rich areas, the effect of groundwater will further aggravate the interaction between the tunnel and the fault, making the problem more complicated.

[0003] At present, the research on earthquake / creep-induced complex fault activation in water-rich tunnels mainly relies on numerical simulation and theoretical analysis. However, these methods often cannot fully reflect the complexity and nonlinear characteristics in actual engineering. Therefore, the test results have certain limitations and uncertainties. Traditional test equipment and methods have many limitations in simulating earthquake environments and tunnel structures. Traditional centrifuge equipment can only simulate the activation of faults of a certain type. There is a lack of equipment that can simulate three-dimensional geostress, overweight and groundwater storage environment and can induce fault slip under the coupling conditions of different fault types; there is a lack of equipment that can simulate the activation of different fault types such as normal / reverse faults and horizontal faults, different fault dips, etc. under the action of three-dimensional geostress, seismic force and groundwater storage environment; the traditional tunnel surface force loading test system cannot simulate the differences in tunnel disasters caused by different principal stress directions at different depths, and the existing equipment cannot simulate the response of tunnels under true three-dimensional stress-water-rich-earthquake / creep-overweight and other multi-field coupling environments. Therefore, developing a test equipment and method that can simulate the activation of complex faults in water-rich tunnels under real earthquake / creep environments is of great significance for improving the stability and safety of tunnel engineering. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a centrifuge test device and method for earthquake / creep-induced activation of complex faults in tunnels, which can be used to carry out centrifuge tests on earthquake / creep-induced activation of complex faults in water-rich tunnels indoors, and realize experimental simulation of tunnel specimens in a true three-dimensional stress-water-rich-earthquake-overweight and other multi-field coupling environments.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] A centrifuge test device for earthquake / creep-induced tunnel complex fault activation, comprising an overweight loading system, a seismic wave loading system, a true three-dimensional loading device for a complex fault tunnel, a physical model of a composite lining fault tunnel, and a deformation-stress-vibration comprehensive monitoring system, wherein the overweight loading system comprises a centrifuge body, a test hanging basket, and a counterweight, the seismic wave loading system comprises a lower vibration table base, a lower exciter, a lower vibration table linear guide rail, a lower vibration table linear guide slider, an upper vibration table base, an upper exciter, an upper vibration table linear guide rail, an upper vibration table linear guide slider, a vibration table surface, and a stopper, the true three-dimensional loading device for a complex fault tunnel comprises a main frame, a top cover, an oil cylinder, an inner pressure-bearing sealing frame, a pressure head, and a pad, the physical model of a composite lining fault tunnel comprises a tunnel specimen, a lining, a sheath, and an inner lining plug, and the deformation-stress-vibration comprehensive monitoring system comprises a pre-buried optical fiber, a water pressure box, a pressure box, and a vibration wave monitor;

[0007] The centrifuge body provides supergravity centrifugal force by high-speed rotation, the test hanging baskets are installed on both sides of the centrifuge body and have two states: horizontal and vertical. The counterweight block and the vibration table are installed on the two test hanging baskets respectively;

[0008] The seismic wave loading system is composed of two vibration tables. The vibration table base of the lower vibration table is fixed on the test basket of the centrifuge. The lower exciter is installed and fixed on the lower vibration table base, and its two ends are attached to the upper vibration table base. The linear guide rail of the lower vibration table is installed and fixed on the lower vibration table base. One end of the linear guide slider of the lower vibration table is installed on the linear guide rail of the lower vibration table, and the other end is installed and fixed on the lower part of the upper vibration table base. The vibration table base of the upper vibration table is connected to the lower vibration table linear guide through the lower vibration table linear guide. The upper vibration exciter is installed and fixed on the upper vibration table base, and its two ends are in contact with the upper vibration table base. The upper vibration table linear guide rail is installed and fixed on the upper vibration table base. One end of the upper vibration table linear guide slider is installed on the upper vibration table linear guide rail, and the other end is installed and fixed on the lower part of the upper vibration table base. The upper vibration table base is connected to the upper vibration table base through the upper vibration table linear guide rail. The upper vibration table base is connected to the complex fault tunnel true three-way loading device.

[0009] The main frame is installed on the vibration table of the upper vibration table, and the top cover is installed above the main frame to form an installation space for the internal sealing frame together with the main frame; the oil cylinder is installed and fixed in the reserved holes of the main frame and the top cover, 16 oil cylinders are installed in all directions, and the oil cylinder is connected to the external controller, the inner pressure-bearing sealing frame is installed in the space formed by the external frame to form a closed sample placement space, the pressure head is installed and fixed in the reserved hole of the inner pressure-bearing seal and connected to the oil cylinder, and the pad is installed in the inner pressure-bearing sealing frame in close contact with the tunnel sample;

[0010] The tunnel specimen is a scaled-down model of a simulated tunnel containing faults installed in an internal pressure-bearing sealing frame; the lining is installed in the tunnel specimen close to the tunnel specimen; the jacket is installed in the tunnel close to the lining; the lining plug is installed in the space formed by the jacket to form a closed space with the jacket to isolate internal water from external water; wireless sensors are installed between the tunnel specimen, lining, jacket and lining plug; a monitoring camera is installed in the lining plug.

[0011] The deformation-stress-vibration integrated monitoring system monitors the deformation, stress and response of the composite lining fault tunnel physical model under vibration waves.

[0012] The embedded optical fiber is installed in various directions in the tunnel sample and between the layers of the composite lining, the water pressure box is placed between the internal pressure-bearing sealing frame and the physical model of the composite lining fault tunnel, the pressure box is installed between the oil cylinder and the pressure head, and the vibration wave monitor is embedded in the tunnel sample and installed between the layers of the composite lining.

[0013] A centrifuge test method for earthquake / creep-induced activation of complex faults in water-rich tunnels, using the above-mentioned centrifuge test equipment for earthquake / creep-induced activation of complex faults in tunnels, comprises the following steps:

[0014] Step 1: Prepare tunnel specimens;

[0015] Step 2: Install the lining, the jacket, the deformation-stress-vibration integrated monitoring system, and the monitoring camera into the tunnel sample, inject a proper amount of water into the space formed by the jacket, and then install the lining plug on both sides of the jacket to form a composite lining fault tunnel physical model, ensuring that the lining plug completely seals the tunnel;

[0016] Step 3: Use a lifting device to load the composite lining fault tunnel physical model into the internal sealed frame, and select a suitable pad so that the fault dip angle of the composite lining fault tunnel physical model after being loaded into the internal sealed frame meets the test requirements;

[0017] Step 4: inject water into the inner pressure-bearing sealing frame to cover the top plate of the inner pressure-bearing sealing frame, bring the pressure head into close contact with the physical model of the composite lining fault tunnel, and check the sealing of the inner pressure-bearing frame;

[0018] Step 5: Close the top cover of the external frame and ensure that the upper oil cylinder is connected to the upper pressure head of the internal sealing frame;

[0019] Step 6: To simulate the activation of the normal and reverse faults of the water-rich tunnel induced by earthquakes and three-dimensional geostress, the following steps can be used:

[0020] a. Start the oil cylinder on the true three-dimensional loading device of the complex fault tunnel to apply pre-pressure to the physical model of the composite lining fault tunnel;

[0021] b. Read the deformation-stress-vibration integrated monitoring system and monitoring camera data to determine whether the wireless sensors and monitoring cameras are working properly;

[0022] c. Apply confining pressure. The same confining pressure is applied on the upper and lower sides through the oil cylinders on the upper and lower sides. Confining pressure is applied in other directions, increasing from top to bottom due to different depths;

[0023] d. After the confining pressure is applied, the creep of the composite lining fault tunnel physical model is observed. After a period of time, the exciter of the shaking table is started, and the shaking table surface is vibrated at a high frequency through the exciter. The shaking table surface applies seismic waves to the composite lining fault tunnel physical model to simulate the activation of the normal and reverse faults of the water-rich tunnel induced by earthquakes and three-dimensional ground stress;

[0024] Step 7: To simulate the activation of horizontal faults in a water-rich tunnel induced by overweight and three-dimensional stress, the following steps can be used:

[0025] a. Start the cylinder on the true three-way loading device of the complex fault tunnel to apply pre-pressure to the physical model of the composite lining fault tunnel. The pre-pressure should be greater than the pre-pressure in step 7 to prevent the composite lining fault tunnel physical model from sliding as a whole when testing the centrifuge;

[0026] b. Apply confining pressure according to the test plan;

[0027] c. After the confining pressure is applied, read the deformation-stress-vibration integrated monitoring system and monitoring camera data to determine whether the wireless sensor and monitoring camera are working properly;

[0028] d. Start the centrifuge, apply a speed within 10g, and observe whether there are any safety hazards in the test;

[0029] e. Slowly increase the centrifuge speed to the target speed to simulate the activation of horizontal faults in the water-rich tunnel induced by overweight and three-dimensional stress;

[0030] Step 8: After the physical model of the composite lining fault tunnel reaches the expected test condition or is damaged, the experiment is ended, and the seismic table and centrifuge are stopped first, the pressure is reduced to zero, the centrifuge and vibration table are turned off, the true three-dimensional loading device of the complex fault tunnel is turned off, and the equipment is repaired;

[0031] Step 9: Analyze and process the detection data recorded by the deformation-stress-vibration integrated monitoring system and the monitoring camera.

[0032] The beneficial effects of the present invention are:

[0033] The present invention can simulate a water-rich fault-containing tunnel sample under a three-dimensional stress state, activate the fault of the tunnel sample by adjusting the pressure on the upper and lower sides of the tunnel sample, further cause the tunnel sample to creep along the fault, and study the influence of tunnel fault creep on the tunnel and lining; the water-rich fault-containing tunnel sample of the present invention can be activated by the fault excited by the seismic force generated by the vibration table under the action of three-dimensional stress, so as to simulate the squeezing damage of the lining caused by the slip of the tunnel sample and the influence of water disasters; the present invention can simulate the creep damage of the fault of the tunnel sample under the overweight generated by the high-speed rotation of the centrifuge; the present invention can realize the activation simulation test of faults of different occurrences, and can realize the creep simulation test of forward, reverse and horizontal faults; the present invention can simulate the influence of water disasters caused by fault creep on the lining structure in the tunnel under the condition of overwater, and the response of the lining and surrounding rock under the multi-field coupling activation under the condition of water-rich; the present invention realizes a high degree of restoration of the real environment of the tunnel sample indoors through the multi-field coupling of true three-dimensional stress-water-rich-earthquake-overweight, which is of great significance for improving the stability and safety of tunnel engineering.

[0034] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is the overall structure diagram of the centrifuge test equipment for earthquake / creep-induced tunnel complex fault activation of the present invention;

[0036] Figure 2 It is a combined structural diagram of the seismic wave loading system of the earthquake / creep-induced tunnel complex fault activation centrifuge test equipment of the present invention and the true three-dimensional loading device for the complex fault tunnel;

[0037] Figure 3 It is a half-section view of the combined structure of the seismic wave loading system of the earthquake / creep-induced tunnel complex fault activation centrifuge test equipment and the complex fault tunnel true three-way loading device of the present invention;

[0038] Figure 4It is a front cross-sectional view of the combined structure of the seismic wave loading system of the earthquake / creep-induced tunnel complex fault activation centrifuge test equipment and the complex fault tunnel true three-way loading device;

[0039] Figure 5 It is a side sectional view of the combined structure of the seismic wave loading system of the earthquake / creep-induced tunnel complex fault activation centrifuge test equipment and the complex fault tunnel true three-way loading device of the present invention;

[0040] Figure 6 Horizontal section diagram of the combined structure of the seismic wave loading system of the centrifuge test equipment for earthquake / creep-induced tunnel complex fault activation and the true three-dimensional loading device for complex fault tunnels;

[0041] Figure 7 It is a structural schematic diagram of the seismic wave loading system of the centrifuge test equipment for earthquake / creep-induced tunnel complex fault activation of the present invention;

[0042] Figure 8 It is a cross-sectional schematic diagram of a complex fault tunnel true three-dimensional loading device of the earthquake / creep-induced tunnel complex fault activation centrifuge test equipment of the present invention;

[0043] Fig. 9 It is a schematic structural diagram of the internal sealing frame of the centrifuge test equipment for earthquake / creep-induced tunnel complex fault activation of the present invention;

[0044] Fig.10 A structural diagram of a composite lining fault tunnel physical model of an earthquake / creep-induced tunnel complex fault activation centrifuge test device of the present invention;

[0045] Fig.11 This is a stress distribution diagram of the first embodiment of the present invention;

[0046] Fig.12 This is a stress distribution diagram of the second embodiment of the present invention.

[0047] 1-centrifuge body, 2-test hanging basket, 3-counterweight, 4-lower vibration table base, 5-lower vibration exciter, 6-lower vibration table linear guide slide, 7-lower vibration table linear guide slider, 8-upper vibration table base, 9-upper vibration exciter, 10-upper vibration table linear guide slide, 11-upper vibration table linear guide slider, 12-vibration table top, 13-main frame, 14-top cover, 15-oil cylinder, 16-internal pressure sealing frame, 17-pressure head, 18-pad, 19-tunnel sample, 20-lining, 21-sheath, 22-lining plugging, 23-block, embedded optical fiber 24, water pressure box 25, pressure box 26, vibration wave monitor 27. DETAILED DESCRIPTION

[0048] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0049] In order to solve the problems existing in the prior art, such as Figure 1-9 As shown, the present invention provides a centrifuge test device for earthquake / creep-induced complex fault activation in tunnels, including an overweight loading system, a seismic wave loading system, a true three-dimensional loading device for complex fault tunnels, a composite lining fault tunnel physical model, and a deformation-stress-vibration comprehensive monitoring system.

[0050] The overweight loading system includes a centrifuge body 1, a test basket 2, and a counterweight block 3; the bottom of the centrifuge body 1 is buried deep underground, and provides overweight centrifugal force through high-speed rotation, which is used to achieve overweight loading during the test; the test basket 2 is installed on both sides of the centrifuge body 1, and has a horizontal state and a vertical state, and is used to install the overweight loading system and the composite lining fault tunnel physical model; the counterweight block 3 and the vibration table are respectively installed on the two experimental baskets 2, and are used for counterweighting during the test.

[0051] The seismic wave loading system includes a lower vibration table base 4, a lower vibration exciter 5, a lower vibration table linear guide rail 6, a lower vibration table linear guide slider 7, an upper vibration table base 8, an upper vibration exciter 9, an upper vibration table linear guide rail 10, an upper vibration table linear guide slider 11, a vibration table surface 12, and a stopper 23; the lower vibration table base 4 is mounted and fixed on a test basket 3 of a centrifuge, and is used to install and fix other structures of the vibration table and a true three-way loading device for a complex fault tunnel; the lower vibration exciter 5 is mounted on the lower vibration table base 4 and is limited by the stopper 23 at both ends, and the lower vibration exciter 5 is connected to the control terminal, and is used to generate and send seismic waves in one direction; the lower vibration table linear guide rail 6 is mounted and fixed on the lower vibration table base 4; one end of the lower vibration table linear guide slider 7 is mounted on the lower vibration table linear guide rail 6, and the other end is mounted and fixed on the lower part of the upper vibration table base 8; The lower vibration table linear guide slide 6 and the lower vibration table linear guide slider 7 constitute the lower vibration table linear guide, which is used to connect the lower vibration table base 4 and the upper vibration table base 8, and is used to transmit the seismic wave to the upper vibration table base 8 when the lower exciter 5 applies the seismic wave; the upper vibration table base 8 is connected to the lower vibration table base 4 through the lower vibration table linear guide, and is used to transmit the seismic wave in one direction; the upper exciter 9 is installed on the upper vibration table base 8, and the upper exciter 9 is connected to the control terminal, and is used to generate and send seismic waves in one direction; the upper vibration table linear guide slide 10 is installed and fixed on the upper vibration table base 8; one end of the upper vibration table linear guide slider 11 is installed on the lower vibration table linear guide slide 10, and the other end is installed and fixed on the lower part of the upper vibration table table top 12; the vibration table table top 12 of the upper vibration table is connected to the main frame 13 of the true three-way loading device for complex fault tunnels.

[0052] The complex fault tunnel true three-way loading device comprises a main frame 13, a top cover 14, a cylinder 15, an inner pressure-bearing sealing frame 16, a pressure head 17, and a pad 18; the main frame 13 is installed and fixed on the vibration table surface 8 of the upper vibration table, and is used to connect the overweight loading system and the complex fault tunnel true three-way loading device; the top cover 14 is installed on the upper side of the main frame 13, and together with the main frame 13 forms an installation space for the internal sealing frame; the cylinder 15 is installed and fixed in the reserved holes of the main frame 13 and the top cover 14, and 16 cylinders 15 are installed and fixed on each side of the frame structure formed by the main frame 13 and the top cover, and the cylinder 15 is connected to the control terminal, and is used to apply loads in various directions during the test; the cylinder 15 of the external frame When applying load, different oil cylinders 15 in the same direction can apply different forces, or they can apply forces of the same magnitude; the inner pressure-bearing sealing frame 16 is installed in the enclosed space formed by the main frame 13, and is used to install the composite lining fault tunnel physical model and realize sealing under water-rich conditions; the pressure head 17 is installed in the reserved hole of the inner pressure-bearing seal 11 and is connected to the oil cylinder 15, and is used to apply the load generated by the oil cylinder 15 to the composite lining fault tunnel physical model; the pad 18 is installed in the inner pressure-bearing sealing frame 16 and is attached to the tunnel sample 19. The inclination angle of the tunnel sample 19 can be changed by replacing the pad 18, and the stress area of ​​the tunnel sample 19 can also be changed by adjusting the position of the pad 18;

[0053] The composite lining fault tunnel physical model includes a tunnel sample 19, a lining 20, a jacket 21, and an inner lining plug 22; the tunnel sample 19 is a scaled-down model of an actual tunnel containing a fault installed in an inner pressure-bearing sealing frame, wherein the reduction ratio of the model should be greater than the maximum overweight multiple produced by the centrifuge; the lining 20 is installed in the tunnel sample closely to the tunnel sample to maintain the stability of the tunnel sample 19; the jacket 21 is installed in the tunnel sample 19 closely to the lining 20 to isolate the lining 20 from the external environment, reduce the corrosion degree of the lining 20 under water-rich conditions, and also maintain the tunnel sample 19 to a certain extent. Stability; the lining plug 22 is installed in the space formed by the jacket 21 to form a closed space with the jacket 21 to isolate internal water from external water, and is used to seal the tunnel opening of the tunnel sample 19 to prevent water injected into the internal sealing frame from entering the tunnel when simulating water-rich conditions, which may cause a large deviation between the test results and the actual project; wireless sensors are installed between the tunnel sample 19 and the lining 20, and between the lining 20 and the jacket 21 to monitor the real-time status of the composite lining fault tunnel physical model; a monitoring camera is installed in the closed space formed by the jacket 21 and the lining plug 22 to record the internal status of the composite lining fault tunnel physical model during the test;

[0054] The deformation-stress-vibration integrated monitoring system monitors the deformation, stress and response of the composite lining fault tunnel physical model under vibration waves; the deformation-stress-vibration integrated monitoring system includes a pre-buried optical fiber 24, a water pressure box 25, a pressure box 26, and a vibration wave monitor 27; the pre-buried optical fiber 24 is installed in various directions in the tunnel sample 19 and between the layers of lining 20 of the composite lining, and is used to measure the catastrophic process of the tunnel sample 19 and the composite lining during the test; the water pressure box 25 is placed between the inner pressure-bearing sealing frame 16 and the composite lining fault tunnel physical model, and is used to measure the two water pressures; the pressure box 26 is installed between the oil cylinder 15 and the pressure head 17, and is used to monitor the pressure size and creep displacement; the vibration wave monitor 27 is pre-buried in the tunnel sample 19 and installed between the layers of lining 20 of the composite lining, and is used to measure vibration waves.

[0055] The first embodiment of the present invention is as follows:

[0056] A method for activating normal and reverse faults of a water-rich tunnel induced by simulating earthquakes and three-dimensional geostress, using the above-mentioned centrifuge test equipment for earthquake / creep-induced tunnel complex fault activation, comprises the following steps:

[0057] Step 1, preparing a tunnel sample 19 with a horizontal fault direction;

[0058] Step 2: Install the lining 20, the jacket 21, the sensor, and the monitoring camera into the tunnel sample 19 to form a composite lining fault tunnel physical model, inject a proper amount of water into the space formed by the jacket, and then install the lining plug on both sides of the jacket to ensure that the lining plug completely seals the tunnel;

[0059] Step 3, using a lifting device to load the composite lining fault tunnel physical model into the internal sealed frame, and selecting a suitable pad 18, so that after the composite lining fault tunnel physical model is loaded into the internal sealed frame, the fault dip angle of the tunnel 14 sample meets the test requirements;

[0060] Step 4: After water is injected into the inner pressure-bearing sealing frame 16, the top plate of the inner pressure-bearing sealing frame 16 is tightly covered, and the pressure head 17 is closely contacted with the physical model of the composite lining fault tunnel, and the sealing of the inner pressure-bearing frame is checked;

[0061] Step 5: Close the top cover of the outer frame and ensure that the upper oil cylinder is connected to the upper pressure head of the inner sealing frame;

[0062] Step 6, start the oil cylinder 15 on the true three-dimensional loading device of the complex fault tunnel to apply pre-pressure to the physical model of the composite lining fault tunnel;

[0063] Step 7: Read the data of the wireless sensor and the monitoring camera to determine whether the wireless sensor and the monitoring camera are working properly;

[0064] Step 8: Apply confining pressure, and the three-dimensional stress is as follows Fig.11 As shown, the lateral shear force increases from top to bottom along the normal direction, and the normal direction is a uniformly distributed stress, which accelerates the creep stage;

[0065] Step 9: After the confining pressure is applied, the vibration exciter 5 of the vibration table is started, and the control terminal controls the vibration frequency of the vibration table to 90 Hz. The vibration exciter causes the vibration table surface to vibrate at a high frequency, and the vibration table surface 8 applies seismic waves to the physical model of the composite lining fault tunnel to achieve the activation of the normal and reverse faults of the water-rich tunnel induced by the simulated earthquake and three-dimensional ground stress;

[0066] Step 10: After the physical model of the composite lining fault tunnel reaches the expected test condition or is damaged, the experiment is ended, the vibration table is turned off, the pressure is reduced to zero, and the equipment is repaired for next use;

[0067] Step 11: Analyze and process the detection data recorded by the sensors and monitoring cameras.

[0068] The second embodiment of the present invention is as follows:

[0069] A method for simulating the activation phenomenon of horizontal faults in a water-rich tunnel induced by overweight and three-dimensional stress, using the above-mentioned centrifuge test equipment for earthquake / creep-induced activation of complex faults in a tunnel, comprises the following steps:

[0070] Step 1, preparing a tunnel sample 19 with a normal fault;

[0071] Step 2: Install the lining 20, the jacket 21, the sensor, and the monitoring camera into the tunnel sample 19 to form a composite lining fault tunnel physical model, inject a proper amount of water into the space formed by the jacket, and then install the lining plug on both sides of the jacket to ensure that the lining plug 22 completely seals the tunnel;

[0072] Step 3, using a lifting device to load the composite lining fault tunnel physical model into the internal sealed frame, and selecting a suitable pad 18, so that after the composite lining fault tunnel physical model is loaded into the internal sealed frame, the fault dip angle of the tunnel 14 sample meets the test requirements;

[0073] Step 4: After water is injected into the inner pressure-bearing sealing frame 16, the top plate of the inner pressure-bearing sealing frame 16 is tightly covered, and the pressure head 17 is closely contacted with the physical model of the composite lining fault tunnel, and the sealing of the inner pressure-bearing frame is checked;

[0074] Step 5: Close the top cover of the external frame and ensure that the upper oil cylinder is connected to the upper pressure head of the internal sealing frame;

[0075] Step 6, start the oil cylinder 15 on the complex fault tunnel true three-way loading device to apply pre-pressure to the composite lining fault tunnel physical model, the pre-pressure should be greater than the pre-pressure in step 7 to prevent the composite lining fault tunnel physical model from sliding as a whole when testing the centrifuge;

[0076] Step 7: Apply confining pressure according to test requirements, such as Fig.12 As shown, the lateral stress increases from top to bottom along the normal direction, and shear force is applied in the normal direction;

[0077] Step 8: After the confining pressure is applied, the centrifuge body 1 is started, and a rotation speed within 10g is applied to observe whether there are any safety hazards in the test;

[0078] Step 9: Read the data of the wireless sensor and the monitoring camera to determine whether the wireless sensor and the monitoring camera are working properly;

[0079] Step 10, according to the test plan, the centrifuge body 1 is subjected to a rotation acceleration of 80 g to simulate fault activation of the tunnel sample 19, and creep occurs along the fault;

[0080] Step 11, slowly increasing the rotation speed of the centrifuge body 1 to the target speed, so as to simulate the activation of the horizontal fault of the water-rich tunnel induced by overweight and three-dimensional stress;

[0081] Step 13: After the physical model of the composite lining fault tunnel reaches the expected test condition or is destroyed, the experiment ends, the pressure is reduced to zero, the centrifuge is turned off, and the equipment is repaired;

[0082] Step 14: Analyze and process the detection data recorded by the sensors and monitoring cameras.

[0083] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A centrifuge test device for earthquake / creep-induced complex fault activation in water-rich tunnels, characterized in that: The equipment includes an overweight loading system, a seismic wave loading system, a true three-dimensional loading device for a complex fault tunnel, a physical model of a composite lining fault tunnel, and a deformation-stress-vibration integrated monitoring system; the overweight loading system includes a centrifuge body, a test basket, and a counterweight; the seismic wave loading system includes a lower vibration table base, a lower exciter, a lower vibration table linear guide rail, a lower vibration table linear guide slider, an upper vibration table base, an upper exciter, an upper vibration table linear guide rail, an upper vibration table linear guide slider, a vibration table surface, and a stopper; the complex fault tunnel The three-way loading device of the tunnel includes a main frame, a top cover, a cylinder, an inner pressure-bearing sealing frame, a pressure head, and a pad; the physical model of the composite lining fault tunnel includes a tunnel sample, a lining, a sheath, and an inner lining plug; the deformation-stress-vibration comprehensive monitoring system includes a pre-buried optical fiber, a water pressure box, a pressure box, and a vibration wave monitor; the earthquake / creep-induced water-rich tunnel complex fault activation centrifuge test equipment activates the tunnel sample fault by adjusting the pressure on the upper and lower sides of the tunnel sample, and further causes the tunnel sample to creep along the fault; the centrifuge body provides ultra-high pressure through high-speed rotation The centrifugal force is heavy; the test hanging basket is installed on both sides of the centrifuge body; the counterweight block and the vibration table are respectively installed on the two experimental hanging baskets; the vibration table base of the lower vibration table is fixed on the test hanging basket of the centrifuge; the lower exciter is installed and fixed on the lower vibration table base, and the two ends are attached to the upper vibration table base; the linear guide rail of the lower vibration table is installed and fixed on the lower vibration table base; one end of the linear guide slider of the lower vibration table is installed on the linear guide rail of the lower vibration table, and the other end is installed and fixed on the lower part of the upper vibration table base; the vibration table of the upper vibration table The base is connected to the vibration table surface of the lower vibration table through the linear guide rail of the lower vibration table; the upper exciter is installed and fixed on the base of the upper vibration table, and its two ends are in contact with the upper vibration table surface; the linear guide rail slide of the upper vibration table is installed and fixed on the base of the upper vibration table; one end of the linear guide slider of the upper vibration table is installed on the linear guide rail slide of the upper vibration table, and the other end is installed and fixed on the lower part of the upper vibration table surface; the upper vibration table surface is connected to the upper vibration table base through the upper vibration table linear guide; the upper vibration table surface is connected to the true three-way loading device of the complex fault tunnel.

2. According to claim 1, the centrifuge test equipment for earthquake / creep-induced complex fault activation in water-rich tunnels is characterized by: The main frame is installed on the vibration table surface; the top cover is installed above the main frame; the oil cylinder is installed and fixed in the reserved space between the main frame and the top cover; multiple oil cylinders are installed on each side; the inner pressure-bearing sealing frame is installed in the space formed by the outer frame to form a closed sample placement space; the pressure head is installed and fixed in the reserved cavity of the inner pressure-bearing seal and is connected to the oil cylinder; the pad is installed in the inner pressure-bearing sealing frame in a manner close to the tunnel pattern.

3. According to claim 1, the centrifuge test equipment for earthquake / creep-induced water-rich tunnel complex fault activation is characterized by: The tunnel specimen is a scaled-down model of a simulated tunnel containing faults installed in an internal pressure-bearing sealing frame; the lining is installed in the tunnel specimen close to the tunnel specimen; the jacket is installed in the tunnel close to the lining; the lining plug is installed in the space formed by the jacket to form a closed space with the jacket to isolate internal water from external water; wireless sensors are installed between the tunnel specimen, lining, jacket and lining plug; and a monitoring camera is installed in the lining plug.

4. The centrifuge test equipment for earthquake / creep-induced complex fault activation in water-rich tunnels according to claim 1, characterized in that: The deformation-stress-vibration integrated monitoring system monitors the deformation, stress and response of the composite lining fault tunnel physical model under vibration waves; the pre-buried optical fiber is installed in various directions in the tunnel sample and between the layers of the composite lining; the water pressure box is placed between the internal pressure-bearing sealing frame and the composite lining fault tunnel physical model; the pressure box is installed between the oil cylinder and the pressure head; the vibration wave monitor is pre-buried in the tunnel sample and installed between the layers of the composite lining.

5. The experimental method of the centrifuge test equipment for earthquake / creep-induced water-rich tunnel complex fault activation according to claim 1, characterized in that: The following steps are involved: Step 1: Prepare tunnel specimens; Step 2: Install the lining, sheath, sensor, and monitoring camera into the tunnel sample, inject a proper amount of water into the space formed by the sheath, and then install the lining plug on both sides of the sheath to form a composite lining fault tunnel physical model, ensuring that the lining plug completely seals the tunnel; Step 3: Use a lifting device to load the composite lining fault tunnel physical model into the internal sealed frame, and select a suitable pad so that the fault dip angle of the composite lining fault tunnel physical model after being loaded into the internal sealed frame meets the test requirements; Step 4: inject water into the inner pressure-bearing sealing frame to cover the top plate of the inner pressure-bearing sealing frame, bring the pressure head into close contact with the physical model of the composite lining fault tunnel, and check the sealing of the inner pressure-bearing frame; Step 5: Close the top cover of the external frame and ensure that the upper oil cylinder is connected to the upper pressure head of the internal sealing frame; Step 6: To simulate the activation of the normal and reverse faults of the water-rich tunnel induced by earthquakes and three-dimensional geostress, the following steps can be used: a. Start the oil cylinder on the true triaxial loading device to apply preload to the physical model of the composite lining fault tunnel; b. Read the data of wireless sensors and monitoring cameras to determine whether the wireless sensors and monitoring cameras are working properly; c. Apply confining pressure. The same confining pressure is applied on the upper and lower sides through the oil cylinders on the upper and lower sides. Confining pressure is applied in other directions, increasing from top to bottom due to different depths; d. After the confining pressure is applied, the creep of the composite lining fault tunnel physical model is observed. After a period of time, the exciter of the shaking table is started, and the shaking table surface is vibrated at a high frequency through the exciter. The shaking table surface applies seismic waves to the composite lining fault tunnel physical model to simulate the activation of the normal and reverse faults of the water-rich tunnel induced by earthquakes and three-dimensional ground stress; Step 7: To simulate the activation of horizontal faults in a water-rich tunnel induced by overweight and three-dimensional stress, the following steps can be used: a. Start the oil cylinder on the true triaxial loading device to apply pre-pressure to the composite lining fault tunnel physical model. The pre-pressure should be greater than the pre-pressure in step 6 to prevent the composite lining fault tunnel physical model from sliding as a whole when testing the centrifuge; b. Apply confining pressure according to the test plan; c. After the confining pressure is applied, read the data of the wireless sensor and the monitoring camera to determine whether the wireless sensor and the monitoring camera are working properly; d. Start the centrifuge, apply a speed within 10g, and observe whether there are any safety hazards in the test; e. Slowly increase the centrifuge speed to the target speed to simulate the activation of horizontal faults in the water-rich tunnel induced by overweight and three-dimensional stress; Step 8: After the physical model of the composite lining fault tunnel reaches the expected test condition or is damaged, the experiment is ended, and the seismic table and the centrifuge are stopped first, the pressure is reduced to zero, the centrifuge and the vibration table are turned off, the true triaxial loading device is turned off, and the equipment is repaired; Step 9: Analyze and process the detection data recorded by the wireless sensors and monitoring cameras.

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