A tunnel model joint generation and dynamic instability simulation test method and system

Abstract

The application provides a tunnel model joint generation and dynamic instability simulation test method and system, and belongs to the technical field of tunnel model joint generation. The method comprises the following steps: a tunnel model with a rectangular cross section and a tunnel in the middle is spliced by using a plurality of triangular electromagnetic blocks, the tunnel model is fixed in a main frame of a dynamic and static combined loading device, and the magnetic attraction force between the triangular electromagnetic blocks is controlled; a vertical static load loading system is used to apply a vertical load to the tunnel model, and a horizontal static load loading system is used to apply a horizontal load to the tunnel model; an electromagnetic control unit is used to change the magnetic attraction force between the triangular electromagnetic blocks to generate a tunnel model joint, and a joint tunnel model is obtained; a movable excitation system is used to apply a dynamic disturbance to the joint tunnel model; an ultrahigh-speed camera is used to shoot images of the joint tunnel model and upload the images to an upper computer; the upper computer analyzes the images of the joint tunnel model to obtain instability and failure characteristics of the joint tunnel model under the dynamic disturbance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tunnel model joint generation, in particular to a tunnel model joint generation and dynamic instability simulation test method and system. BACKGROUND

[0002] With the increase of tunnel construction intensity and depth, the geological environment and stress environment thereof are more and more complex, and dynamic disasters such as tunnel rock burst, falling and collapse frequently occur, so it is of great engineering significance to carry out deep jointed rock mass tunnel engineering dynamics test to reveal the dynamic disaster mechanism of deep complex geological tunnel and propose corresponding prevention and control methods.

[0003] At present, the research on deep jointed rock mass tunnel engineering dynamics test is relatively less, most of which only studies the influence of fault structure on the dynamic response characteristics of tunnel, and the instrument and equipment used is mainly a large-scale shaking table, which cannot simulate the characteristics of complex joint grid of engineering surrounding rock, complex joint mechanical parameters and complex stress environment, and the test requires complex, low repeatability and high price.

[0004] Therefore, it is of great significance to develop a random jointed rock mass tunnel dynamic instability test system which can simulate the complex joint grid of engineering surrounding rock, complex joint mechanical characteristics and complex stress environment and propose a corresponding test scheme. SUMMARY

[0005] To achieve the above purpose, the present application provides a tunnel model joint generation and dynamic instability simulation test method and system, which uses modular triangular electromagnetic blocks to construct a tunnel model, and accurately adjusts the magnetic attraction force between each triangular electromagnetic block through an electromagnetic control unit, overcomes the limitations of traditional jointed rock tunnel test systems that cannot simulate random joints and adjust the mechanical parameters of structural surfaces, realizes dynamic simulation of jointed rock mass mechanical characteristics, proposes a random automatic joint generation method, can generate a joint network that meets the geological conditions according to the experimental conditions, significantly improves the test accuracy and efficiency, integrates a dynamic and static combined loading device and an ultra-high-speed camera observation technology, realizes high-precision observation and data acquisition of jointed rock instability and sliding characteristics under complex stress conditions, and the vertical and horizontal static load loading systems can simulate complex static stress fields, and the exciter as a dynamic disturbance source realizes accurate control of stress wave parameters, fully restores the real stress state of underground space, and provides reliable data support for tunnel engineering dynamic disaster protection design.

[0006] In the first aspect, the present application provides a tunnel model joint generation and dynamic instability simulation test method, which is implemented based on a dynamic and static combined loading device, the device includes a main frame, a movable excitation system, a vertical static load loading system, a horizontal static load loading system, an ultra-high-speed camera and an upper computer, and the method includes:

[0007] (1) A tunnel model with a rectangular cross section and a tunnel in the middle is assembled by splicing several triangular electromagnetic blocks, and the tunnel model is fixed in the main frame of the dynamic and static combined loading device. Each triangular electromagnetic block is equipped with an electromagnetic control unit to control the magnetic attraction between the triangular electromagnetic blocks.

[0008] (2) Apply vertical load to the tunnel model through the vertical static load system and apply horizontal load to the tunnel model through the horizontal static load system.

[0009] (3) By changing the magnetic attraction between the triangular electromagnetic blocks through the electromagnetic control unit, the joint model of the tunnel is generated, and the joint tunnel model is obtained.

[0010] (4) Apply dynamic disturbance to the jointed tunnel model through a movable excitation system.

[0011] (5) Take images of the jointed tunnel model using an ultra-high-speed camera and upload them to the host computer.

[0012] (6) The host computer analyzes the joint tunnel model image to obtain the instability and failure characteristics of the joint tunnel model under dynamic disturbance.

[0013] Optionally, in step (3), the specific steps for generating tunnel model joints by changing the magnetic attraction between the triangular electromagnetic blocks through the electromagnetic control unit are as follows:

[0014] Initially, the electromagnetic control unit controls the magnetic attraction between the triangular electromagnetic blocks to be the contact force of the complete rock block, and the simulated tunnel model is a homogeneous, complete single-structure rock mass.

[0015] Subsequently, joint parameters are generated using a random automatic joint generation method or a manually set method. Based on the joint parameters, the electromagnetic control unit is controlled to change the magnetic attraction between the triangular electromagnetic blocks, simulating real rock joints. This transforms the tunnel model from a homogeneous, complete single-structure rock mass into a real, complex jointed rock mass.

[0016] Optionally, the method for randomly and automatically generating joints specifically includes:

[0017] Based on the actual surrounding rock conditions in tunnel engineering, five target scores R are defined for different surrounding rock categories, as follows:

[0018] .

[0019] Determine the range of the two-dimensional coordinates of the tunnel model and establish the two-dimensional coordinates of the tunnel model, and set the target surrounding rock category of the tunnel model.

[0020] Define the initial joint state space as S={}, and the action state function as A={a}. + :J(x i ,yi ,L, , ),a - :J(x i ,y i ,L, , )}, where a + :J(x i ,y i ,L, , ) indicates the coordinate position (x) i ,y i Add a line of length L and inclination angle at the ,) Joint contact strength parameters The joints, a - :J(x i ,y i ,L, , () indicates that the section is deleted.

[0021] Using the uniaxial compressive strength R of the rock block b Number of joints per unit volume J v Joint contact strength parameter C f Joint dip angle Angle with tunnel axis The evaluation reward function for assessing the surrounding rock category is constructed using five factors, including groundwater parameter Q. The specific formula is as follows:

[0022] .

[0023] and For fixed values, , , The evaluation was conducted using the number of joints per unit volume, joint contact strength parameters, and joint dip angle, as detailed below:

[0024] .

[0025] .

[0026] .

[0027] .

[0028] In the formula, s i s represents the number of joints per meter of the upper lateral line in the i-th joint group. k This indicates the number of non-grouped joints per cubic meter of rock mass, and C is the rated electromagnetic force of the test system.

[0029] By randomly executing the action state function A={a + :J(x i ,y i ,L, , ),a - :J(x i ,y i ,L, , A new joint is generated into the joint state space. After the t-th execution, the joint state space is S={J}. 1， J 2， J 3，…， J t}

[0030] The length L and dip angle of all joints Joint contact strength parameters The input is fed into the evaluation reward function to calculate the evaluation score of the current jointed tunnel model. .

[0031] The current tunnel model's evaluation score The current tunnel model's surrounding rock category is determined by comparing it with the target score R of the five defined surrounding rock categories. If the current tunnel model's surrounding rock category is the set target surrounding rock category, joint generation is stopped and the current joint state space is output. If the current tunnel model's surrounding rock category does not conform to the set target surrounding rock category, the next step is executed.

[0032] Determine the evaluation score of the current jointed tunnel model. The relationship between the score and the target surrounding rock category, and the evaluation score of the current jointed tunnel model. If the score is higher than the target surrounding rock category, the next action state function will randomly add a joint operation. If the current joint tunnel model's evaluation score is higher... If the score is lower than that of the target surrounding rock category, the next action state function will execute the deletion of the joint operation from the previous step, and then repeat the previous step.

[0033] Optionally, the method for manually setting joint parameters specifically includes:

[0034] Determine the range of the two-dimensional coordinates of the tunnel model and establish the two-dimensional coordinates of the tunnel model.

[0035] Initialize the joint state space.

[0036] The final joint state space is formed by setting the number of joints, the two-dimensional coordinates of the two endpoints of each joint, and the joint contact strength parameters.

[0037] In a second aspect, the present application provides a tunnel model joint generation and dynamic instability simulation test system, comprising a dynamic and static combined loading device, an electromagnetic tunnel model and an electromagnetic control unit.

[0038] The dynamic and static combined loading device comprises a main frame, a movable excitation system, a vertical static load loading system, a horizontal static load loading system, an ultra-high-speed camera and an upper computer.

[0039] The main frame is a hollow cuboid, used for mounting and bearing the movable excitation system, the vertical static load loading system, the horizontal static load loading system and the electromagnetic tunnel model.

[0040] The upper gear belt and the locking device allow the dynamic loading system to move in the space range on the left side of the central axis of the vertical static load loading system and can be locked and fixed.

[0041] The movable excitation system comprises a signal transmitter, a power amplifier, an exciter, a plurality of excitation heads of different sizes and shapes, a movable slide rail and a slide locking device. The signal transmitter is connected with the power amplifier, outputs a waveform signal and amplifies the waveform signal through the power amplifier. The power amplifier is connected with the exciter, and the waveform signal and energy are realized through the exciter. The exciter is installed with the excitation heads of different sizes and shapes, and applies dynamic disturbance to the joint tunnel model. The exciter is invertedly fixed on the movable slide rail at the top of the middle cavity of the main frame, and the slide locking device ensures that the exciter is stable at the target position.

[0042] The vertical static load loading system comprises an axial hydraulic cylinder and a vertical loading plate. The cylinder barrel of the axial hydraulic cylinder is invertedly fixed at the top right side of the middle cavity of the main frame. The end of the piston rod of the axial hydraulic cylinder is fixedly connected with the top end of the vertical loading plate. A rectangular slot is formed on the left side of the vertical loading plate for the action of the movable excitation system. The size of the rectangular slot meets the action range of the excitation head.

[0043] The horizontal static load loading system comprises a lateral hydraulic cylinder and a horizontal loading plate. The cylinder barrel of the lateral hydraulic cylinder is horizontally fixed on the side of the middle cavity of the main frame. The end of the piston rod of the lateral hydraulic cylinder is fixedly connected with the side of the horizontal loading plate.

[0044] The ultra-high-speed camera is located in front of the main frame and connected with the upper computer, used for shooting the image of the joint tunnel model.

[0045] The electromagnetic tunnel model is a cuboid with a rectangular cross section and a tunnel in the middle, which is formed by splicing a plurality of triangular electromagnetic blocks and fixed at the bottom of the middle cavity of the main frame.

[0046] The electromagnetic control unit is arranged in the triangular electromagnetic blocks, used for controlling the magnetic attraction force between the triangular electromagnetic blocks.

[0047] After the above technical scheme is adopted, the present application has at least the following beneficial effects:

[0048] (1) The tunnel model is constructed by using modular triangular electromagnetic blocks, and the magnetic attraction force between the triangular electromagnetic blocks is accurately adjusted through an electromagnetic control unit, so that the limitations of the traditional jointed rock mass tunnel test system, such as the inability to simulate random joints and the adjustment of the mechanical parameters of the structural plane, are overcome, and the dynamic simulation of the mechanical properties of the jointed rock mass is realized. The design has three advantages: first, the different joint networks can be quickly constructed through magnetic force recombination, solving the problem of the non-reusable traditional rock test piece; second, the modular structure is convenient for expansion, and various rock structures from simple to complex can be flexibly simulated; third, the magnetic force regulation can accurately simulate the mechanical properties of the joint surface. The present application can flexibly simulate different surrounding rock types and joint distribution characteristics, and provides controllable experimental conditions for studying the jointed rock instability mechanism of underground space under the action of dynamic and static coupling.

[0049] (2) The present application creatively proposes a method for automatically generating random joints, which can adaptively generate joint networks in accordance with experimental conditions and geological conditions, significantly improving the accuracy and efficiency of the test. At the same time, the action space is iteratively generated to generate random joint parameters and store them in the joint state space. On this basis, an evaluation reward function is used to optimize the joint space distribution, ensuring that the generated joint length, inclination, contact strength and other parameters meet the existing engineering standards, providing a basis for tunnel surrounding rock stability analysis.

[0050] (3) The present application integrates a dynamic and static combined loading device and an ultra-high-speed camera observation technology to realize high-precision observation and data acquisition of the jointed rock instability and sliding characteristics under complex stress conditions. The vertical and horizontal static load loading system can simulate complex static stress fields, and the exciter as a dynamic disturbance source can realize accurate control of stress wave parameters, fully restoring the real stress state of underground space and providing reliable data support for tunnel engineering dynamic disaster protection design. BRIEF DESCRIPTION OF DRAWINGS

[0051] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, a brief introduction will be given below to the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0052] Figure 1 A structural schematic diagram of a tunnel model joint generation and dynamic instability simulation test system is provided for the embodiments of the present disclosure.

[0053] Figure 2 A flowchart of a tunnel model joint generation and dynamic instability simulation test method is provided for the embodiments of the present disclosure. DETAILED DESCRIPTION

[0054] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0055] As shown in the drawings, Figure 1 The tunnel model joint generation and dynamic instability simulation test system provided by the embodiments of the present application comprises a dynamic and static combined loading device, an electromagnetic tunnel model 7 and an electromagnetic control unit.

[0056] The dynamic and static combined loading device comprises a main frame 1, a movable excitation system 2, a vertical static load loading system 3, a horizontal static load loading system 4, an ultra-high-speed camera 5 and an upper computer 6.

[0057] The main frame 1 is a hollow cuboid, and the test area space defined by the hollow cavity has a length, a width and a height of at least 1.2 m, 0.3 m and 1 m respectively, and is used for mounting and bearing the movable excitation system 2, the vertical static load loading system 3, the horizontal static load loading system 4 and the electromagnetic tunnel model 7.

[0058] The movable excitation system 2 comprises a signal transmitter, a power amplifier, an exciter, a plurality of excitation heads of different sizes and shapes, a movable slide rail and a slide locking device. The signal transmitter is connected with the power amplifier, outputs a waveform signal and amplifies the waveform signal through the power amplifier. The power amplifier is connected with the exciter, and the waveform signal and energy are realized through the exciter. The exciter is installed with the excitation heads of different sizes and shapes, and applies dynamic disturbance to the joint tunnel model. The exciter is invertedly fixed on the movable slide rail at the top of the middle cavity of the main frame 1, and the slide locking device ensures that the exciter is stable at the target position.

[0059] The vertical static load loading system 3 comprises an axial hydraulic cylinder and a vertical loading plate. The cylinder barrel of the axial hydraulic cylinder is invertedly fixed at the right side of the top of the middle cavity of the main frame 1. The end of the piston rod of the axial hydraulic cylinder is fixedly connected with the top of the vertical loading plate. A rectangular groove for the action of the movable excitation system 2 is formed on the left side of the vertical loading plate, and the size of the rectangular groove meets the action range of the excitation head.

[0060] The horizontal static load loading system 4 comprises a lateral hydraulic cylinder and a horizontal loading plate. The cylinder barrel of the lateral hydraulic cylinder is horizontally fixed on the side of the middle cavity of the main frame 1. The end of the piston rod of the lateral hydraulic cylinder is fixedly connected with the side of the horizontal loading plate.

[0061] The horizontal static load loading system 4 comprises a lateral hydraulic cylinder and a horizontal loading plate. The cylinder barrel of the lateral hydraulic cylinder is horizontally fixed on the side of the middle cavity of the main frame 1. The end of the piston rod of the lateral hydraulic cylinder is fixedly connected with the side of the horizontal loading plate.

[0062] The ultra-high-speed camera 5 is located in front of the main frame 1 and connected with the upper computer 6, and is used for shooting the joint tunnel model image.

[0063] The electromagnetic tunnel model 7 is a rectangular cuboid with a tunnel in the middle, which is spliced by a plurality of triangular electromagnetic blocks, and is fixed at the bottom of the middle cavity of the main frame 1.

[0064] The electromagnetic control unit is arranged in the triangular electromagnetic block and electrically connected with the triangular electromagnetic block, and is used for controlling the magnetic attraction force between the triangular electromagnetic blocks.

[0065] As shown in Figure 2 Based on the simulation test system, the tunnel model joint generation and dynamic instability simulation test method provided by the embodiment of the present disclosure comprises the following steps.

[0066] (1) A tunnel model with a rectangular cross section and a tunnel in the middle is spliced by a plurality of triangular electromagnetic blocks, and the tunnel model is fixed in the main frame of the dynamic-static combined loading device. An electromagnetic control unit is arranged in each triangular electromagnetic block to control the magnetic attraction force between the triangular electromagnetic blocks.

[0067] The tunnel model is constructed by using the modular triangular electromagnetic blocks, and the magnetic attraction force between the triangular electromagnetic blocks is accurately adjusted by the electromagnetic control unit, which overcomes the limitations of the traditional joint surrounding rock tunnel test system that cannot simulate random joints and adjust the mechanical parameters of the structural plane, and realizes the dynamic simulation of the mechanical properties of the jointed rock mass. The design has three advantages: first, the different joint networks can be quickly constructed by magnetic force recombination, which solves the problem of non-reusable traditional rock test pieces; second, the modular structure is convenient for expansion, and various rock structures from simple to complex can be flexibly simulated; third, the magnetic force regulation can accurately simulate the mechanical properties of the joint surface. The present application can flexibly simulate different surrounding rock types and joint distribution characteristics, and provides controllable experimental conditions for studying the joint surrounding rock instability mechanism of underground space under the action of dynamic and static coupling.

[0068] (2) The vertical static loading system is used to apply vertical load to the tunnel model, and the horizontal static loading system is used to apply horizontal load to the tunnel model, so as to simulate the real complex static stress field of underground space.

[0069] (3) The magnetic attraction force between the triangular electromagnetic blocks is changed by the electromagnetic control unit to generate the joint of the tunnel model, and the specific steps are as follows.

[0070] At the beginning, the electromagnetic control unit controls the magnetic attraction force between the triangular electromagnetic blocks to be the contact force of the complete rock block, and the tunnel model is simulated as a homogeneous, complete single structure rock mass.

[0071] Subsequently, joint parameters are generated using either a random automatic joint generation method or a manually set method. Based on the joint parameters, the electromagnetic control unit is controlled to change the magnetic attraction between the triangular electromagnetic blocks, simulating real rock joints. This transforms the tunnel model from a homogeneous, complete single-structure rock mass into a real, complex jointed rock mass. The two joint generation methods are as follows.

[0072] The methods for randomly and automatically generating joints specifically include:

[0073] Based on the actual surrounding rock conditions of tunnel engineering, five target scores R are defined for each surrounding rock category. The target scores R range from 1 to 100. The following formula gives the score range for different surrounding rock categories:

[0074] .

[0075] Determine the range of the two-dimensional coordinates of the tunnel model and establish the two-dimensional coordinates of the tunnel model, and set the target surrounding rock category of the tunnel model.

[0076] Define the initial joint state space as S={}, and the action state function as A={a}. + :J(x i ,y i ,L, , ),a - :J(x i ,y i ,L, , )}, where a + :J(x i ,y i ,L, , ) indicates the coordinate position (x i ,y i Add a line of length L and inclination angle at the ,) Joint contact strength parameters The joints, a - :J(x i ,y i ,L, , () indicates that the section is deleted.

[0077] Using the uniaxial compressive strength R of the rock block b Number of joints per unit volume J v Joint contact strength parameter C f Joint dip angle Angle with tunnel axis and groundwater parameter Q, five factors are used to construct the evaluation reward function of the surrounding rock category, and the evaluation reward function is used to evaluate the generated joint state space parameters to determine whether the generated joint meets the preset surrounding rock category requirements of the tunnel model. The specific formula is as follows:

[0078] .

[0079] The electromagnetic block is used to simulate the rock block, and the groundwater effect is not considered, so and are set to fixed values, 、 、 The number of joints per unit volume, joint contact strength parameters and joint dip angle are used for evaluation, and the specific formula is as follows:

[0080] .

[0081] .

[0082] .

[0083] .

[0084] In the formula, s i represents the number of joint strips per meter on the upper side line of the i th group of joints, s k represents the number of non-grouped joint strips per cubic meter of rock mass, and C is the rated electromagnetic force of the test system.

[0085] A new joint is generated to the joint state space by randomly executing the action state function A={a + :J(x i ,y i ,L, , ),a - :J(x i ,y i ,L, , }, and when the t th execution is performed, the joint state space is S={J 1， J 2， J 3，…， J t}.

[0086] The length L, dip angle and joint contact strength parameter of all joints are input into the evaluation reward function to calculate the evaluation score of the current joint tunnel model.

[0087] The evaluation score Determine the surrounding rock category of the current tunnel model by comparing with the defined five surrounding rock category target scores R, if the surrounding rock category of the current tunnel model is the set target surrounding rock category, stop generating joints, output the current joint state space, if the surrounding rock category of the current tunnel model does not conform to the set target surrounding rock category, execute the next step.

[0088] Judge the evaluation score of the current joint tunnel model The size relationship with the score of the target surrounding rock category, if the evaluation score of the current joint tunnel model is higher than the score of the target surrounding rock category, the next action state function executes the operation of randomly adding a joint, if the evaluation score of the current joint tunnel model is lower than the score of the target surrounding rock category The next action state function executes the operation of deleting the joint in the last step, and then repeats the last step.

[0089] By creatively proposing a random automatic joint generation method, a joint network that meets the geological conditions can be generated adaptively according to the experimental conditions, which significantly improves the test accuracy and efficiency. At the same time, the action space iteratively generates random joint parameters and stores them in the joint state space, and then uses the evaluation reward function to optimize the joint space distribution, ensuring that the length, dip angle, and contact strength of the generated joints meet the existing engineering standards, providing a basis for tunnel surrounding rock stability analysis.

[0090] The method of manually setting joint parameters specifically includes:

[0091] Determine the range of two-dimensional coordinates of the tunnel model and establish the two-dimensional coordinates of the tunnel model.

[0092] Initialize the joint state space.

[0093] Set the number of joints, the two-dimensional coordinates of the two endpoints of each joint, and the joint contact strength parameters to form the final joint state space.

[0094] By manually setting joint parameters, the joint generation can be customized.

[0095] (4) Apply dynamic disturbance to the joint tunnel model through a movable excitation system, which comprehensively restores the real stress state of the underground tunnel.

[0096] (5) Take images of the joint tunnel model through a super-speed camera and upload them to the upper computer.

[0097] (6) The upper computer analyzes the images of the joint tunnel model to obtain the instability and failure characteristics of the joint tunnel model under dynamic disturbance.

[0098] ​Through the integration of dynamic and static combined loading device and ultra-high speed camera observation technology, the high-precision observation and data collection of joint surrounding rock instability slip characteristics under complex stress conditions are realized. The vertical and horizontal static load loading system can simulate complex static stress field, and the stress wave parameters are accurately controlled by the exciter as a dynamic disturbance source, which fully restores the real stress state of underground space and provides reliable data support for the design of tunnel engineering dynamic disaster protection.

[0099] Although the present application has been disclosed as above with examples, it is not intended to limit the present application, and any person skilled in the art can make some changes and modifications without departing from the spirit and scope of the present application. Therefore, the protection scope of the present application shall be subject to the right claims.

Claims

1. A tunnel model joint generation and dynamic instability simulation test method, characterized in that, The method is implemented based on a dynamic-static combined loading device, and the device comprises a main frame, a movable excitation system, a vertical static load loading system, a horizontal static load loading system, a super-speed camera and an upper computer. (1) A tunnel model with a rectangular cross section and a tunnel in the middle is spliced by a plurality of triangular electromagnetic blocks, and the tunnel model is fixed in the main frame of the dynamic-static combined loading device, wherein each triangular electromagnetic block is internally provided with an electromagnetic control unit to control the magnetic attraction force between the triangular electromagnetic blocks; (2) The vertical static load loading system is used to apply a vertical load to the tunnel model, and the horizontal static load loading system is used to apply a horizontal load to the tunnel model; (3) The electromagnetic control unit is used to change the magnetic attraction force between the triangular electromagnetic blocks to generate joints of the tunnel model, and a jointed tunnel model is obtained; (4) The movable excitation system is used to apply dynamic disturbance to the jointed tunnel model; (5) The super-speed camera is used to shoot images of the jointed tunnel model and upload the images to the upper computer; (6) The upper computer analyzes the images of the jointed tunnel model to obtain the instability and failure characteristics of the jointed tunnel model under dynamic disturbance. In step (3), the specific steps of changing the magnetic attraction force between the triangular electromagnetic blocks by the electromagnetic control unit to generate joints of the tunnel model are as follows: Initially, the electromagnetic control unit controls the magnetic attraction force between the triangular electromagnetic blocks to be the contact force of the complete rock block, and the tunnel model simulates a homogeneous, complete single-structure rock mass; Subsequently, a random automatic joint generation method or a manual setting method is used to generate joint parameters, and the electromagnetic control unit is controlled according to the joint parameters to change the magnetic attraction force between the triangular electromagnetic blocks, to simulate real rock joints, so that the tunnel model is converted from a homogeneous, complete single-structure rock mass to a real, complex jointed rock mass.

2. The tunnel model joint generation and dynamic instability simulation test method according to claim 1, characterized in that, The random automatic joint generation method specifically comprises: Five kinds of target scores R of surrounding rock categories are defined according to the actual surrounding rock conditions of the tunnel project, and the specific steps are as follows: ； The range of two-dimensional coordinates of the tunnel model is determined, and the two-dimensional coordinates of the tunnel model are established, and the target surrounding rock category of the tunnel model is set; Define the initial joint state space as S = {}, and the action state function as A = {a + : J(x i ,y i ,L, , ), a - : J(x i ,y i ,L, , )}, wherein a + : J(x i ,y i ,L, , ) represents adding a joint with a length L, an inclination , and a joint contact strength parameter at the coordinate position (x i ,y i ,), and a - : J(x i ,y i ,L, , ) represents deleting the joint; The uniaxial compressive strength R of rock mass b The number of joints J per unit volume v The joint contact strength parameter C f The joint dip angle The angle between the tunnel axis and the joint And the groundwater parameter Q, five factors to build an evaluation reward function to evaluate the surrounding rock classification, the specific formula is as follows: ； and is a constant value, , , The joint number per unit volume, joint contact strength parameters and joint dip angle are used for evaluation, as follows: ； ； ； ； where s i represents the number of joints per meter of the upper side line of the i-th group of joints, s k represents the number of non-grouped joints per cubic meter of rock mass, and C is the rated electromagnetic force of the test system. By randomly executing the action state function A = {a + : J(x i ,y i ,L, , ), a - : J(x i ,y i ,L, , )} to generate a new joint to the joint state space, when the tth time is executed, the joint state space is S = {J1, J 2， J 3，…, J t}. The length L, dip angle , and joint contact strength parameter of all joints are input into the evaluation reward function to calculate the evaluation score of the current joint tunnel model ; an evaluation score of the current tunnel model determining the surrounding rock category of the current tunnel model in comparison with the defined target score R of the five surrounding rock categories, if the surrounding rock category of the current tunnel model is the set target surrounding rock category, stopping the generation of joints and outputting the current joint state space, if the surrounding rock category of the current tunnel model does not conform to the set target surrounding rock category, performing the next step; determining an evaluation score of the current joint tunnel model a size relationship with the score of the target surrounding rock category, if the evaluation score of the current joint tunnel model is higher than the score of the target surrounding rock category , the next action state function executes a random increase of one joint operation, if the evaluation score of the current joint tunnel model is lower than the score of the target surrounding rock category , the next action state function executes a deletion of the last step joint operation, and then repeats the last step.

3. The tunnel model joint generation and dynamic instability simulation test method according to claim 1, characterized in that, The manual setting method of joint parameters specifically comprises: The range of two-dimensional coordinates of the tunnel model is determined, and the two-dimensional coordinates of the tunnel model are established; The joint state space is initialized; The number of joints, the two-dimensional coordinates of the two end points of each joint and the joint contact strength parameters are set to form the final joint state space.

4. A system for implementing the tunnel model joint generation and dynamic instability simulation test method according to any one of claims 1-3, characterized in that, The dynamic-static combined loading device, the electromagnetic tunnel model and the electromagnetic control unit are included. The dynamic-static combined loading device comprises a main frame, a movable excitation system, a vertical static load loading system, a horizontal static load loading system, a super-speed camera and an upper computer. The main frame is a hollow cuboid for mounting and bearing the movable excitation system, the vertical static load loading system, the horizontal static load loading system and the electromagnetic tunnel model; The upper gear strip and the locking device allow the dynamic loading system to move in the left space range of the central axis of the vertical static load loading system and can be locked. The movable vibration system comprises a signal transmitter, a power amplifier, a vibrator, a plurality of vibration heads of different sizes and shapes, a movable slide rail and a slide locking device, the signal transmitter is connected with the power amplifier, outputs a waveform signal and amplifies the waveform signal through the power amplifier, the power amplifier is connected with the vibrator, and the waveform signal and energy are realized through the vibrator, the vibrator is installed with the vibration heads of different sizes and shapes, and dynamic disturbance is applied to the joint tunnel model, the vibrator is inverted and fixed on the movable slide rail at the top of the middle cavity of the main frame, and the slide locking device ensures that the vibrator is stable at the target position; The vertical static load loading system comprises an axial hydraulic cylinder and a vertical loading plate, a cylinder barrel of the axial hydraulic cylinder is inverted and fixed at the top right side of the middle cavity of the main frame, a piston rod end of the axial hydraulic cylinder is fixedly connected with a top end of the vertical loading plate, a rectangular groove for actuation of the movable vibration system is formed in the left side of the vertical loading plate, and the size of the rectangular groove meets the actuation range of the vibration head; The horizontal static load loading system comprises a lateral hydraulic cylinder and a horizontal loading plate, a cylinder barrel of the lateral hydraulic cylinder is horizontally fixed on the side of the middle cavity of the main frame, and a piston rod end of the lateral hydraulic cylinder is fixedly connected with the side of the horizontal loading plate; The ultra-high-speed camera is located in front of the main frame and connected with the upper computer, and is used for shooting the image of the joint tunnel model; The electromagnetic tunnel model is a rectangular cuboid with a tunnel in the middle, which is composed of a plurality of triangular electromagnetic blocks and fixed at the bottom of the middle cavity of the main frame; The electromagnetic control unit is arranged in the triangular electromagnetic block and electrically connected with the triangular electromagnetic block, and is used for controlling the magnetic attraction force between the triangular electromagnetic blocks.

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