Tunnel model joint generation and dynamic instability simulation test method and system

Abstract

The invention 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: splicing a plurality of triangular electromagnetic blocks into a tunnel model of which the cross section is rectangular and the middle is a tunnel, fixing the tunnel model in a main body frame of a dynamic and static combined loading device, and controlling the magnetic attraction force between the triangular electromagnetic blocks; applying a vertical load to the tunnel model through the vertical static load loading system, and applying a horizontal load to the tunnel model through the horizontal static load loading system; changing the magnetic attraction force between the triangular electromagnetic blocks through an electromagnetic control unit to generate tunnel model joints, and obtaining a joint tunnel model; applying dynamic disturbance to the joint tunnel model through a movable excitation system; shooting images of the joint tunnel model through an ultra-high-speed camera and uploading the images to an upper computer; and the upper computer analyzes the images of the joint tunnel model to obtain the instability failure characteristics of the joint tunnel model under dynamic disturbance.

Description

Technical Field

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

[0002] With the increase in the intensity and depth of tunnel construction, the geological environment and stress environment in which they are located are becoming more and more complex. Tunnel dynamic disasters such as rock bursts, block falling, and collapse are frequent. Conducting dynamic tests on deep jointed rock tunnel engineering has important engineering significance for revealing the dynamic disaster mechanism of deep complex geological tunnels and proposing corresponding prevention and control methods.

[0003] At present, there are relatively few experimental studies on the dynamics of deep jointed rock tunnel engineering. Most of them only study the impact of fault structure on the dynamic response characteristics of tunnels, and the instruments and equipment used are mainly large vibration tables. This test is not only unable to simulate the complex joint grid and complex mechanical parameters of the surrounding rock of on-site engineering projects, but also has complex test requirements, low repeatability, and high cost.

[0004] Therefore, it is of great significance to develop a dynamic instability test system for random jointed rock tunnels that can simulate the complex joint grids, complex joint mechanical properties, and complex stress environment of the engineering surrounding rock and propose corresponding test plans. Summary of the Invention

[0005] To achieve the above-mentioned objectives, the present invention provides a tunnel model joint generation and dynamic instability simulation test method and system, which adopts modular triangular electromagnetic blocks to construct a tunnel model, and accurately adjusts the magnetic attraction between each triangular electromagnetic block through an electromagnetic control unit, thereby overcoming the limitations of traditional jointed surrounding rock tunnel test systems that cannot simulate random joints and adjust the mechanical parameters of the structural surface, realizing dynamic simulation of the mechanical properties of jointed rock mass, and proposing a random automatic joint generation method, which can adaptively generate a joint network that meets geological conditions according to experimental conditions, significantly improving the accuracy and efficiency of the test, integrating a dynamic and static combined loading device with ultra-high-speed camera observation technology, realizing high-precision observation and data acquisition of the instability and sliding characteristics of the jointed surrounding rock under complex stress conditions, and the vertical and horizontal static load loading systems can simulate complex static stress fields. The exciter is used as a dynamic disturbance source to realize the precise control of stress wave parameters, fully restoring the real stress state of the underground space, and providing reliable data support for the dynamic disaster protection design of tunnel engineering.

[0006] In a first aspect, the present invention provides a method for simulating the generation of joints and dynamic instability in a tunnel model. The method is implemented based on a dynamic and static combined loading device, which includes a main frame, a movable excitation system, a vertical static loading system, a horizontal static loading system, an ultra-high-speed camera, and a host computer. The method includes: (1) A tunnel model with a rectangular cross-section and a tunnel in the middle is formed by splicing several triangular electromagnetic blocks, and the tunnel model is fixed in the main frame of the dynamic and static combined loading device. An electromagnetic control unit is set inside each triangular electromagnetic block to control the magnetic attraction between the triangular electromagnetic blocks.

[0007] (2) A vertical static load system is used to apply a vertical load to the tunnel model, and a horizontal load is applied to the tunnel model through a horizontal static load system.

[0008] (3) The electromagnetic control unit is used to change the magnetic attraction between the triangular electromagnetic blocks to generate tunnel model joints and obtain a joint tunnel model.

[0009] (4) Dynamic disturbance is applied to the jointed tunnel model through a movable excitation system.

[0010] (5) Use an ultra-high-speed camera to capture images of the joint tunnel model and upload them to the host computer.

[0011] (6) The host computer analyzes the image of the jointed tunnel model and obtains the instability and failure characteristics of the jointed tunnel model under dynamic disturbance.

[0012] Optionally, in step (3), the specific steps of generating the tunnel model joints by changing the magnetic attraction between the triangular electromagnetic blocks by the electromagnetic control unit are as follows: Initially, the electromagnetic control unit controls the magnetic attraction between the triangular electromagnetic blocks to be the contact force of the complete rock blocks, and the simulated tunnel model is a homogeneous, complete single-structure rock mass.

[0013] Subsequently, joint parameters are generated using a random automatic joint generation method or a manually set method, and the electromagnetic control unit is controlled according to the joint parameters to change the magnetic attraction between the triangular electromagnetic blocks to simulate real rock joints, so that the tunnel model is transformed from a homogeneous, complete single-structure rock mass to a real, complex joint structure rock mass.

[0014] Optionally, the random automatic joint generation method specifically includes: Based on the actual surrounding rock conditions of tunnel projects, five target scores R for surrounding rock categories are defined as follows: .

[0015] 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.

[0016] 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 length L and an inclination angle , joint contact strength parameters The joints, a - :J(x i ,y i ,L, , ) indicates deleting the joint.

[0017] The uniaxial compressive strength of rock R b , the number of joints per unit volume J v , joint contact strength parameter C f , joint dip Angle with tunnel axis The five factors of groundwater parameter Q are used to construct the evaluation reward function for evaluating surrounding rock categories. The specific formula is as follows: .

[0018] and is a fixed value, 、 、 The evaluation is carried out using the number of joints per unit volume, joint contact strength parameters and joint inclination, as follows: .

[0019] .

[0020] .

[0021] .

[0022] Where s i represents the number of joints per meter on the upper side of the i-th group of joints, s k It represents the number of non-grouped joints per cubic meter of rock mass, and C is the rated electromagnetic force of the test system.

[0023] By randomly executing the action-state function A={a + :J(x i ,yi ,L, , ),a - :J(x i ,y i ,L, , )} generates a new joint to joint state space. After executing the tth time, the joint state space is S={J 1， J 2， J 3，…， J t}.

[0024] The length L and inclination angle of all joints , joint contact strength parameters Input into the evaluation reward function to calculate the evaluation score of the current joint tunnel model .

[0025] The evaluation score of the current tunnel model The surrounding rock category of the current tunnel model is compared with the target scores R of the five defined surrounding rock categories to determine the surrounding rock category. If the surrounding rock category of the current tunnel model is the set target surrounding rock category, joint generation is stopped and the current joint state space is output. If the surrounding rock category of the current tunnel model does not meet the set target surrounding rock category, the next step is executed.

[0026] Determine the evaluation score of the current joint tunnel model The relationship between the score of the target surrounding rock category and the score of the current joint tunnel model is If the score of the target rock mass category is higher than the score of the target rock mass category, the next action state function will randomly add a joint operation. If the evaluation score of the current joint tunnel model is If the score is lower than the target rock mass category, the next action state function will delete the joint operation in the previous step and then repeat the previous step.

[0027] Optionally, the method of manually setting joint parameters specifically includes: The range of the two-dimensional coordinates of the tunnel model is determined and the two-dimensional coordinates of the tunnel model are established.

[0028] Initialize the joint state space.

[0029] The number of joints, the two-dimensional coordinates of the two endpoints of each joint and the joint contact strength parameters are set to form the final joint state space.

[0030] In a second aspect, the present invention 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.

[0031] The dynamic and static combined loading device includes a main frame, a movable excitation system, a vertical static load system, a horizontal static load system, an ultra-high-speed camera and a host computer.

[0032] The main frame is a hollow cuboid, which is used to install and carry the movable excitation system, vertical static load system, horizontal static load system and electromagnetic tunnel model.

[0033] There are gear strips and locking devices on it, which allow the dynamic loading system to move within the space on the left side of the central axis of the vertical static loading system and to be locked and fixed.

[0034] The movable excitation system includes a signal transmitter, a power amplifier, an exciter, several excitation heads of different sizes and shapes, a movable slide rail and a sliding locking device. The signal transmitter is connected to the power amplifier, outputs a waveform signal and amplifies it through the power amplifier. The power amplifier is connected to the exciter, and the waveform signal and energy are actuated through the exciter. The exciter is installed with excitation heads of different sizes and shapes to apply dynamic disturbance to the joint tunnel model. The exciter is inverted and fixed on the movable slide rail at the top of the middle cavity of the main frame. The slide rail locking device ensures that the exciter is firmly in the target position.

[0035] The vertical static load loading system includes an axial hydraulic cylinder and a vertical loading plate. The cylinder barrel of the axial hydraulic cylinder is inverted and fixed on the right side of the top of the middle cavity of the main frame. The end of the piston rod of the axial hydraulic cylinder is fixedly connected to the top of the vertical loading plate. A rectangular groove for actuating the movable excitation system is opened on the left side of the vertical loading plate. The size of the rectangular groove meets the actuation range of the excitation head.

[0036] The horizontal static load system includes a lateral hydraulic cylinder and a horizontal loading plate. The cylinder barrel of the lateral hydraulic cylinder is horizontally fixed to the side of the middle cavity of the main frame, and the end of the piston rod of the lateral hydraulic cylinder is fixedly connected to the side of the horizontal loading plate.

[0037] The ultra-high-speed camera is located in front of the main frame and is connected to the host computer for capturing images of the joint tunnel model.

[0038] The electromagnetic tunnel model is a cuboid with a rectangular cross-section and a tunnel in the middle, which is composed of several triangular electromagnetic blocks and is fixed at the bottom of the middle cavity of the main frame.

[0039] The electromagnetic control unit is arranged inside the triangular electromagnetic blocks and is used for controlling the magnetic attraction between the triangular electromagnetic blocks.

[0040] After adopting the above technical solution, the present invention has at least the following beneficial effects: (1) The present invention uses modular triangular electromagnetic blocks to construct a tunnel model, and accurately adjusts the magnetic attraction between the triangular electromagnetic blocks through the electromagnetic control unit, overcoming the limitations of the traditional jointed surrounding rock tunnel test system that cannot simulate random joints and adjust the mechanical parameters of the structural surface, and realizes the dynamic simulation of the mechanical properties of the jointed rock mass. This design has three major advantages: first, different joint networks can be quickly constructed through magnetic reorganization, solving the problem that traditional rock specimens cannot be reused; second, the modular structure is easy to expand and can flexibly simulate various rock structures from simple to complex; third, magnetic control can accurately simulate the mechanical properties of the joint surface. The present invention can flexibly simulate different surrounding rock types and joint distribution characteristics, providing controllable experimental conditions for studying the instability mechanism of jointed surrounding rock in underground space under the action of dynamic and static coupling.

[0041] (2) The present invention creatively proposes a random automatic joint generation method, which can adaptively generate a joint network that meets geological conditions according to experimental conditions, significantly improving the accuracy and efficiency of the test. At the same time, it performs action space iteration to generate random joint parameters and stores them in the joint state space. On this basis, the evaluation reward function is used to optimize the joint space distribution to ensure that the generated joint length, inclination, contact strength and other parameters meet the existing engineering standards, providing a basis for the stability analysis of tunnel surrounding rock.

[0042] (3) The present invention integrates a dynamic and static combined loading device with ultra-high-speed video observation technology to achieve high-precision observation and data acquisition of the unstable sliding characteristics of jointed surrounding rock under complex stress conditions. The vertical and horizontal static loading systems can simulate complex static stress fields. The exciter acts as a dynamic disturbance source to achieve precise control of stress wave parameters, fully restoring the actual stress state of the underground space and providing reliable data support for the design of dynamic disaster protection in tunnel engineering. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0044] Figure 1 A schematic structural diagram of a tunnel model joint generation and dynamic instability simulation test system provided in an embodiment of the present disclosure.

[0045] Figure 2 A flow chart of a tunnel model joint generation and dynamic instability simulation test method is provided for an embodiment of the present disclosure. DETAILED DESCRIPTION

[0046] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0047] like Figure 1 As shown, an embodiment of the present disclosure provides a tunnel model joint generation and dynamic instability simulation test system, including a dynamic and static combined loading device, an electromagnetic tunnel model 7 and an electromagnetic control unit.

[0048] The dynamic and static combined loading device includes a main frame 1, a movable excitation system 2, a vertical static load system 3, a horizontal static load system 4, an ultra-high-speed camera 5 and a host computer 6.

[0049] The main frame 1 is a hollow rectangular parallelepiped, and the length × width × height of the test area defined by the cavity is at least 1.2m × 0.3m × 1m, which is used to install and carry 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.

[0050] There are gear strips and locking devices on it, which allow the dynamic loading system to move within the space on the left side of the central axis of the vertical static loading system 3 and to be locked and fixed.

[0051] The movable excitation system 2 includes a signal transmitter, a power amplifier, an exciter, several excitation heads of different sizes and shapes, a movable slide rail and a sliding locking device. The signal transmitter is connected to the power amplifier, outputs a waveform signal and amplifies it through the power amplifier. The power amplifier is connected to the exciter, and the waveform signal and energy are actuated through the exciter. The exciter is installed with excitation heads of different sizes and shapes to apply dynamic disturbance to the joint tunnel model. The exciter is inverted and fixed on the movable slide rail at the top of the middle cavity of the main frame 1. The slide rail locking device ensures that the exciter is firmly in the target position.

[0052] The vertical static load loading system 3 includes an axial hydraulic cylinder and a vertical loading plate. The cylinder barrel of the axial hydraulic cylinder is inverted and fixed on 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 to the top of the vertical loading plate. A rectangular groove for actuating the movable excitation system 2 is provided on the left side of the vertical loading plate. The size of the rectangular groove meets the actuation range of the excitation head.

[0053] The horizontal static load system 4 includes a lateral hydraulic cylinder and a horizontal loading plate. The cylinder barrel of the lateral hydraulic cylinder is horizontally fixed to the side of the middle cavity of the main frame 1, and the end of the piston rod of the lateral hydraulic cylinder is fixedly connected to the side of the horizontal loading plate.

[0054] The ultra-high-speed camera 5 is located in front of the main frame 1 and is connected to the host computer 6 for shooting images of the joint tunnel model.

[0055] The electromagnetic tunnel model 7 is a cuboid with a rectangular cross section and a tunnel in the middle, which is formed by splicing a number of triangular electromagnetic blocks and is fixed at the bottom of the middle cavity of the main frame 1.

[0056] The electromagnetic control unit is arranged inside the triangular electromagnetic block and electrically connected to the triangular electromagnetic block, and is used for controlling the magnetic attraction between the triangular electromagnetic blocks.

[0057] like Figure 2 As shown, based on the above simulation test system, the embodiment of the present disclosure provides a tunnel model joint generation and dynamic instability simulation test method, including: (1) A tunnel model with a rectangular cross-section and a tunnel in the middle is formed by splicing several triangular electromagnetic blocks, and the tunnel model is fixed in the main frame of the dynamic and static combined loading device. An electromagnetic control unit is set inside each triangular electromagnetic block to control the magnetic attraction between the triangular electromagnetic blocks.

[0058] Modular triangular electromagnetic blocks are used to construct the sleeping model, and the electromagnetic control unit is used to accurately adjust the magnetic attraction between each triangular electromagnetic block, which overcomes the limitations of the traditional jointed surrounding rock tunnel test system that cannot simulate random joints and adjust the mechanical parameters of the structural surface, and realizes the dynamic simulation of the mechanical properties of the jointed rock mass. This design has three major advantages: first, different joint networks can be quickly constructed through magnetic reorganization, which solves the problem that traditional rock specimens cannot be reused; second, the modular structure is easy to expand and can flexibly simulate various rock structures from simple to complex; third, magnetic control can accurately simulate the mechanical properties of the joint surface. The present invention can flexibly simulate different surrounding rock types and joint distribution characteristics, and provides controllable experimental conditions for studying the instability mechanism of jointed surrounding rock in underground space under dynamic and static coupling.

[0059] (2) Vertical loads are applied to the tunnel model through the vertical static load system, and horizontal loads are applied to the tunnel model through the horizontal static load system to simulate the real complex static stress field in the underground space.

[0060] (3) The electromagnetic control unit is used to change the magnetic attraction between the triangular electromagnetic blocks to generate tunnel model joints. The specific steps are as follows.

[0061] Initially, the electromagnetic control unit controls the magnetic attraction between the triangular electromagnetic blocks to be the contact force of the complete rock blocks, and the simulated tunnel model is a homogeneous, complete single-structure rock mass.

[0062] Subsequently, joint parameters are generated using a random automatic joint generation method or a manually set method. The electromagnetic control unit is controlled according to the joint parameters to change the magnetic attraction between the triangular electromagnetic blocks to simulate real rock joints. This transforms the tunnel model from a homogeneous, complete single-structure rock mass to a real, complex joint structure rock mass. The two joint generation methods are as follows.

[0063] The random automatic joint generation method specifically includes: Based on the actual surrounding rock conditions of tunnel projects, five target scores R for surrounding rock categories are defined. The target score R ranges from 1 to 100. The following formula gives the score ranges for different surrounding rock categories: .

[0064] 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.

[0065] 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 length L and an inclination angle , joint contact strength parameters The joints, a - :J(x i ,y i ,L, , ) indicates deleting the joint.

[0066] The uniaxial compressive strength of rock R b , the number of joints per unit volume J v , joint contact strength parameter C f , joint dip Angle with tunnel axis The evaluation reward function for evaluating the surrounding rock category is constructed based on the five factors of the groundwater parameter Q. The evaluation reward function is used to evaluate the generated joint state space parameters to determine whether the generated joints meet the surrounding rock category requirements of the preset tunnel model. The specific formula is as follows: .

[0067] The use of electromagnetic blocks to simulate rock blocks does not take into account the effect of groundwater, so and Set to a fixed value, 、 、 The evaluation is carried out using the number of joints per unit volume, joint contact strength parameters and joint inclination, as follows: .

[0068] .

[0069] .

[0070] .

[0071] Where s i represents the number of joints per meter on the upper side of the i-th group of joints, s k It represents the number of non-grouped joints per cubic meter of rock mass, and C is the rated electromagnetic force of the test system.

[0072] By randomly executing the action-state function A={a + :J(x i ,y i ,L, , ),a - :J(x i ,y i ,L, , )} generates a new joint to joint state space. After executing the tth time, the joint state space is S={J 1， J 2， J 3，…， J t}.

[0073] The length L and inclination angle of all joints , joint contact strength parameters Input into the evaluation reward function to calculate the evaluation score of the current joint tunnel model .

[0074] The evaluation score of the current tunnel model The surrounding rock category of the current tunnel model is compared with the target scores R of the five defined surrounding rock categories to determine the surrounding rock category. If the surrounding rock category of the current tunnel model is the set target surrounding rock category, joint generation is stopped and the current joint state space is output. If the surrounding rock category of the current tunnel model does not meet the set target surrounding rock category, the next step is executed.

[0075] Determine the evaluation score of the current joint tunnel model The relationship between the score of the target surrounding rock category and the score of the current joint tunnel model is If the score of the target rock mass category is higher than the score of the target rock mass category, the next action state function will randomly add a joint operation. If the evaluation score of the current joint tunnel model is If the score is lower than the target rock mass category, the next action state function will delete the joint operation in the previous step and then repeat the previous step.

[0076] By creatively proposing a random automatic joint generation method, it is possible to adaptively generate a joint network that meets geological conditions based on experimental conditions, significantly improving the accuracy and efficiency of the test. At the same time, the action space iteration is performed to generate random joint parameters and store them in the joint state space. On this basis, the evaluation reward function is used to optimize the joint space distribution to ensure that the generated joint length, inclination, contact strength and other parameters meet existing engineering standards, providing a basis for tunnel surrounding rock stability analysis.

[0077] The methods for manually setting joint parameters include: The range of the two-dimensional coordinates of the tunnel model is determined and the two-dimensional coordinates of the tunnel model are established.

[0078] Initialize the joint state space.

[0079] The number of joints, the two-dimensional coordinates of the two endpoints of each joint and the joint contact strength parameters are set to form the final joint state space.

[0080] By manually setting the joint parameters, you can customize the joint generation.

[0081] (4) Dynamic disturbances were applied to the jointed tunnel model through a movable excitation system, fully restoring the actual stress state of the underground tunnel.

[0082] (5) Use an ultra-high-speed camera to capture images of the joint tunnel model and upload them to the host computer.

[0083] (6) The host computer analyzes the image of the jointed tunnel model and obtains the instability and failure characteristics of the jointed tunnel model under dynamic disturbance.

[0084] By integrating a dynamic and static combined loading device with ultra-high-speed camera observation technology, high-precision observation and data collection of the unstable sliding characteristics of jointed surrounding rock under complex stress conditions can be achieved. The vertical and horizontal static loading systems can simulate complex static stress fields. The exciter acts as a dynamic disturbance source to achieve precise control of stress wave parameters, fully restoring the actual stress state of the underground space and providing reliable data support for the design of dynamic disaster protection in tunnel engineering.

[0085] Although the present invention has been disclosed above by way of embodiments, they are not intended to limit the present invention. Any person skilled in the art may make slight changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. A tunnel model joint formation and dynamic instability simulation test method, characterized in that: The method is implemented based on a dynamic and static combined loading device, which includes a main frame, a movable excitation system, a vertical static loading system, a horizontal static loading system, an ultra-high-speed camera, and a host computer. The method includes: (1) A tunnel model with a rectangular cross-section and a tunnel in the middle is formed by splicing several triangular electromagnetic blocks, and the tunnel model is fixed in the main frame of the dynamic and static combined loading device. An electromagnetic control unit is provided inside each triangular electromagnetic block to control the magnetic attraction between the triangular electromagnetic blocks; (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; (3) The electromagnetic control unit is used to change the magnetic attraction between the triangular electromagnetic blocks to generate the tunnel model joints and obtain the joint tunnel model; (4) Apply dynamic disturbance to the jointed tunnel model through a movable excitation system; (5) Use an ultra-high-speed camera to capture images of the joint tunnel model and upload them to the host computer; (6) The host computer analyzes the image of the jointed tunnel model and obtains the instability and failure characteristics of the jointed tunnel model under dynamic disturbance.

2. The tunnel model joint generation and dynamic instability simulation test method according to claim 1 is characterized in that: In step (3), the specific steps of generating tunnel model joints by changing the magnetic attraction between the triangular electromagnetic blocks through the electromagnetic control unit are as follows: Initially, the electromagnetic control unit controls the magnetic attraction between the triangular electromagnetic blocks to be the contact force of the complete rock blocks, and the simulated tunnel model is a homogeneous, complete single-structure rock mass; Subsequently, joint parameters are generated using a random automatic joint generation method or a manually set method, and the electromagnetic control unit is controlled according to the joint parameters to change the magnetic attraction between the triangular electromagnetic blocks to simulate real rock joints, so that the tunnel model is transformed from a homogeneous, complete single-structure rock mass to a real, complex joint structure rock mass.

3. The tunnel model joint generation and dynamic instability simulation test method according to claim 2 is characterized in that: The random automatic joint generation method specifically includes: Based on the actual surrounding rock conditions of tunnel projects, five target scores R for surrounding rock categories are defined as follows: ； 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 type of the tunnel model; 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 length L and an inclination angle , joint contact strength parameters The joints, a - :J(x i ,y i ,L, , ) means deleting the joint; The uniaxial compressive strength of rock R b , the number of joints per unit volume J v , joint contact strength parameter C f , joint dip Angle with tunnel axis The five factors of groundwater parameter Q are used to construct the evaluation reward function for evaluating surrounding rock categories. The specific formula is as follows: ； and is a fixed value, 、 、 The evaluation is carried out using the number of joints per unit volume, joint contact strength parameters and joint inclination, as follows: ； ； ； ； Where s i represents the number of joints per meter on the upper side 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, , )} generates a new joint to joint state space. After executing the tth time, the joint state space is S={J1,J 2， J 3，…, J t }; The length L and inclination angle of all joints , joint contact strength parameters Input into the evaluation reward function to calculate the evaluation score of the current joint tunnel model ; The evaluation score of the current tunnel model The surrounding rock category of the current tunnel model is compared with the target scores R of the five defined surrounding rock categories to determine the surrounding rock category. If the surrounding rock category of the current tunnel model meets the set target surrounding rock category, joint generation stops and the current joint state space is output. If the surrounding rock category of the current tunnel model does not meet the set target surrounding rock category, the next step is executed. Determine the evaluation score of the current joint tunnel model The relationship between the score of the target surrounding rock category and the score of the current joint tunnel model is If the score of the target rock mass category is higher than the score of the target rock mass category, the next action state function will randomly add a joint operation. If the evaluation score of the current joint tunnel model is If the score is lower than the target rock mass category, the next action state function will delete the joint operation in the previous step and then repeat the previous step.

4. The tunnel model joint generation and dynamic instability simulation test method according to claim 2 is characterized in that: The method for manually setting joint parameters specifically includes: Determining the range of the two-dimensional coordinates of the tunnel model and establishing the two-dimensional coordinates of the tunnel model; Initialize the joint state space; The number of joints, the two-dimensional coordinates of the two endpoints of each joint and the joint contact strength parameters are set to form the final joint state space.

5. A tunnel model joint generation and dynamic instability simulation test system according to any one of claims 1 to 4, characterized in that: It includes a dynamic and static combined loading device, an electromagnetic tunnel model and an electromagnetic control unit; The dynamic and static combined loading device includes a main frame, a movable excitation system, a vertical static loading system, a horizontal static loading system, an ultra-high-speed camera and a host computer; The main frame is a hollow cuboid, used to install and carry the movable excitation system, vertical static load system, horizontal static load system and electromagnetic tunnel model; There are gear strips and locking devices on it, which allow the dynamic loading system to move within the space to the left of the vertical static loading system center axis and be locked and fixed; The movable excitation system includes a signal transmitter, a power amplifier, an exciter, several excitation heads of different sizes and shapes, a movable slide rail, and a sliding locking device. The signal transmitter is connected to the power amplifier, outputting a waveform signal that is amplified by the power amplifier. The power amplifier is connected to the exciter, transmitting the waveform signal and energy through the exciter to achieve actuation. The exciter is equipped with excitation heads of different sizes and shapes to apply dynamic disturbances to the jointed tunnel model. The exciter is inverted and fixed on the movable slide rail at the top of the middle cavity of the main frame. The slide rail locking device ensures that the exciter is firmly positioned at the target position. The vertical static load system includes an axial hydraulic cylinder and a vertical loading plate. The cylinder barrel of the axial hydraulic cylinder is inverted and fixed to the right side of the top of the middle cavity of the main frame. The end of the piston rod of the axial hydraulic cylinder is fixedly connected to the top of the vertical loading plate. A rectangular slot for the movable excitation system to actuate is opened on the left side of the vertical loading plate. The size of the rectangular slot meets the actuation range of the excitation head. The horizontal static load system includes a lateral hydraulic cylinder and a horizontal loading plate. The cylinder barrel of the lateral hydraulic cylinder is horizontally fixed to the side of the middle cavity of the main frame, and the end of the piston rod of the lateral hydraulic cylinder is fixedly connected to the side of the horizontal loading plate. The ultra-high-speed camera is located in front of the main frame and connected to the host computer to capture images of the joint tunnel model; The electromagnetic tunnel model is a cuboid with a rectangular cross section and a tunnel in the middle, which is made up of several triangular electromagnetic blocks and fixed at the bottom of the middle cavity of the main frame; The electromagnetic control unit is arranged inside the triangular electromagnetic block and electrically connected to the triangular electromagnetic block, and is used for controlling the magnetic attraction between the triangular electromagnetic blocks.

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