A simulation experiment method and device for impact dynamic disaster induced by thick and multi-layer water-bearing overburden rock

Abstract

A simulation experiment method and device for impact dynamic disaster induced by thick and multi-layer water-bearing overburden rock, characterized in that the device comprises a sealed box, a horizontal loading module, a vertical elastic loading module, a transient impact triggering module, a water-bearing overburden rock model and an array pipe water filling module; the array pipe water filling module is installed at the bottom of the box (11) through a mounting hole and a sealing ring (63), and the upper part of the array pipe water filling module is embedded in the water-bearing overburden rock model, and the inside is provided with array water pipes (62) with different lengths, and each water pipe is connected with a separate flow valve (65) and a pressure valve (64). The vertical elastic loading module solves the difficulty of large-size rock layer simulation, and provides reliable experimental equipment for disaster simulation.

Description

Technical Field

[0001] This invention relates to a mine safety technology, and more particularly to a geological disaster simulation technology, specifically a method and apparatus for simulating impact dynamic disasters induced by thick and multi-layered water-bearing overburden. Background Technology

[0002] The lithology of the thick sandstone and aquifer layers is mostly coarse-grained and medium-grained sandstone, with thicknesses exceeding 200 mm. These thick aquifer sandstone layers are often sub-critical and primary critical layers in the high-level roof, significantly influencing mining-induced overburden movement and the surrounding rock stress environment. The confined water within the aquifer sandstone layers interacts with rockburst hazards. Under conditions of thick sandstone roofs, strong mine earthquakes and rockbursts occur frequently during mining operations, severely impacting mine safety. The fracturing of thick aquifer sandstone layers releases a large amount of energy, and under the combined effects of its own weight, water pressure, or additional loads from overlying rock layers, further destabilizes the underlying rock structure. Currently, the mechanisms by which thick sandstone and aquifer roofs induce hazards are unclear. The related gestation and development mechanisms following frequent strong mine earthquakes and rockbursts in mining areas remain undefined, and targeted monitoring, early warning, and control capabilities are weak, becoming a major challenge hindering safe coal mine production.

[0003] Currently, laboratory-based similarity simulation experiments are an important means of studying the mechanism of fault-activated shock dynamic disasters induced by thick and multi-layered water-bearing overburden, as well as related monitoring, early warning, and prevention technologies. At present, laboratories lack experimental equipment and methods for studying shock dynamic disasters induced by thick and multi-layered water-bearing overburden. This is because coal seam thickness is generally 3–10 m; to facilitate excavation and sensor placement within the roadway, the size similarity ratio is generally 20–30; the model layer thickness for a single 200 m thick sandstone layer reaches 7–10 m; if the thickness of the rock strata below the thick water-bearing sandstone plus the coal seam is 200 m, the model thickness for this part also reaches 7–10 m; the entire model frame size exceeds 14–20 m. Figure 1 As shown, not only are the vertical model frames enormous, but to simulate the fracture of rock strata, when the thickness of the massive sandstone model layer is 7–10 m, the model length must be at least 21–30 m to accurately simulate the fracture of the roof. Therefore, similar simulations of high-lying, massive overburden are difficult to conduct in the laboratory, and even if successfully developed, the experiments are time-consuming and labor-intensive. Furthermore, different rock strata have different water-bearing characteristics. How to simulate the enormous energy released instantaneously during the fracture of massive water-bearing sandstone, and how to realistically simulate the stress accumulation and impact patterns in mining environments with different multi-layered water-bearing overburdens, are urgent problems that need to be solved. Summary of the Invention

[0004] The purpose of this invention is to address the problem that existing methods for simulating the mechanism of damage caused by massive and thick rock strata are difficult to establish at a simulated scale, resulting in a lack of experimental data and difficulty in providing effective guidance for safety control in such mines. The invention provides a method and apparatus for simulating impact dynamic disasters induced by massive and multi-layered water-bearing overburden to meet safety control needs.

[0005] One of the technical solutions of this invention is:

[0006] A simulation experiment method for shock dynamic disasters induced by thick and multi-layered water-bearing overburden is characterized by the following steps: 1) Constructing multiple water-bearing overburden models based on actual underground geological conditions and similarity theory, so as to change the initial conditions of the water-bearing overburden models to conduct different experiments; installing pressure cells, strain sensors, and acoustic emission sensors inside the models; the top of the models is a thick water-bearing sandstone 51, the thickness of which is no more than 10% of the thickness of the thick water-bearing sandstone to be simulated;

[0007] 2) The horizontal loading module drives the array of horizontal pressure plates 24 to apply a horizontal load to the model; the vertical elastic loading module applies a vertical load to the top of the model; during the application of the vertical load, the array springs 34 compress and store elastic energy.

[0008] 3) Water is supplied to different rock layers inside the model through array water pipes 62 of varying lengths in the array tube water filling module. Each water pipe controls the water filling speed and water pressure of each rock layer through a separate flow valve 65 and pressure valve 64.

[0009] 4) Mining and roadway excavation are carried out on the simulated working face in simulated coal seam 53;

[0010] 5) A transient impact is applied to the thick water-bearing sandstone 51 at the top of the model through the transient impact triggering module; at the moment the thick water-bearing sandstone breaks, the array spring 34 releases its stored energy instantly, driving the thick water-bearing sandstone to break and apply strong disturbance to the bottom of the model; the pressure box, strain sensor and acoustic emission sensor installed in the model record the corresponding parameters and send them to the data processing module for analysis and processing.

[0011] 6) Change the spring size and stiffness to alter the vertical load, simulating the different energies released instantaneously upon the fracture of massive water-bearing sandstone of varying thickness and strength. Repeat steps 1) to 5) to simulate the induced stress accumulation and impact patterns in the stope when massive rock strata release different energies. Spring parameter values ​​are taken from the following formula:

[0012]

[0013]

[0014]

[0015] CE U represents the energy similarity ratio; U is the energy released by the spring replacing the rock layer; J is the moment of inertia of the roof section. b is the width of the rock stratum, h is the thickness of the rock stratum replaced by the spring; q is the unit length equivalent load of the weight of the roof and the additional load of the overlying rock stratum; l is the cantilever length of the roof; E is the elastic modulus; k is the spring stiffness; x is the spring deformation; n is the number of springs.

[0016] 7) Change the water pressure of different thick water-bearing sandstones and each rock layer, and repeat steps 1) to 6) to simulate the stress accumulation and impact law of different initial water pressures in the mining area.

[0017] The second technical solution of the present invention is:

[0018] An experimental device for simulating impact dynamic disasters induced by thick and multi-layered water-bearing overburden is characterized by: a sealed box, a horizontal loading module, a vertical elastic loading module, a transient impact triggering module, a water-bearing overburden model, and an array tube water filling module; the sealed box includes a box body 11, a cover plate 12, a sealing strip 13, and a water guide hole 14, with horizontal loading modules installed around the box body 11; the horizontal loading module includes multiple horizontal hydraulic loading cylinders 22, an in-hole sealing ring 23, and a horizontal pressure plate 24; the vertical loading module includes a vertical pressure rod 33, a vertical pressure plate 36, a spring 34, an in-hole sealing ring 35, and a vertical hydraulic loading cylinder 31; the transient impact triggering module includes an impact anvil 43, an impact pressure plate 45, an impact anvil 43, and an impact hammer 42; the water-bearing overburden model includes thick water-bearing sandstone 51, ordinary water-bearing rock layers 52, and coal seams 53; the array tube water filling module includes a water filling module body 61 and an array water guide pipe 6. 2. Flow valve 65 and pressure valve 64; The extension rod of the horizontal hydraulic loading cylinder 22 passes through the mounting hole of the housing 11 and the sealing ring 23 inside the hole, and is connected to the horizontal pressure plate 24; A sliding vertical pressure rod 33 is installed on the cover plate 12, the lower part of the vertical pressure rod 33 is connected to the vertical pressure plate 36, and a spring 34 is installed on the top of the vertical pressure rod 33 on the cover plate 12. Multiple vertical pressure rods 33 pass through the crossbeam 32, and vertical hydraulic loading cylinders 31 are provided on the left and right sides of the crossbeam 32; An impact pressure rod 44 is installed in the middle of the crossbeam 32, the bottom of the impact pressure rod 44 is connected to the impact pressure plate 45, and an impact anvil 43 is installed on the top; An impact hammer 42 is above the impact anvil 43; The bottom of the housing 11 is equipped with an array tube water filling module through the mounting hole and the sealing ring 63. The upper part of the array tube water filling module is buried inside the water-bearing overburden model, and the inside is equipped with array water guide pipes 62 of different lengths. Each water guide pipe is connected to a separate flow valve 65 and pressure valve 64.

[0019] The beneficial effects of this invention are:

[0020] This invention solves the problem of simulating the safety of geological conditions in massive water-bearing sandstone and coal seams with a thickness of over 200 meters and ordinary water-bearing rock strata with a thickness of over 200 meters by using a vertical elastic loading module. On the one hand, it greatly reduces the simulation height of water-bearing sandstone and coal seams and ordinary water-bearing rock strata, enabling laboratory preparation. By loading spring force to simulate the pressure load of actual rock strata, the experiment is closer to the actual failure situation of rock strata. On the other hand, for the first time, water injection is used in related models to simulate the impact of actual water-bearing strata on rockburst, making the simulation test environment closer to the natural environment, greatly improving the accuracy of the experiment, providing first-hand data for simulated strata mining, and contributing to mine safety.

[0021] The method of this invention is reliable, the experimental setup is simple and easy to implement, and it has a high degree of simulation. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the composition and structure of the giant non-rock layer of the present invention.

[0023] Figure 2 This is a schematic diagram of the experimental apparatus of the present invention.

[0024] Figure 3 This is a schematic diagram of the tunnel excavation process of the present invention.

[0025] Figure 4 This is a top view of the array tube water filling module of the present invention. Detailed Implementation

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0027] like Figure 2-3 As shown.

[0028] An experimental method for simulating shock dynamic disasters induced by thick and multi-layered water-bearing overburden includes the following steps:

[0029] 1) Based on the actual geological conditions and similarity theory, multiple water-bearing overburden experimental models were constructed to allow for different experiments by varying the initial conditions of the water-bearing overburden models (initial conditions include parameters such as rock layer thickness, strength, and water content). Pressure cells, strain sensors, and acoustic emission sensors were installed within the models (installation methods and data acquisition and processing were the same as in existing technologies). The top of the model consisted of a very thick water-bearing sandstone layer 51, with a thickness not exceeding 1% of the thickness of the simulated very thick water-bearing sandstone layer. The experimental models are as follows: Figure 2 As shown, it includes a sealed box, a horizontal loading module, a vertical elastic loading module, a transient impact triggering module, a water-bearing overburden model, and an array tube water filling module. The coal seam has 54 mining roadways (e.g., Figure 3The sealed box includes a box body 11, a cover plate 12, a sealing strip 13, and a water guide hole 14. A horizontal loading module is installed around the box body 11. The horizontal loading module includes multiple horizontal hydraulic loading cylinders 22, an in-hole sealing ring 23, and a horizontal pressure plate 24. The vertical loading module includes a vertical pressure rod 33, a vertical pressure plate 36, a spring 34, an in-hole sealing ring 35, and a vertical hydraulic loading cylinder 31. The transient impact triggering module includes an impact anvil 43, an impact pressure plate 45, an impact anvil 43, and an impact hammer 42 (which can be driven by suspension, a hydrogen cannon, or a dynamic hydraulic device). The water-bearing overburden model includes a very thick water-bearing sandstone 51 (thickness not less than 200 meters), an ordinary water-bearing rock layer 52, and a coal seam 53 (the combined thickness of the two is not less than 200 meters). The array tube water filling module includes a water filling module body 61, an array water guide pipe 62, a flow valve 65, and a pressure valve 64. The extension rod of the horizontal hydraulic loading cylinder 22 passes through the mounting hole and the sealing ring 23 inside the box 11 and connects to the horizontal pressure plate 24; a sliding vertical pressure rod 33 is installed on the cover plate 12, the lower part of the vertical pressure rod 33 is connected to the vertical pressure plate 36, and a spring 34 is installed on the top of the vertical pressure rod 33 on the cover plate 12. Multiple vertical pressure rods 33 pass through the crossbeam 32, and vertical hydraulic loading cylinders 31 are provided on the left and right sides of the crossbeam 32; an impact pressure rod 44 is installed in the middle of the crossbeam 32, the bottom of the impact pressure rod 44 is connected to the impact pressure plate 45, and an impact anvil 43 is installed on the top; an impact hammer 42 is above the impact anvil 43; an array tube water filling module is installed at the bottom of the box 11 through the mounting hole and the sealing ring 63, and the upper part of the array tube water filling module is buried inside the water-bearing overburden model. The inside is equipped with array water guide pipes 62 of different lengths, and each water guide pipe is connected to a separate flow valve 65 and pressure valve 64.

[0030] 2) The horizontal loading module drives the array of horizontal pressure plates 24 to apply a horizontal load to the model; the vertical elastic loading module applies a vertical load to the top of the model; during the application of the vertical load, the array spring 34 (elastic force value adjustable) compresses and stores elastic energy;

[0031] 3) Water is supplied to different rock layers inside the model through array water pipes 62 of varying lengths in the array tube water filling module. Each water pipe controls the water pressure and water volume of each rock layer through a separate flow valve 65 and pressure valve 64.

[0032] 4) Mining and roadway excavation are carried out on the simulated working face in simulated coal seam 53;

[0033] 5) A transient impact is applied to the thick water-bearing sandstone 51 at the top of the model through the transient impact triggering module; at the moment the thick water-bearing sandstone breaks, the array spring 34 releases its stored energy instantly, driving the thick water-bearing sandstone to break and apply strong disturbance to the bottom of the model; the pressure box, strain sensor and acoustic emission sensor installed in the model record the corresponding parameters and send them to the data processing module for analysis and processing.

[0034] 6) Change the spring size and stiffness to alter the vertical load, simulating the different energies released instantaneously upon the fracture of massive water-bearing sandstone of varying thickness and strength. Repeat steps 1) to 5) to simulate the induced stress accumulation and impact patterns in the stope when massive rock strata release different energies. Spring parameter values ​​are taken from the following formula:

[0035]

[0036]

[0037]

[0038] C E U represents the energy similarity ratio; U is the energy released by the spring replacing the rock layer; J is the moment of inertia of the roof section. b is the width of the rock stratum, h is the thickness of the rock stratum replaced by the spring; q is the unit length equivalent load of the weight of the roof and the additional load of the overlying rock stratum; l is the cantilever length of the roof; E is the elastic modulus; k is the spring stiffness; x is the spring deformation; n is the number of springs.

[0039] 7) Change the water pressure of different thick water-bearing sandstones and each rock layer, and repeat steps 1) to 6) to simulate the stress accumulation and impact law of different initial water pressures in the mining area.

[0040] Through repeated experiments, the obtained data can be input into the existing mine safety database and processed using appropriate software to obtain the occurrence law of shock dynamic disasters induced by thick and multi-layered water-bearing overburden, providing first-hand information for disaster prevention and control. Based on the experimental results of this invention, corresponding prevention and control methods can be designed to prevent disasters and fundamentally ensure mine safety.

[0041] The parts not covered in this invention are the same as or can be implemented using existing technologies.

Claims

1. A simulation experimental method for shock dynamic disasters induced by thick and multi-layered water-bearing overburden, characterized by the following steps: 1) Based on the actual geological conditions and similarity theory in the well, multiple water-bearing overburden models were built so as to change the initial conditions of the water-bearing overburden models to conduct different experiments; pressure boxes, strain sensors and acoustic emission sensors were installed in the models, and the top of the models was a huge water-bearing sandstone (51), the thickness of which was no more than 10% of the thickness of the huge water-bearing sandstone to be simulated. 2) Apply a horizontal load to the model using the horizontal loading module to drive the horizontal pressure plate (24) set in the array; apply a vertical load to the top of the model using the vertical elastic loading module; during the application of the vertical load, the spring (34) set in the array compresses and stores elastic energy; 3) Water is supplied to different rock layers inside the model through array water pipes (62) of varying lengths in the array tube water filling module. Each water pipe controls the water filling speed and water pressure of each rock layer through a separate flow valve (65) and pressure valve (64). 4) Mining and tunnel excavation are carried out on the simulated working face in the simulated coal seam (53); 5) A transient impact is applied to the thick water-bearing sandstone (51) at the top of the model through the transient impact triggering module; at the moment the thick water-bearing sandstone breaks, the spring (34) set in the array releases the stored energy instantly, driving the thick water-bearing sandstone to break and apply strong disturbance to the bottom of the model; the pressure box, strain sensor and acoustic emission sensor installed in the model record the corresponding parameters and send them to the data processing module for analysis and processing; 6) Change the spring size and stiffness to alter the vertical load and simulate the different energies released instantaneously upon the fracture of massive water-bearing sandstone of varying thickness and strength. Repeat steps 1) to 5) to simulate the induced stress accumulation and impact patterns in the stope when massive rock strata release different energies. Spring parameter values ​​are taken from the following formula: C E U represents the energy similarity ratio; U is the energy released by the spring replacing the rock layer; J is the moment of inertia of the roof section. b is the width of the rock stratum, h is the thickness of the rock stratum replaced by the spring; q is the unit length equivalent load of the weight of the roof and the additional load of the overlying rock stratum; l is the cantilever length of the roof; E is the elastic modulus; k is the spring stiffness; x is the spring deformation; n is the number of springs. 7) Change the water pressure of different thick water-bearing sandstones and each rock layer, and repeat steps 1) to 6) to simulate the stress accumulation and impact law of different initial water pressures in the mining area.

2. The experimental method according to claim 1, characterized in that: The transient impact triggering module includes an impact hammer driven by a suspension, hydrogen cannon, or dynamic hydraulic device.

3. The experimental method according to claim 1, characterized in that: Initial conditions include rock layer thickness, strength, and water content.

4. The experimental method according to claim 1, characterized in that: The thickness of the massive water-bearing sandstone is not less than 200 meters, and the thickness of the rock strata below the massive water-bearing sandstone plus the coal seam is not less than 200 meters.

5. A simulation experimental device for shock dynamic disasters induced by thick and multi-layered water-bearing overburden, characterized in that: it includes a sealed box, a horizontal loading module, a vertical elastic loading module, a transient impact triggering module, a water-bearing overburden model, and an array tube water filling module; The sealed box includes a box body (11), a cover plate (12), a sealing strip (13), and a water guide hole (14). Horizontal loading modules are installed around the box body (11). The horizontal loading module includes multiple horizontal hydraulic loading cylinders (22), a first hole inner sealing ring (23), and a horizontal pressure plate (24). The vertical elastic loading module includes a vertical pressure rod (33), a vertical pressure plate (36), a spring (34), a second hole inner sealing ring (35), and a vertical hydraulic loading cylinder (31). The transient impact triggering module includes an impact anvil (43), an impact pressure plate (45), and an impact hammer (42). The water-bearing overburden model includes a thick water-bearing sandstone (51), a common water-bearing rock layer (52), and a coal seam (53). The array tube water filling module includes a water filling module body (61), an array water guide pipe (62), a flow valve (65), and a pressure valve (64). The extension rod of the horizontal hydraulic loading cylinder (22) passes through the mounting hole and the first hole of the box body (11). An inner sealing ring (23) is connected to a horizontal pressure plate (24); a sliding vertical pressure rod (33) is installed on the cover plate (12), the lower part of the vertical pressure rod (33) is connected to a vertical pressure plate (36), a spring (34) is installed on the top of the vertical pressure rod (33), multiple vertical pressure rods (33) pass through a crossbeam (32), and vertical hydraulic loading cylinders (31) are provided on the left and right sides of the crossbeam (32); an impact pressure rod (44) is installed in the middle of the crossbeam (32). The bottom of the impact pressure bar (44) is connected to the impact pressure plate (45), and the top is equipped with an impact anvil (43); above the impact anvil (43) is the impact hammer (42); the bottom of the box (11) is equipped with the array tube water filling module through the mounting hole and the sealing ring (63). The upper part of the array tube water filling module is buried inside the water-bearing overburden model. The inside is equipped with array water guide pipes (62) of different lengths. Each water guide pipe is connected to a separate flow valve (65) and pressure valve (64).

6. The experimental apparatus according to claim 5, characterized in that: The impact hammer (42) is driven by a suspension, a hydrogen cannon, or a dynamic hydraulic device.

7. The experimental apparatus according to claim 5, characterized in that: The spring force of the spring (34) is adjustable.

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