A mine dynamic disaster coupling simulation test device and method

Abstract

The application discloses a kind of mine power disaster coupling simulation test device and method, by setting true triaxial loading system, hydraulic servo loading system, gas pressurization and control system, vacuum pumping system, high-pressure gas impact system, outburst and impact response system and data acquisition and control terminal;True triaxial loading system applies three mutually independent controllable principal stress load to coal sample, hydraulic servo loading system is connected with true triaxial loading system, realizes three-way stress independent loading, keeps and unloads;Gas pressurization and control system and vacuum pumping system realize the controllable regulation of coal sample gas content state and gas pressure, for simulating the complex mechanical environment of deep mine gas-containing coal body, can realize the coupling process test of rock burst and gas outburst, support the coupling mechanism research of mine typical power disaster, make up the deficiency that existing equipment is difficult to adapt to such composite disaster experiment, and provide experimental basis for the prevention and control of deep mine power disaster.

Description

Technical Field

[0001] This invention belongs to the field of coal mine dynamic disaster testing and simulation technology, and specifically relates to a coupled simulation test device and method for mine dynamic disasters. Background Technology

[0002] Rockbursts are a common dynamic disaster in deep coal mining, and their occurrence is usually accompanied by complex mechanical behaviors such as high ground stress, instability of surrounding rock structures, and transient energy release. In gas-bearing coal seams, there is a significant gas-solid coupling effect between gas pressure and the mechanical response of the coal body, making the incubation and triggering mechanism of rockbursts even more complex.

[0003] Existing studies on coal and rock rock bursts mostly employ uniaxial or conventional triaxial loading methods, which fail to accurately simulate the triaxial non-isotropic stress environment of underground coal seams. Furthermore, most test setups only consider the static loading process, neglecting the influence of transient dynamic disturbances during rock bursts. In addition, while some gas-fired coal test setups can achieve gas injection, they cannot introduce controllable impact loads under true triaxial stress conditions, leading to significant discrepancies between test results and actual engineering conditions.

[0004] The invention disclosed in CN107024420A is a triaxial servo seepage device for dynamic disturbance fluid-structure coupling in gas-bearing coal and rock. Its key technical features include an axial loading device, a triaxial pressure chamber above the axial loading device, a dynamic disturbance device at the top of the triaxial pressure chamber, and a gas injection system connected to the triaxial pressure chamber via a conduit. Based on a conventional pressure chamber, a disturbance rod is installed inside the upper pressure-bearing component. An axial point disturbance load is applied by connecting a vibrator to achieve the combined loading of triaxial pressure and axial dynamic disturbance force, simulating the vibration disturbance experienced during coal and rock mining. This allows for a more accurate analysis of the evolution of permeability during coal and rock mining. While traditional conventional triaxial tests simultaneously apply dynamic disturbance axial loads of different frequencies, they cannot introduce controllable impact loads under true triaxial stress conditions.

[0005] The invention disclosed in CN115201087B is a true triaxial seepage test system and method. Its key technical features include a pressure chamber and a true triaxial loading unit. The sample is placed in the pressure chamber, and the true triaxial loading unit loads the sample. A first loading component applies a lateral load to the sample using a first pressure rod and a first pressure head, causing deformation. A second loading component applies a front-to-back liquid load to the sample using a liquid pressurization device. A third loading component applies a vertical axial load to the sample using a second pressure rod and a second pressure head, causing deformation. Gas channels are provided in the base and the second pressure head, connecting to the sample. A gas control unit can perform vacuuming or gas filling operations on the sample through the gas channels, facilitating the smooth conduct of the test. However, the true triaxial seepage test method, using the aforementioned true triaxial seepage test system, combines different loading methods to simulate actual coal seam seepage conditions. Nevertheless, it cannot introduce controllable impact loads under true triaxial stress conditions.

[0006] Therefore, there is an urgent need for a test device that can simultaneously apply gas pressure loading and transient impact load under true triaxial stress conditions in order to realistically simulate the occurrence process of gas-bearing coal rockburst. Summary of the Invention

[0007] The purpose of this invention is to address the shortcomings of the prior art by providing a mine dynamic disaster coupling simulation test device and method, which realizes multi-field coupled loading of true triaxial stress, gas pressure and impact load, and realistically simulates the process of gas-bearing coal rockburst.

[0008] To solve the above technical problems, the technical solution adopted by the present invention is as follows: A mine dynamic disaster coupling simulation test device includes a true triaxial loading system and a hydraulic servo loading system, a gas pressurization and control system, a vacuum system, a high-pressure gas impact system and a outburst and impact response system connected to the system, as well as a data acquisition and control terminal connected to the signals of each system. The hydraulic servo loading system is connected to the true triaxial loading system and provides loading power to it; The gas pressurization and control system and the vacuum system are connected to the true triaxial loading system, which are used to vacuum the coal sample and inject gas into the coal sample to regulate the gas content and gas pressure of the coal sample. The high-pressure gas impact system includes a high-pressure gas release device, which applies an impact load to the coal sample by instantaneously releasing high-pressure gas. The outburst and impact response system includes a pressure sensor for real-time monitoring of gas pressure in the outburst and impact response channel and a coal and gas outburst outlet arranged in parallel with it. The pressure sensor collects the instantaneous pressure signal generated during the impact or outburst process and feeds it back to the data acquisition and control system. The coal and gas outburst outlet is used to provide a release channel and simulate the emission path of coal and gas outburst in the mine. The data acquisition and control terminal is used to acquire, record and centrally control the loading stress, gas pressure and impact response signals in real time.

[0009] The true triaxial loading system includes a base, a reaction support structure mounted on the base, and a true triaxial loading cavity positioned above the reaction support structure for placing coal samples. The true triaxial loading cavity is equipped with an X-axis loading cylinder mechanism, a Y-axis loading cylinder mechanism, and a Z-axis loading cylinder mechanism, which independently apply loads to the coal sample.

[0010] The X-axis loading cylinder mechanism and the Y-axis loading cylinder mechanism are each provided in two sets, and are symmetrically arranged on the corresponding outer end faces of the true triaxial loading cavity. Each loading cylinder mechanism includes a loading cylinder, a piston rod, and a loading head. The loading cylinder is fixedly installed on the reaction support structure. Its piston rod extends horizontally toward the true triaxial loading cavity, and the end of the piston rod abuts against the lateral loading plate arranged on the outside of the true triaxial loading cavity through the loading head and applies lateral principal stress to the coal sample.

[0011] The Z-axis loading cylinder mechanism is installed above the true triaxial loading cavity and includes a loading cylinder, a piston rod, and a loading head. The loading cylinder is fixed by a mounting base, while the piston rod extends downward in the vertical direction. The lower end of the piston rod contacts the top loading surface of the true triaxial loading cavity through a loading plate, and is used to apply vertical principal stress to the coal sample.

[0012] The hydraulic servo loading system is connected to the loading cylinders in the X, Y, and Z directions via high-pressure oil pipes, and achieves independent control of the three-dimensional stress through valve groups. The hydraulic servo loading system also includes a first pressure sensor for acquiring real-time pressure signals during the loading process, a constant-speed and constant-pressure hydraulic pump connected to the first pressure sensor, and a hydraulic pump display screen. The constant-speed and constant-pressure hydraulic pump is used to provide stable and controllable loading pressure.

[0013] The gas boosting and control system includes a second pressure sensor, a high-pressure gas storage tank, and a gas boosting pump connected in sequence via pipelines. The second pressure sensor monitors the internal gas pressure value entering the true triaxial loading cavity in real time, and the pipeline between it and the high-pressure gas storage tank is also equipped with an outlet valve for controlling the gas supply and the regulating valve for adjusting the gas pressure output from the high-pressure gas storage tank. The gas booster pump is connected to the gas source and pressurizes it.

[0014] The high-pressure gas release device of the high-pressure gas impact system includes a firing barrel, a striking piston installed in the firing barrel, an electromagnet, and a gas storage tank located at the end, and the gas storage tank is equipped with a pneumatic valve interface for introducing gas. The firing barrel also contains bullets for impact, and the front end of the firing barrel is connected to a true triaxial loading cavity.

[0015] A method for a coupled simulation test device for mine dynamic disasters includes the following steps: (1) Before the test, prepare the coal sample to be tested, cover its outer surface with a flexible sealing material, and then place it in the true triaxial loading cavity; (2) Activate the auxiliary pressurization function in the hydraulic servo loading system to gradually bring the loading end face in the X, Y and Z directions closer to the coal sample, so as to achieve rapid contact between the loading end face and the coal sample to be tested. When the loading end face is completely in contact with the coal sample to be tested, turn off the auxiliary pressurization. (3) Start the constant speed and constant pressure hydraulic pump of the hydraulic servo loading system, control the loading cylinders in the X, Y and Z directions respectively, apply the predetermined triaxial principal stress to the coal sample to be tested, and monitor the stress in each direction in real time through the first pressure sensor. (4) Turn on the vacuum system to vacuum the true triaxial loading cavity and related gas paths. After the vacuum level reaches the required level, turn off the vacuum system. (5) Start the gas boosting and control system, and use the gas boosting pump to deliver the boosted gas to the high-pressure gas storage tank. The output pressure is precisely adjusted by the pressure regulating valve so that the gas slowly fills the true triaxial loading cavity and reaches adsorption equilibrium. Then, turn off the gas boosting and control system. (6) Under the condition that the true triaxial stress and gas pressure are both in a stable state, start the high-pressure gas impact system to simulate the transient release of elastic energy and dynamic disturbance process of the surrounding rock during the occurrence of rockburst; (7) Under the action of impact loading, stress instability and rapid gas release occur inside the coal sample to be tested. The released gas enters the outburst and impact response system through the coal and gas outburst port. The pressure sensor collects the instantaneous pressure signal generated during the impact or outburst process and feeds it back to the data acquisition and control system. (8) After the high-pressure gas impact loading is completed, first shut down the outburst and impact response system to stop the additional disturbance to the coal sample; then depressurize the true triaxial loading cavity through the hydraulic servo loading system until the internal pressure of the cavity is completely released; (9) Open the true triaxial loading chamber, take out the coal sample, observe and record the macroscopic damage morphology, crack distribution characteristics and outburst damage of the coal sample, and organize, store and back up the stress, gas pressure and impact response data collected during the test.

[0016] The beneficial effects of this invention are: (1) This invention discloses a mine dynamic disaster coupling simulation test device and method, which is composed of a true triaxial loading system, a hydraulic servo loading system, a gas pressurization and control system, a vacuum system, a high-pressure gas impact system, an outburst and impact response system, and a data acquisition and control terminal. The true triaxial loading system is used to apply three mutually perpendicular and independently controllable principal stress loads to the coal sample to construct a device that can simulate the original stress environment of the coal seam inside the coal sample. The hydraulic servo loading system is connected to the true triaxial loading system to provide loading power for the true triaxial loading system and realize triaxial loading. The independent loading, holding, and unloading of stress; the gas pressurization and control system and the vacuum system are all connected to the true triaxial loading system. This system is used to vacuum the coal sample and fill it with gas, so as to achieve controllable adjustment of the gas-containing state and gas pressure of the coal sample. It can be used to simulate the complex mechanical environment of gas-containing coal bodies in deep mines, realize the coupling process test of rockburst and gas outburst, support the study of the coupling mechanism of two types of typical dynamic disasters in mines, make up for the shortcomings of existing equipment in adapting to such composite disaster experiments, and provide an experimental basis for the prevention and control of dynamic disasters in deep mines.

[0017] (2) This invention realizes multi-field coupled loading of true triaxial stress, gas pressure and impact load, which can realistically simulate the mechanical environment of gas-containing coal rockburst; by introducing a high-pressure gas transient impact system, it solves the problem that existing test devices are difficult to simulate transient dynamic disturbances of rockburst; the device loading method is controllable, the test safety is high and the repeatability is good, providing a reliable test platform for the study of rockburst and gas dynamic disaster mechanism; it can provide important test basis for the prevention and control technology and engineering application of typical dynamic disasters in mines.

[0018] (3) The high-pressure gas impact system is connected to the true triaxial loading system. After the coal sample is in the set true triaxial stress and gas pressure coupling state, the high-pressure gas in the gas storage unit is released instantaneously by triggering the high-pressure gas release device and acts on the coal sample through the bullet to form a sudden dynamic load, so as to simulate the impact effect generated by the instantaneous release of elastic energy stored in the surrounding rock when the rock pressure occurs.

[0019] (4) The outburst and impact response system is connected to the true triaxial loading system and is used to characterize and record the gas outburst induced by rock pressure through the response structure when the coal sample is unstable and damaged; the data acquisition and control terminal is connected to the signals of the above systems respectively and is used to collect, record and centrally control the loading stress, gas pressure and impact response signals in real time. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 yes Figure 1 Schematic diagram of the true triaxial loading system in section A; Figure 3 yes Figure 1 Enlarged view of section B; Figure 4 yes Figure 1 Enlarged view of section C; Figure 5 yes Figure 1 Enlarged view of section D in the middle; Figure 6 yes Figure 1 Enlarged view of section E in the middle; Figure 7 yes Figure 1 Cross-sectional view of the FF plane. Detailed Implementation

[0021] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0022] This invention provides a coupled simulation test device and method for mine dynamic disasters, such as... Figures 1 to 7 As shown.

[0023] This invention provides a simulation test device for rockburst-induced gas outburst based on true triaxial loading. The device uses a true triaxial loading system A as the core experimental body. The stress, failure, and gas release behavior of the coal sample all occur within the true triaxial loading system A. The other systems are arranged around the true triaxial loading system A to provide loading conditions or to observe the response.

[0024] The device includes a true triaxial loading system (A), a hydraulic servo loading system (B), a gas pressurization and control system (C), a vacuum system (D), a high-pressure gas impact system (E), a protrusion and impact response system (F), and a data acquisition and control terminal (G).

[0025] like Figure 2As shown, the true triaxial loading system A includes a rigid base 11, a reaction support structure 12, a true triaxial loading cavity 13, a coal sample to be tested 14, an X-axis loading cylinder 15, a Y-axis loading cylinder 16, a Z-axis loading cylinder 17, and a high-pressure gas impact pipe 18. The lower part of the true triaxial loading host 1 is provided with a rigid base 11, which is used to bear the weight of the entire loading host and absorb the reaction force generated during the loading process. The reaction support structure 12 is provided on the base 11, and the reaction support structure 12 is symmetrically arranged and fixedly connected to the base 11 to provide stable reaction support for the horizontal loading components.

[0026] The reaction support structure 12 adopts an integral structural design, with a wedge-shaped or block-like shape, which can maintain high structural stiffness and stability under large loads. A true triaxial loading cavity 13, i.e., a sample sealed loading cavity, is set between the reaction support structures 12. The sample sealed loading cavity is formed by multiple high-strength loading plates and is used to place the coal sample 14 to be tested. The sample sealed loading cavity has a regular cubic or approximately cubic structure, with its six opposite end faces serving as three mutually perpendicular force-bearing surfaces. Each loading end face of the sample sealed loading cavity is equipped with a sealing structure to ensure that the cavity remains well-sealed during loading.

[0027] In the sealed loading cavity of the sample, an X-axis loading cylinder 15 and a Y-axis loading cylinder 16 are respectively arranged in two mutually perpendicular horizontal directions. Each X-axis loading cylinder 15 includes a loading cylinder, a piston rod, and a loading head. The loading cylinder is fixedly installed on the reaction support structure 12, and its piston rod extends horizontally toward the sealed loading cavity of the sample. The end of the piston rod abuts against the lateral loading plate of the sealed loading cavity of the sample through the loading head, and is used to apply lateral principal stress to the coal sample. The X-axis loading cylinder 15 and the Y-axis loading cylinder 16 are orthogonally arranged and independently controlled to achieve independent loading of principal stress in the two horizontal directions. A Z-axis loading cylinder 17 is arranged in the vertical direction of the sealed loading cavity of the sample. The Z-axis loading cylinder 17 is installed above the sealed loading cavity of the sample, and its loading cylinder is fixed by a mounting base. The piston rod extends downward vertically. The lower end of the piston rod contacts the top loading surface of the sealed loading cavity of the sample through the loading plate, and is used to apply vertical principal stress to the coal sample to simulate the pressure conditions of the overlying surrounding rock.

[0028] With the above structural configuration, the true triaxial loading host 1 can simultaneously apply three mutually perpendicular principal stress loads of independently adjustable magnitude to the coal sample, forming a true triaxial stress state. The loading components are mechanically decoupled through the reaction support structure 12 and independent installation method, avoiding mutual interference between loads in different directions during the loading process.

[0029] like Figure 3As shown, the hydraulic servo loading system B includes a first pressure sensor 21, a constant-speed and constant-pressure hydraulic pump 22, and a hydraulic pump display screen 23. The first pressure sensor 21 is used to collect real-time pressure signals during the loading process; the constant-speed and constant-pressure hydraulic pump 22 provides stable and controllable loading pressure, and an auxiliary pressurizing pump is used for rapid contact between the loading end face and the coal sample in the initial stage of the test; the hydraulic pump display screen 23 displays the operating parameters of the hydraulic pump and allows for setting loading parameters and monitoring operation. The hydraulic servo loading system 2 is connected to loading cylinders in the X, Y, and Z directions via high-pressure oil pipes, and achieves independent adjustment, loading, holding, and unloading of the three-dimensional stress through valve groups.

[0030] like Figure 4As shown, the gas pressurization and control system C includes a second pressure sensor 301, a reference bar 302, an outlet valve 303, a pressure regulating gauge 304, a pressure regulating valve 305, a high-pressure gas storage tank 306, a storage tank pressure gauge 307, an air compressor 308, a driving pressure regulator 309, a driving pressure gauge 310, a gas booster pump 311, a gas cylinder pressure gauge 312, and a CH4 gas cylinder 313. The second pressure sensor 301 is used to monitor the gas pressure inside the true triaxial loading chamber in real time and transmits the collected pressure signal to the data acquisition and control system 7, realizing real-time monitoring and closed-loop feedback control of the gas pressure inside the coal sample. The reference bar 302 is used to connect and fix the gas pipeline, playing a supporting and pressure-stabilizing role during gas transportation, ensuring the reliability and stability of the gas connection. The outlet valve 303 is used to control the on / off state of gas entering the true triaxial loading system; by opening or closing the outlet valve, the start and stop control of the gas loading process is realized. Pressure gauge 304 displays the output gas pressure value after adjustment by pressure regulating valve 305, allowing operators to intuitively grasp the actual gas pressure state loaded onto the coal sample. Pressure regulating valve 305 precisely regulates the gas pressure output from high-pressure gas storage tank 306, ensuring that the gas pressure entering the true triaxial loading chamber can be set and controlled according to test requirements. High-pressure gas storage tank 306 stores high-pressure gas after being pressurized by gas booster pump 311, providing a stable and continuous gas pressure source for the test process. Tank pressure gauge 307 displays the gas pressure state inside high-pressure gas storage tank 306 in real time, allowing for determination of whether the gas pressure inside the tank meets test requirements. Air compressor 308 provides a stable driving gas source for gas booster pump 311, providing power support for the booster pump's operation by outputting compressed air. Drive pressure regulating valve 309 adjusts the driving gas pressure output by air compressor 308, maintaining the driving pressure entering gas booster pump 311 within a suitable range. The driving pressure gauge 310 displays the real-time pressure value of the driving gas, facilitating monitoring of the working status of the air compressor 308 and the driving pressure regulating valve 309, and ensuring the stability of the pressurization process. The gas booster pump 311 is the core actuator of the gas pressurization and control system, used to pressurize the low-pressure gas from the CH4 cylinder 313 to the high-pressure state required for the test, and then deliver it to the high-pressure gas storage tank 306 for storage. The cylinder pressure gauge 312 displays the remaining gas pressure inside the CH4 cylinder 313, reflecting the gas source status in real time, and facilitating the determination of whether the cylinder needs to be replaced or replenished. The CH4 cylinder 313 provides the methane gas required for the test and is the basic gas source unit of the entire gas pressurization and control system, providing the original gas source for coal sample gas loading.

[0031] like Figure 5As shown, the vacuum system D includes a vacuum tank 41, a vacuum gauge 42, and a vacuum pump 43. The vacuum pump 43 is used to evacuate the true triaxial loading chamber and related gas paths. By continuously pumping out air and residual gas from the chamber, it ensures the coal sample test environment reaches the predetermined vacuum level, creating favorable initial conditions for subsequent gas loading. The vacuum tank 41 serves as a vacuum buffer and storage unit, stabilizing the vacuum pressure and buffering gas fluctuations during the vacuuming process, thereby improving the stability and reliability of the vacuuming process. The vacuum gauge 42 displays the real-time vacuum level values ​​inside the true triaxial loading chamber and vacuum tank 41, allowing operators to visually assess the current vacuuming effect and determine whether the required vacuum environment for the test is met.

[0032] like Figure 6 As shown, the high-pressure gas impact system E includes a firing tube cap 51, an 8mm bullet 52, a guide fixing sleeve 53, a firing barrel 54, a fixing flange 55, an electromagnet 56, an impact piston 57, a gas storage tank 58, and a pneumatic valve interface 59. The front end of the firing barrel is connected to the true triaxial loading cavity 1. The gas storage tank 58 is used to store high-pressure gas. By instantaneously releasing the high-pressure gas during the test, the 8mm bullet 52 is used to apply an impact load to the coal sample 14 to be tested.

[0033] like Figure 7As shown, the outburst and impact response system F includes a pressure sensor 61, a coal and gas outburst port 62, a rupture disc 63, a reference bar 64, a dryer 65, and a gas flow meter 66. The pressure sensor 61 monitors the gas pressure changes in the outburst and impact response channel in real time, acquiring and feeding back the instantaneous pressure signal generated during the impact or outburst to the data acquisition and control system 7, thereby achieving dynamic monitoring of the pressure response characteristics of the coal sample after impact disturbance. The coal and gas outburst port 62 provides a release channel for the gas inside the coal sample and the broken coal body during the test. When the coal sample is damaged under impact disturbance or high gas pressure, the outburst port can simulate the emission path of coal and gas outbursts in actual mines. The rupture disc 63, as a safety pressure relief and trigger response element, ruptures when the system pressure exceeds a set threshold, thereby simulating the sudden instability and release process of a rockburst or gas outburst, while also protecting the pipeline and equipment. Reference bar 64 is used to fix and support the pipelines and connecting components in the outburst and impact response system, ensuring stable connection and reliable operation of each component under impact disturbance conditions. Dryer 65 is used to dehumidify the gas discharged through outburst port 62, preventing moisture from entering subsequent testing instruments and pipelines and affecting measurement accuracy and equipment operational stability. Gas flow meter 66 is used to measure the flow rate of gas discharged through coal and gas outburst port 62 in real time during the test, and transmits the flow data to data acquisition and control system 7, providing quantitative basis for analyzing the gas release law during the rock pressure-induced gas outburst process.

[0034] The data acquisition and control system G is used to centrally control the hydraulic servo loading system B, the gas boosting and control system C, and the high-pressure gas impact system E, and to acquire true triaxial stress, gas pressure, and impact response data in real time.

[0035] The method for this mine dynamic disaster coupling simulation test device specifically includes the following steps: Before the test, the coal sample 14 was first processed to ensure its dimensions met the geometric requirements of the true triaxial loading cavity 13, and to ensure that all loading surfaces of the coal sample were flat and that dimensional errors were within the allowable range. To improve the airtightness of the coal sample during gas filling and impact loading, metal sheets were placed at the corners of the coal sample to form a rigid frame, and a flexible sealing material was wrapped around the outer surface of the coal sample. The sealing material was then firmly bonded to the metal sheets through an adhesive method to form an integral sealing structure, thereby preventing gas leakage during the test.

[0036] The sealed coal sample 14 is placed inside the true triaxial loading chamber 13, ensuring alignment between the coal sample and the three-dimensional loading end faces. The auxiliary pressurization function of the hydraulic servo loading system 2 is activated, causing the loading end faces in the X, Y, and Z directions to gradually approach the coal sample 14, achieving rapid contact between the loading end faces and the coal sample 14. Once the loading end faces are fully in contact with the coal sample 14, the auxiliary pressurization is deactivated.

[0037] The constant-speed, constant-pressure hydraulic pump 22 of the hydraulic servo loading system B is activated. By controlling the X-axis loading cylinder 15, Y-axis loading cylinder 16, and Z-axis loading cylinder 17 respectively, a predetermined triaxial principal stress is applied to the coal sample. During loading, the stress in each direction can be adjusted independently to achieve a non-equipotential true triaxial stress loading mode, thus reproducing the original geostress environment of the coal seam. The stress in each direction is monitored in real time by the first pressure sensor 21. Once the triaxial stress reaches the set value and remains stable, the next stage of the test begins.

[0038] After confirming that there is no residual gas in the true triaxial loading chamber, the vacuum system D is activated, and the vacuum pump 43 is started to evacuate the loading chamber and related gas paths. The vacuum level inside the chamber is monitored in real time using the vacuum gauge 42. Once the chamber pressure reaches the set vacuum level and remains stable, the vacuum system 4 is shut down to provide good initial conditions for subsequent gas filling. After the vacuuming is completed, the vacuum system D is shut down.

[0039] The gas pressurization and control system C is activated, and gas from CH4 cylinder 313 is pressurized by gas booster pump 311 and delivered to high-pressure gas storage tank 306. The output pressure is precisely regulated by pressure regulating valve 305, allowing the gas to slowly fill the true triaxial loading chamber. The gas pressure change inside the coal sample is monitored in real time by second pressure sensor 301. When the gas pressure reaches a predetermined value, it remains stable, placing the coal sample 14 under a coupled loading state of true triaxial stress and gas pressure, which is maintained for a period of time to reach adsorption equilibrium. After adsorption equilibrium is reached under stable conditions of true triaxial stress and gas pressure, the gas pressurization and control system C is turned off and remains unchanged for a period of time.

[0040] Under conditions where both true triaxial stress and gas pressure are stable, the high-pressure gas impact system E is activated. High-pressure gas is injected into the gas storage tank 58 via a pneumatic device. When the pressure reaches the set value, the high-speed release mechanism controlled by the electromagnet 56 is triggered, causing the high-pressure gas to be released instantaneously and pushing the 8mm bullet 52 along the firing barrel 54 to act at high speed on the coal sample 14 to be tested. In a very short time, a high-amplitude dynamic load is formed, thereby simulating the transient release of elastic energy and dynamic disturbance process of the surrounding rock during the occurrence of rockburst.

[0041] Under impact loading, stress instability and rapid gas release occur inside the coal sample. The released gas enters the outburst and impact response system F through the coal and gas outburst port 62. When the instantaneous pressure exceeds the set threshold of the rupture disc 63, the rupture disc 63 ruptures, thus characterizing the rockburst-induced gas outburst phenomenon in the coal sample. The pressure sensor 61 and the gas flow meter 66 monitor the pressure changes and gas flow rate in real time during the outburst process, providing data support for analyzing the disaster response characteristics.

[0042] During the impact loading process, the data acquisition and control system G collects and records multi-source information in real time, including stress change data in the X, Y and Z directions of the true triaxial loading system, dynamic change data of gas pressure inside the coal sample 14 to be tested, and impact response signal obtained by the external test module. At the same time, the deformation and failure process of the coal sample 14 to be tested is monitored and recorded synchronously.

[0043] After the high-pressure gas impact loading is completed, the outburst and impact response system E is first shut down to stop any additional disturbance to the coal sample. Then, the true triaxial loading chamber is depressurized via the hydraulic servo loading system B, gradually reducing the loading stress in all three directions to a safe range until the internal pressure is completely released. After confirming that there is no residual pressure in the loading chamber and that the system is in a safe state, the true triaxial loading chamber is opened, and the coal sample 14 is removed. The macroscopic damage morphology, crack distribution characteristics, and outburst damage of the coal sample 14 are observed and recorded. The stress, gas pressure, and impact response data collected during the test are organized, stored, and backed up. After data saving, the inside of the true triaxial loading chamber and related pipelines are cleaned and maintained, and the integrity of all connecting parts and sealing structures is checked. Finally, the data acquisition and control system G is shut down and the equipment power is disconnected, ending the test.

[0044] If this patent uses terms such as "first" and "second" to define components, those skilled in the art should know that the use of "first" and "second" is merely for the convenience of describing the invention and simplifying the description, and the above terms have no special meaning.

[0045] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this invention is defined by the appended claims and their equivalents.

[0046] In the description of this invention, it should be understood that the terms "front", "rear", "left", "right", "center", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to facilitate the description of this invention and to simplify the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this invention.

Claims

1. A coupled simulation test device for mine dynamic disasters, characterized in that: It includes a true triaxial loading system and a hydraulic servo loading system, a gas boosting and control system, a vacuum system, a high-pressure gas impact system and a protrusion and impact response system connected to its control system, as well as a data acquisition and control terminal connected to the signals of each system; The hydraulic servo loading system is connected to the true triaxial loading system and provides loading power to it; The gas pressurization and control system and the vacuum system are connected to the true triaxial loading system, which are used to vacuum the coal sample and inject gas into the coal sample to regulate the gas content and gas pressure of the coal sample. The high-pressure gas impact system includes a high-pressure gas release device, which applies an impact load to the coal sample by instantaneously releasing high-pressure gas. The outburst and impact response system includes a pressure sensor for real-time monitoring of gas pressure in the outburst and impact response channel and a coal and gas outburst outlet arranged in parallel with it. The pressure sensor collects the instantaneous pressure signal generated during the impact or outburst process and feeds it back to the data acquisition and control system. The coal and gas outburst outlet is used to provide a release channel and simulate the emission path of coal and gas outburst in the mine. The data acquisition and control terminal is used to acquire, record and centrally control the loading stress, gas pressure and impact response signals in real time.

2. The mine dynamic disaster coupling simulation test device according to claim 1, characterized in that: The true triaxial loading system includes a base, a reaction support structure mounted on the base, and a true triaxial loading cavity positioned above the reaction support structure for placing coal samples. The true triaxial loading cavity is equipped with an X-axis loading cylinder mechanism, a Y-axis loading cylinder mechanism, and a Z-axis loading cylinder mechanism, which independently apply loads to the coal sample.

3. The mine dynamic disaster coupling simulation test device according to claim 2, characterized in that: The X-axis loading cylinder mechanism and the Y-axis loading cylinder mechanism are each provided in two sets, and are symmetrically arranged on the corresponding outer end faces of the true triaxial loading cavity. Each loading cylinder mechanism includes a loading cylinder, a piston rod, and a loading head. The loading cylinder is fixedly installed on the reaction support structure. Its piston rod extends horizontally toward the true triaxial loading cavity, and the end of the piston rod abuts against the lateral loading plate arranged on the outside of the true triaxial loading cavity through the loading head and applies lateral principal stress to the coal sample.

4. The mine dynamic disaster coupling simulation test device according to claim 3, characterized in that: The Z-axis loading cylinder mechanism is installed above the true triaxial loading cavity and includes a loading cylinder, a piston rod, and a loading head. The loading cylinder is fixed by a mounting base, while the piston rod extends downward in the vertical direction. The lower end of the piston rod contacts the top loading surface of the true triaxial loading cavity through a loading plate, and is used to apply vertical principal stress to the coal sample.

5. The mine dynamic disaster coupling simulation test device according to claim 4, characterized in that: The hydraulic servo loading system is connected to the loading cylinders in the X, Y, and Z directions via high-pressure oil pipes, and achieves independent control of the three-dimensional stress through valve groups. The hydraulic servo loading system also includes a first pressure sensor for acquiring real-time pressure signals during the loading process, a constant-speed and constant-pressure hydraulic pump connected to the first pressure sensor, and a hydraulic pump display screen. The constant-speed and constant-pressure hydraulic pump is used to provide stable and controllable loading pressure.

6. The mine dynamic disaster coupling simulation test device according to claim 4, characterized in that: The gas boosting and control system includes a second pressure sensor, a high-pressure gas storage tank, and a gas boosting pump connected in sequence via pipelines. The second pressure sensor monitors the internal gas pressure value entering the true triaxial loading cavity in real time, and the pipeline between it and the high-pressure gas storage tank is also equipped with an outlet valve for controlling the gas supply and the regulating valve for adjusting the gas pressure output from the high-pressure gas storage tank. The gas booster pump is connected to the gas source and pressurizes it.

7. The mine dynamic disaster coupling simulation test device according to claim 5, characterized in that: The high-pressure gas release device of the high-pressure gas impact system includes a firing barrel, a striking piston installed in the firing barrel, an electromagnet, and a gas storage tank located at the end, and the gas storage tank is equipped with a pneumatic valve interface for introducing gas. The firing barrel also contains bullets for impact, and the front end of the firing barrel is connected to a true triaxial loading cavity.

8. A method for a coupled simulation test device for mine dynamic disasters according to any one of claims 5 to 7, characterized in that, Includes the following steps: (1) Before the test, prepare the coal sample to be tested, cover its outer surface with a flexible sealing material, and then place it in the true triaxial loading cavity; (2) Activate the auxiliary pressurization function in the hydraulic servo loading system to gradually bring the loading end face in the X, Y and Z directions closer to the coal sample, so as to achieve rapid contact between the loading end face and the coal sample to be tested. When the loading end face is completely in contact with the coal sample to be tested, turn off the auxiliary pressurization. (3) Start the constant speed and constant pressure hydraulic pump of the hydraulic servo loading system, control the loading cylinders in the X, Y and Z directions respectively, apply the predetermined triaxial principal stress to the coal sample to be tested, and monitor the stress in each direction in real time through the first pressure sensor. (4) Turn on the vacuum system to vacuum the true triaxial loading cavity and related gas paths. After the vacuum level reaches the required level, turn off the vacuum system. (5) Start the gas boosting and control system, and use the gas boosting pump to deliver the boosted gas to the high-pressure gas storage tank. The output pressure is precisely adjusted by the pressure regulating valve so that the gas slowly fills the true triaxial loading cavity and reaches adsorption equilibrium. Then, turn off the gas boosting and control system. (6) Under the condition that the true triaxial stress and gas pressure are both in a stable state, start the high-pressure gas impact system to simulate the transient release of elastic energy and dynamic disturbance process of the surrounding rock during the occurrence of rockburst; (7) Under the action of impact loading, stress instability and rapid gas release occur inside the coal sample to be tested. The released gas enters the outburst and impact response system through the coal and gas outburst port. The pressure sensor collects the instantaneous pressure signal generated during the impact or outburst process and feeds it back to the data acquisition and control system. (8) After the high-pressure gas impact loading is completed, first shut down the outburst and impact response system to stop the additional disturbance to the coal sample; then depressurize the true triaxial loading cavity through the hydraulic servo loading system until the internal pressure of the cavity is completely released; (9) Open the true triaxial loading chamber, take out the coal sample, observe and record the macroscopic damage morphology, crack distribution characteristics and outburst damage of the coal sample, and organize, store and back up the stress, gas pressure and impact response data collected during the test.

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