Impact-gas hybrid dynamic disaster in-situ simulation test system and method

Abstract

The invention discloses an impact-gas hybrid dynamic disaster in-situ simulation test system and method, and relates to the technical field of deep mines and engineering. The system comprises an outer shell and an inner shell, the inner shell is located in the outer shell, a three-way pressurizing device, a counter-force frame and a collapse device are arranged between the outer shell and the inner shell, a mining robot is arranged behind the inner shell, a heating plate is arranged below the inner shell, and the counter-force frame and the outer shell are each provided with an inflation hole. The test method comprises the following steps: loading a coal rock test piece, applying three-dimensional stress, simulating ground temperature, filling gas, keeping air pressure balance of an inner cavity and an outer cavity, and simulating induced disasters through operation of the mining robot and roof collapse. According to the method, the onsite coal seam occurrence environment and the disaster evolution process can be comprehensively restored, integrated simulation of the single disaster and the composite disaster is achieved, the method can be used for analyzing the composite disaster evolution disaster-inducing law and the critical condition for converting the single disaster into the composite disaster, and technical support is provided for deep mine disaster prevention and control.

Description

Technical Field

[0001] This invention relates to the field of deep mining and deep engineering technology, specifically to an in-situ simulation test system and method for shock-gas composite dynamic disasters. Background Technology

[0002] In underground coal mining, the phenomenon of coal and gas suddenly erupting from the coal face into the working space within a very short time is called a coal and gas outburst (or simply outburst). Outbursts are an extremely complex dynamic phenomenon in coal mines, capable of suddenly ejecting large amounts of gas and coal / rock from the coal seam into the roadway or mining area within a very short time, accompanied by certain dynamic effects such as overturning mine cars and damaging supports. Rockbursts refer to the sudden and violent destructive dynamic phenomenon caused by the instantaneous release of elastic deformation energy in the coal (rock) mass around the mine roadway or working face, often accompanied by instantaneous displacement of the coal (rock) mass, ejection, loud noises, and blast waves. Rockbursts and coal and gas outbursts are two of the most typical dynamic hazards encountered in coal mining. In shallow mining, the interaction between the two hazards is not very significant, usually manifesting as a single disaster pattern. As my country's coal mining gradually enters the deep mining stage, due to the characteristics of high stress and high gas occurrence in deep mines, the interaction between the two disasters has begun to emerge and intensify. This shows that the two disasters influence, induce, and reinforce each other, resulting in coupled disasters. Deep disasters have been fully transformed into shock-gas composite dynamic disasters.

[0003] Due to the suddenness, concealment, and destructive nature of coal and gas outbursts and rockbursts, conducting on-site research is extremely difficult and dangerous. Therefore, physical simulation experiments are an effective method. Currently, the concept of studying coal and gas outbursts and rockbursts separately can no longer meet the needs of deep mine dynamic disaster management. Therefore, studying deep mine dynamic disasters as a whole, and developing integrated prediction and prevention technologies, has become a major requirement for the safe and efficient mining of coal in deep mines. Summary of the Invention

[0004] The purpose of this invention is to propose an in-situ simulation test system and method for shock-gas composite dynamic disasters, so as to solve the problems existing in the prior art.

[0005] The technical solution adopted by this invention is as follows: Firstly, this invention proposes an in-situ simulation test system for shock-gas composite dynamic disasters, comprising:

[0006] outer shell;

[0007] The inner shell is placed inside the outer shell and is used to hold the coal and rock specimens;

[0008] The three-dimensional pressurization device is respectively placed on the top, left side and front end of the inner shell, and is used to apply three-dimensional pressure to the coal and rock specimen. The rear end of each pressurization device is fixed to the inner wall of the outer shell. The three-dimensional pressurization device includes a composite cylinder and a distributed pressure plate. The composite cylinder is fixedly connected to the distributed pressure plate through a piston rod.

[0009] The reaction frame is located inside the outer shell, below and on the right side of the inner shell. Its front end is fixedly connected to the outer wall of the inner shell, and its rear end is fixedly connected to the inner wall of the outer shell. Slots are opened inside the reaction frame, and an air hole II and a sensor hole communicating with the inner shell are arranged in the two slots respectively.

[0010] The caving device includes a vertical caving mechanism and a caving pressure plate. The vertical caving mechanism is fixed above the outer shell and is connected to the caving pressure plate via a piston rod. The caving device is used to generate impact loads on coal and rock specimens.

[0011] The mining robot, located at the rear of the inner shell, is used to mine coal and rock specimens.

[0012] As a further improvement of the present invention, the composite cylinder is composed of multiple individual cylinders, the distributed pressure plate is composed of multiple individual pressure plates, the individual cylinders and the individual pressure plates are connected by piston rods, the individual pressure plates are arranged in an array on the upper surface of the coal and rock specimen, and there is space between the individual pressure plates.

[0013] As a further improvement of the present invention, the vertical collapse mechanism includes a plurality of individual hydraulic cylinders arranged in a linear manner, the collapse pressure plate is an integral pressure plate, and the collapse pressure plate is located in the space between the individual pressure plates.

[0014] As a further improvement of the present invention, the outer shell is cylindrical, closed at both ends, and supported at the bottom by a base. The inner shell is cuboid, closed at one end, and connected to the rear end cover of the outer shell at the other end.

[0015] As a further improvement of the present invention, an air inlet I is provided on the outer shell.

[0016] As a further improvement of the present invention, a heating plate is provided below the inner shell for heating the coal and rock specimen.

[0017] As a further improvement of the present invention, an openable sealing baffle is provided in the middle of the rear end cover of the outer shell, and the sealing baffle is made of a brittle material.

[0018] Secondly, this invention also proposes an in-situ simulation test method for shock-gas composite dynamic disasters, employing the aforementioned in-situ simulation test system for shock-gas composite dynamic disasters, comprising the following steps:

[0019] Step S1: For mines where shock-gas combined dynamic disaster simulation is to be carried out, the triaxial stress, ground temperature, gas pressure, and physical and mechanical parameters of the coal seam, roof and floor are tested on site. Based on the actual parameters on site and similarity theory, the test plan is formulated and coal and rock specimens are prefabricated.

[0020] Step S2: Open the sealing baffle, load the coal and rock specimen, install the sensor and mining robot, and then close the sealing baffle;

[0021] Step S3: Start the triaxial pressurization device to apply triaxial stress to the coal and rock specimen in a distributed manner to simulate the stress distribution law of the three zones in the field;

[0022] Step S4: Activate the heating plate to heat the coal and rock specimens, simulating the on-site ground temperature;

[0023] Step S5: Open the air inlet II and fill the coal and rock specimen with methane gas. After the coal and rock specimen is saturated with adsorption, open the air inlet I and fill the outer shell with methane gas to maintain the gas pressure balance between the inner and outer shells and the coal and rock specimen.

[0024] Step S6: When the stress, temperature, and gas pressure of the coal and rock specimen are similar to those on site, start the mining robot and begin mining operations;

[0025] Step S7: If no outburst occurs during the mining operation, activate the vertical collapse structure to simulate the roof collapse on site and apply impact load to the coal and rock specimens until an impact-gas combined dynamic disaster is induced; if an outburst occurs during the mining operation, repeat steps 2-6 and reduce the mining operation speed until no outburst occurs during the mining operation, and then activate the vertical collapse structure to induce an impact-gas combined dynamic disaster.

[0026] Step S8: After the experiment, collect the experimental data, analyze the evolution and disaster-causing laws of shock-gas composite dynamic disasters, and compare and study the critical conditions for the transformation from single disasters to composite disasters.

[0027] Compared with the prior art, the present invention has the following technical advantages:

[0028] (1) This invention realizes in-situ simulation of impact-gas composite dynamic disaster from all aspects, including specimen materials, occurrence environment, and evolution process: in terms of specimen materials, the similarity of physical and mechanical properties of coal seams in the field is considered; in terms of occurrence environment, the stress, temperature and gas pressure conditions of coal seams in the coal mine are realistically restored; in terms of evolution process, the evolution process of disaster induced by external disturbance conditions is realized through mining robot mining and roof collapse activities, avoiding the unreasonable operation of traditional artificially induced disasters.

[0029] (2) This invention realizes the integrated simulation of single disasters and compound disasters. It can carry out simulation tests of single dynamic disasters (such as outburst, extrusion, dumping, impact, etc.) and impact-gas compound dynamic disasters, as well as simulation tests of the mutual induction, mutual reinforcement and coupling of different disasters to cause disaster evolution.

[0030] (3) By setting up inner and outer cavities and balanced pressure, the present invention achieves a relatively stable state of coal seam gas pressure under dynamic load disturbance conditions such as mining and collapse, which is more consistent with the actual situation and solves the problem that the internal gas pressure will drop rapidly once the coal body is damaged in the traditional simulation process. Attached Figure Description

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] Figure 1 This is a cross-sectional view of the in-situ simulation test system for impact-gas composite dynamic disasters of the present invention;

[0033] Figure 2 This is a cross-sectional view of the in-situ simulation test system for impact-gas composite dynamic disasters of the present invention;

[0034] Figure 3 This is a diagram showing the distribution of the distributed pressure plate and the collapse pressure plate in the in-situ simulation test system for impact-gas composite dynamic disasters of the present invention.

[0035] In the figure, 1-outer shell; 2-inner shell; 3-base; 4-coal and rock specimen; 5, 8, 16-composite hydraulic cylinder; 6, 9, 17-distributed pressure plate; 7, 10-reaction frame; 11-vertical caving mechanism; 12-caving pressure plate; 13-air inlet I; 14-air inlet II; 15-sensor hole; 18-mining robot; 19-sealing baffle; 20-heating plate; 21-hydraulic cylinder piston rod; 22-caving mechanism piston rod. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0037] like Figure 1 and Figure 2As shown, the present invention provides an in-situ simulation test system for impact-gas composite dynamic disasters, comprising an outer shell 1, an inner shell 2, a three-way pressurization device, reaction frames 7 and 10, a collapse device, and a mining robot 18. Specifically, the outer shell 1 is cylindrical, made of steel plate, with a diameter of 2 meters and a length of 4 meters, and is closed at both ends. The bottom of the outer shell 1 is supported by a base 3. The inner shell 2 is a cuboid, with the front end face (i.e., Figure 2 The outer shell 1 is enclosed on its left side. The inner shell 2 has a square cross-section with a side length of 1 meter. The inner shell 2 is located in the middle of the outer shell 1 and is used to place the coal and rock specimen 4. A three-dimensional pressurization device is located between the outer shell 1 and the inner shell 2 to apply three-dimensional pressure to the coal and rock specimen 4. Figure 1 and Figure 2 The pressure is measured in the X, Y, and Z directions. Specifically, the three-way pressurization device is located on the top, left side, and front end of the inner shell 2, respectively, and includes compound cylinders 5, 8, and 16, as well as distributed pressure plates 6, 9, and 17. Figure 3 As shown, taking the combined hydraulic cylinder 5 as an example, it includes 64 individual hydraulic cylinders arranged in a 4x16 (width) x 16 (length) array. Each individual hydraulic cylinder is connected to one of the individual pressure plates in the distributed pressure plate 6 via a piston rod. The distributed pressure plate 6 contacts the coal and rock specimen 4 (the inner shell 2 opens here), leaving space between the individual pressure plates. Each individual hydraulic cylinder is equipped with a solenoid valve, which is controlled by a PLC to coordinate the operation of the grouped solenoid valves, thereby controlling the hydraulic cylinder piston rod 21 to drive the individual pressure plate to apply pressure to the coal and rock specimen 4 to simulate the stress of deep rock strata. It should be noted that this composite hydraulic cylinder 5, 8, and 16 has two working modes. The first mode is that all the individual hydraulic cylinders in each composite hydraulic cylinder 5, 8, and 16 operate simultaneously, driving all the individual pressure plates to apply pressure to the coal and rock specimen 4 via the hydraulic cylinder piston rod 21. The second mode is that some of the individual hydraulic cylinders operate simultaneously, applying local pressure to the coal and rock specimen 4 to form distributed stress. The two types of pressure can simulate the equilibrium and non-equilibrium stress of the coal seam, making the simulation more realistic and the test data more accurate.

[0038] The reaction frames 7 and 10 are located inside the outer shell 1, below and to the right of the inner shell 2. Slots are formed inside the reaction frames 7 and 10, with an inflation port II14 and a sensor connection hole 15 respectively arranged in each slot, communicating with the outer shell 1. The two reaction frames 7 and 10 support the inner shell 2 and the pressure applied by the pressurizing device, and their rear ends are fixed to the inner wall of the outer shell 1. The sensor connection hole 15 connects to a pressure gauge for measuring gas pressure, a concentration sensor, and temperature and humidity sensors for measuring the internal temperature and humidity of the coal and rock specimen 4.

[0039] The collapse device includes a vertical collapse mechanism 11 and a collapse pressure plate 12. The vertical collapse mechanism 11 is located above the outer shell 1, and the collapse pressure plate 12 is located between the inner shell 2 and the outer shell 1. The vertical collapse mechanism 11 and the collapse pressure plate 12 are fixedly connected. Specifically, the vertical collapse mechanism 11 is a composite hydraulic cylinder consisting of four individual hydraulic cylinders arranged in a row. The collapse pressure plate 12 is an integral steel plate distributed in the space between the individual pressure plates of the distributed pressure plates 6, 9, and 17, and is staggered from the individual pressure plates. When the collapse device is working, the collapse pressure plate 12 is driven by the four individual hydraulic cylinders in the composite hydraulic cylinder to move downward from above the coal and rock specimen 4, impacting the coal and rock specimen 4 to simulate the impact load caused by roof collapse. Unlike the static pressure generated by the pressurizing device on the coal and rock specimen 4, the collapse device generates dynamic pressure.

[0040] A square opening is made on the rear end cover of the outer shell 1. This square opening is fixedly connected to the rear port edge of the inner shell 2, providing support for the inner shell 2 from the rear end. The square opening is used to place the coal and rock specimen 4 into the inner shell 2. After the coal and rock specimen 4 is placed, this square opening is sealed with a sealing baffle 19. The sealing baffle 19 is made of a brittle material, which can seal gas pressure but cannot withstand the impact load of coal and rock.

[0041] A mining robot 18 was placed inside the inner shell between the coal and rock specimen 4 and the square opening to simulate the disturbance generated by actual coal mining operations. The mining robot 18 is a robotic arm with a roller at the front end, which applies mining disturbance to the coal and rock specimen 4. The mining robot 18 is a traditional industrial robot, and details are not described in detail.

[0042] In addition, an air inlet I13 is provided on the outer shell 1, and a heating plate 20 is provided below the inner shell 2.

[0043] The simulation test system of the present invention uses a three-way pressurization device, a heating plate and an inner and outer cavity air-filling structure to simultaneously simulate ground stress, ground temperature and gas pressure, so as to achieve a high degree of similarity between the specimen material and the on-site conditions.

[0044] By integrating pressurization, mining, and caving devices, this system can conduct single-hazard experiments as well as simulate complex disaster processes where two hazards mutually induce and reinforce each other, overcoming the limitations of traditional single-hazard research. The inclusion of mining robots and vertical caving devices replicates the natural disturbances of on-site mining operations and roof collapse, avoiding the irrationality of human-induced disturbances. Through the dual-cavity design of the outer shell 1 and inner shell 2, and gas pressure balance control, even if the coal and rock specimen 4 is disturbed and damaged, the gas pressure can still maintain relative stability, solving the problem of pressure instability in traditional simulations.

[0045] This invention also proposes an in-situ simulation test method for shock-gas composite dynamic disasters, comprising the following steps:

[0046] Step S1: For mines where shock-gas combined dynamic disaster simulation is to be carried out, conduct on-site testing of the three-dimensional geostress, geothermal temperature, gas pressure, and physical and mechanical parameters of the coal seam, roof, and floor; formulate an experimental plan based on the actual on-site parameters and similarity theory, and prefabricate coal and rock specimens 4.

[0047] Step S2: Open the sealing baffle 19, load the coal and rock specimen 4, install the sensor and mining robot 18, and then close the sealing baffle 19.

[0048] Step S3: Start the triaxial pressurization device to apply triaxial stress to the coal and rock specimen 4 in a distributed manner to simulate the stress distribution law of the three zones in the field;

[0049] Step S4: Start the heating plate 20 to heat the coal and rock specimen 4 to simulate the on-site ground temperature.

[0050] Step S5: Open the air inlet II14 and fill it with gas. Wait until the coal and rock specimen 4 is saturated with adsorption, then open the air inlet I13 and fill it with gas to maintain the pressure balance between the inner and outer cavities.

[0051] Step S6: When the coal seam stress, temperature, and gas pressure are similar to those at the site, start the mining robot 18 to begin mining operations. The disturbance caused by the robot's mining can induce coal and gas outbursts, which manifest as the rapid movement of coal and gas into the mining space, i.e., the outburst dynamic phenomenon.

[0052] Step S7: If no outburst occurs during the mining operation, activate the vertical collapse structure 11 to simulate roof collapse and apply impact load to the coal and rock specimen 4 until an impact-gas combined dynamic disaster is induced. If an outburst occurs prematurely during the mining operation, repeat steps 2-6 and reduce the mining speed until no outburst occurs during the mining operation. Then, activate the vertical collapse structure 11 to induce an impact-gas combined dynamic disaster. This step adjusts the mining speed based on whether an outburst occurs prematurely during the mining operation and then induces a combined disaster through roof collapse. This allows for precise research on the critical conditions for the transformation from a single disaster (gas outburst) to a combined disaster (collapse-induced impact-gas outburst).

[0053] Step S8: After the experiment, collect experimental data, analyze the evolution and hazard-causing patterns of shock-gas composite dynamic disasters, and compare and study the critical conditions for the transformation from single disasters to composite disasters. Through the collection of data throughout the entire process, the evolution and hazard-causing patterns of composite disasters can be systematically analyzed, providing direct technical support for the prediction and prevention of composite disasters.

[0054] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited thereto. Various changes that can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention are all within the protection scope of the claims of the present invention.

Claims

1. An in-situ simulation test system for shock-gas composite dynamic disasters, characterized in that, include: Outer shell (1); The inner shell (2) is placed inside the outer shell (1) and is used to place the coal and rock specimen (4); The three-dimensional pressurization device is placed on the top, left side and front end of the inner shell (2) respectively, and is used to apply three-dimensional pressure to the coal and rock specimen (4). The rear end of each pressurization device is fixed to the inner wall of the outer shell (1). The three-dimensional pressurization device includes a composite cylinder (5, 8, 16) and a distributed pressure plate (6, 9, 17). The composite cylinder (5, 8, 16) is fixedly connected to the distributed pressure plate (6, 9, 17) through a piston rod. The reaction frame (7, 10) is located inside the outer shell (1), below and on the right side of the inner shell (2). Its front end is fixedly connected to the outer wall of the inner shell (2), and its rear end is fixedly connected to the inner wall of the outer shell (1). Slots are opened inside the reaction frame (7, 10), and an air inlet II (14) and a sensor hole (15) communicating with the inner shell (2) are arranged in the two slots respectively. The caving device includes a vertical caving mechanism (11) and a caving pressure plate (12). The vertical caving mechanism (11) is fixed above the outer shell (1). The vertical caving mechanism (11) is connected to the caving pressure plate (12) through a piston rod. The caving device is used to generate impact loads on the coal and rock specimen (4). The mining robot (18) is located behind the inner shell (2) and is used to mine coal and rock specimens (4).

2. The in-situ simulation test system for shock-gas composite dynamic disasters according to claim 1, characterized in that, The composite cylinder (5) is composed of multiple individual cylinders, and the distributed pressure plate (6) is composed of multiple individual pressure plates. The individual cylinders and individual pressure plates are connected by piston rods. The individual pressure plates are arranged in an array on the upper surface of the coal and rock specimen (4), and there is space between the individual pressure plates.

3. The in-situ simulation test system for shock-gas composite dynamic disasters according to claim 2, characterized in that, The vertical collapse mechanism (11) includes multiple individual hydraulic cylinders arranged in a linear arrangement, and the collapse pressure plate (12) is an integral pressure plate located in the space between the individual pressure plates.

4. The in-situ simulation test system for shock-gas composite dynamic disasters according to claim 1, characterized in that, The outer shell (1) is cylindrical, closed at both ends, and supported at the bottom by a base (3). The inner shell (2) is cuboid, closed at one end, and connected to the rear end cover of the outer shell (1) at the other end.

5. The in-situ simulation test system for shock-gas composite dynamic disasters according to claim 1, characterized in that, An air inlet I (13) is provided on the outer shell (1).

6. The in-situ simulation test system for shock-gas composite dynamic disasters according to claim 1, characterized in that, A heating plate (20) is provided below the inner shell (2) for heating the coal and rock specimen (4).

7. The in-situ simulation test system for shock-gas composite dynamic disasters according to claim 1, characterized in that, The outer shell (1) has an openable sealing baffle (19) in the middle of the rear end cover, and the sealing baffle (19) is made of brittle material.

8. A method for in-situ simulation testing of shock-gas combined dynamic disasters, employing the in-situ simulation testing system for shock-gas combined dynamic disasters as described in any one of claims 1-7, characterized in that, Includes the following steps: Step S1: For mines that need to carry out shock-gas composite dynamic disaster simulation, conduct on-site testing of the three-dimensional geostress, geothermal temperature, gas pressure and physical and mechanical parameters of coal seam, roof and floor, formulate test plan based on actual on-site parameters and similarity theory, and prefabricate coal and rock specimens (4). Step S2: Open the sealing baffle (19), load the coal and rock specimen (4), install the sensor and mining robot (18), and then close the sealing baffle (19); Step S3: Start the triaxial pressurization device to apply triaxial stress to the coal and rock specimen (4) in a distributed manner to simulate the stress distribution law of the three zones in the field; Step S4: Start the heating plate (20) to heat the coal and rock specimen (4) to simulate the on-site ground temperature; Step S5: Open the air inlet II (14) and fill the coal and rock specimen (4) with gas. After the coal and rock specimen (4) is saturated with adsorption, open the air inlet I (13) and fill the outer shell (1) with gas to maintain the pressure balance between the inner and outer shells and the coal and rock specimen (4). Step S6: When the stress, temperature and gas pressure of the coal and rock specimen (4) are similar to those on site, start the mining robot (18) and begin mining operations; Step S7: If no outburst occurs during the mining operation, activate the vertical collapse structure (11) to simulate the collapse of the roof on site and apply impact load to the coal and rock specimen (4) until an impact-gas composite dynamic disaster is induced; if an outburst occurs during the mining operation, repeat steps 2-6 and reduce the mining operation speed until no outburst occurs during the mining operation, and then activate the vertical collapse structure (11) to induce an impact-gas composite dynamic disaster. Step S8: After the experiment, collect the experimental data, analyze the evolution and disaster-causing laws of shock-gas composite dynamic disasters, and compare and study the critical conditions for the transformation from single disasters to composite disasters.

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