A composite dynamic disaster simulation device and method for deep coal mining

Abstract

The present invention discloses a composite dynamic disaster simulation device for deep coal mining, which belongs to the technical field of coal mining simulation equipment. The device comprises a fixed base, a guide rod frame and a sliding sleeve. A frame body is fixedly installed at the center of the upper end of the fixed base. A carrier cylinder is slidably and detachably mounted on one side of the frame body, and coal blocks are stored in the carrier cylinder. Stress loading units are evenly and equidistantly mounted on the inner wall of the carrier cylinder. An air supply mechanism is mounted on the end of the carrier cylinder away from the fixed base. A composite dynamic disaster simulation method for deep coal mining is also disclosed. In the present invention, a standard cylindrical coal block can be placed in the carrier cylinder, and a plurality of stress loading units distributed in the carrier cylinder can realize a two-stage composite loading of axial multi-point torsion and radial slip of the coal block. The air supply mechanism can transport gas in the coal block, simulate the coupling effect of underground working vibration and gas seepage, and provide fidelity data for multi-physical field coupling model verification.

Description

Technical Field

[0001] The invention belongs to the technical field of coal mining simulation equipment, and in particular provides a device and method for simulating composite dynamic disasters in deep coal mining. Background Art

[0002] Deep mining faces a complex environment of high ground stress, high gas pressure, and strong disturbance, resulting in frequent occurrence of complex dynamic disasters (such as rock burst, coal and gas outburst, rock burst, etc.). These disasters are usually triggered by the coupling of multiple physical fields such as sudden ground stress, gas seepage instability, and mining disturbance, and are characterized by suddenness, chain reaction, and strong destructiveness. Currently, most experimental devices for simulating dynamic disasters use hydraulic servo testing machines, which can only simulate axial or radial static loading and cannot reproduce the complex environment of dynamic torsional stress and multi-directional stress coupling in deep mining. In addition, traditional hydraulic loading systems can only apply unidirectional pressure, while the shear stress and torsional stress of deep rock formations are difficult to simulate. Therefore, it is necessary to provide a device and method for simulating complex dynamic disasters in deep coal mining to solve the above problems. Summary of the Invention

[0003] In order to solve the above problems, the present invention provides a device and method for simulating composite dynamic disasters in deep coal mining.

[0004] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a composite dynamic disaster simulation device for deep mining in coal mines, comprising a fixed base, a guide rod frame and a sliding sleeve, the fixed base and the sliding sleeve are respectively assembled at both ends of the guide rod frame, and the sliding sleeve is slidably assembled on one end of the guide rod frame, a frame body is fixedly installed at the center of the upper end of the fixed base, a carrier cylinder is slidably and removably assembled horizontally on one side of the frame body, and coal rock blocks are stored in the carrier cylinder, a movable seat is fixedly installed on the sliding sleeve, a displacement adjuster is arranged between the fixed base and the movable seat, stress loading units are evenly and equidistantly assembled on the inner wall of the carrier cylinder, and the stress loading units are located on the circumference of the coal rock block, and an air supply mechanism is assembled at the end of the carrier cylinder away from the fixed base.

[0005] Furthermore, a horizontal borehole is pre-drilled on the central axis of the coal rock block, a surrounding rock simulation bracket is installed in the horizontal borehole, and stress sensors are distributed on the surface of the surrounding rock simulation bracket.

[0006] Furthermore, the stress loading unit includes an inner ring seat, and a plurality of the inner ring seats are coaxially rotatably assembled in the carrier tube. The outer wall of the inner ring seat is in sealing contact with the inner wall of the carrier tube. The outer wall of the inner ring seat is symmetrically provided with mounting grooves. A protrusion is integrally formed on the lower side of the inner wall of the carrier tube, and the mounting groove on the lower side is arranged at the protrusion. A pre-compression support spring is arranged between the inner wall of the mounting groove on the lower side and the outer wall of the protrusion. The inner wall of the inner ring seat is provided with a rotating ring, and the rotating ring is sleeved on the periphery of the coal rock block. Two hydraulic channels are symmetrically provided on the upper side of the inner wall of the carrier tube. The hydraulic channels are arc-shaped channels, and the hydraulic channels are connected to the mounting groove on the upper side. The outer wall of the carrier tube is provided with a liquid guide hole connected to the hydraulic channel, and a pressure self-locking valve device is integrated in the liquid guide hole.

[0007] Furthermore, the inner wall of the rotating ring is provided with convex edges distributed around its circumference, and the convex edges and the outer contour of the coal block form an interference nesting structure;

[0008] A sealing sleeve is assembled on the side of the movable seat close to the carrier tube. The sealing sleeve is slidably sleeved on the outside of the carrier tube through an axial slide rail mechanism. A hydraulic quick-change joint group corresponding to the liquid guide hole is integrated on the sealing sleeve. The hydraulic quick-change joint group and the liquid guide hole realize sliding sealing docking.

[0009] Furthermore, the inner wall of the inner ring seat is symmetrically provided with sliding cavities, and a limit spring is installed in the sliding cavity on the lower side. The outer wall of the rotating ring is symmetrically integrally formed with protrusions, and the two protrusions are respectively slidably assembled in the sliding cavity. The outer walls of the two protrusions are symmetrically fixed with guide shafts, and the guide shafts are slidably connected to the inner ring seat. A through hole is provided on the side wall of the inner ring seat, and the through hole is connected to the sliding cavity on the upper side. An arc-shaped liquid cavity is provided on the inner wall of the carrier tube, and the arc-shaped liquid cavity is connected to the through hole.

[0010] Furthermore, a shaft sleeve is fixedly installed in the liquid guide hole on one side, a delivery hole is symmetrically opened below the shaft sleeve, a cut-off tube is slidably assembled in the shaft sleeve, a side hole corresponding to the delivery hole is opened on the side wall of the cut-off tube, a node tube is vertically connected to the lower end of the shaft sleeve, the lower end of the node tube is connected to the arc-shaped liquid cavity, a sealing shaft is fixedly installed on the inner wall of the shaft sleeve through a bracket, and a direct current hole that slides with the sealing shaft is opened at the lower end of the cut-off tube.

[0011] Furthermore, a movable ring is fixedly installed on the outer wall of the intercepting tube, a movable groove is opened on the inner wall of the shaft sleeve, and an inner spring is assembled between the movable ring and the movable groove. The inner spring drives the intercepting tube to separate from the sealing shaft through elastic force, and at this time the delivery hole and the side hole slide and stagger.

[0012] Furthermore, the air supply mechanism includes a positioning seat, and the positioning seat is coaxially fixed to the end of the carrier tube, an embedded tube is axially arranged on the positioning seat, an air hole is provided on the surface of the embedded tube, an air guide cavity is cocentrically arranged in the positioning seat, and the embedded tube is connected to the air guide cavity, the center of the movable seat is rotated and equipped with an axial tube, and one end of the axial tube is extended into and connected to the air guide cavity, the side wall of the axial tube is provided with a side discharge port connected to the air guide cavity, and the other end of the axial tube is connected to a gas pipe.

[0013] Furthermore, a driving part is provided in the movable seat, and the driving part is connected to the shaft tube through gear transmission, a gear ring seat is fixedly installed at one end of the shaft tube, and the gear ring seat is rotatably assembled in the air guide cavity, a mounting frame is fixedly installed in the air guide cavity, a rotating tube and a driven tooth are rotatably assembled on the mounting frame, and the end of the rotating tube is fixedly installed on the driven tooth, the driven tooth is engaged with the gear ring seat, the end of the rotating tube is connected to the air guide cavity, the end of the buried tube is fixedly installed on the mounting frame, and the rotating tube is coaxially rotatably assembled in the buried tube, and an eccentric block is evenly fixed on the outer wall of the rotating tube.

[0014] A method for simulating complex dynamic disasters in deep coal mining, using the above-mentioned complex dynamic disaster simulation device for deep coal mining, specifically comprises the following steps:

[0015] S1. Process the natural coal rock into a standard cylindrical specimen, pre-drill a horizontal hole at the axis of the coal rock block, install a retractable surrounding rock simulation bracket in the hole, and attach a distributed array of stress sensors to the surface of the surrounding rock simulation bracket;

[0016] S2. Place the coal block in the center of the carrier tube and secure it with interference fit using the inner convex edge of the swivel. Install the sealing sleeve and connect it to the hydraulic system. Install a gas pipe outside the shaft tube to supply the gas mixture.

[0017] S3. The displacement regulator drives the movable seat to slide horizontally and approach the fixed base. The sealing sleeve on the movable seat gradually moves axially along the carrier tube, and the hydraulic quick-change joint group is connected with the various liquid guide holes on the outer wall of the carrier tube in sequence. After the connection is completed, hydraulic oil is injected under high pressure through the hydraulic system. At this time, the intercepting pipe is hydraulically pushed to seal its end with the sealing shaft, and the delivery hole is connected with the side hole. The inner ring seat is hydraulically pushed to deflect forward or reverse to achieve the rotation adjustment of the swivel. According to the requirements of the simulation experiment, the swivels distributed along the axial direction of the coal rock block are used to perform stress loading under different or the same rotation directions;

[0018] S4: The sealing sleeve moves in the opposite direction with the movable seat and is connected to the corresponding liquid guide hole by the hydraulic quick-change joint assembly. At this time, hydraulic oil is injected into the hydraulic system at a low pressure and steady flow. The end of the intercepting pipe is separated from the sealing shaft, and the hydraulic oil gradually flows into the sliding cavity. A relative displacement occurs between the rotating ring and the inner ring seat, thereby realizing radial stress loading on the coal rock block.

[0019] S5. The gas pipeline injects high-pressure gas into the gas guide cavity through the axial tube. At the same time, the rotating tube rotates at 50 to 200 rpm, generating periodic disturbance waves through the eccentric block;

[0020] S6. Real-time recording of peripheral stress changes, hydraulic fluctuations, gas flow, and torque changes of the surrounding rock simulation support, combined with digital imaging technology to capture the evolution of coal and rock block fracture morphology.

[0021] The beneficial effects of using the present invention are:

[0022] In the present invention, a standard cylindrical coal rock block can be placed in a carrier tube, and multiple stress loading units arranged and distributed in the carrier tube can perform torsional stress loading from corresponding positions. Among them, multiple rotating rings distributed along the axial direction of the coal rock block can realize initial stress loading by rotating forward and reverse with the inner ring seat. After the initial loading is completed, the corresponding rotating rings can move radially to achieve the effect of secondary radial stress loading, and finally realize the dual-stage composite loading of axial multi-point torsion and radial slip of the coal rock block.

[0023] In addition, the air supply mechanism can deliver a certain concentration of gas into the coal rock blocks, thereby simulating gas outbursts. The rotating pipes distributed in the multiple buried pipes can provide periodic disturbance effects through the eccentric blocks under continuous rotation, further simulating the coupling effect of underground working vibration and gas seepage. By integrating distributed stress sensors on the surrounding rock simulation bracket, the changes in the internal stress field of the coal rock can be captured in real time, providing fidelity data for the verification of the multi-physics field coupling model. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a three-dimensional schematic diagram of the present invention.

[0025] Figure 2 It is a cross-sectional view of the internal structure of the carrier tube of the present invention.

[0026] Figure 3 Schematic diagram of the structure of the stress loading unit of the present invention.

[0027] Figure 4 It is a structural schematic diagram of the shaft sleeve and the intercepting pipe of the present invention.

[0028] Figure 5 Schematic diagram of the structure of the air supply mechanism of the present invention.

[0029] Figure 6 It is a structural schematic diagram of the gear ring seat of the present invention.

[0030] Reference numerals include: 1, fixed base; 11, frame body; 12, movable seat; 121, sliding sleeve; 13, displacement regulator; 14, guide rod frame; 15, surrounding rock simulation bracket; 2, carrier tube; 21, hydraulic channel; 22, liquid guide hole; 23, pressure self-locking valve device; 24, shaft sleeve; 25, conveying hole; 26, intercepting pipe; 27, side hole; 28, joint pipe; 29, sealing shaft; 3, stress loading unit; 31, Inner ring seat; 32. Support spring; 33. Rotating ring; 34. Raised edge; 35. Guide shaft; 36. Sliding cavity; 37. Through hole; 38. Arc-shaped liquid cavity; 4. Air supply mechanism; 41. Positioning seat; 42. Buried pipe; 43. Air guide cavity; 44. Shaft tube; 45. Rotating tube; 46. Gear ring seat; 47. Mounting frame; 48. Driven gear; 49. Driving unit; 410. Eccentric block; 5. Sealing sleeve; 51. Hydraulic quick-change connector assembly. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] Example 1

[0033] Reference Figures 1 to 6 A composite dynamic disaster simulation device for deep mining in coal mines includes a fixed base 1, a guide rod frame 14 and a sliding sleeve 121. The fixed base 1 and the sliding sleeve 121 are respectively assembled at both ends of the guide rod frame 14, and the sliding sleeve 121 is slidably assembled on one end of the guide rod frame 14. A frame body 11 is fixedly installed at the center of the upper end of the fixed base 1. A carrier cylinder 2 is slidably and removably assembled horizontally on one side of the frame body 11, and coal rock blocks are stored in the carrier cylinder 2. A movable base 12 is fixedly installed on the sliding sleeve 121, and a displacement adjuster 13 is arranged between the fixed base 1 and the movable base 12. Stress loading units 3 are evenly and equidistantly assembled on the inner wall of the carrier cylinder 2, and the stress loading units 3 are located on the circumference of the coal rock block. An air supply mechanism 4 is assembled at the end of the carrier cylinder 2 away from the fixed base 1.

[0034] The lower surface of the movable base 12 is provided with wheels for easy movement.

[0035] The displacement regulator 13 is a ball screw mechanism driven by a servo motor, which can achieve high-precision displacement regulation of the movable seat 12 .

[0036] A stress loading unit 3 is provided in the carrier tube 2 and a coal rock block is placed therein. Stress is applied to the coal rock block by the stress loading unit 3 to simulate the disaster situation.

[0037] The gas supply mechanism 4 supplies gas such as methane to the coal rock blocks to simulate the corresponding disaster situation.

[0038] Specifically, a horizontal borehole is pre-drilled on the central axis of the coal rock block, a surrounding rock simulation bracket 15 is installed in the horizontal borehole, and stress sensors are distributed on the surface of the surrounding rock simulation bracket 15.

[0039] The surrounding rock simulation support 15 is an expandable metal mesh structure, and the optical fiber strain gauge embedded in its surface can monitor the three-dimensional stress changes in real time.

[0040] Among them, horizontal boreholes can be drilled in proportion to actual tunnels, and their hole walls are filled with polyurethane material to simulate the mechanical properties of the surrounding rock.

[0041] Specifically, the stress loading unit 3 includes an inner ring seat 31, and multiple inner ring seats 31 are coaxially rotated and assembled in the carrier tube 2. The outer wall of the inner ring seat 31 is in sealing contact with the inner wall of the carrier tube 2. The outer wall of the inner ring seat 31 is symmetrically provided with mounting grooves. A protrusion is integrally formed on the lower side of the inner wall of the carrier tube 2, and the lower mounting groove is arranged at the protrusion. A pre-compression support spring 32 is arranged between the inner wall of the lower mounting groove and the outer wall of the protrusion. The inner wall of the inner ring seat 31 is provided with a rotating ring 33, and the rotating ring 33 is sleeved on the periphery of the coal rock block. Two hydraulic channels 21 are symmetrically provided on the upper side of the inner wall of the carrier tube 2. The hydraulic channel 21 is an arc-shaped channel, and the hydraulic channel 21 is connected to the upper mounting groove. The outer wall of the carrier tube 2 is provided with a liquid guide hole 22 connected to the hydraulic channel 21, and a pressure self-locking valve device 23 is integrated in the liquid guide hole 22.

[0042] By injecting hydraulic oil into the hydraulic channel 21, the inner ring seat 31 is driven to rotate, and then the swivel 33 is driven to rotate, thereby applying steering stress to the coal rock block. The pre-compression support spring 32 is used to reset the inner ring seat 31 and the swivel 33.

[0043] Hydraulic oil can be filled in each hydraulic channel 21 and maintain a relatively fixed state between the inner ring seat 31 and the carrier tube 2. When the hydraulic oil enters one of the liquid guide holes 22 through the pressure self-locking valve device 23, the other liquid guide hole 22 will discharge the hydraulic oil of the corresponding hydraulic channel 21, and the inner ring seat 31 will gradually deflect, thereby realizing torsional stress loading on the coal rock block.

[0044] It should be noted that the inner ring seats 31 in multiple stress loading units 3 can rotate in the same or different directions, for example, three in a group can deflect in the same direction (simulating the shear stress concentration on the roof of the goaf), or each can rotate in opposite directions (forming a local shear band), so as to flexibly simulate complex stress conditions.

[0045] Specifically, the inner wall of the rotating ring 33 is circumferentially distributed with convex edges 34, which form an interference fit nesting structure with the outer contour of the coal block, ensuring that there is no relative sliding between the rotating ring 33 and the coal block during loading, so that the rotation of the rotating ring 33 can apply stress to the coal block.

[0046] A sealing sleeve 5 is installed on the side of the movable seat 12 close to the carrier tube. The sealing sleeve 5 is slidably sleeved on the outside of the carrier tube 2 through an axial slide rail mechanism. The sealing sleeve 5 is integrated with a hydraulic quick-change joint group 51 corresponding to the liquid guide hole 22. The hydraulic quick-change joint group 51 and the liquid guide hole 22 are connected in a sliding and sealed manner, which facilitates the adjustment of the flow rate of hydraulic oil in the hydraulic channel 21 after the hydraulic quick-change joint group 51 and the liquid guide hole 22 are connected.

[0047] Specifically, the inner wall of the inner ring seat 31 is symmetrically provided with sliding cavities 36, and a limit spring is installed in the lower sliding cavity 36. The outer wall of the rotating ring 33 is symmetrically integrally formed with protrusions, and the two protrusions are respectively slidably assembled in the sliding cavity 36. The outer walls of the two protrusions are symmetrically fixed with guide shafts 35, and the guide shafts 35 are slidably connected to the inner ring seat 31. A through hole 37 is provided on the side wall of the inner ring seat 31, and the through hole 37 is connected to the upper sliding cavity 36. An arc-shaped liquid cavity 38 is provided on the inner wall of the carrier tube 2, and the arc-shaped liquid cavity 38 is connected to the through hole 37.

[0048] When the inner ring seat 31 rotates forward or reverse, the arc-shaped liquid cavity 38 is always connected to the through hole 37, so that the hydraulic oil can enter the sliding cavity 36 through the arc-shaped liquid cavity 38, thereby enabling the rotating ring 33 to slide radially and realize radial stress loading on the coal rock block.

[0049] Specifically, a shaft sleeve 24 is fixedly installed in the liquid guide hole 22 on one side, and a delivery hole 25 is symmetrically opened below the shaft sleeve 24. A cut-off tube 26 is slidably assembled in the shaft sleeve 24, and a side hole 27 corresponding to the delivery hole 25 is opened on the side wall of the cut-off tube 26. The lower end of the shaft sleeve 24 is vertically connected to a node tube 28, and the lower end of the node tube 28 is connected to the arc-shaped liquid cavity 38. A sealing shaft 29 is fixedly installed on the inner wall of the shaft sleeve 24 through a bracket, and a direct current hole that slides with the sealing shaft 29 is opened at the lower end of the cut-off tube 26.

[0050] Specifically, a movable ring is fixedly installed on the outer wall of the intercepting tube 26, a movable groove is opened on the inner wall of the shaft sleeve 24, and an inner spring is installed between the movable ring and the movable groove. The inner spring drives the intercepting tube 26 to separate from the sealing shaft 29 through the elastic force. At this time, the conveying hole 25 and the side hole 27 slide and stagger.

[0051] When the hydraulic oil is injected into the shaft sleeve 24 under high pressure, the intercepting tube 26 can slide axially under the hydraulic pressure, so that the direct flow hole at its end contacts the sealing shaft 29 in a sealed manner. At this time, the delivery hole 25 contacts the side hole 27, and the hydraulic oil quickly enters the hydraulic channel 21.

[0052] When hydraulic oil is injected into the shaft sleeve 24 at low pressure, the intercepting tube 26 causes the direct flow hole and the sealing shaft 29 to slip off under the action of the elastic force of the internal spring, while the delivery hole 25 and the side hole 27 are staggered, and the hydraulic oil can enter the arc-shaped liquid cavity 38 at low speed, thereby realizing radial stress loading of the swivel 33.

[0053] Specifically, the air supply mechanism 4 includes a positioning seat 41, and the positioning seat 41 is coaxially fixed to the end of the carrier tube 2. An embedded tube 42 is axially arranged on the positioning seat 41, and an air hole is provided on the surface of the embedded tube 42. An air guide cavity 43 is cocentrically arranged in the positioning seat 41, and the embedded tube 42 is connected to the air guide cavity 43. The movable seat 12 is centrally rotated and equipped with an axis tube 44, and one end of the axis tube 44 is extended into and connected to the air guide cavity 43. The side wall of the axis tube 44 is provided with a side discharge port connected to the air guide cavity 43, and the other end of the axis tube 44 is connected to a gas pipe.

[0054] There are multiple groups of buried pipes 42. In this embodiment, there are three groups of buried pipes 42. The three groups of buried pipes 42 can be set to different lengths.

[0055] The gas can enter the gas guide cavity 43 through the shaft tube 44 and eventually be discharged into the coal rock block through the buried pipes 42, forming a radial gas channel network, which can simulate the gas release characteristics of strata at different depths.

[0056] Specifically, a driving part 49 is provided in the movable seat 12, and the driving part 49 is connected to the shaft tube 44 through gear transmission. A gear ring seat 46 is fixedly installed at one end of the shaft tube 44, and the gear ring seat 46 is rotatably assembled in the air guide cavity 43. A mounting frame 47 is fixedly installed in the air guide cavity 43. A rotating tube 45 and a driven tooth 48 are rotatably assembled on the mounting frame 47, and the end of the rotating tube 45 is fixedly installed on the driven tooth 48. The driven tooth 48 is engaged with the gear ring seat 46. The end of the rotating tube 45 is connected to the air guide cavity 43. The end of the buried tube 42 is fixedly installed on the mounting frame 47, and the rotating tube 45 is coaxially rotatably assembled in the buried tube 42. The outer wall of the rotating tube 45 is evenly fixed with an eccentric block 410.

[0057] The rotation of the shaft tube 44 drives the rotating tubes 45 and the eccentric block 410 to rotate continuously through the gear transmission, thereby forming a periodic disturbance wave.

[0058] When the rotating tube 45 is driven to rotate continuously, the eccentric mass 410 will rotate around the axis of the rotating tube 45 itself. A rotating tube 45 of a specific length rotates with the eccentric masses distributed on it, generating a periodic exciting force of a specific frequency. The number of eccentric masses installed on multiple rotating tubes 45 of different lengths is different (the mass or eccentricity of the eccentric mass can also be designed and adjusted for different lengths). Therefore, rotating tubes of different lengths will generate different centrifugal forces at the same rotation speed, resulting in different amplitudes of the simple harmonic disturbances generated by them. The superposition of multiple simple harmonic waves of the same frequency with different amplitudes and fixed phase differences will generate a non-sinusoidal, more complex disturbance wave. The disturbance wave is transmitted to the coal rock block through the buried pipe 42, causing the periodic opening and closing of micro-cracks in the coal body, accelerating the gas adsorption and desorption process. At the same time, the rearrangement of coal rock particles caused by vibration can change the permeability, simulating the dynamic evolution of the gas migration path under mining disturbance.

[0059] During the above process, the gas penetration rate increased by 40% compared with static gas injection, and a crack network expanded in the stress concentration area of ​​the coal rock, simulating the precursor of the outburst.

[0060] Therefore, the gas pressure of the axial pipe 44 can be adjusted in stages (for example, from 1 MPa to 2 MPa, and then to 3 MPa), and the rotation speed of the rotating pipe 45 can be gradually increased from 50 rpm to 100 rpm to generate low-frequency vibration (0.8 to 1.6 Hz) to induce coal creep. Combined with stepped pressure-increasing gas injection, the critical point of coal rock rheology-seepage coupling instability can be observed, thereby simulating the multi-field coupling disaster-causing mechanism of complex dynamic disasters.

[0061] Example 2

[0062] A method for simulating a composite dynamic disaster in deep coal mining is provided, which uses a composite dynamic disaster simulation device for deep coal mining in the first embodiment and specifically comprises the following steps:

[0063] S1. Process the natural coal rock into a standard cylindrical specimen, pre-drill a horizontal hole at the axis of the coal rock block, install a retractable surrounding rock simulation bracket 15 in the hole, and attach a distributed array of stress sensors to the surface of the surrounding rock simulation bracket 15;

[0064] S2. Place the coal block in the center of the carrier tube 2 and secure it with an interference fit of 0.5mm to 1.2mm using the inner convex edge 34 of the swivel 33. Install the sealing sleeve 5 and connect it to the hydraulic system. Install a gas pipe on the outside of the shaft tube 44 to supply the gas mixture.

[0065] The gas pipeline interface is equipped with an explosion-proof solenoid valve, which is linked to the gas concentration monitor to automatically cut off the gas source when the concentration exceeds the limit (≥1%);

[0066] S3. The displacement regulator 13 drives the movable seat 12 to slide horizontally and approach the fixed base 1. The sealing sleeve 5 on the movable seat 12 gradually moves axially along the carrier tube 2, and the hydraulic quick-change joint assembly 51 is sequentially connected to the liquid guide holes 22 on the outer wall of the carrier tube 2. After the connection is completed, hydraulic oil is injected under high pressure through the hydraulic system. At this time, the intercepting tube 26 is hydraulically pushed to seal its end with the sealing shaft 29, and the delivery hole 25 is connected to the side hole 27. The inner ring seat 31 is hydraulically pushed to deflect forward or reverse, realizing the rotation adjustment of the swivel 33. According to the requirements of the simulation experiment, the swivel 33 distributed along the axial direction of the coal rock block is used to apply stress loading under different or the same rotation direction;

[0067] For stress loading of different directions of the swivel 33, in actual application, the hydraulic circuits of adjacent stress loading units 3 are set in reverse, with the oil filling pressure of one stress loading unit 3 set to 15 MPa and the oil discharge pressure of the other stress loading unit 3 set to 12 MPa, forming a shear gradient;

[0068] S4: The sealing sleeve 5 moves in the opposite direction along with the movable seat 12, and is connected to the corresponding liquid guide hole 22 by the hydraulic quick-change joint assembly 51. At this time, hydraulic oil is injected at a low pressure and steady flow through the hydraulic system, and the end of the intercepting tube 26 is separated from the sealing shaft 29. The hydraulic oil gradually flows into the sliding cavity 36, and a relative displacement occurs between the rotating ring 33 and the inner ring seat 31, thereby realizing radial stress loading on the coal rock block.

[0069] The initial radial loading can maintain a pressure of 2 MPa for 10 minutes to close the initial cracks in the coal rock, and then increase the pressure to 5 MPa at a rate of 0.2 MPa / min to simulate the slow accumulation of mining stress.

[0070] S5. The gas pipeline injects high-pressure gas into the gas guide cavity 43 through the shaft tube 44. At the same time, the rotating tube 45 rotates at 50 to 200 rpm, generating periodic disturbance waves through the eccentric block 410.

[0071] The concentration of high-pressure gas is 90%-100%, and the pressure range is 0.5-5MPa;

[0072] S6, real-time recording of stress changes, hydraulic fluctuations, gas flow, and torque changes in the surrounding rock simulation support 15, and combining digital imaging technology to capture the evolution of coal and rock block fracture morphology;

[0073] Digital imaging technology can use high-speed cameras;

[0074] Then, according to the coal rock crack morphology and data curve, the disaster type (impact ground pressure / burst / combined type) can be divided and a classification database can be established.

[0075] In addition to the above embodiments, multiple sets of hydraulic quick-change joints 51 can be set on the sealing sleeve 5, respectively corresponding to the positions of the liquid guide holes 22 on the outer wall of the carrier tube 2, so that multiple sets of swivels 33 can be selectively stressed at the same time to simulate corresponding disasters.

[0076] The above content is only a preferred embodiment of the present invention. For ordinary technicians in this field, according to the concept of the present invention, many changes can be made in the specific implementation method and application scope. As long as these changes do not deviate from the concept of the present invention, they all fall within the scope of protection of the present invention.

Claims

1. A composite dynamic disaster simulation device for deep coal mining, characterized by: The invention comprises a fixed base (1), a guide rod frame (14) and a sliding sleeve (121), wherein the fixed base (1) and the sliding sleeve (121) are respectively mounted on two ends of the guide rod frame (14), and the sliding sleeve (121) is slidably mounted on one end of the guide rod frame (14); a frame body (11) is fixedly mounted at the center of the upper end of the fixed base (1); a carrier cylinder (2) is slidably and detachably mounted on one side of the frame body (11) in a horizontal manner, and coal rock blocks are stored in the carrier cylinder (2); a movable base (12) is fixedly mounted on the sliding sleeve (121); a displacement regulator (13) is provided between the fixed base (1) and the movable base (12); stress loading units (3) are evenly and equidistantly mounted on the inner wall of the carrier cylinder (2), and the stress loading units (3) are located on the outer periphery of the circumference of the coal rock blocks; an air supply mechanism (4) is mounted on the end of the carrier cylinder (2) away from the fixed base (1); The stress loading unit (3) includes an inner ring seat (31), and a plurality of the inner ring seats (31) are coaxially rotatably assembled in the carrier tube (2). The outer wall of the inner ring seat (31) is in sealing contact with the inner wall of the carrier tube (2). The outer wall of the inner ring seat (31) is symmetrically provided with mounting grooves. A protrusion is integrally formed on the lower side of the inner wall of the carrier tube (2). The lower side mounting groove is arranged at the protrusion. A pre-compression support spring (32) is assembled between the inner wall of the lower side mounting groove and the outer wall of the protrusion. The inner wall of the inner ring seat (31) is equipped with a rotating ring (33), and the rotating ring (33) is sleeved on the outer periphery of the coal rock block. Two hydraulic channels (21) are symmetrically opened on the upper side of the inner wall of the carrier tube (2). The hydraulic channels (21) are arc-shaped channels, and the hydraulic channels (21) are connected to the mounting groove on the upper side. The outer wall of the carrier tube (2) is opened with a liquid guide hole (22) connected to the hydraulic channel (21), and a pressure self-locking valve device (23) is integrated in the liquid guide hole (22); By injecting hydraulic oil into the hydraulic channel (21), the inner ring seat (31) is driven to rotate, and the rotating ring (33) is driven to rotate, thereby applying a steering stress to the coal rock block, and the pre-compression support spring (32) is used to reset the inner ring seat (31) and the rotating ring (33); The inner ring seats (31) in the plurality of stress loading units (3) can rotate in the same or different directions.

2. A composite dynamic disaster simulation device for deep coal mining according to claim 1, characterized in that: A horizontal borehole is pre-drilled on the central axis of the coal rock block, a surrounding rock simulation bracket (15) is installed in the horizontal borehole, and stress sensors are distributed on the surface of the surrounding rock simulation bracket (15).

3. The deep coal mining composite dynamic disaster simulation device according to claim 1, characterized in that: The inner wall of the rotating ring (33) is provided with convex edges (34) distributed around its circumference, and the convex edges (34) form an interference nesting structure with the outer contour of the coal block; A sealing sleeve (5) is mounted on the side of the movable seat (12) close to the carrier tube (2). The sealing sleeve (5) is slidably sleeved on the outside of the carrier tube (2) via an axial slide rail mechanism. A hydraulic quick-change joint group (51) corresponding to the liquid guide hole (22) is integrated on the sealing sleeve (5). The hydraulic quick-change joint group (51) and the liquid guide hole (22) are connected in a sliding and sealed manner.

4. The deep coal mining composite dynamic disaster simulation device according to claim 1, characterized in that: The inner wall of the inner ring seat (31) is symmetrically provided with sliding cavities (36) on the upper and lower sides, and a limit spring is installed in the lower sliding cavity (36). The outer wall of the rotating ring (33) is symmetrically formed with protrusions, and the two protrusions are respectively slidably assembled in the sliding cavity (36). The outer walls of the two protrusions are symmetrically fixed with guide shafts (35), and the guide shafts (35) are slidably connected to the inner ring seat (31). The side wall of the inner ring seat (31) is provided with a through hole (37), and the through hole (37) is connected to the upper sliding cavity (36). The inner wall of the carrier cylinder (2) is provided with an arc-shaped liquid cavity (38), and the arc-shaped liquid cavity (38) is connected to the through hole (37).

5. A composite dynamic disaster simulation device for deep coal mining according to claim 4, characterized in that: A shaft sleeve (24) is fixedly installed in the liquid guide hole (22) on one side, and a delivery hole (25) is symmetrically opened below the shaft sleeve (24). A cut-off pipe (26) is slidably assembled in the shaft sleeve (24), and a side hole (27) corresponding to the delivery hole (25) is opened on the side wall of the cut-off pipe (26). The lower end of the shaft sleeve (24) is vertically connected to a node pipe (28), and the lower end of the node pipe (28) is connected to the arc-shaped liquid cavity (38). A sealing shaft (29) is fixedly installed on the inner wall of the shaft sleeve (24) through a bracket, and a direct current hole that slides with the sealing shaft (29) is opened at the lower end of the cut-off pipe (26).

6. A composite dynamic disaster simulation device for deep coal mining according to claim 5, characterized in that: A movable ring is fixedly mounted on the outer wall of the intercepting tube (26), and a movable groove is provided on the inner wall of the shaft sleeve (24). An inner spring is installed between the movable ring and the movable groove. The inner spring drives the intercepting tube (26) to separate from the sealing shaft (29) through elastic force, and at this time, the delivery hole (25) and the side hole (27) slide and stagger.

7. The deep coal mining composite dynamic disaster simulation device according to claim 1, characterized in that: The air supply mechanism (4) includes a positioning seat (41), and the positioning seat (41) is coaxially fixed to the end of the carrier (2), and an embedded tube (42) is axially arranged on the positioning seat (41), and an air hole is opened on the surface of the embedded tube (42), and an air guide cavity (43) is cocentrically arranged in the positioning seat (41), and the embedded tube (42) is connected to the air guide cavity (43), and the center of the movable seat (12) is rotated and equipped with an axis tube (44), and one end of the axis tube (44) is extended into and connected to the air guide cavity (43), and the side wall of the axis tube (44) is provided with a side discharge port connected to the air guide cavity (43), and the other end of the axis tube (44) is connected to a gas pipeline.

8. The deep coal mining composite dynamic disaster simulation device according to claim 7, characterized in that: A driving part (49) is provided in the movable seat (12), and the driving part (49) is connected to the shaft tube (44) through gear transmission. A gear ring seat (46) is fixedly installed on one end of the shaft tube (44), and the gear ring seat (46) is rotatably assembled in the air guide cavity (43). A mounting frame (47) is fixedly installed in the air guide cavity (43). A rotating tube (45) and a driven tooth (48) are rotatably assembled on the mounting frame (47), and the end of the rotating tube (45) is fixedly installed on the driven tooth (48). The driven tooth (48) is meshed with the gear ring seat (46). The end of the rotating tube (45) is connected to the air guide cavity (43). The end of the buried tube (42) is fixedly installed on the mounting frame (47), and the rotating tube (45) is coaxially rotatably assembled in the buried tube (42). An eccentric block (410) is evenly fixedly installed on the outer wall of the rotating tube (45).

9. A method for simulating complex dynamic disasters in deep coal mining, using a complex dynamic disaster simulation device for deep coal mining according to any one of claims 1 to 8, specifically comprising the following steps: S1. Processing natural coal rock into a standard cylindrical sample, pre-drilling a horizontal borehole at the axis of the coal rock block, installing a retractable surrounding rock simulation bracket (15) in the borehole, and attaching a distributed array of stress sensors to the surface of the surrounding rock simulation bracket (15); S2. Place the coal rock block in the center of the carrier tube (2), achieve interference fixation through the inner convex edge (34) of the rotating ring (33), install the sealing sleeve (5) and connect the hydraulic system, and configure a gas pipeline outside the shaft tube (44) to supply the gas mixture; S3, the displacement regulator (13) drives the movable seat (12) to slide horizontally and approach the fixed base (1), the sealing sleeve (5) on the movable seat (12) gradually moves axially along the carrier tube (2) and makes the hydraulic quick-change joint group (51) and the liquid guide holes (22) on the outer wall of the carrier tube (2) docked in sequence. After the docking is completed, the hydraulic oil is injected into the hydraulic system at high pressure. At this time, the intercepting pipe (26) is pushed by the hydraulic pressure to seal its end with the sealing shaft (29), and the delivery hole (25) and the side hole (27) are docked. The inner ring seat (31) is pushed by the hydraulic pressure to deflect in the forward or reverse direction to realize the rotation adjustment of the swivel (33). According to the requirements of the simulation experiment, the swivel (33) distributed along the axial direction of the coal rock block is used to perform stress loading under different or the same rotation directions; S4, the sealing sleeve (5) moves in the opposite direction along with the movable seat (12), and is connected to the corresponding liquid guide hole (22) by the hydraulic quick-change joint group (51). At this time, the hydraulic oil is injected into the hydraulic system at a low pressure and steady flow, and the end of the intercepting pipe (26) is separated from the sealing shaft (29). The hydraulic oil gradually flows into the sliding cavity (36), and a relative displacement is generated between the rotating ring (33) and the inner ring seat (31), thereby realizing radial stress loading on the coal rock block; S5, the gas pipeline injects high-pressure gas into the gas guide cavity (43) through the shaft tube (44), and at the same time, the rotating tube (45) rotates at 50 to 200 rpm, generating a periodic disturbance wave through the eccentric block (410); S6. Real-time recording of the peripheral stress changes, hydraulic fluctuations, gas flow, and torque changes of the surrounding rock simulation support (15) is performed, and digital imaging technology is used to capture the evolution of the fracture morphology of the coal and rock blocks.

Images