CN109142053B - Coal body outburst test method under coal seam permeability influence mining action - Google Patents
Coal body outburst test method under coal seam permeability influence mining action Download PDFInfo
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- 239000003245 coal Substances 0.000 title claims abstract description 123
- 230000035699 permeability Effects 0.000 title claims abstract description 31
- 238000005065 mining Methods 0.000 title claims abstract description 20
- 238000010998 test method Methods 0.000 title claims abstract description 10
- 230000009471 action Effects 0.000 title claims description 10
- 238000012360 testing method Methods 0.000 claims abstract description 126
- 238000003825 pressing Methods 0.000 claims abstract description 57
- 239000012530 fluid Substances 0.000 claims abstract description 31
- 239000004484 Briquette Substances 0.000 claims abstract description 30
- 239000000843 powder Substances 0.000 claims abstract description 24
- 238000004519 manufacturing process Methods 0.000 claims abstract description 5
- 238000000034 method Methods 0.000 claims description 14
- 239000002245 particle Substances 0.000 claims description 14
- 230000005641 tunneling Effects 0.000 claims description 10
- 230000008859 change Effects 0.000 claims description 7
- 238000006073 displacement reaction Methods 0.000 claims description 7
- 239000012780 transparent material Substances 0.000 claims description 7
- 239000000654 additive Substances 0.000 claims description 5
- 238000002156 mixing Methods 0.000 claims description 5
- 230000000996 additive effect Effects 0.000 claims description 4
- 239000011230 binding agent Substances 0.000 claims description 3
- 238000001035 drying Methods 0.000 claims description 3
- 238000011049 filling Methods 0.000 claims description 3
- 238000000227 grinding Methods 0.000 claims description 3
- 238000002347 injection Methods 0.000 claims description 3
- 239000007924 injection Substances 0.000 claims description 3
- 238000012216 screening Methods 0.000 claims description 3
- 238000003756 stirring Methods 0.000 claims description 3
- 230000000694 effects Effects 0.000 abstract description 4
- 238000004088 simulation Methods 0.000 abstract 1
- 238000007789 sealing Methods 0.000 description 12
- 230000008569 process Effects 0.000 description 7
- 238000011161 development Methods 0.000 description 5
- 239000011435 rock Substances 0.000 description 4
- 230000006835 compression Effects 0.000 description 3
- 238000007906 compression Methods 0.000 description 3
- 230000001808 coupling effect Effects 0.000 description 3
- 238000011160 research Methods 0.000 description 2
- 238000012800 visualization Methods 0.000 description 2
- KEQXNNJHMWSZHK-UHFFFAOYSA-L 1,3,2,4$l^{2}-dioxathiaplumbetane 2,2-dioxide Chemical compound [Pb+2].[O-]S([O-])(=O)=O KEQXNNJHMWSZHK-UHFFFAOYSA-L 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000007767 bonding agent Substances 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000003292 glue Substances 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 238000011068 loading method Methods 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229920000515 polycarbonate Polymers 0.000 description 1
- 239000004417 polycarbonate Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/08—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
- G01N15/08—Investigating permeability, pore-volume, or surface area of porous materials
- G01N15/082—Investigating permeability by forcing a fluid through a sample
- G01N15/0826—Investigating permeability by forcing a fluid through a sample and measuring fluid flow rate, i.e. permeation rate or pressure change
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0014—Type of force applied
- G01N2203/0016—Tensile or compressive
- G01N2203/0019—Compressive
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0058—Kind of property studied
- G01N2203/0069—Fatigue, creep, strain-stress relations or elastic constants
- G01N2203/0075—Strain-stress relations or elastic constants
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/02—Details not specific for a particular testing method
- G01N2203/025—Geometry of the test
- G01N2203/0256—Triaxial, i.e. the forces being applied along three normal axes of the specimen
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Abstract
The invention discloses a coal body outburst test method under the effect that coal seam permeability influences mining, which comprises the following steps: the manufacturing test device comprises a concave-shaped sealed cavity and a transparent box, wherein a notch part of the sealed cavity forms a test piece placing cavity, a front pressing plate is provided with a front pressing rod, the left side, the right side and the rear side of the test piece placing cavity are provided with side pressing plates, the head ends of the side pressing plates are provided with air holes, the side pressing plates are provided with side pressing rods, an upper pressing plate is arranged above an upper backing plate in a front-back adjacent mode, the upper pressing plates are provided with upper pressing rods, the end of each upper pressing rod adopts a structure that a spherical ball is arranged between two clamping plates, the side wall of the sealed cavity is provided with a fluid inlet hole, and the side wall of; preparing coal powder; preparing a briquette test piece; mounting a briquette test piece; applying a triaxial stress; applying gas pressure; carrying out a test; replacing briquette test pieces with different permeability and strength in the same group of other tests; and (6) collating the test data. Therefore, triaxial real simulation tests of coal bed permeability and strength and coal and gas outburst are carried out.
Description
Technical Field
The invention belongs to the technical field of coal mine safety, and particularly relates to a coal body outburst test method under the effect that coal seam permeability influences mining.
Background
Coal is the main body of energy in China, and it is clearly indicated in the outline of long-term development planning in energy (2004-2020), that "China adheres to an energy strategy of overall development of oil gas and new energy with coal as the main body and electric power as the center". Obviously, the coal industry is the basic industry of China, whether the coal industry can be healthily, stably and continuously developed or not is related to national energy safety. In the primary energy consumption structure of China, coal accounts for about 67%, and is expected to account for more than 50% in 2050, so that the coal is always the dominant main energy of China for a long period of time.
However, the mining disaster accidents such as rock burst, gas, flood and fire, which accompany coal mining, not only cause great loss of people's lives and properties and environmental disasters, but also restrict the development of coal industrial production and the sustainable development of the whole national economy and society. The gas disaster accident is the most prominent in mining disaster accidents, and is a major problem to be solved urgently in the development of mining industry in China.
Coal and gas outburst is an extremely complex dynamic disaster phenomenon, and is a strong dynamic process that coal rock containing gas under a coal mine rapidly moves from a coal rock layer to a working face in a crushed shape and is accompanied with the ejection of a large amount of gas. The coal and gas outburst is actually the result of the coupling effect of the coal bed stress and the gas pressure in the tunneling process of the working face. Therefore, a dynamic test of disturbing a coal bed in the working face tunneling process under the coupling action of stress and gas pressure is developed, the real-time visualization of coal and gas outburst can be realized through the high-strength transparent material, and theoretical support and engineering guidance can be provided for risk identification of the coal and gas outburst.
At present, domestic and foreign scholars have few researches on coal body outburst under the coal bed permeability influence mining action, only indoor researches are focused on only considering the coupling action of triaxial stress and gas pressure, coal bed permeability change and mining influence are not considered, and an effective test device and method are still lacked for simulating the coal bed permeability under the true triaxial stress state to influence the coal body outburst under the mining action, so that the influences of the coal bed permeability and various parameters on the coal and gas outburst under the true triaxial stress state are researched.
Disclosure of Invention
The invention aims to provide a coal body outburst test method under the coal bed permeability influence mining action, which is used for researching the influence of the coal bed permeability and strength on coal and gas outburst under a true triaxial stress state.
Therefore, the technical scheme adopted by the invention is as follows: a coal body outburst test method under the effect of coal seam permeability influencing mining comprises the following steps:
step one, manufacturing a test device;
the test device comprises a concave-shaped seal cavity, a notch of the seal cavity faces the front, a transparent box which is equal in height and width to the notch is arranged in front of the seal cavity, the rear part and the top of the transparent box are both open and just connected with the notch, the transparent box and the seal cavity share the same bottom plate, and a plurality of front pressure plates made of transparent materials are arranged between the notch of the seal cavity and the transparent box in a left-right close manner, so that the notch of the seal cavity forms a test piece placing cavity;
each front pressure plate is provided with a front pressure rod, the front pressure rods penetrate through the transparent box from front to back to be connected with the corresponding front pressure plate, the front pressure rods corresponding to the front pressure plates are independently controlled, and the tunneling speed of the working face is simulated through sequential unloading; the left side, the right side and the rear side of the test piece placing cavity are respectively provided with a side pressing plate, the head end of each side pressing plate is inserted into the corresponding side wall of the sealed cavity, the head end of each side pressing plate is provided with an air hole for communicating the test piece placing cavity with the sealed cavity, each side pressing plate is respectively provided with a side pressing rod, and the side pressing rods penetrate through the sealed cavity from outside to inside and are connected with the tail ends of the side pressing plates; the upper edge of the inner wall of the test piece placing cavity and the transparent box share the same upper base plate, a plurality of upper pressure plates are arranged above the upper base plate in a front-back adjacent mode, each upper pressure plate is provided with an upper pressure rod, the end of each upper pressure rod adopts a structure that a spherical ball is arranged between two clamping plates, the upper pressure rods corresponding to the upper pressure plates are independently controlled, and different loads are applied to reflect the uneven deformation of the coal seam roof under the non-uniform load;
the side wall of the sealed cavity is provided with a fluid inlet hole, and the side wall of the transparent box is provided with a fluid outlet hole;
step two, preparing coal powder, crushing and grinding raw coal to a required particle size range, screening the ground coal powder through a vibrating screen, and drying for later use;
step three, preparing a briquette test piece, mixing coal powder according to the particle size ratio, adding a coal powder binder in proportion, stirring uniformly, and filling the coal powder into a mold to press the coal powder into a square briquette test piece;
step four, mounting a molded coal test piece, and placing the pressed molded coal test piece into a test piece placing cavity of the test device;
applying triaxial stress, and applying stress to the side pressure rods, the front pressure rod and the upper pressure rod at the left, right and rear parts of the test device to make the briquette test piece be subjected to triaxial constraint;
step six, applying gas pressure, injecting gas into the test device through the fluid inlet hole, and enabling the gas to enter the molded coal test piece through the air holes in the left side pressure plate, the right side pressure plate and the rear side pressure plate, so that a certain gas pressure is formed in the molded coal test piece, and the next step is performed after the gas injection pressure is kept unchanged;
step seven, performing a test, namely sequentially withdrawing the front pressing plate from left to right or from right to left in the direction away from the briquette test piece according to the set stress or displacement change rate, obtaining coal seam deformation data by recording the displacement amounts of the left side pressing plate, the right side pressing plate, the rear side pressing plate and the upper pressing plate at different positions, and simultaneously recording the gas flow change of the fluid outlet;
step eight, replacing briquette coal test pieces with different permeability and strength in the same group of other tests, and repeating the steps four to seven;
and step nine, collating the test data.
Preferably, in the eighth step, the briquette test pieces with different permeability and strength are prepared by adjusting the particle size ratio of the pulverized coal, the type and the amount of the additive.
More preferably, in the third step, the ratio of the total weight of the powder is less than 40 meshes: 40-60 mesh: 60-80 meshes: 80-100 meshes: and (4) preparing three briquette test pieces with different permeability rates according to the grain diameter proportion of 1:1:1:1:1, 1:2:1:2:5 and 1:2:4:1:6 of more than 100 meshes, and performing the same group of other tests in the step eight.
Preferably, in the first step, the two fluid inlet holes are symmetrically arranged on the rear side wall of the sealed cavity; the fluid outlet holes are arranged on the left side wall or the right side wall of the transparent box; accordingly, in step six, gas is simultaneously injected into the test device through the two fluid inlets. The mode that the fluid is symmetrically fed into the rear side wall of the sealed cavity body from left to right is adopted, so that the pressure of the fluid injected into the sealed cavity body is fast and stable, the fluid uniformly enters the test piece placing cavity through the air holes in the side pressure plates in three directions, the test preparation time is saved, and the test efficiency is improved.
More preferably, in the third step, the briquette test piece is a square block with the thickness of 600mm × 600mm × 100mm, and correspondingly, in the first step, the test piece placing cavity is also a square cavity with the thickness of 600mm × 600mm × 100 mm.
More preferably, in the second step, the raw coal is crushed and ground and then dried at 105-110 ℃ for 22-26 hours.
The invention has the beneficial effects that: the stress applied to each pressing plate can truly simulate the triaxial original rock stress state of a coal bed, the gas pressure can be simulated by applying a gas source, the progressive unloading of the front pressing plate simulates the tunneling process of a working face, the unloading speed can simulate the tunneling speed of the working face, the deformation of a briquette test piece can be obtained by obtaining the displacement variation of each pressing rod, the real-time visualization of coal and gas outburst can be realized through a transparent material, and the briquette test pieces with different strengths and permeabilities can be simulated by adjusting the particle size ratio of pulverized coal and the types and the amounts of additives, so that the coal body outburst test method under the coal bed permeability influence mining action is provided, and theoretical support and engineering guidance are provided for the safety production of a coal mine.
Drawings
FIG. 1 is a top view of the test apparatus.
Fig. 2 is a cross-sectional view a-a of fig. 1.
Fig. 3 is a sectional view taken along line B-B of fig. 1.
Fig. 4 is an enlarged view of the end of the upper platen.
The figures are labeled as follows: the device comprises a seal cavity 1, a transparent box 2, a front pressure plate 3, a front pressure rod 4, a bottom plate 5, a test piece placing cavity 6, a side pressure plate 7, a side pressure rod 8, an upper backing plate 9, an upper pressure plate 10, an upper pressure rod 11, a fluid inlet hole 12, a fluid outlet hole 13, a first seal ring 14a, a second seal ring 14b, a third seal ring 14c, a fourth seal gasket 14d, a cover plate 15, a bolt 16 and a molded coal test piece 17.
Detailed Description
The invention will be further illustrated by the following examples in conjunction with the accompanying drawings:
a coal body outburst test method under the effect of coal seam permeability influencing mining comprises the following steps:
step one, manufacturing a testing device.
Referring to fig. 1-3, the testing device mainly comprises a sealed cavity 1, a transparent box 2, a front pressure plate 3, a front pressure rod 4, a side pressure plate 7, a side pressure rod 8, an upper backing plate 9, an upper pressure plate 10 and an upper pressure rod 11.
The whole sealing cavity 1 is concave, and the notch of the sealing cavity 1 faces the front.
A transparent box 2 with the same height and width as the notch part is arranged in front of the sealed cavity 1. The transparent box 2 is open at the back and the top and is just connected with the notch part. The transparent box 2 and the sealed cavity 1 share the same bottom plate 5, namely the transparent box 2 is only provided with a left side wall, a right side wall and a front side wall. A plurality of front pressing plates 3 made of transparent materials are arranged between the notch part of the seal cavity 1 and the transparent box 2 in a left-right close manner, so that the notch part of the seal cavity 1 forms a test piece placing cavity 6, and the test piece placing cavity 6 is used for placing a briquette test piece 17.
Each front pressing plate 3 is provided with a front pressing rod 4, the front pressing rods 4 penetrate through the transparent box 2 from front to back to be connected with the corresponding front pressing plate 3, the front pressing rods 4 corresponding to the front pressing plates 3 are independently controlled, and the tunneling speed of the working face is simulated through sequential unloading. The front pressing plate 3 and the transparent box 2 are both made of transparent materials, and a tester can observe the crack propagation condition of the surface of the test piece in the test process. The transparent material is especially high strength and toughness transparent polycarbonate plate, and has excellent performance.
The left side, the right side and the rear side of the test piece placing cavity 6 are respectively provided with a side pressing plate 7, the head end of the side pressing plate 7 is inserted into the corresponding side wall of the sealed cavity 1, and the head end of the side pressing plate 7 is provided with an air hole 7a for communicating the test piece placing cavity 6 and the sealed cavity 1. Each side pressure plate 7 is provided with a side pressure rod 8, and the side pressure rods 8 penetrate through the sealed cavity 1 from outside to inside to be connected with the tail ends of the side pressure plates 7. Preferably, the side pressure plate 7 adopts a structure that a vertical parting strip is arranged in a rectangular outer frame, and the vertical parting strip is just staggered with the vent hole 7a, so that fluid in the sealed cavity 1 can enter the test piece placing cavity 6 through the vent hole 7 a.
The upper edges of the inner walls of the test piece placing cavity 6 and the transparent box 2 share the same upper backing plate 9, and a plurality of upper pressure plates 10 are arranged above the upper backing plate 9 in a front-back close mode. Each upper pressure plate 10 is equipped with an upper pressure rod 11, the end of the upper pressure rod 11 adopts a structure (shown in fig. 4) that a spherical ball 11b is installed between two clamping plates 11a, and the upper pressure rod 11 corresponding to each upper pressure plate 10 is independently controlled and reflects the uneven deformation of the coal seam roof under the uneven load by applying different loads. Because the upper pressure plate 10 is arranged by a plurality of blocks, the upper base plate 9 is additionally arranged, the sealing performance of the test piece placing cavity 6 is ensured, and a coal seam roof and a goaf are simulated.
A fluid inlet hole 12 is formed in the side wall of the sealed cavity 1, and fluid is introduced into the sealed cavity 1 through the fluid inlet hole 12; the side wall of the transparent box 2 is provided with a fluid outlet 13, and fluid is discharged through the fluid outlet 13 in the test process. Preferably, the two fluid inlet holes 12 are symmetrically arranged on the rear side wall of the sealed cavity 1; the fluid outlet holes 13 are all arranged on the left side wall or the right side wall of the transparent box 2.
Further, the specimen-placing chamber 6 is preferably a square chamber having the same length and width.
The bottom plate 5 and the cover plate 15 are fixed to the side wall of the sealed cavity 1 by bolts 16. In order to ensure the sealing performance of the test device, a first sealing ring 14a is arranged between the bottom plate 5 and the sealing cavity 1 and between the bottom plate and the test piece placing cavity 6; second sealing rings 14b are arranged between the sealing cavity 1 and the side pressure rod 8 and between the sealing cavity 1 and the side pressure plate 7; a third sealing ring 14c is arranged between the sealing cavity 1 and the cover plate 15; a fourth gasket 14d is disposed between the seal cavity 1 and the upper mat 9.
Preferably, the front pressure lever 4 is in threaded connection with the front pressure plate 3, and the side pressure lever 8 is in threaded connection with the side pressure plate 7, or other fixed connection modes can be adopted.
Preferably, the number of the upper pressing plates 10 is seven, and the upper pressing rod 11 corresponding to each upper pressing plate 10 is controlled by a respective independent control part to reflect the uneven deformation of the coal seam roof; the number of the front pressing plates 3 is six, the front pressing rods 4 corresponding to the front pressing plates 3 are respectively controlled by respective independent control parts, and the tunneling speed of the working face is simulated through sequential unloading.
The test device has the characteristics that:
1. true triaxial stress can be applied from the front and back, the left and right sides and the upper side, the end of the upper pressure plate adopts a structure that a spherical ball is arranged between two clamping plates, and non-uniform load can be applied, so that non-uniform deformation of the top plate is truly simulated.
2. The front pressure plate adopts a structure of combining a plurality of blocks, and the tunneling process of the working face is simulated by gradual unloading; the upper pressure plate adopts a plurality of combined and optimized end head structures of the upper pressure rod, the upper pressure plate is respectively and independently controlled to simulate the loading of non-uniform load of the coal seam roof, and the upper base plate simulates the coal seam roof and a goaf; compared with a manual tunneling mode, the method simulates the actual working condition more truly, and therefore the test precision is improved.
3. The pressure plates on the rear side, the left side and the right side of the test piece are provided with air holes, the test piece can be inflated through the fluid inlet holes to reach certain gas pressure, and the bottom, the front and the upper part of the test piece are provided with no gas source supply holes, so that the actual working condition can be reflected more truly, and the test precision is improved.
4. The test device adopts a sealing structure, and can apply related gas pressure, so that the real working condition is reflected.
And step two, preparing coal powder, crushing and grinding raw coal to a required particle size range, screening the ground coal powder through a vibrating screen, and drying for later use. Preferably, the raw coal is crushed, ground and dried at 105-110 ℃ for 22-26 hours.
And step three, preparing a briquette test piece, namely mixing the coal powder according to the particle size ratio, adding the coal powder binder in proportion, uniformly stirring, and filling the coal powder into a mold to press the coal powder into a square briquette test piece.
Preferably, the briquette coal test piece is a square block with the thickness of 600mm × 600mm, 600mm × 100mm and 100mm, and correspondingly, in the step one, the test piece placing cavity 6 is also a square cavity with the thickness of 600mm × 600mm, 600mm and × 100 mm.
And step four, mounting the molded coal test piece, and placing the pressed molded coal test piece into the test piece placing cavity 6 of the test device.
And fifthly, applying triaxial stress to apply stress to the left, right and rear side compression bars 8, the front compression bar 4 and the upper compression bar 11 of the test device, so that the molded coal test piece is subjected to triaxial constraint.
And sixthly, applying gas pressure, injecting gas into the test device through the fluid inlet holes 12, and enabling the gas to enter the molded coal test piece through the air holes 7a in the left side pressure plate, the right side pressure plate and the rear side pressure plate 7, so that a certain gas pressure is formed in the molded coal test piece, and the molded coal test piece enters the next step after the gas injection pressure is kept unchanged. When there are two fluid inlet holes 12, gas is simultaneously injected into the test device through the two fluid inlet holes 12.
And seventhly, performing a test, namely sequentially withdrawing the front pressing plate 3 from left to right or from right to left according to the set stress or displacement change rate to the direction far away from the briquette coal test piece, recording the displacement of the left, right and rear side pressing plates 7 and the upper pressing plate 10 at different positions to obtain coal seam deformation data, and simultaneously recording the gas flow change of the fluid outlet hole 13.
And step eight, replacing briquette coal test pieces with different permeability and strength in the same group of other tests, and repeating the steps from four to seven.
And step eight, the briquette test pieces with different permeability and strength are obtained by adjusting the particle size ratio of the pulverized coal, the type and the dosage of the additive. In the third step, preferably, the ratio of the total weight of the powder is less than 40 meshes: 40-60 mesh: 60-80 meshes: 80-100 meshes: and (4) preparing three briquette test pieces with different permeability rates according to the grain diameter proportion of 1:1:1:1:1, 1:2:1:2:5 and 1:2:4:1:6 of more than 100 meshes, and performing the same group of other tests in the step eight.
For example, coal powder with different particle sizes is prepared by mixing coal powder with a particle size of less than 40 meshes: 40-60 mesh: 60-80 meshes: 80-100 meshes: mixing the materials in a mass ratio of more than 100 meshes to 1:1:1:1, adding 5% of milk white glue as a bonding agent, pressing the mixture into a briquette test piece, and performing repeated tests according to the following table:
the relationship between the permeability and strength of the coal seam and the coal and gas outburst can be researched by repeating the test according to the table or changing the type and the amount of the additive.
Claims (5)
1. A coal body outburst test method under the coal seam permeability influence mining action is characterized by comprising the following steps:
step one, manufacturing a test device;
the test device comprises a concave-shaped seal cavity (1), a notch of the seal cavity (1) faces the front, a transparent box (2) which is equal in height and width to the notch is arranged in front of the seal cavity (1), the rear part and the top part of the transparent box (2) are both open and just connected with the notch, the transparent box (2) and the seal cavity (1) share the same bottom plate (5), and a plurality of front pressure plates (3) made of transparent materials are arranged between the notch of the seal cavity (1) and the transparent box (2) in a left-right close manner, so that the notch of the seal cavity (1) forms a test piece placing cavity (6);
each front pressure plate (3) is provided with a front pressure rod (4), the front pressure rods (4) penetrate through the transparent box (2) from front to back to be connected with the corresponding front pressure plate (3), the front pressure rods (4) corresponding to each front pressure plate (3) are independently controlled, and the tunneling speed of a working face is simulated through sequential unloading; the left side, the right side and the rear side of the test piece placing cavity (6) are respectively provided with a side pressing plate (7), the head end of each side pressing plate (7) is inserted into the corresponding side wall of the sealed cavity (1), the head end is provided with an air hole (7a) for communicating the test piece placing cavity (6) with the sealed cavity (1), each side pressing plate (7) is respectively provided with a side pressing rod (8), and each side pressing rod (8) penetrates through the sealed cavity (1) from outside to inside to be connected with the tail end of each side pressing plate (7); the test piece placing cavity (6) and the upper edge of the inner wall of the transparent box (2) share the same upper base plate (9), a plurality of upper pressure plates (10) are arranged above the upper base plate (9) in a front-back adjacent mode, each upper pressure plate (10) is provided with an upper pressure rod (11), the end of each upper pressure rod (11) adopts a structure that a spherical ball (11b) is arranged between two clamping plates (11a), the upper pressure rods (11) corresponding to the upper pressure plates (10) are independently controlled, and different loads are applied to reflect the uneven deformation of the coal seam roof under the non-uniform load;
a fluid inlet hole (12) is formed in the side wall of the sealed cavity (1), and a fluid outlet hole (13) is formed in the side wall of the transparent box (2);
step two, preparing coal powder, crushing and grinding raw coal to a required particle size range, screening the ground coal powder through a vibrating screen, and drying for later use;
step three, preparing a briquette test piece, mixing coal powder according to the particle size ratio, adding a coal powder binder in proportion, stirring uniformly, and filling the coal powder into a mold to press the coal powder into a square briquette test piece;
step four, mounting a molded coal test piece, and placing the pressed molded coal test piece into a test piece placing cavity (6) of the test device;
applying triaxial stress, and applying stress to the left, right and rear side pressure rods (8), the front pressure rod (4) and the upper pressure rod (11) of the test device to make the briquette test piece be subjected to triaxial constraint;
step six, applying gas pressure, injecting gas into the test device through the fluid inlet holes (12), and enabling the gas to enter the molded coal test piece through the air holes (7a) on the left side pressure plate, the right side pressure plate and the rear side pressure plate (7), so that a certain gas pressure is formed in the molded coal test piece, and the molded coal test piece enters the next step after the gas injection pressure is kept unchanged;
seventhly, performing a test, namely sequentially withdrawing the front pressing plate (3) from left to right or from right to left in the direction away from the briquette test piece according to the set stress or displacement change rate, obtaining coal seam deformation data by recording the displacement of the left side pressing plate, the right side pressing plate, the rear side pressing plate (7) and the upper pressing plate (10) at different positions, and simultaneously recording the gas flow change of the fluid outlet hole (13);
step eight, replacing briquette coal test pieces with different permeability and strength in the same group of other tests, and repeating the steps four to seven;
and step nine, collating the test data.
2. The method for testing coal body outburst under the coal seam permeability influence mining action according to claim 1, wherein the method comprises the following steps: and step eight, the briquette test pieces with different permeability and strength are obtained by adjusting the particle size ratio of the pulverized coal, the type and the dosage of the additive.
3. The method for testing coal body protrusion under the coal seam permeability influence mining action according to claim 1, wherein: in the third step, the ratio of the particle size of the powder to the particle size of less than 40 meshes is as follows: 40-60 mesh: 60-80 meshes: 80-100 meshes: and (4) preparing three briquette test pieces with different permeability rates according to the grain diameter proportion of 1:1:1:1:1, 1:2:1:2:5 and 1:2:4:1:6 of more than 100 meshes, and performing the same group of other tests in the step eight.
4. The coal bed permeability influence mining coal body protrusion test method according to claim 1, is characterized in that in the third step, the briquette coal test piece is a square block with the thickness of 600mm × 600mm × 100mm, and correspondingly, in the first step, the test piece placing cavity (6) is also a square cavity with the thickness of 600mm × 600mm × 100 mm.
5. The method for testing coal body outburst under the coal seam permeability influence mining action according to claim 1, wherein the method comprises the following steps: in the second step, the raw coal is dried for 22-26 hours at 105-110 ℃ after being crushed and ground.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU1704017A1 (en) * | 1989-12-19 | 1992-01-07 | Pasko Boris | Method of determination of contact strength of frozen coal |
| CN104090087A (en) * | 2014-07-18 | 2014-10-08 | 中国矿业大学(北京) | Coal mine collapse column bursting water geological mechanics fluid-solid coupling test device |
| CN104458418A (en) * | 2014-12-15 | 2015-03-25 | 中国矿业大学(北京) | Working face coal wall stability control simulation experiment table and application method |
| CN104568706A (en) * | 2015-01-29 | 2015-04-29 | 湖南科技大学 | Fluid-solid coupled similar simulation experimental platform |
| CN105259032A (en) * | 2015-09-30 | 2016-01-20 | 山东科技大学 | Method for testing coal brittleness on spot in real time |
-
2018
- 2018-08-20 CN CN201810948183.8A patent/CN109142053B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU1704017A1 (en) * | 1989-12-19 | 1992-01-07 | Pasko Boris | Method of determination of contact strength of frozen coal |
| CN104090087A (en) * | 2014-07-18 | 2014-10-08 | 中国矿业大学(北京) | Coal mine collapse column bursting water geological mechanics fluid-solid coupling test device |
| CN104458418A (en) * | 2014-12-15 | 2015-03-25 | 中国矿业大学(北京) | Working face coal wall stability control simulation experiment table and application method |
| CN104568706A (en) * | 2015-01-29 | 2015-04-29 | 湖南科技大学 | Fluid-solid coupled similar simulation experimental platform |
| CN105259032A (en) * | 2015-09-30 | 2016-01-20 | 山东科技大学 | Method for testing coal brittleness on spot in real time |
Non-Patent Citations (2)
| Title |
|---|
| 煤层气开采中煤储层参数动态演化的物理模拟试验与数值模拟分析研究;刘东;《中国博士学位论文全文数据库 工程科技Ⅰ辑》;20141130(第11期);全文 * |
| 煤层瓦斯抽采过程中煤岩变形的物理模拟实验;许江 等;《煤炭学报》;20150331;第40卷(第3期);全文 * |
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