CN110675273B - Method for judging water and sand bursting disasters of coal face - Google Patents
Method for judging water and sand bursting disasters of coal face Download PDFInfo
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- CN110675273B CN110675273B CN201910979960.XA CN201910979960A CN110675273B CN 110675273 B CN110675273 B CN 110675273B CN 201910979960 A CN201910979960 A CN 201910979960A CN 110675273 B CN110675273 B CN 110675273B
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Abstract
The invention discloses a method for judging water and sand bursting disasters of a coal face, which comprises the following steps of: s1: measuring the thickness h1 of a loose layer above the water level of the area to be evaluated and the thickness d of a water-bearing layer at the lower part of the loose layer; s2: testing physical and mechanical properties of a sand body and a bedrock of the unconsolidated formation; s3: monitoring the water flow velocity v of the underground drainage hole; s4: calculating the cracking width psi of the bedrock fracture; s5: calculating the height delta h of the soil column formed in the bedrock fracture when the damage occurs; s6: calculating the remaining sliding force F of the earth pillar The residue is left (ii) a S7: calculating the residual resistance I of the earth pillar; s8: setting a judgment basis G for starting of the water bursting and sand bursting disasters; s9: calculating the maximum height H of the safety head cr . The method for judging the water bursting and sand bursting disasters of the coal face can realize scientific evaluation of the water bursting and sand bursting dangers and provide reasonable basis for drainage water before mining, so that the risk of the water bursting and sand bursting disasters of the face through a thin bedrock and thick loose water-containing layer area is reduced.
Description
Technical Field
The invention relates to the technical field of coal mine disaster prevention and control, in particular to a method for judging water and sand bursting disasters of a coal face of a thin bedrock and a thick loose aquifer.
Background
The western coal resources in China are abundant in reserves, the occurrence conditions of the coal are simple, and the method is extremely suitable for large-scale mechanized mining. The working conditions of thin bedrock thickness, large loose layer thickness and large water head height in the loose layer are commonly met in the process of mining shallow coal. Because the bedrock thickness is small, the whole bedrock stratum completely collapses under the influence of mining, the rock body fracture penetrates through the whole bedrock stratum to form a fracture channel for connecting a loose aquifer and a goaf, so that water sand is burst to a coal face along the bedrock fracture, the hydraulic support and mining equipment are buried by the accumulated sand body, the hydraulic support cannot move forwards along with the pushing of the face, the burst water burst sand mixture causes the sudden increase of underground water burst amount, and the water carrying the silt sand cannot be directly discharged by a water pump, so that the normal mining working progress is seriously influenced, and the life safety of underground workers is seriously threatened.
In recent years, western mining areas have been affected by multiple water bursting and sand bursting accidents, and mine production units do a large amount of disaster prevention and control work aiming at water bursting and sand bursting, and the main work comprises the following steps: before mining, water is drained, and cement slurry is poured into a loose layer at the top of the bedrock, so that great manpower, material resources and financial resources are consumed while a certain disaster prevention and reduction effect is achieved.
At present, the core problems of mine production units in the aspect of prevention and control of water bursting and sand bursting disasters of a working face are as follows: the water and sand bursting disaster happens to the working face of the thin bedrock and the thick loose aquifer meeting the conditions.
The control factors of the water bursting and sand bursting accidents of the working face of the thin bedrock and the thick loose aquifer are many, and the control factors relate to geological formation conditions, mining thickness, roof bedrock damage forms, physical and mechanical properties of sand and soil bodies of the loose aquifer and water head height of the loose aquifer, a large number of expert and scholars develop extensive and deep researches, but quantitative evaluation cannot be formed on the water bursting and sand bursting disasters of the working face of the thin bedrock and the thick loose aquifer at present.
In view of the above, it is necessary to provide a method for judging water and sand bursting disasters of a coal face of a thin bedrock and a thick loose aquifer.
Disclosure of Invention
The invention aims to provide a method for judging water bursting and sand bursting disasters of a coal face of a thin bedrock and a thick loose aquifer, which can provide a powerful basis for preventing and treating the water bursting and sand bursting disasters in the coal mining process.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
the technical scheme of the invention provides a method for judging water and sand bursting disasters of a coal face, which comprises the following steps:
s1: measuring the thickness h1 of a loose layer above the water level of the area to be evaluated and the thickness d of a water-bearing layer at the lower part of the loose layer;
s2: the physical and mechanical properties of the sand body and the bedrock of the unconsolidated formation are tested, and specific test indexes comprise:
severe gamma of loose layer sand soil body and dryness and gravity gamma of loose layer sand soil body t Saturated gravity gamma of loose layer sand soil body sat Shear strength tau of unconsolidated formation sand body f Cohesive force c of loose-bed sand soil body and internal friction angle of loose-bed sand soil body
Weakening coefficient lambda formed by weakening strength of loose-bed sand soil body by water, internal friction angle alpha of rock mass and heavy gamma of water w ；
S3: monitoring the water flow velocity v of the underground hydrophobic hole;
s4: calculating the cracking width psi of the bedrock fracture;
s5: calculating the height delta h of the soil column formed in the bedrock fracture when the damage occurs;
s6: calculating the residual sliding force F of the soil column The residue is left ；
S7: calculating the residual resistance I of the earth pillar;
s8: setting a judgment basis G for starting of the water bursting and sand bursting disasters;
s9: calculating the maximum height H of the safety head cr 。
Further, the crack width ψ in the step S4 is calculated by the following formula:
Further, the column height Δ h in step S5 is calculated by the following formula:
Further, the soil column in the step S6 has residual slip force F The residue is left Calculated by the following formula:
in the formula: i is the hydraulic gradient.
Further, the earth pillar residual resistance I in the step S7 is calculated by the following formula:
Ι＝(f+λc)·Δh-(γ t +γ w i)ψΔh＝(f+λc-γ t ψ-γ w ψi)·Δh
in the formula: f is the frictional resistance of the sand body of the unconsolidated formation, and i is the hydraulic gradient.
Further, the judgment of the start of the water-bursting and sand-bursting disaster in the step S8 is based on the criterion G ═ I-F The residue is left ；
If G is greater than 0, determining the state is stable;
if G is equal to 0, determining that the state is critical;
if G < 0, the state is judged to be broken.
Further, the maximum height H in the step S9 cr Calculated by the following formula:
further, the method also includes step S10: the height of the water head of the loose-bed sand soil body is reduced by prolonging the water drainage time.
Further, the weakening coefficient λ in step S2 is measured by the triaxial soil test.
By adopting the technical scheme, the method has the following beneficial effects:
the method for judging the water burst and sand burst disaster of the coal face can comprehensively analyze the source attribute and the channel attribute of disaster formation aiming at the special geological mining environment of the western mining area, establishes a theoretical model of water burst and sand burst of the thin bedrock thick loose aquifer working face under the influence of comprehensive factors by utilizing the mining professional knowledge, soil mechanics, hydromechanics and rock mechanics theories, deduces the water sand starting criterion after the formation of bedrock cracks, and provides a powerful basis for preventing and controlling the water burst and sand burst disaster in the coal mining process.
According to the method for judging the water burst and sand burst disaster of the coal face, the scientific evaluation of the water burst and sand burst risk can be realized before the face is recovered through calculation, and meanwhile, a reasonable basis is provided for drainage water before recovery, so that the risk of the water burst and sand burst disaster of the face through a thin bedrock and thick loose water-containing layer region is reduced.
Drawings
FIG. 1 is a schematic representation of an overview of formation of bed fractures in a bed collapse zone;
FIG. 2 is a schematic diagram of a water bursting and sand bursting critical hydraulic gradient calculation model;
FIG. 3 is a schematic diagram of the calculation of the fracture width of the bedrock in the region A of FIG. 1.
Detailed Description
The following further describes embodiments of the present invention with reference to the accompanying drawings. In which like parts are designated by like reference numerals. It should be noted that the terms "front," "back," "left," "right," "upper" and "lower" used in the following description refer to directions in the drawings, and the terms "inner" and "outer" refer to directions toward and away from, respectively, the geometric center of a particular component.
As shown in fig. 1-2, a method for determining a water bursting and sand bursting disaster of a coal face according to an embodiment of the present invention includes the following steps:
s1: the thickness h1 of the unconsolidated layer above the water level of the area to be evaluated and the thickness d of the aquifer below the unconsolidated layer were measured.
S2: the physical and mechanical properties of the sand body and the bedrock of the unconsolidated formation are tested, and specific test indexes comprise:
severe gamma of loose-bed sand soil body and dryness of loose-bed sand soil body t Saturated gravity gamma of loose layer sand soil body sat Shear strength tau of unconsolidated formation sand body f Cohesive force c of loose-bed sand soil body and internal friction angle of loose-bed sand soil body
Weakening coefficient lambda formed by weakening strength of loose-bed sand soil body by water, internal friction angle alpha of rock mass and heavy gamma of water w 。
S3: the water flow velocity v of the downhole hydrophobic bore is monitored.
S4: the cracking width psi of the bedrock fracture 4 is calculated.
S5: the height Δ h of the pillar 5 formed in the bedrock fracture 4 when failure occurred was calculated.
S6: calculating the remaining sliding force F of the earth pillar Remains of 。
S7: and calculating the residual resistance I of the soil column.
S8: and setting a judgment basis G for starting of the water bursting and sand bursting disasters.
S9: calculating the maximum height H of the safety head cr 。
The method for judging the water and sand bursting disasters of the coal face is mainly used for judging the water and sand bursting disasters of the coal face of a thin bedrock and a thick loose aquifer.
The bedrock 2 covers the coal seam 1, and loose layer sand soil bodies cover the bedrock 2. The rear part of the coal seam 1 is a goaf, and the inside of the goaf is filled with crushed expanded bedrock. When the bedrock in the goaf is not yet crushed, the boundary is a before-crushing boundary 31'; after the matrix in the gob breaks, it expands, with the actual boundary of the broken and expanded matrix being the broken boundary 31. And bedrock fractures 4 are formed between the fractured boundary 31 and the bedrock 2 above the coal seam 1. The downhole drainage hole is positioned downhole and used for draining water in the downhole.
As shown in fig. 2, water exists in the loose-bed sandy soil body, and after the bedrock fractures 4 are formed, the water collects silt and flows downwards from the bedrock fractures 4, but due to certain viscosity of the silt, earth pillars 5 are formed above the top plate of the coal seam 1.
The height delta H of the soil column 5 is equal to H-H.
Residual slip force F of earth pillar The residue is left Is the force remaining in the column that can slide down when failure first occurs, e.g. shear force.
The remaining resistance I of the column is the force remaining in the column against which it can slide down when failure first occurs, e.g. the adhesive force.
The judgment is based on the criterion G of the start of the water bursting and sand bursting disasters, and the criterion G is based on the residual soil column resistance I and the residual soil column sliding force F Win (win) The difference of (d) gives:
if G is larger than 0, the soil column 5 is judged to be in a stable state, and water and sand can not be broken; if G is equal to 0, the soil column 5 is judged to be in a critical state; if G is less than 0, the soil column 5 is judged to be in a damaged state, water and sand collapse can occur, muddy water can collapse into the working face through the bedrock fractures 4, and the normal excavation working progress is influenced.
Finally, the maximum height H of the safe water head is calculated according to the data cr Meaning that the head of the water in the unconsolidated or thin bedrock thick unconsolidated aquifer is below H cr Or the height of the water head from the coal seam 1 is less than H cr No water and sand bursting will occur.
Therefore, the method for judging the water burst and sand burst disaster of the coal face can realize scientific evaluation of the water burst and sand burst risk before stoping of the face through calculation, and simultaneously provides reasonable basis for drainage water before stoping, so that the risk of the water burst and sand burst disaster of the face through a thin bedrock thick loose water-containing layer area is reduced.
Preferably, as shown in fig. 3, the crack width ψ in step S4 is calculated by the following formula:
Preferably, the column height Δ h in step S5 is calculated by the following formula:
Through monitoring the water velocity v of the underground drain hole, the underground drain hole can be vertically arranged, so that the falling speed of water flow and cement sand can be monitored.
According to the formula: mg Δ h-1/2 xmv 2 Push out
Preferably, the soil column in the step S6 has residual slip force F The residue is left Calculated by the following formula:
in the formula: i is the hydraulic gradient.
Preferably, the residual earth column resistance I in the step S7 is calculated by the following formula:
Ι＝(f+λc)·Δh-(γ t +γ w i)ψΔh＝(f+λc-γ t ψ-γ w ψi)·Δh
in the formula: f is the frictional resistance of the sand body of the unconsolidated formation, and i is the hydraulic gradient.
Preferably, the judgment result of the start of the water-bursting and sand-bursting disaster in the step S8 is based on G-I-F The residue is left ；
If G is larger than 0, the soil column 5 is judged to be in a stable state;
if G is equal to 0, judging that the earth pillar 5 is in a critical state;
and if G is less than 0, judging that the soil column 5 is in a damaged state.
Preferably, the maximum height H in step S9 cr Calculated by the following formula:
preferably, the judging method further includes step S10: the height of the water head of the loose-bed sand soil body is reduced by prolonging the water drainage time, so that the water head is lower than H cr To avoid water and sand bursting.
Preferably, the weakening coefficient λ in step S2 is measured by triaxial soil test.
The calculation of the maximum allowable water head height during the stoping is beneficial to the development of analysis in production practice of production units, and the maximum coal seam thickness which is allowed to be mined under the condition of a certain water head height can be calculated by simply deforming a calculation formula of the maximum allowable water head height according to actual needs.
The method can provide quantitative evaluation basis for the prevention and control of the water bursting and sand bursting disasters of the working surface of the thin bedrock and the thick loose aquifer, so that the dangerous working surface is guided to carry out drainage in a local area and reinforcement treatment of grouting slurry at the bottom of the loose layer, and the waste of manpower, material resources and financial resources of grouting engineering is reduced to the greatest extent on the premise of ensuring the safety production of a coal mine.
According to the needs, the above technical schemes can be combined to achieve the best technical effect.
The foregoing is considered as illustrative only of the principles and preferred embodiments of the invention. It should be noted that, for those skilled in the art, several other modifications can be made on the basis of the principle of the present invention, and the protection scope of the present invention should be regarded.
Claims (3)
1. A method for judging water bursting and sand bursting disasters of a coal face is characterized by comprising the following steps of:
s1: measuring the thickness h1 of a loose layer above the water level of the area to be evaluated and the thickness d of a water-bearing layer at the lower part of the loose layer;
s2: the physical and mechanical properties of the sand body and the bedrock of the unconsolidated formation are tested, and specific test indexes comprise:
severe gamma of loose-bed sand soil body and dryness of loose-bed sand soil body t Saturated gravity gamma of loose layer sand soil body sat Shear strength tau of unconsolidated formation sand body f Cohesive force c of loose-bed sand soil body and internal friction angle of loose-bed sand soil body
Weakening coefficient lambda formed by weakening strength of loose-bed sand soil body by water, internal friction angle alpha of rock mass and heavy gamma of water w ；
S3: monitoring the water flow velocity v of the underground hydrophobic hole;
s4: calculating the cracking width psi of the bedrock fracture, wherein the cracking width psi is calculated by the following formula:
s5: calculating the height delta h of the soil column formed in the bedrock fracture when the damage occurs, wherein the height delta h of the soil column is calculated by the following formula:
s6: calculating the remaining sliding force F of the earth pillar The residue is left Wherein the earth pillar has a residual slip force F The residue is left Calculated by the following formula:
in the formula: i is hydraulic gradient;
s7: calculating the residual resistance I of the soil column, wherein the residual resistance I of the soil column is calculated by the following formula:
Ι＝(f+λc)·Δh-(γ t +γ w i)ψΔh＝(f+λc-γ t ψ-γ w ψi)·Δh
in the formula: f is the frictional resistance of the sand body of the unconsolidated formation, and i is the hydraulic gradient;
s8: setting a judgment basis G for the start of the water bursting and sand bursting disasters, wherein the judgment basis G for the start of the water bursting and sand bursting disasters is I-F The residue is left ；
If G is greater than 0, determining the state is stable;
if G is equal to 0, determining that the state is critical;
if G is less than 0, judging as a destruction state;
s9: calculating the maximum height H of the safety head cr Wherein the maximum height H cr Calculated by the following formula:
2. the judging method according to claim 1, further comprising step S10: the height of the water head of the loose-bed sand soil body is reduced by prolonging the water drainage time.
3. The method according to claim 1, wherein the weakening coefficient λ in step S2 is measured by triaxial soil test.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105332738A (en) * | 2015-08-24 | 2016-02-17 | 西安科技大学 | Early warning method of coal mining subsidence |
| CN107165626A (en) * | 2017-06-30 | 2017-09-15 | 徐州市耐力高分子科技有限公司 | A kind of coal-face floods prevention method with cranny development country rock top plate |
| CN107436349A (en) * | 2017-07-27 | 2017-12-05 | 中国神华能源股份有限公司 | It is a kind of to be used for the appraisal procedure that husky danger is assessed of being burst to the gushing water of roof |
| WO2018192067A1 (en) * | 2017-04-19 | 2018-10-25 | 中国矿业大学 | Water disaster prevention and treatment design method for mine taking coal bed as main aquifer |
-
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- 2019-10-15 CN CN201910979960.XA patent/CN110675273B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105332738A (en) * | 2015-08-24 | 2016-02-17 | 西安科技大学 | Early warning method of coal mining subsidence |
| WO2018192067A1 (en) * | 2017-04-19 | 2018-10-25 | 中国矿业大学 | Water disaster prevention and treatment design method for mine taking coal bed as main aquifer |
| CN107165626A (en) * | 2017-06-30 | 2017-09-15 | 徐州市耐力高分子科技有限公司 | A kind of coal-face floods prevention method with cranny development country rock top plate |
| CN107436349A (en) * | 2017-07-27 | 2017-12-05 | 中国神华能源股份有限公司 | It is a kind of to be used for the appraisal procedure that husky danger is assessed of being burst to the gushing water of roof |
Non-Patent Citations (4)
| Title |
|---|
| "Study on the law of surface cracks while coal mining in the thin bedrock and thick unconsolidated layer of Yu-Shen-Fu mining area";Wu Zuoqi等;《E3S Web of Conferences》;20180131;第53卷(第1期);第1-5页 * |
| "Surface crack and sand inrush disaster induced by high-strength mining: example from the Shendong coal field, China";Weitao Yan等;《Geosciences Journal》;20180430;第22卷(第2期);第347-357页 * |
| "浅埋开采工作面水沙溃涌灾害预测及防治对策";刘洋等;《西安科技大学学报》;20161130;第36卷(第6期);第775-781页 * |
| "煤矿工作面上方地表裂缝分布、宽度与水平变形之关系研究";陈冉丽等;《金属矿山》;20150430(第4期);第79-82页 * |
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