CN113250715A - Gob-side entry retaining method for layered mining under coal mine - Google Patents
Gob-side entry retaining method for layered mining under coal mine Download PDFInfo
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- CN113250715A CN113250715A CN202110609334.9A CN202110609334A CN113250715A CN 113250715 A CN113250715 A CN 113250715A CN 202110609334 A CN202110609334 A CN 202110609334A CN 113250715 A CN113250715 A CN 113250715A
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- 239000003245 coal Substances 0.000 title claims abstract description 48
- 238000005065 mining Methods 0.000 title claims abstract description 42
- 238000000034 method Methods 0.000 title claims abstract description 40
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 37
- 239000010959 steel Substances 0.000 claims abstract description 37
- 230000003014 reinforcing effect Effects 0.000 claims abstract description 17
- 239000002023 wood Substances 0.000 claims abstract description 16
- 239000002184 metal Substances 0.000 claims abstract description 8
- 230000001681 protective effect Effects 0.000 claims abstract description 3
- 239000011435 rock Substances 0.000 claims description 24
- 238000005553 drilling Methods 0.000 claims description 12
- 238000005520 cutting process Methods 0.000 claims description 9
- 230000000717 retained effect Effects 0.000 claims description 8
- 238000005086 pumping Methods 0.000 claims description 5
- 238000000605 extraction Methods 0.000 claims description 3
- 239000002699 waste material Substances 0.000 claims description 2
- 239000010878 waste rock Substances 0.000 claims description 2
- 238000001514 detection method Methods 0.000 claims 1
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- 238000010276 construction Methods 0.000 abstract description 3
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D11/00—Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
- E21D11/04—Lining with building materials
- E21D11/10—Lining with building materials with concrete cast in situ; Shuttering also lost shutterings, e.g. made of blocks, of metal plates or other equipment adapted therefor
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D11/00—Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
- E21D11/14—Lining predominantly with metal
- E21D11/15—Plate linings; Laggings, i.e. linings designed for holding back formation material or for transmitting the load to main supporting members
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D23/00—Mine roof supports for step- by- step movement, e.g. in combination with provisions for shifting of conveyors, mining machines, or guides therefor
- E21D23/0004—Mine roof supports for step- by- step movement, e.g. in combination with provisions for shifting of conveyors, mining machines, or guides therefor along the working face
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D23/00—Mine roof supports for step- by- step movement, e.g. in combination with provisions for shifting of conveyors, mining machines, or guides therefor
- E21D23/04—Structural features of the supporting construction, e.g. linking members between adjacent frames or sets of props; Means for counteracting lateral sliding on inclined floor
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21F—SAFETY DEVICES, TRANSPORT, FILLING-UP, RESCUE, VENTILATION, OR DRAINING IN OR OF MINES OR TUNNELS
- E21F7/00—Methods or devices for drawing- off gases with or without subsequent use of the gas for any purpose
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Abstract
The invention belongs to the technical field of coal mining, and discloses a gob-side entry retaining method for coal mining by layering, which comprises a lower separated mining working face, wherein a roadway is arranged on one side of the working face and is reserved as a stoping roadway of the next working face in the mining process of the working face, the roadway is supported by a steel shed support, a metal mesh protective top is laid on the top of the steel shed support, and a coal wall of the next working face is arranged on one side of the roadway. According to the invention, the lower-layer gob-side entry retaining is realized by taking measures such as roadway reinforcing support, anchor cables for construction on the coal wall side, wood joist top protection, concrete wall roadway side support, gas drainage after gob-side entry retaining and the like, so that one roadway is less excavated during mining on the lower-layer working face, and Y-shaped ventilation is realized, thereby relieving the problem of shortage of mine excavation and replacement; the ventilation environment of the lower layered working face is improved, and the problem that the gas at the corner exceeds the limit is solved; can also improve the recovery rate of coal resources and create better safety and economic benefits.
Description
Technical Field
The invention belongs to the technical field of coal mining, and particularly relates to a gob-side entry retaining method for layered mining under a coal mine.
Background
At present, the coal mining of China generally comprises three processes of once mining full height, fully mechanized top coal caving and layered mining, and the gob-side entry retaining technology is gradually mature on the working face of once mining full height, fully mechanized top coal caving and upper layered mining and is widely applied; when the lower-layer mining is carried out, an upper-layer mining goaf is arranged above the roadway, the integrity of a top plate is poor, so that the roadway support is difficult, the space reserved between an end support and a roadside support wall is difficult to maintain, and the roadside support wall bears high pressure; and the goaf is arranged above and on one side of the roadway behind the retained roadway, so that gas in the gob-side roadway is easily gathered and exceeds the limit, and the difficulty of gob-side retained roadway is large.
The invention is provided in view of the above.
Disclosure of Invention
The invention provides a method for mining gob-side entry retaining in a coal mine by layering, which can effectively solve the problems existing in the process of mining gob-side entry retaining in the layering, thereby realizing the gob-side entry retaining in the layering, improving the ventilation environment of mining gob-side entry retaining in the layering, solving the problem of tension in mine excavation and replacement, improving the recovery rate of coal resources of a stope face in the layering, and the like.
In order to achieve the purpose, the invention provides the following technical scheme: a gob-side entry retaining method for layered mining under a coal mine comprises a lower layered stope face, wherein an entry retaining roadway is arranged on one side of the lower layered stope face, the entry retaining roadway is supported by a steel shed support, and a metal mesh protective top is laid between the steel shed support and an entry retaining roadway top plate; the lower layered stope working face is provided with working face cutting holes;
before the working face is stoped, a roadway protection support mounting chamber is arranged at the rear of the working face cutting hole and at the side of the old pond at the intersection of the roadway and the roadway retaining roadway, and a roadway protection support is mounted in the mounting chamber; a working surface hydraulic support is arranged in the working surface incision; installing a supplementary reinforced anchor cable on the next lower layered coal seam; supporting a steel shed top beam by using a single column for advance support in the entry retaining roadway and in front of the working face cut hole; a third row of end supports, a second row of end supports and a first row of end supports are sequentially arranged at the position where the entry retaining roadway intersects with the working face undercut hole from left to right;
the lower layered stoping working face starts to carry out stoping, after the working face hydraulic support moves forwards, the roadway protection support moves along with the working face hydraulic support, meanwhile, the corresponding end support first row is removed, a roadway-side supporting wall reserved space is formed between the roadway protection support and the roadway retaining roadway behind the hydraulic support, two sides of the roadway-side supporting wall reserved space are maintained by single columns, and the tops of the single columns are provided with wood joist retaining tops; when the working face is advanced to a certain depth and the space range reserved on the roadside supporting wall meets the requirement, hanging a filling mold bag and pouring concrete to form a roadside supporting wall support;
the method for mining the gob-side entry retaining by layering under the coal mine comprises the following steps:
firstly, detecting and analyzing a roof rock stratum, and researching the roof rock stratum structure;
secondly, calculating and analyzing the pressure of the entry retaining roadway;
thirdly, reinforcing and supporting the roadway and determining the strength of a roadside supporting wall according to the pressure of the retained roadway;
fourthly, determining a supporting mode of a space reserved on the roadside supporting wall and supporting;
fifthly, hanging a filling mold bag in the reserved space and pumping concrete to pour a roadside supporting wall;
and sixthly, performing gas drainage work to ensure that the gas concentration of the gob-side roadway does not exceed the limit.
And (3) analyzing the roof rock stratum structure, wherein the upper part of the lower layered working face is an upper layered working face which is mined, and the roof of the lower layered working face is divided into the following layers from bottom to top according to the past engineering experience: the roof coal that sets up, the artificial roof of manual work laid, irregular caving zone, regular caving zone, crack area and the crooked area that sinks, in order to confirm the structure of layering roof down, need survey the analysis to the roof structure.
According to a preferable technical scheme of the invention, the roof rock stratum of the upper layered working face is detected by adopting a method that ground drilling and underground drilling are used for drilling peeking, based on the geology and the mining condition of the lower layered working face, a roadway roof is formed by cementing caving gangue during upper layered mining, a rock stratum above the roadway is vertically pressed downwards to the roadway, the roadside support wall needs to bear the weight of rock strata of irregular caving zones and regular caving zones above the roadway, the structure and the pressure of the roof rock stratum of the roadside support wall need to be analyzed, and the support capability of the roadside support wall is ensured to be matched with the pressure of an upper roof.
As a preferred technical solution of the present invention, the reinforced support of the entry retaining roadway includes but is not limited to:
1) the top plate is reinforced and supported, the top plate of the lower layered roadway is broken, the gob-side entry retaining roadway is influenced by mining twice, and in order to prevent the top plate from leaking waste rocks, a metal net and a wood joist are adopted for protecting the top;
2) the method comprises the following steps of (1) reinforcing and supporting a coal slope, wherein a lower layered entry retaining roadway is generally supported by a steel shed, so that the supporting capability of the coal slope is insufficient, and reinforcing anchor cables are additionally arranged on the coal wall of a lower section before the working face is mined, so that the roadway slope is reinforced;
3) the method comprises the following steps of advanced support, wherein the advanced support of a working face is arranged in a certain range (generally 20-30m) in front of the working face, and the advanced support mode is that a single column supports a steel roof beam; before the working face is pushed, removing shed legs, close to the working face, of the roadway steel shed support in a certain range in front of the working face;
4) the end support is adopted, the working surface is not provided with an end support, the end adopts a single column and a pi-shaped beam, one beam is supported by three columns, and the pi-shaped beam and the steel shed top beam are arranged in a crossed manner; when the steel shed enters the end socket, the end socket support is required to be carried out in time; after the end support is finished, the single column of the advance support can be removed;
5) the lagging support, wherein the end support extends to the rear of the working face and is used as a working face lagging support and a reinforcing support of a retained roadway section, the lagging support distance is generally 200-300 m, and the lagging support can be adjusted or removed according to the mine pressure observation condition outside the range;
stoping on a working face, moving the hydraulic support forwards, moving the roadway protecting support forwards to prevent gangue in a goaf from being flushed, removing the corresponding first row of end supports, arranging single columns on two sides of the reserved space in time, and arranging wood joists above the single columns and between the top beams of the two steel sheds; the single column, the wood joist and the roadway support the top plate of the upper part of the space reserved by the roadside supporting wall to prevent the gangue leakage of the top plate of the space reserved by the roadside supporting wall.
As a preferred technical scheme of the invention, a top beam of a steel shed support is arranged between the roadside support wall and the top plate, a wood joist is arranged in front of the steel shed and the top beam, the weight of a top plate rock stratum presses down the steel shed top beam, at the moment, the steel shed top beam forms stress concentration, the pressing down can cause compression damage to the top of the roadside support wall, the wood joist needs to be additionally arranged between the steel shed top beams, the top stress area of the roadside support wall is increased, and the pressure on the top of the roadside support wall is reduced;
regarding the construction of the roadside support wall, arranging a grouting pump station in the entry retaining roadway, wherein the grouting pump station comprises a stock ground, a feeding belt, a stirrer and a grouting pump; connecting a grouting pipe to a roadside support wall pouring point from a pump station position; and after the filling mold bag is hung, connecting the grouting pipe with a grouting opening reserved on the mold bag, and sealing the opening of the bag, so that the concrete can be pumped to pour the roadside support wall.
As a preferred technical solution of the present invention, the supporting method between the reserved space and the roadside support wall includes, but is not limited to:
supporting by a head, arranging single columns on two sides of the reserved space in time, arranging wood joists above the single columns, and after the hydraulic support moves forwards, moving the roadway protecting support forwards to prevent the waste rock in the goaf from being washed in, and removing the space between the two steel shed top beams at the corresponding first row end; the single column, the wood joist and the roadway support the top plate of the upper part of the space reserved by the roadside supporting wall to prevent the gangue leakage of the top plate of the space reserved by the roadside supporting wall.
As a preferable technical scheme of the invention, the gas treatment means in the goaf comprises but is not limited to arrangement of ground gas extraction well drainage gas, roadway roof drilling drainage gas and roadside support wall arrangement gas drainage hole drainage gas.
Compared with the prior art, the invention has the following beneficial effects:
1. the method analyzes the roof rock stratum structure and the range of the upper-layer mined-out goaf; reinforcing the support in the roadway and analyzing the support parameters of the roadside support wall; the wood joist and the roadway protecting support control the crushing of the top plate; the purposes of lower-layer gob-side entry retaining are achieved by measures such as anchor cable control rib stripping and gas drainage control gas concentration, the ventilation environment of a lower-layer mining working face is improved, the problem that upper corner gas is out of limit is solved, the recovery rate of coal resources is improved, and good safety and economic benefits are created.
Drawings
FIG. 1 is a schematic plan view of a work surface installation of the present invention;
FIG. 2 is a schematic plan view of a gob-side entry retaining process;
FIG. 3 is a cross-sectional view AA of the first embodiment of the present invention, showing the working face advance support;
FIG. 4 is a cross-sectional view BB of the first embodiment of the present invention, which is a schematic view of the end-on support of the working face;
fig. 5 is a first cross-sectional view of a component CC according to the first embodiment of the present invention, which is a schematic view of a space support for a roadside support wall;
fig. 6 is a second sectional view of the CC shown in fig. one of the present invention, i.e. a schematic view of a space support reserved on a roadside support wall;
FIG. 7 is a first cross-sectional view of DD illustrating the lagging support and entry retaining of the working face according to the first embodiment of the present invention;
FIG. 8 is a second cross-sectional view of the DD constructed in accordance with the first embodiment of the present invention, after lagging support and entry retaining on the working face;
FIG. 9 is a schematic view of the gas control measures of the present invention.
In the figure: 1. a lower layered stope face; 2. a roadway keeping roadway; 3. a lower stratified coal seam; 4. cutting holes on the working surface; 5. a steel shed support; 6. a lane protecting support; 7. a roadway support mounting chamber; 8. repairing the beaten reinforced anchor cable; 9. a working face hydraulic support; 10. a lower layered working face gob; 11. supporting a first row by an end; 12. supporting a second row by an end; 13. supporting a third row by an end; 14. a wood joist; 15. a monolithic column; 16. lagging the first row; 17. a second row is delayed and supported; 18. a space is reserved on the roadside support wall; 19. roadside support walls; 20. a metal mesh; 21. an upper layered goaf; 22. a gas drainage hole reserved in the roadside support wall; 23. a top plate gas drainage hole.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
As shown in fig. 1 to 9, the invention provides a gob-side entry retaining method for coal mining by layers, which comprises a lower-layer stope working face 1, an entry retaining roadway 2 is arranged on one side of the lower-layer stope working face 1, the entry retaining roadway 2 is supported by a steel shed support 5, and a metal net 20 is laid between the steel shed support 5 and a top plate of the entry retaining roadway 2 for protecting the top; the lower layered stope working face 1 is provided with a working face cutting hole 4;
before stoping of the working face, a tunnel protection bracket mounting chamber 7 is arranged on the old pond side at the intersection of the working face notch 4 and the tunnel retaining roadway 2, and a tunnel protection bracket 6 is mounted in the mounting chamber 7; a working face hydraulic support 9 is arranged in the working face cutting hole 4; a repaired reinforced anchor cable 8 is installed on the next lower layered coal seam 3; in the entry retaining roadway 2 and in front of the working face cut hole 4, a single column 15 is adopted to support a steel roof beam for advance support; the crossing position of the entry retaining roadway 2 and the working face cutting hole 4 is sequentially provided with a third row 13 of end supports, a second row 12 of end supports and a first row 11 of end supports from left to right, and the single column 15 comprises an advance support single column;
the lower layered stoping working face 1 starts to stope, after the working face hydraulic support 9 moves forwards, the roadway-protecting support 6 moves along with the working face hydraulic support 9, meanwhile, the corresponding end support first row 11 is removed, a roadside support wall reserved space 18 is formed between the roadway-protecting support 6 and the roadway-retaining roadway 2 behind the hydraulic support, two sides of the roadside support wall reserved space 18 are maintained by single columns 15, and the tops of the single columns 15 are provided with wooden support beams 14 for protecting the tops; when the working face is advanced to a certain depth and the range of the space 18 reserved on the roadside support wall meets the requirement, hanging a filling mold bag and pouring concrete to form the roadside support wall 19;
the method for mining the gob-side entry retaining by layering under the coal mine comprises the following steps:
firstly, detecting and analyzing a roof rock stratum, and researching the roof rock stratum structure;
secondly, calculating and analyzing the pressure of the entry retaining roadway;
thirdly, reinforcing and supporting the roadway and determining the strength of a roadside supporting wall according to the pressure of the retained roadway;
fourthly, determining a supporting mode of a space reserved on the roadside supporting wall and supporting;
fifthly, hanging a filling mold bag in the reserved space and pumping concrete to pour a roadside supporting wall;
and sixthly, performing gas drainage work to ensure that the gas concentration of the gob-side roadway does not exceed the limit, and hanging a filling mold bag and pouring concrete to form a roadside support wall support when the working face is advanced to a certain depth and the roadside support wall is reserved with a space 18 to meet the requirements.
And (3) performing working surface conditions along the gob-side entry retaining:
the method comprises the following steps of mining a 3# coal seam on a working face where the gob-side entry retaining is located, wherein the average buried depth is 335 m, the average total thickness of the coal seam is 6.06m, the layered fully mechanized mining process is adopted, the upper layer is mined for 3.06m, a goaf is formed, the thickness of the lower layer is 3m, the gob-side entry retaining is required to be carried out on a lower layered working face 1, the lower layered entry retaining is a trapezoidal section, the upper width is 3.5m, the lower width is 4.2m, and steel shed support is adopted, and the shed distance is 700 mm.
The specific implementation process is as follows:
first step, roof strata structural analysis
By the method of downhole drilling peeping, the downhole drilling depth is 53m, and the distribution of drilling rock layers is as follows: 0-10m is an irregular falling zone, 10-43m is a regular falling zone, and cracks above 43m develop;
drilling a hole 362m to the coal bed on the working surface by a ground drilling peeping method, and growing a downward crack of 260m-330 m; 330m-352m are regular falling zones; 352m till the coal seam is an irregular caving zone;
and (3) obtaining the structure of the working face roof from bottom to top by analyzing results of two methods and combining the comprehensive histogram of the mine: 0.4m is a reserved false roof; 0.4-10m is an irregular falling belt; 10-32m is a regular falling zone; 32-102m is the thickness of the fissure zone; the rock stratum above 102m is a bending subsidence zone.
Secondly, the pressure of the roadside support wall is calculated and analyzed
Based on the geology and the mining condition of the lower layered working face 1, the top plate of the roadway 2 is formed by cementing caving gangue during upper layered mining, a rock stratum above the roadway 2 is vertically pressed down on the roadway 2, the roadside support wall 19 needs to bear the weight of an irregular caving zone and a regular caving zone rock stratum above the roadway 2, the structure and the pressure of the top plate rock stratum of the roadside support wall 19 need to be analyzed, and the supporting capability of the roadside support wall 19 is guaranteed to be matched with the pressure of an overlying top plate;
designing a roadside support wall 19 to be 1.2m wide and 3m high, building by pumping concrete through C40, wherein the wall body is located in a gob 10 by 0.5m, the roadway is 0.7m, and the width of the retained roadway is 3.15 m;
in order to keep the roadway 2 stable, according to the moment balance theory, the rock mass above the roadway 2 and the roadside support wall 19 are in a moment balance state for the left top corner on the coal seam, and after calculation, when the roadside support wall 19 is 1.2m wide and the roadway 2 is 3.15m wide, the maximum load borne by the roadside support wall 19 is 11796 kN/m; calculating the bearing capacity of the roadside support wall 19 cast by C40 concrete to be 21060 kN/m; according to engineering practice experience, when the roadway-side support safety coefficient is greater than 1.2, the support strength can be considered to meet the requirement, and the bearing capacity safety coefficient of the wall in the project is as follows:
satisfy the requirement ofAnd (5) the safety requirements of the roadside support wall.
Thirdly, strengthening and supporting the roadway
1, reinforcing and supporting a top plate, crushing a top plate of a lower layered roadway, performing mining influence twice on a roadway 2 after gob-side entry retaining, and adding a layer of top plate metal net 20 when tunneling the roadway to prevent the top plate from leaking gangue, wherein meshes are 50mm multiplied by 50 mm;
2, reinforcing roadway side supporting, wherein before the mining of the working face 1, reinforcing roadway sides are reinforced by additionally arranging reinforcing anchor cables 8 on the coal wall of the lower section, the length of each anchor cable is 8000mm, the diameter of each anchor cable is 17.8mm, each side is additionally arranged with two anchor cables, the anchor lifting height is 1.3m, the distance between the anchor cables is 1500mm, and the row spacing is 1400 mm;
3, advance support, in 20m in front of the working face 1, the working face 1 is arranged, and the support mode is as follows: the single columns 15 support the top beam of the steel shed support 5, one beam is supported by three columns, the single column 15 close to the working face is 3400mm away from the coal wall of the working face, the middle single column 15 is 3900mm away from the coal wall of the working face, and one single column 15 far away from the working face is 3100mm away from the coal wall of the working face;
when the working surface 1 is not pushed, the shed legs on the working surface side of the steel shed support 5 within 5m in front of the working surface 1 are dismantled;
4, supporting ends, wherein an end support is not arranged on a working surface, the ends are supported by a single column and a pi-shaped beam, and the pi-shaped beam and a top beam of the steel shed are arranged in a crossed manner for 3 rows; end supports are required to be carried out in time when every two steel sheds enter an end, the length of a pi-shaped beam is 2m, one beam is supported by three columns, the first row of end supports are 550mm away from a working surface, the second row of end supports 12 are arranged along the central line of a roadway 2, the row distance of the end supports is 1200mm, and the distance of single columns is 700 mm; after the end supports are completed, the corresponding advance support single columns can be removed; in the production process, the position of a first hydraulic support 9 on the working face needs to be adjusted in time, the first hydraulic support 9 does not need to enter the roadway 2, the supporting top beam of the roadway is prevented from being rolled, and gangue leakage caused by overlarge distance between the first hydraulic support 9 and the top beam of the roadway is prevented;
5, lagging support, wherein the end supports of the second row and the third row are continued to the rear of the working face and are used as reinforcing supports of a first row 16, a second row 17 and a retained roadway section of the lagging support of the working face 1, the lagging support distance is 200m, and the lagging support can be adjusted or removed according to the mine pressure observation condition outside the range;
fourthly, a space is reserved for the roadside support wall
Before the support is installed on the working face 1, a roadway protection support 6 is installed, and a cavity chamber 7 for installing the roadway protection support 6 is arranged on the old pond side of the intersection of the working face cutting hole 4 and the roadway 2 and is positioned behind a working face 11# hydraulic support 9; the roadway protection support 6 can effectively support a side top plate of the gob 10, prevent gangue in the gob 10 from rushing into the roadway 2 and damage a roadside support wall 19 to reserve a space 18;
the lower layered working face 1 starts to be mined, after the hydraulic support 9 moves forwards, the lane-protecting support 6 moves along with the hydraulic support 9, corresponding first-row end supports are removed, a roadside support wall reserved space 18 is formed between the lane-protecting support and the roadway 2 behind the hydraulic support, two sides of the roadside support wall reserved space 18 are maintained by single columns 15, and the tops of the single columns 15 are provided with wooden joists 14 for top protection; when the working face is advanced to a certain depth and the range of the space 18 reserved on the roadside supporting wall meets the requirement, a filling mold bag can be hung;
fifthly, roadside supporting wall construction
Arranging a grouting pump station in the entry retaining roadway, wherein the distance between the pump station and a working face is 500m, and the grouting pump station comprises a stock ground, a feeding belt, a stirrer and a grouting pump; connecting a grouting pipe to a pouring point of the roadside support wall 19 from the position of a pump station; after the filling mold bag is hung, connecting a grouting pipe with a grouting opening reserved on the mold bag, and sealing the opening of the bag, so that concrete can be pumped to pour the roadside support wall; when pumping concrete, filling the filling mold bag to ensure that the filled filling mold bag is fully contacted with a roadway roof;
sixth, gas treatment
After gob-side entry retaining, the upper part and one side of the roadway 2 are gob areas 10, gas is easy to gather, gas treatment is needed, and a roadside support wall is adopted to reserve a gas drainage hole 22 and a roof gas drainage drill hole 23 to treat gas on a working face; the diameter of a top plate gas drainage drill hole is 94mm, the distance between the top plate gas drainage drill holes is 15m, the hole depth is 5m, the distance between the top plate gas drainage drill hole and the center line of a roadway is 800mm, the top plate gas drainage drill hole is deviated to the working face side, a sleeve is arranged in the drill hole, the length of the sleeve is 4m, the outer diameter phi 90mm is 2.0mm, the sleeve is connected to a branch pipe through a phi 80mm drill hole connecting pipe, the sleeve is flame-retardant and antistatic armored rubber pipe and then is connected to a main pipe, and finally the sleeve reaches a ground gas extraction pump station to form a gas drainage system; the method is characterized in that a gas drainage hole is reserved in the upper portion of a filling mold bag, the diameter of the gas drainage hole is 300mm, the distance between the gas drainage hole and a bottom plate is 2000mm, the hole distance is 15m, when the filling mold bag with the gas drainage hole is hung, after the filling mold bag is hung, a drainage pipe is installed in a gas drainage hole reserved in the filling mold bag, the length of the drainage pipe is 1500mm, the diameter of the drainage pipe is 300mm, the gas drainage pipe in the filling mold bag is connected to a branch pipe through a phi 3000mm connecting pipe flame-retardant and antistatic armored rubber pipe and then connected to a main pipe, and finally the drainage pipe reaches a ground gas drainage pump station to form a gas drainage system.
By the method, the lower layered working face completes gob-side entry retaining, changes U-shaped ventilation into Y-shaped ventilation, and effectively solves the problem of corner gas overrun; one roadway is dug less, so that the problem of tension in mine excavation and replacement is solved; the entry retaining cost is basically consistent with the entry driving cost, the width of the coal pillar is 20m, the length of the entry retaining is 1200m, 100800 tons of coal pillar resources are recovered more, and the created economic benefit reaches more than 2000 ten thousand yuan.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
Claims (6)
1. A coal mine lower-layer mining gob-side entry retaining method comprises a lower-layer stoping working face and is characterized in that: a roadway retaining roadway is arranged on one side of the lower layered stoping working surface, the roadway retaining roadway is supported by a steel shed support, and a metal mesh protective roof is laid between the steel shed support and a roadway retaining roadway roof; the lower layered stope working face is provided with working face cutting holes;
before the working face is stoped, a roadway protection support mounting chamber is arranged at the rear of the working face cutting hole and at the side of the old pond at the intersection of the roadway and the roadway retaining roadway, and a roadway protection support is mounted in the mounting chamber; a working surface hydraulic support is arranged in the working surface incision; installing a supplementary reinforced anchor cable on the next lower layered coal seam; supporting a steel shed top beam by using a single column for advance support in the entry retaining roadway and in front of the working face cut hole; a third row of end supports, a second row of end supports and a first row of end supports are sequentially arranged at the position where the entry retaining roadway intersects with the working face undercut hole from left to right;
the lower layered stoping working face starts to carry out stoping, after the working face hydraulic support moves forwards, the roadway protection support moves along with the working face hydraulic support, meanwhile, the corresponding end support first row is removed, a roadway-side supporting wall reserved space is formed between the roadway protection support and the roadway retaining roadway behind the hydraulic support, two sides of the roadway-side supporting wall reserved space are maintained by single columns, and the tops of the single columns are provided with wood joist retaining tops; when the working face is advanced to a certain depth and the space range reserved on the roadside supporting wall meets the requirement, hanging a filling mold bag and pouring concrete to form a roadside supporting wall support;
the method for mining the gob-side entry retaining by layering under the coal mine comprises the following steps:
firstly, detecting and analyzing a roof rock stratum, and researching the roof rock stratum structure;
secondly, calculating and analyzing the pressure of the entry retaining roadway;
thirdly, reinforcing and supporting the roadway and determining the strength of a roadside supporting wall according to the pressure of the retained roadway;
fourthly, determining a supporting mode of a space reserved on the roadside supporting wall and supporting;
fifthly, hanging a filling mold bag in the reserved space and pumping concrete to pour a roadside supporting wall;
and sixthly, performing gas drainage work to ensure that the gas concentration of the gob-side roadway does not exceed the limit.
2. The method for layered mining gob-side entry retaining under coal mines according to claim 1, wherein: the roof rock stratum detection method of the lower layered stope face is characterized in that ground drilling and underground drilling are used for drilling peeking, and the roof rock stratum structure is analyzed in combination with rock mechanical parameter testing.
3. The method for layered mining gob-side entry retaining under coal mines according to claim 1, wherein: the reinforcing support of the roadway comprises but is not limited to:
1) the top plate is reinforced and supported, the top plate of the stoping roadway of the lower layered working face is a goaf of the upper layered working face and is in a broken state, the gob-side roadway is influenced by mining of the working face and mining of the next working face twice, and in order to prevent the top plate from leaking waste rocks, a metal mesh and a wood joist are adopted for protecting the top;
2) the method comprises the following steps of (1) reinforcing and supporting a coal side, wherein a lower layered entry retaining roadway is generally supported by a steel shed, and before a working face is mined, reinforcing anchor cables are additionally arranged on a coal wall of a lower section to reinforce the coal wall of the roadway;
3) the method comprises the following steps of advanced support, wherein the advanced support of a working face is arranged in a certain range (generally 20-30m) in front of the working face, and the advanced support mode is that a single column supports a steel roof beam; before the working face is pushed, removing shed legs, close to the working face, of the roadway steel shed support in a certain range in front of the working face;
4) the end support is adopted, the working surface is not provided with an end support, the end adopts a single column and a pi-shaped beam, one beam is supported by three columns, and the pi-shaped beam and the steel shed top beam are arranged in a crossed manner; when the steel shed enters the end socket, the end socket support is required to be carried out in time; after the end support is finished, the single column of the advance support can be removed;
5) and (4) lagging support, wherein the end support extends to the rear of the working face and is used as a reinforcing support for the lagging support and the entry retaining section of the working face, the lagging support distance is generally 200-300 m, and the lagging support can be adjusted or removed according to the mine pressure observation condition outside the range.
4. The method for layered mining gob-side entry retaining under coal mines according to claim 1, wherein: a top beam of the steel shed support is arranged between the roadside support wall and the top plate, and a wood joist retaining cap is arranged between the steel shed top beams, so that the wall body is prevented from being damaged due to concentrated pressure on the upper portion of the roadside support wall, and waste rock leakage of the top plate is controlled.
5. The method for layered mining gob-side entry retaining under coal mines according to claim 1, wherein: the support mode of the space reserved on the roadside support wall includes but is not limited to:
stoping the lower layered stope face, moving the hydraulic support of the working face forwards, moving the roadway protecting support forwards to prevent the gangue in the gob of the lower layered working face from rushing in, removing the corresponding end support first row, and arranging single columns on two sides of the space reserved on the roadside support wall in time, wherein a wood joist is arranged above the single column and positioned between the top beams of the two steel sheds; the single column, the wood joist and the roadway support the top plate of the upper part of the space reserved by the roadside supporting wall to prevent the gangue leakage of the top plate of the space reserved by the roadside supporting wall.
6. The method for layered mining gob-side entry retaining under coal mines according to claim 1, wherein: the method for treating the gas in the lower layered working face goaf comprises but is not limited to arrangement of a ground gas extraction well, gas drainage of a roadway roof drill hole and gas drainage of a reserved roadway-side support wall.
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| CN114704320A (en) * | 2021-11-10 | 2022-07-05 | 中国矿业大学 | I-shaped tray and gob-side entry retaining mining side supporting structure |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN114704320A (en) * | 2021-11-10 | 2022-07-05 | 中国矿业大学 | I-shaped tray and gob-side entry retaining mining side supporting structure |
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