阅读说明：本技术 一种急倾斜特厚硬煤层爆破和大直径钻孔联合卸压方法 (Combined pressure relief method for blasting and large-diameter drilling of steeply inclined super-thick hard coal seam ) 是由 何江 吴江湖 丁永红 马志锋 苗伟东 李明 李晓伟 乔国民 于 2021-08-06 设计创作，主要内容包括：本发明公开了一种急倾斜特厚硬煤层爆破和大直径钻孔联合卸压方法,具体包括以下步骤：首先急倾斜特厚硬煤层开采过程中,顶板侧巷道与底板侧巷道错层布置,多个钻孔应力计安装在两巷上并覆盖整条巷道,用于监测巷道围岩应力变化；再根据煤体及煤层顶底板力学性质,确定爆破孔与大直径钻孔的安装参数,并在顶板侧巷道布置大直径钻孔和爆破孔,底板侧巷道布置爆破孔；最后在爆破大直径联合卸压钻孔施工完后,根据钻孔应力计监测到的应力值评价卸压效果；本一种急倾斜特厚硬煤层爆破和大直径钻孔联合卸压方法,不仅能够降低急倾斜煤层应力集中和冲击危险程度,卸压效果更好,而且有效提高回采率,更加适合急倾斜特厚硬煤层的特殊性。(The invention discloses a combined pressure relief method for blasting and large-diameter drilling of a steep and extremely-thick hard coal seam, which specifically comprises the following steps: firstly, in the mining process of a steeply inclined extra-thick hard coal seam, a top plate side roadway and a bottom plate side roadway are arranged in a staggered manner, and a plurality of borehole stressometers are arranged on the two roadways and cover the whole roadway and are used for monitoring the stress change of surrounding rocks of the roadway; determining installation parameters of the blast holes and the large-diameter drill holes according to the mechanical properties of the coal body and the top and bottom plates of the coal bed, arranging the large-diameter drill holes and the blast holes in the top plate side roadway, and arranging the blast holes in the bottom plate side roadway; finally, after the blasting large-diameter combined pressure relief drilling construction is finished, evaluating the pressure relief effect according to the stress value monitored by the drilling stress meter; the combined pressure relief method for blasting and large-diameter drilling of the steeply inclined super-thick hard coal seam can reduce stress concentration and impact danger degree of the steeply inclined coal seam, is better in pressure relief effect, effectively improves recovery rate, and is more suitable for particularity of the steeply inclined super-thick hard coal seam.)

1. A combined pressure relief method for blasting and large-diameter drilling of a steep and extremely-thick hard coal seam is characterized by comprising the following steps:

s1, in the mining process of the steeply inclined super-thick hard coal seam, a roof side roadway (4) and a floor side roadway (7) are arranged in a staggered manner, and a plurality of borehole stressometers (8) are arranged on the two roadways and cover the whole roadway and are used for monitoring the stress change of surrounding rocks of the roadways;

s2, determining parameters of the hole diameter, the hole depth, the distance and the position from the bottom plate of the blast hole (6) and the large-diameter drill hole (5) according to the mechanical properties of the coal body and the coal seam roof and bottom plate, arranging the large-diameter drill hole (5) and the blast hole (6) in the roof side roadway (4), and arranging the blast hole (6) in the bottom plate side roadway (7);

s3, after the blast hole (6) and the large-diameter drill hole (5) are constructed, evaluating the pressure relief effect according to the stress value monitored by the drill hole stress meter (8);

when the numerical value of the drilling stress meter (8) is larger than the monitoring early warning value, the evaluation is poor, and when the numerical value of the drilling stress meter (8) is smaller than the monitoring early warning value, the evaluation is good.

2. The combined pressure relief method for blasting and large-diameter drilling of the steeply inclined super-thick hard coal seam according to claim 1, wherein the roof-side roadway (4) is staggered and arranged at the next level of the floor-side roadway (7) in step S1.

3. The combined pressure relief method for blasting and large-diameter drilling of the steeply inclined super-thick hard coal seam according to claim 2, wherein the burial depth of each borehole stress gauge (8) in step S1 is 8-10m, and the distance between adjacent boreholes is 5-30 m.

4. The combined pressure relief method for blasting and large-diameter drilling of the steeply inclined ultra-thick hard coal seam according to any one of claims 1 to 3, wherein the large-diameter drilling (5) in the roof side roadway (4) in the step S2 is respectively positioned on the right upper side and the bottom plate thereof;

a plurality of large-diameter drill holes (5) on the right upper of the roof side roadway (4) are positioned on the same plane, the aperture of each large-diameter drill hole (5) is larger than 100mm, the hole depth is the distance between the roof side roadway (4) and the top of the floor side roadway (7), the adjacent distance is 1-2m, and the distance between the hole opening and the floor of the roof side roadway (4) is 0.8-1.5 m; a plurality of large-diameter boreholes (5) are arranged in the middle of the floor of the roof-side drift (4), the corresponding bore diameter is greater than 100mm, and the bore depth is three times the drift width of the roof-side drift (4).

5. The combined pressure relief method for blasting and large-diameter drilling of the steeply inclined and extremely thick hard coal seam according to claim 4, characterized in that a plurality of blast holes (6) in the top plate side roadway (4) are positioned at the left and right highwall corners, the diameter of each blast hole (6) is 42mm, the depth of each blast hole is 8-10m, and the adjacent distance is 5m-10 m.

6. The combined pressure relief method for blasting and large-diameter drilling of the steeply inclined ultra-thick hard coal seam according to claim 5, characterized in that the large-diameter drilling (5) at the right upper side of the roof side roadway (4) is arranged at an elevation angle of 10-30 degrees, and the blast hole (6) at the bottom plate of the roof side roadway (4) is arranged at a depression angle of 45 degrees.

7. The combined pressure relief method for blasting and large-diameter drilling of the steeply inclined ultra-thick hard coal seam according to claim 6, characterized in that the large-diameter drilling holes (5) arranged in the roof side roadway (4) and the blasting holes (6) arranged thereon are arranged at intervals along the roadway direction, and four large-diameter drilling holes (5) are arranged between every two blasting holes (6).

8. The combined pressure relief method for blasting and large-diameter drilling of the steeply inclined super-thick hard coal seam according to claim 7, wherein the plurality of blast holes (6) in the bottom plate side roadway (7) in the step S2 are located at the left upper side of the bottom plate side roadway, each blast hole has a hole diameter of 42mm, a hole depth of 8-10m, adjacent intervals of 5m-10m, and a hole opening is 0.5-1.2m on the bottom plate of the bottom plate side roadway (7) and is arranged at a depression angle of 30-45 degrees.

9. The combined pressure relief method for blasting and large-diameter drilling of the steeply inclined super-thick hard coal seam according to any one of claims 1 to 3, wherein in step S3, if the pressure relief effect is poor, the arrangement density of the large-diameter drilling holes (5) and the blast holes (6) of the roof side roadway (4) and the arrangement density of the blast holes (6) of the floor side roadway (7) are increased;

and evaluating the pressure relief effect again after the construction is finished until the pressure relief effect is good.

10. The combined pressure relief method for blasting and large-diameter drilling of the steeply inclined and extremely thick hard coal seam according to claim 9, characterized in that when the corresponding blast holes (6) in the roof side drift (4) and the floor side drift (7) are blasted, the number of the blast holes per time does not exceed 6.

Technical Field

The invention relates to the field of prevention and control of impact mine pressure, in particular to a combined pressure relief method for blasting and large-diameter drilling of a steeply inclined super-thick hard coal seam.

Background

Rock burst is a typical mine dynamic phenomenon, has great harmfulness to safety production of coal mines, and along with the increase of mining depth, the possibility and the harm of rock burst increase. When mining the steeply inclined and extremely thick hard coal, the problems of unobvious pressure relief effect, poor safety, fewer related pressure relief measures and the like exist during stoping of a working face due to mining conditions and the particularity of mechanical properties of a coal bed of the steeply inclined and extremely thick hard coal.

The existing research shows that the ultra-thick hard coal is easy to accumulate energy during working face extraction due to the harder mechanical effect of the coal quality. In order to ensure safe and efficient production of coal mines, measures suitable for complete pressure relief of steeply inclined super-thick coal seams are required. However, the existing pressure relief measures have the following three problems: firstly, the existing measures for steeply inclined super-thick hard coal are few, and the currently adopted measures cannot realize full pressure relief of the coal seam; secondly, the recovery rate is lower when the steeply inclined extra-thick hard coal working face is recovered; and thirdly, the pressure relief measure parameters are not matched with the field conditions of the working face.

Disclosure of Invention

The invention provides a combined pressure relief method for blasting and large-diameter drilling of a steeply inclined super-thick hard coal seam, which can reduce stress concentration and impact danger degree of the steeply inclined coal seam, relieve pressure in a targeted manner, achieve better pressure relief effect, effectively improve the recovery rate of the existing working face, ensure that pressure relief measure parameters are matched with the field conditions of the working face, and is more suitable for the particularity of the steeply inclined super-thick hard coal seam.

In order to achieve the purpose, the combined pressure relief method for blasting and large-diameter drilling of the steeply inclined extra-thick hard coal seam specifically comprises the following steps:

s1, arranging a top plate side roadway and a bottom plate side roadway in a staggered manner in the mining process of the steeply inclined ultra-thick hard coal seam, and installing a plurality of borehole stress meters on the two roadways and covering the whole roadway for monitoring the stress change of surrounding rocks of the roadway;

s2, determining parameters of the hole diameter, the hole depth, the distance and the position from the bottom plate of the blast hole and the large-diameter drill hole according to the mechanical properties of the coal body and the coal seam roof and bottom plate, and arranging the large-diameter drill hole and the blast hole in a top plate side roadway and arranging the blast hole in a bottom plate side roadway;

s3, after the blast hole and the large-diameter drill hole are constructed, evaluating the pressure relief effect according to the stress value monitored by the drill hole stress meter;

when the drilling stress count value is larger than the monitoring early warning value, the drilling stress count value is judged to be poor, and when the drilling stress count value is smaller than the monitoring early warning value, the drilling stress count value is judged to be good.

Further, the roof-side course staggering is arranged at the next level of the floor-side course in step S1.

Further, the burying depth of each drilling stress meter in the step S1 is 8-10m, and the distance between adjacent drilling stress meters is 5-30 m.

Further, the method is characterized in that in the step S2, the large-diameter drill holes on the top plate side roadway are respectively positioned on the right side and the bottom plate of the top plate side roadway;

a plurality of large-diameter drill holes on the right side of the top plate side roadway are positioned on the same plane, the aperture of each large-diameter drill hole is larger than 100mm, the hole depth is the distance between the top plate side roadway and the top of the bottom plate side roadway, the adjacent distance is 1-2m, and the distance between an opening and the bottom plate of the top plate side roadway is 0.8-1.5 m; and a plurality of large-diameter drill holes on the bottom plate of the top plate side roadway are arranged in the middle of the bottom plate of the top plate side roadway, the corresponding hole diameter is larger than 100mm, and the hole depth is three times of the roadway width of the top plate side roadway.

Furthermore, a plurality of blast holes on the roadway on the side of the top plate are positioned at the left and right upper corners, the aperture of each blast hole is 42mm, the hole depth is 8-10m, and the adjacent distance is 5m-10 m;

furthermore, the large-diameter drill holes at the right side of the top plate side roadway are arranged at an elevation angle of 10-30 degrees, and the blast holes at the bottom plate of the top plate side roadway are arranged at a depression angle of 45 degrees.

Furthermore, the large-diameter drill holes arranged in the top plate side roadway and the blast holes arranged on the large-diameter drill holes are arranged at intervals along the roadway direction, and four large-diameter drill holes are arranged between every two blast holes.

Further, a plurality of blast holes on the bottom plate side roadway are positioned on the left side of the bottom plate side roadway in the step S2, each hole is 42mm in diameter, 8-10m in depth, 5m-10m in adjacent distance, 0.5-1.2m in hole opening to the bottom plate of the bottom plate side roadway and is arranged at a depression angle of 30-45 degrees.

Further, in step S3, if the pressure relief effect is poor, increasing the arrangement density of the large-diameter drill holes and the blast holes in the top plate side roadway and the arrangement density of the blast holes in the bottom plate side roadway;

and evaluating the pressure relief effect again after the construction is finished until the pressure relief effect is good.

Further, when the corresponding blasting holes on the top plate side roadway and the bottom plate side roadway are blasted, the number of the blasting holes in each time is not more than 6.

Compared with the prior art, the combined pressure relief method for blasting and large-diameter drilling of the steeply inclined super-thick hard coal seam is characterized in that

In the mining process of the steeply inclined extra-thick hard coal seam, the top plate side roadway and the bottom plate side roadway are arranged in a staggered manner, so that the staggered arrangement mode effectively improves the recovery rate on the existing working face and increases the economic benefit of the coal mine;

the method for forming combined pressure relief of blasting large diameter can reduce stress concentration and impact danger degree of steeply inclined coal seams, achieves better pressure relief effect on surrounding rocks and deep coal bodies of roadways and is more suitable for specificity of steeply inclined extremely thick hard coal seams;

the large-diameter drill holes and the blast holes are arranged at different positions, different installation parameters are arranged on a working surface, and a plurality of borehole stress meters are utilized to cover the whole roadway, so that the stress change of surrounding rock of the roadway is monitored, the monitored stress value is evaluated for pressure relief effect, and the pressure relief measure parameters are matched with the field conditions of the working surface;

drawings

FIG. 1 is an overall flow chart of the present invention;

FIG. 2 is a diagram of a blasting large aperture combined pressure relief arrangement of the present invention;

FIG. 3 is a layout of a stress monitoring system in the present invention;

in the figure: 1. the method comprises the following steps of coal seam roof, 2 working faces, 3 coal seam floor, 4 roof side roadway, 5 major diameter drilled hole, 6 blast hole, 7 floor side roadway, 8 drilling stress meter, 9 goaf.

Detailed Description

The invention will be further explained with reference to the drawings.

As shown in fig. 1, the combined pressure relief method for blasting and large-diameter drilling of the steeply inclined ultra-thick hard coal seam specifically comprises the following steps:

s1, in the mining process of the steeply inclined super-thick hard coal seam, the top plate side roadway 4 and the bottom plate side roadway 7 are arranged in a staggered mode, and a plurality of borehole stress meters 8 are installed on the two roadways and cover the whole roadway and are used for monitoring stress changes of surrounding rocks of the roadway;

s2, determining parameters of the hole diameter, the hole depth, the distance and the distance between the blast hole 6 and the large-diameter drill hole 5 from the bottom plate according to the mechanical properties of the coal body and the top and bottom plates of the coal seam, arranging the large-diameter drill hole 5 and the blast hole 6 in the top plate side roadway 4, and arranging the blast hole 6 in the bottom plate side roadway 7;

s3, after the construction of the large-diameter drill hole 5 and the large-diameter combined pressure relief drill hole of the blast hole 6 is finished, evaluating the pressure relief effect according to the stress value monitored by the drill hole stress meter 8, and if the pressure relief effect is poor, increasing the arrangement density of the large-diameter drill hole 5 and the blast hole 6 of the top plate side roadway 4 and the arrangement density of the blast hole 6 of the bottom plate side roadway 7;

and evaluating the pressure relief effect again after the construction is finished until the pressure relief effect is good.

The present invention will be further described with reference to the following examples.

In the mining process of the steeply inclined extra-thick hard coal seam, the top plate side roadway 4 and the bottom plate side roadway 7 are arranged in a staggered manner, preferably, the top plate side roadway 4 is arranged at the next layer of the bottom plate side roadway 7 in a staggered manner, so that the staggered arrangement mode effectively improves the recovery rate on the existing working face 2, and increases the economic benefit of a coal mine;

as shown in fig. 3, a plurality of borehole stress meters 8 are arranged on the roof side roadway 4 and the floor side roadway 7, the buried depth of each borehole stress meter 8 is 8-10m, and the distance between adjacent borehole stress meters is 5-30 m; monitoring the stress change of surrounding rocks of the roadway by covering the whole roadway;

considering the particularity of the mechanical properties of the steeply inclined super-thick hard coal seam, namely, the pressure relief of the blast holes 6 only affects the peripheral area of a roadway and cannot relieve deep stress of the super-thick coal seam, and the plastic area formed by the large-diameter drill holes 5 adopted by the hard coal seam cannot effectively relieve high stress and is easy to accumulate energy when a working face 2 is used for mining, so that the large-diameter drill holes 5 and the blast holes 6 are arranged in a top plate side roadway 4, and the blast holes 6 are arranged in a bottom plate side roadway 7, and the parameters of all the drill holes are determined;

as shown in fig. 2, preferably, the large-diameter drilled holes 5 on the roof side drifts 4 are respectively located on the right upper and the bottom plate thereof;

a plurality of large-diameter drill holes 5 on the right side of the roof side roadway 4 are positioned on the same plane, the aperture of each large-diameter drill hole 5 is larger than 100mm, the hole depth is the distance between the roof side roadway 4 and the top of the floor side roadway 7, the adjacent distance is 1-2m, and the distance between the hole opening and the bottom plate of the roof side roadway 4 is 0.8-1.5 m; a plurality of large-diameter drill holes 5 on the bottom plate of the roof side roadway 4 are arranged in the middle of the roof side roadway 4, the corresponding hole diameter is larger than 100mm, and the hole depth is three times of the roadway width of the roof side roadway 4;

a plurality of blast holes 6 on the top plate side roadway 4 are positioned at the left and right upper corners, the aperture of each blast hole 6 is 42mm, the hole depth is 8-10m, and the adjacent distance is 5m-10 m;

further, the large-diameter drill holes 5 at the right upper side of the top plate side roadway 4 are arranged at an elevation angle of 10-30 degrees, and the blast holes 6 at the bottom plate of the top plate side roadway 4 are arranged at a depression angle of 45 degrees.

Further, the large-diameter drill holes 5 arranged in the roof-side tunnel 4 and the blast holes 6 arranged thereon are arranged at intervals in the tunnel direction, that is, four large-diameter drill holes 5 are arranged between every two blast holes 6.

And a plurality of blast holes 6 on the bottom plate side roadway 7 are positioned on the left side of the bottom plate side roadway 7, each hole has the diameter of 42mm, the hole depth is 8-10m, the adjacent distance is 5m-10m, the hole opening is 0.5-1.2m on the bottom plate of the bottom plate side roadway 7 and is arranged at a depression angle of 30-45 degrees.

When the top plate side roadway 4 is provided with the large-diameter drill hole 5 and the blast hole 6, and the bottom plate side roadway 7 is provided with the blast hole 6, namely after the blasting large-diameter combined pressure relief drill hole construction is finished, evaluating the pressure relief effect according to the stress value monitored by the drill hole stress meter 8, and providing a judgment basis for judging whether pressure relief needs to be enhanced;

when the numerical value of the borehole stress meter 8 is greater than the monitoring early warning value, the numerical value is evaluated to be poor, the pressure relief measures are taken to increase the arrangement density of the large-diameter boreholes 5 and the blast holes 6 of the top plate side roadway 4 and the arrangement density of the blast holes 6 of the bottom plate side roadway 7, and the pressure relief effect is evaluated again after the construction is finished until the pressure relief effect is good;

and when the numerical value of the borehole stress meter 8 is smaller than the monitoring early warning value, the result is evaluated to be good.

When the corresponding blasting holes 6 on the roof side roadway 4 and the floor side roadway 7 are blasted, the number of the blasting holes in each time is not more than 6.

The combined pressure relief method for blasting and large-diameter drilling of the steeply inclined super-thick hard coal seam has important engineering significance and great economic benefit in the aspects of efficient pressure relief of the working face 2, safe production of a coal mine, reasonable benefit improvement and the like, and has wide application prospect.