WO2014187171A1

WO2014187171A1 - Method for networked reinforcement of cross boreholes of outburst coal seam

Info

Publication number: WO2014187171A1
Application number: PCT/CN2014/071554
Authority: WO
Inventors: 林柏泉; 高亚斌; 杨威; 沈春明; 李贺
Original assignee: 中国矿业大学
Priority date: 2013-05-20
Filing date: 2014-01-27
Publication date: 2014-11-27
Also published as: CN103306713B; CN103306713A

Abstract

Disclosed is a method for networked reinforcement of cross boreholes of an outburst coal seam, which is particularly applicable to the reinforcement of the cross boreholes for pre-extracting coal roadway strip gas in the outburst coal seam. By means of the method, 30 to 60 days before the digging of a coal seam roadway, gas extraction from the cross boreholes which extend outwardly by a distance of H2 on both sides of a pre-digging coal seam roadway is stopped; reinforcement materials are pressurized and injected into the cross boreholes that stop the extracting of gas by a grouting pump at the locations spaced from each other by a distance of H1; a serous fluid is filled into the boreholes and permeates into surrounding coal bodies; and when the reinforcement materials in the boreholes are solidified, a "strong-weak-strong" structure system is formed at both sides of the coal seam roadway, thereby improving the strength and the stress distribution of the outburst coal seam and effectively eliminating the risk in the process of excavation. The present invention can reduce the deformation of both sides of the outburst coal seam roadway by 45% to 65%, reduce the reinforcement workload by 35% to 50% and increase the excavating speed of the coal seam roadway by 40% to 60%.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network reinforcement method for a high-salt coal seam through-hole drilling, and is particularly suitable for a cross-drilling of a strip of gas in a pre-extracted coal roadway in a high coal seam. Reinforcement of the holes. BACKGROUND OF THE INVENTION In China's coal mining industry, with the increase of mining depth, the increase of ground stress and gas pressure increase, the gas disaster of high coal seam is becoming more and more serious, and the regional gas control method of pre-extracted coal gas is getting more and more The more widely used. At present, domestic coal mining enterprises use hydraulic punching and hydraulic cutting to reduce the pre-pumping effect of coal seam gas, thus eliminating the prominent danger of coal roadway driving area. However, the high-explosive coal seam has the characteristics of low strength and easy to be broken. The large amount of pre-extracted coal seam gas in the borehole layer further reduces the strength of the coal body, resulting in uneven distribution of internal stress in the coal seam, top drilling, coal-fired gun and coal in the coal roadway excavation process. Wall-mounted gangs and other dynamic phenomena frequently occur, and coal seam roadways are difficult to support, which seriously restricts the safe and efficient mining of high-soil coal seams. Disclosure of Invention Technical Problem The object of the present invention is to provide a simple and effective method for reinforcing a high-outburst coal seam through-hole drilling network in accordance with the problems existing in the prior art, by selectively facing a high coal seam. Through layer drilling and reinforcement, a network-type reinforcement area is formed in the coal body to form a "strong and weak" structural system on both sides of the coal seam roadway, thereby improving the strength and stress distribution of the high-soil coal seam, so that a large number of through-hole drilling holes are used. The pumped coal roadway is easier to support.

Technical Solution: The network reinforcement method for the high-burst coal seam drilling layer of the invention comprises: arranging the bottom pumping lane along the working surface in the coal seam floor rock layer, and arranging a plurality of drilling grounds in the bottom pumping lane, each from the bottom pumping lane A drill hole is drilled in the direction of the coal seam until the drilled hole penetrates the coal seam roof more than 0.5m, and then the gas drainage is carried out to eliminate the control range of the coal seam roadway; the following steps are also included:

a. 30 to 60 days before the excavation of the coal seam roadway, the gas drainage of the two layers of the pre-excavation coal roadway with the outward extension distance of H2 is stopped, and the gas drainage is stopped by the grouting pump spacing distance HI. The reinforcement material is injected into the borehole to carry out network reinforcement of the coal bodies on both sides of the pre-drilling coal roadway;

b. Continue to extract gas from the through-hole drilling of the uncompressed reinforcing material;

c. When the length of coal body reinforcement on both sides of the coal seam roadway exceeds 100m, the gas extraction and outburst effect shall be inspected according to the “Provisions for Prevention of Coal and Gas Outburst” 1 to 3 days before the excavation of the coal seam roadway. The conventional method is used to dig the coal seam roadway. If the inspection fails, the gas drainage will continue until the standard is reached, and then the coal seam roadway is drilled; d. During the process of excavating the coal seam roadway, continue to inject the reinforcement material into the through-holes of the two layers of the pre-excavation coal roadway with a distance of H2, to ensure that the reinforcement position is ahead of the excavation head by more than 50m or the advanced excavation time is not less than 28 day.

The distance HI between the through-holes of the spacer-injection reinforcing material is 5-20 m.

The distance between the two gangs extending outward is H2, which is 6~15m.

[Advantageous Effects] The present invention is directed to the problem of frequent occurrence of power phenomena and difficulty in support of the coal seam roadway after the coal seam is damaged by the high-burst coal seam, and after the drilling of the floor rock roadway, the gas is selectively selected. The slurry of the reinforcing material is injected into the drilling interval, the slurry is filled and drilled, and penetrates into the surrounding coal body to form a networked reinforcement area, which increases the strength of the coal body, and forms a strong, weak and strong structural system on both sides of the coal seam roadway, thereby improving The strength and stress distribution of the high-soil coal seam make the coal seam roadway pre-extracted by a large number of through-hole drilling more easily supported, effectively eliminating the danger in the mining process. The invention can reduce the deformation of the two sets of high-outburst roadway by 45~65%, the reinforcement work by 35%~50%, and the coal seam roadway speed by 40%~60%, which has wide practicality.

DRAWINGS

Figure 1 is a schematic view of the structure of the present invention;

Figure 2 is a cross-sectional view taken along line A - A of Figure 1;

In the figure: 1-coal top plate, 2-coal layer, 3-coal direct bottom, 4-coal roadway, 5-bottom pumping lane, 6-layer drilling, 7-bore reinforcement zone, HI-adjacent reinforcement drilling The distance between the two, H2- two outwards. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be further described below with reference to the accompanying drawings:

As shown in FIG. 1 and FIG. 2, the high-burst coal seam drilling layer network reinforcement method of the present invention:

Firstly, the bottom pumping lane is arranged along the working surface in the coal seam 2 floor rock layer 5, and the drilling ground is arranged in the bottom pumping lane 5, and the drilling hole 6 is constructed from the drilling ground of each bottom drilling tunnel to the coal seam 2 direction;

Then, according to the dip angle of the coal seam 2 and the extraction radius of the through-hole 6 , the control range of the through-hole 6 is determined, wherein the inclined and steeply inclined coal seam (with an inclination angle between 25° and 90°) is outside the contour of the roadway. The control distance is at least 20m, the out-of-line control distance of the roadway lower profile is at least 10m, and the distance control distance of the gently inclined, near-horizontal coal seam (inclination angle between 0° and 25°) is at least 15m;

From each drilling field of the bottom pumping lane 5, the through-hole drilling 6 is applied to the coal seam 2 until the length of the coal seam roof 1 is not less than 0.5 m, and then the gas drainage is carried out according to the conventional technology to eliminate the control range of the coal seam roadway 4 According to the firmness factor f of the coal seam 2, it is determined that the distance HI between adjacent reinforcing boreholes is 5-20 m, and the distance H2 of the outward extension of the two gangs is 6-15 m, wherein the firmness coefficient f 0.35 is adjacent The distance HI between the reinforced holes is not more than 8 times The extraction radius of the layered borehole 6 and the distance H2 of the two layers extending outward are not more than 10 times the extraction radius of the layered borehole 6. If the robustness factor f<0.35, between the adjacent reinforcement boreholes The extraction radius of the through-drilled hole 6 whose distance is not more than 6 times from the HI, and the extraction radius of the through-drilled hole 6 which is not more than 8 times the distance H2 of the two outward extensions;

For example, if the strength of coal seam 2 is high, the coefficient of robustness f is 0.47, and the extraction radius of the drilled hole 6 is 1.3 m, the distance HI between adjacent reinforcing boreholes is selected to be 7.8 m (less than 8 times of extraction). Radius), the distance H2 of the two gangs extending outward is 10.4m (less than 10 times the extraction radius);

For example, if the strength of the coal seam 2 is small, the solidity factor f is 0.28, and the extraction radius of the through-hole drilling hole 6 is 1.5 m, the distance HI between adjacent reinforcing drilled holes is selected to be 6 m (less than 6 times the extraction radius) ), the distance H2 of the two gangs extending outward is 9m (less than 8 times the extraction radius);

30 to 60 days before the excavation of the coal seam roadway 4, the gas drainage of the two layers of the pre-excavation coal roadway 4 with the outward extension distance of H2 is stopped, and the gas drainage is stopped by the grouting pump spacing distance HI. The cement-based reinforcement material is injected into the layer borehole 6 to reinforce the coal body on both sides of the pre-drilled coal seam roadway 4, and the slurry is filled and drilled and infiltrated into the surrounding coal body to form a drilling reinforcement zone 7 while continuing to separate the holes. When the reinforcing material in the borehole is solidified, the borehole reinforcement zone 7 in the coal seam is spaced apart, and a "strong and weak strong" structural system is formed on both sides of the coal seam roadway 4, Effectively improve the strength and stress distribution of high coal seams. When the length of the coal body reinforcement on both sides of the coal seam roadway 4 exceeds 100m, the gas drainage effect shall be inspected according to the Regulations on Prevention of Coal and Gas Outburst 1 to 3 days before the excavation of the coal seam roadway 4. After passing the inspection, according to the conventional method Digging into the coal seam roadway 4, if the inspection is unqualified, continue the gas drainage until the standard is reached before the coal seam roadway 4 is excavated. During the process of excavating the coal seam roadway 4, continue to press the cement-based reinforcement material in the cross-drilling hole 6 with the outward extension distance H2 of the pre-drilling coal seam roadway 4 to ensure that the reinforcement head advances the head more than 50m or advances the excavation time. Not less than 28 days.

Claims

Claim

1. A network reinforcement method for drilling high-level coal seams, including arranging bottom pumping lanes along the working face in the coal seam (2) floor rock formation, and arranging multiple drill fields in the bottom pumping lane (5) , through the drilling of each layer of the bottom pumping road (5) to the coal seam (6), until the through-hole drilling (6) penetrates the coal seam roof more than 0.5m, and then implement gas drainage to the coal seam roadway (4) The control range is dissected; it is characterized by the following steps:

a. In the coal seam roadway (4) 30~60 days before the excavation, the pre-drilling coal seam roadway (4) the two layers of the outer hole extending distance H2 (6) to stop the gas drainage, through the grouting pump separation distance HI drilling holes for stopping gas drainage

(6) Internally compressing the reinforcing material to network strengthen the coal bodies on both sides of the pre-drilled coal roadway (4);

b. Continue to drill through the holes (6) of the uncompressed reinforcement material;

c. When the length of the coal body reinforcement on both sides of the coal seam roadway (4) exceeds 100m, in the coal seam roadway (4) 1~3 days before the excavation, the gas extraction and outburst effect shall be inspected according to the Regulations on Prevention of Coal and Gas Outburst After passing the inspection, the coal seam roadway (4) shall be excavated according to the conventional method. If the inspection is unqualified, the gas drainage shall continue until the standard is reached, and then the coal seam roadway (4) shall be excavated;

d. During the process of excavating the coal seam roadway (4), continue to inject the reinforcement material into the pre-excavation coal roadway (4) and extend the distance to the outer hole of the H2 (6) to ensure the reinforcement position ahead of the excavation head. More than 50m or advanced boring time is not less than 28 days.

2. The method for reinforcing a high-burst coal seam through-hole drilling network according to claim 1, wherein: the distance HI between the through-holes of the spacer-injection reinforcing material is 5-20 m.

3. The method for reinforcing a high-burst coal seam through-hole drilling network according to claim 1, wherein: the distance between the two gangs extending outwardly is 152, which is 6-15 m.