Deep island working face roadway and ultra-deep large-diameter drill hole arrangement method

Abstract

According to the deep island working face roadway and the ultra-deep large-diameter drill hole arrangement method, negative coal pillar roadways are arranged in low-stress areas in goaf areas on the two adjacent sides of an island working face along a bottom plate, the impact risk of the roadways is eliminated, and therefore the situation that the roadways on the two sides have no impact ground pressure risk is achieved; due to the fact that the stress concentration phenomenon possibly exists in the island working face coal wall, ultra-deep large-diameter drill holes are formed in the stress concentration area of the island working face coal wall, the construction parameters of the drill holes are determined according to the stress distribution condition, a pressure relief protection belt is formed after completion, the pre-pressure-relief effect on the island working face coal wall is effectively achieved, and the safety of the island working face coal wall is improved. And the construction of the ultra-deep large-diameter drill hole plays a role in risk detection on the subsequent to-be-mined coal seam, so that the overall effective pressure relief of the island working face is realized in the mode, the island working face is in a low-stress environment, the subsequent mining of the island working face is facilitated, and the mining efficiency is improved. And a safe and effective method is provided for recovering the left coal pillars in deep rock burst mine strip mining.

Description

Technical Field

[0001] The invention belongs to the technical field of safe production of coal mines, in particular to a method for arranging deep isolated island working face tunnels and ultra-deep large-diameter drilling holes. Background Art

[0002] With the continuous development of coal resources, the depth of underground mining is getting deeper and deeper. Due to the influence of geological conditions and mining technology, deep isolated working faces will be formed during the mining process of rock burst mines. For example, strip mining or unreasonable mining sequence will form isolated working faces. The stress of coal rock mass in deep mines increases, and stress concentration will occur on the isolated working faces, which will make deep isolated working faces more susceptible to rock burst.

[0003] During mining, deep isolated working faces may face the situation of two or three sides being mined out. If the mining method of retaining coal pillars is adopted, the risk of rock burst will be increased due to the influence of structure and burial depth, resulting in the prohibition of mining in the isolated working face.

[0004] Therefore, how to provide a new tunnel and pressure relief drilling layout method to achieve effective pressure relief on the isolated working face, put it in a low stress environment, and facilitate subsequent mining of the isolated working face is the research direction required by the present invention. Summary of the invention

[0005] In view of the problems existing in the above-mentioned prior art, the present invention provides a method for arranging deep isolated island working face tunnels and ultra-deep large-diameter drill holes, which can effectively relieve pressure on the isolated island working face by arranging negative coal pillar tunnels in the goaf on both sides of the isolated island working face and constructing ultra-deep large-diameter drill holes on the coal wall of the isolated island working face, thereby facilitating the subsequent mining of the isolated island working face.

[0006] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a method for arranging deep isolated island working face tunnels and ultra-deep large-diameter drilling holes, the specific steps of which are:

[0007] Step 1: Based on mine pressure theory and numerical simulation, and combined with the layout of goaf on both sides of the isolated working face, determine the stress distribution of goaf on both sides of the isolated working face.

[0008] Step 2: In the low stress area in the goafs on both sides adjacent to the isolated working face, the negative coal pillar tunnels of the isolated working face are arranged along the bottom plates of the goafs on both sides, thereby forming the return air tunnel of the isolated working face and the transport tunnel of the isolated working face in the goafs on both sides, wherein the distance between the return air tunnel of the isolated working face and its nearest coal pillar is L1, and the distance between the transport tunnel of the isolated working face and its nearest coal pillar is L2.

[0009] Step 3. In order to better reduce stress and form a larger plastic zone between the pressure-relieving boreholes, a single row of ultra-deep and large-diameter boreholes is designed on the coal wall of the isolated working face. The distance between each ultra-deep and large-diameter borehole and the top plate is L3, and the distance between each ultra-deep and large-diameter borehole and the bottom plate is L4, and the diameter D of the ultra-deep and large-diameter borehole is determined; then, according to the physical and mechanical parameters of the coal seam of the isolated working face and the inclination length of the coal wall of the working face, combined with the single-row drilling construction method and diameter D, the drilling spacing L5 of the ultra-deep and large-diameter boreholes is determined.

[0010] Step 4: Obtain measured data on coal body stress at the isolated working face, determine the stress distribution of the coal wall, and perform ultra-deep and large-diameter drilling in the stress concentration area of ​​the coal wall at the isolated working face according to the drilling method and drilling parameters determined in step 3; and based on the stress distribution in the stress concentration area, design the ultra-deep and large-diameter drilling depth in the higher stress area to be greater than the ultra-deep and large-diameter drilling depth in the lower stress area.

[0011] Step 5. All ultra-deep and large-diameter boreholes designed on the coal wall of the isolated working face are constructed simultaneously; and during the construction of each ultra-deep and large-diameter borehole, the stress of the coal and rock mass is judged in real time according to the drill cuttings method, so as to timely adjust the depth and spacing of each ultra-deep and large-diameter borehole to ensure that the depth of the ultra-deep and large-diameter boreholes in the higher stress area is always greater than the depth of the ultra-deep and large-diameter boreholes in the lower stress area (that is, if the stress at a certain ultra-deep and large-diameter borehole is greater than the stress at another ultra-deep and large-diameter borehole, then the depth of the ultra-deep and large-diameter borehole must be greater than the depth of the other ultra-deep and large-diameter borehole), and an effective pressure relief protection zone is formed after all the drilling construction is completed.

[0012] Furthermore, the diameter D is selected as the maximum value as possible within the range of 200 mm to 300 mm according to the actual conditions of the mine.

[0013] Furthermore, the drilling distance L5 in step 3 is calculated using the following formula:

[0014] L5=εD / 2

[0015] Where: ε is the rupture range coefficient; D is the diameter of the ultra-deep large-diameter borehole.

[0016] Furthermore, the simultaneous construction of step five is specifically as follows: according to the mine production arrangement, the mine maintenance shift is designed to carry out the drilling construction, and the maximum number of personnel for each maintenance shift is determined, and as many personnel as possible are arranged to participate in the drilling construction in each maintenance shift; thereby realizing the simultaneous construction of ultra-deep and large-diameter drilling holes.

[0017] Furthermore, in the step 5, during the construction of a certain ultra-deep large-diameter drilling hole, if it is found that the amount of coal dust exceeds the threshold or the drill is stuck, the drilling spacing between adjacent ultra-deep large-diameter drilling holes is reduced, and the drilling arrangement is increased to ensure the required pressure relief effect.

[0018] Furthermore, the depth of the ultra-deep large-diameter borehole is not less than 30m.

[0019] Compared with the prior art, the present invention arranges negative coal pillar tunnels along the bottom plate in the low stress areas in the goafs on both sides of the isolated working face, so that the tunnels of the isolated working face are in a low stress environment, eliminating the impact risk of the tunnels and thus achieving no impact ground pressure risk in the tunnels on both sides; after solving the risk of tunnel impact, stress concentration may still occur in the coal wall of the isolated working face. To address this phenomenon, the present invention arranges ultra-deep and large-diameter drilling holes in the stress concentration areas of the coal wall of the isolated working face, determines the construction parameters of the drilling holes according to the stress distribution, and forms a pressure relief protection zone after all the drilling holes are completed, which effectively pre-relieves the pressure on the coal wall of the isolated working face, and the construction of ultra-deep and large-diameter drilling holes plays a role in risk detection for the subsequent coal seams to be mined; the above-mentioned method is used to achieve effective pressure relief of the entire isolated working face, so that it is in a low stress environment, which is convenient for the subsequent mining of the isolated working face, and provides a safe and effective method for recovering coal pillars left over from strip mining in deep impact ground pressure mines. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall layout of the present invention;

[0021] Figure 2 for Figure 1 Sectional view along the AA direction;

[0022] Figure 3 This is a diagram of the arrangement of ultra-deep and large-diameter drilling holes in the present invention.

[0023] In the figure: 1. The first goaf; 2. The second goaf; 3. The return air tunnel of the isolated working face; 4. The transport tunnel of the isolated working face; 5. Fine sandstone; 6. Mudstone; 7. Medium sandstone; 8. Sandy mudstone; 9. Ultra-deep and large-diameter borehole in the area with higher stress; 10. Ultra-deep and large-diameter borehole in the area with lower stress. DETAILED DESCRIPTION

[0024] The present invention will be further described below.

[0025] like Figure 1 and 2 As shown, the specific steps of the present invention are:

[0026] Step 1: Based on the mine pressure theory and numerical simulation, and combined with the layout of the goafs on both sides of the isolated working face, determine the stress distribution of the goafs on both sides of the isolated working face. The goafs on both sides are the first goaf 1 and the second goaf 2.

[0027] Step 2: In the low stress area in the goafs on both sides adjacent to the isolated working face, the negative coal pillar tunnels of the isolated working face are arranged along the bottom plates of the goafs on both sides, thereby forming the return air tunnel 3 of the isolated working face and the transport tunnel 4 of the isolated working face in the goafs on both sides, wherein the distance between the return air tunnel 3 of the isolated working face and its nearest coal pillar is L1, and the distance between the transport tunnel 4 of the isolated working face and its nearest coal pillar is L2.

[0028] Step 3: In order to better reduce stress, a larger plastic zone is formed between the pressure relief holes, such as Figure 3 As shown in the figure, a single row of ultra-deep large-diameter boreholes is designed on the coal wall of the isolated working face. The distance between each ultra-deep large-diameter borehole and the roof is L3, and the distance between each ultra-deep large-diameter borehole and the bottom is L4. The diameter D of the ultra-deep large-diameter borehole is determined. The diameter D is selected as the maximum value within the range of 200mm to 300mm according to the actual conditions of the mine. Then, according to the physical and mechanical parameters of the coal seam of the isolated working face and the inclined length of the coal wall of the working face, combined with the single-row drilling construction method and the diameter D, the drilling spacing L5 of the ultra-deep large-diameter boreholes is determined. The specific formula is as follows:

[0029] L5=εD / 2

[0030] Where: ε is the rupture range coefficient; D is the diameter of the ultra-deep large-diameter borehole.

[0031] Step 4: Obtain measured data on coal body stress at the isolated working face, determine the stress distribution of the coal wall, and perform ultra-deep and large-diameter drilling in the stress concentration area of ​​the coal wall at the isolated working face according to the drilling method and drilling parameters determined in step 3; and based on the stress distribution in the stress concentration area, design the depth of the ultra-deep and large-diameter borehole 9 in the higher stress area to be greater than the depth of the ultra-deep and large-diameter borehole 10 in the lower stress area; and the depth of the ultra-deep and large-diameter borehole shall not be less than 30m.

[0032] Step 5. For all the ultra-deep and large-diameter boreholes designed on the coal wall of the isolated working face, construction is carried out simultaneously. Specifically, according to the mine production arrangement, the mine maintenance shift is designed for drilling construction, and the maximum number of personnel for each maintenance shift is determined (according to the "Limited Number of Personnel Entering the Mine (Pit) in a Single Shift in Coal Mines", the maximum number of personnel for the maintenance shift of the underground coal mining working face in a mine with serious disasters is 40, and the maximum number of personnel for the maintenance shift of the underground coal mining working face in other mines is 30), and as many personnel as possible are arranged to participate in the drilling construction in each maintenance shift; thereby realizing the simultaneous construction of ultra-deep and large-diameter boreholes; and in the process of each ultra-deep and large-diameter drilling construction, the stress of the coal and rock mass is judged in real time according to the drill cuttings method, so as to timely adjust the depth and borehole spacing of each ultra-deep and large-diameter borehole, to ensure that the depth of the ultra-deep and large-diameter borehole 9 in the high-stress area is always greater than the depth of the ultra-deep and large-diameter borehole 10 in the low-stress area, and to form an effective pressure relief protection zone after completing all drilling construction. In addition, if during the construction of an ultra-deep and large-diameter drilling hole, it is found that the amount of coal dust exceeds the threshold or the drill is stuck, the drilling spacing between adjacent ultra-deep and large-diameter drilling holes will be reduced, and the drilling layout will be increased to ensure the required pressure relief effect.

[0033] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for arranging deep isolated island working face tunnels and ultra-deep large-diameter drilling holes, characterized in that: The specific steps are: Step 1: Based on the mine pressure theory and numerical simulation, and combined with the layout of the goaf on both sides of the isolated working face, determine the stress distribution of the goaf on both sides of the isolated working face; Step 2: In the low stress area in the goafs on both sides of the isolated working face, the negative coal pillar tunnels of the isolated working face are arranged along the bottom plates of the goafs on both sides, so as to form the return air tunnel of the isolated working face and the transport tunnel of the isolated working face in the goafs on both sides, wherein the distance between the return air tunnel of the isolated working face and the nearest coal pillar is L1, and the distance between the transport tunnel of the isolated working face and the nearest coal pillar is L2; Step 3: Design a single row of ultra-deep large-diameter boreholes on the coal wall of the isolated working face, with each ultra-deep large-diameter borehole being at a distance of L3 from the roof and L4 from the bottom plate, and determine the diameter D of the ultra-deep large-diameter boreholes; then determine the drilling spacing L5 of the ultra-deep large-diameter boreholes based on the physical and mechanical parameters of the coal seam of the isolated working face and the inclined length of the coal wall of the working face, combined with the single-row drilling construction method and the diameter D; Step 4: Obtain measured data of coal body stress at the isolated working face, determine the stress distribution of the coal wall, and perform ultra-deep large-diameter drilling in the stress concentration area of ​​the coal wall at the isolated working face according to the drilling method and drilling parameters determined in step 3; and according to the stress distribution in the stress concentration area, design the ultra-deep large-diameter drilling depth in the higher stress area to be greater than the ultra-deep large-diameter drilling depth in the lower stress area; Step 5. All ultra-deep and large-diameter boreholes designed on the coal wall of the isolated working face are constructed simultaneously; and during the construction process of each ultra-deep and large-diameter borehole, the stress of the coal and rock mass is judged in real time according to the drill cuttings method, so as to timely adjust the depth and spacing of each ultra-deep and large-diameter borehole to ensure that the depth of ultra-deep and large-diameter boreholes in the higher stress area is always greater than that in the lower stress area, and an effective pressure relief protection zone is formed after all the drilling construction is completed.

2. The deep island working face tunnel and ultra-deep large diameter drilling arrangement method according to claim 1 is characterized in that: The diameter D is selected as the maximum value as possible within the range of 200 mm to 300 mm according to the actual conditions of the mine.

3. The deep island working face tunnel and ultra-deep large diameter drilling arrangement method according to claim 1 is characterized in that: The drilling distance L5 in step 3 is calculated using the following formula: L5=εD / 2 Where: ε is the rupture range coefficient; D is the diameter of the ultra-deep large-diameter borehole.

4. The deep island working face tunnel and ultra-deep large diameter drilling arrangement method according to claim 1 is characterized in that: The specific steps of the step 5 of simultaneous construction are as follows: according to the mine production arrangement, the mine maintenance shifts are designed for drilling construction, and the maximum number of personnel for each maintenance shift is determined, and as many personnel as possible are arranged to participate in the drilling construction in each maintenance shift; thereby achieving simultaneous construction of ultra-deep and large-diameter drilling holes.

5. The deep island working face tunnel and ultra-deep large diameter drilling arrangement method according to claim 1 is characterized in that: In the step 5, during the construction of a certain ultra-deep large-diameter drilling hole, if it is found that the amount of coal dust exceeds the threshold or the drill is stuck, the drilling spacing between adjacent ultra-deep large-diameter drilling holes is reduced, and the drilling arrangement is increased to ensure the required pressure relief effect.

6. The deep island working face tunnel and ultra-deep large diameter drilling arrangement method according to claim 1 is characterized in that: The depth of the ultra-deep large-diameter borehole is not less than 30m.

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