Coal mine tunnel floor heave prevention and control method based on bottom plate blasting pressure relief

Abstract

The invention relates to the field of coal mine tunnel deformation control, in particular to a coal mine tunnel floor heave prevention and treatment method based on bottom plate blasting pressure relief, which comprises the following steps: S1, determining a coal seam side support pressure curve and a coal pillar or entry retaining filling body side support pressure curve of a mining tunnel; the Rankine soil pressure theory is introduced to analyze the stress characteristics of a bottom plate of the mining roadway, and the coal seam side sliding body range and the coal pillar or entry retaining filling body side sliding body range are determined; s2, determining a blasting pressure relief rock stratum in the bottom plate; s3, determining a blasting pressure relief range; and S4, blasting is conducted on the determined blasting pressure relief range through blasting pressure relief drill holes. According to the method, the blasting pressure relief area is selected from the thick and hard coal seam bottom plate and is close to the sliding body, and floor heave prevention and control can be carried out on the basis of constructing the blasting pressure relief area in the minimum range; meanwhile, after the Rankine soil pressure theory is introduced to determine the slippage body, the reasonable blasting pressure relief area range is determined based on the slippage body and the supporting pressure.

Description

Technical Field

[0001] The invention relates to the field of coal mine tunnel deformation control, in particular to a coal mine tunnel floor heave prevention and control method based on floor blasting pressure relief. Background Art

[0002] Coal mine tunnels, especially the mining tunnels on both sides of the working face, face the risk of floor drum deformation during the mining process or after excavation, which will affect the normal production of the mine and threaten the safety of personnel and equipment. Most of the existing prevention and control methods are passive management, that is, cleaning up the part of the floor drum when it appears in the mining tunnel. This method requires multiple cleanings, which affects production and is relatively dangerous during treatment. There is also a treatment method of digging grooves on the bottom plate of the tunnel to relieve pressure, but the amount of grooves is difficult to determine, and digging grooves on the bottom plate of the tunnel affects production. In view of this, providing a method for preventing and controlling floor drums that performs a one-time pressure relief construction operation without affecting the use of the tunnel is of great significance to improving mine production safety and ensuring normal mine production. Summary of the invention

[0003] In view of the above technical problems, the present invention proposes a method for preventing and controlling floor heave in coal mine tunnels based on floor blasting pressure relief, which specifically includes the following steps:

[0004] S1: Determine the side support pressure curve of the coal seam of the mining roadway and the side support pressure curve of the coal pillar or the filling body of the retained roadway; introduce the Rankine earth pressure theory to analyze the stress characteristics of the bottom plate of the mining roadway, and determine the side sliding range of the coal seam and the side sliding range of the coal pillar or the filling body of the retained roadway;

[0005] S2: Determine the blasting decompression rock layer in the base plate

[0006] S21: First, determine the thick hard floor rock layer in the floor;

[0007] S22: Secondly, a thick hard bottom rock layer which is closest to and does not intersect with the side sliding body of the coal seam and the side sliding body of the coal pillar or the retaining road filling body is selected as the blasting pressure relief rock layer;

[0008] S3: Determine the scope of blasting pressure relief

[0009] S31: Calculate the side sliding area S of the coal seam 1 And the side sliding area S of the coal pillar or the reserved filling body 2 ;

[0010] S32: Determine the energy E released by the bottom heave deformation of the coal seam side sliding body per unit area 1 , determine the energy E that can be released by the bottom heave deformation of the side sliding body of the coal pillar or the filling body of the reserved roadway per unit area 2 ; Determine the capacity E that can be absorbed by the compression deformation of the blasting pressure relief area per unit area;

[0011] S33: Determine the area of ​​the blasting pressure relief zone S = (E 1 ×S 1 +E 2 ×S 2 ) / E;

[0012] S34: Determine the boundary of the coal seam side of the blasting pressure relief zone, and the boundary of the coal seam side should reach or exceed the peak position of the support pressure curve of the coal seam side; determine the boundary of the coal pillar or the lane retaining filling body side of the blasting pressure relief zone, and the boundary of the coal pillar or the lane retaining filling body side should reach or exceed the peak position of the support pressure curve of the coal pillar or the lane retaining filling body side; then determine the left and right widths of the blasting pressure relief zone, and the height of the blasting pressure relief zone can be calculated according to the area S of the blasting pressure relief zone;

[0013] S35: determining the top boundary of the blasting pressure relief zone, wherein the top boundary is the top boundary of the blasting pressure relief rock layer, and the bottom boundary of the blasting pressure relief zone can be obtained according to the height of the blasting pressure relief zone;

[0014] S4: Use blasting pressure relief drilling to blast the determined blasting pressure relief range.

[0015] Preferably, in step S21, the thick hard bottom plate rock layer is determined based on the key layer theory, or a rock layer with a larger thickness and a harder lithology is selected based on experience.

[0016] Preferably, step S4 also includes S41: constructing a pressure relief borehole from the mining tunnel to the blasting pressure relief area, charging the pressure relief borehole portion within the blasting pressure relief area, and sealing the pressure relief borehole portion between the blasting pressure relief area and the sliding body; and performing blasting.

[0017] Preferably, step S4 further includes S42: grouting to reinforce the pressure relief drilling section in the side sliding body of the coal seam, the coal pillar or the side sliding body of the lane retaining filling body.

[0018] Beneficial effects of the present invention: The method for preventing and controlling floor heave in coal mine tunnels based on floor blasting and pressure relief of the present invention selects the blasting and pressure relief zone at the floor of a thick and hard coal seam, which is close to the sliding body, and can prevent and control floor heave on the basis of constructing a blasting and pressure relief zone with the minimum construction range. At the same time, after introducing the Rankine earth pressure theory to determine the sliding body, the present invention determines a reasonable range of the blasting and pressure relief zone based on the sliding body and the support pressure. The pressure relief drilling hole can be used for both constructing the blasting and pressure relief zone and reinforcing the floor heave-prone area of ​​the mining tunnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0020] Figure 1It is a front (inclined) cross-sectional view of a method for preventing and controlling floor heave in a coal mine tunnel based on floor blasting pressure relief of the present invention;

[0021] Figure 2 It is a side (direction) cross-sectional view of a method for preventing and controlling floor heave in a coal mine tunnel based on floor blasting pressure relief according to the present invention;

[0022] Figure 3 It is a front (inclined) cross-sectional view of the drilling construction of the method for preventing and controlling floor heave in a coal mine tunnel based on floor blasting pressure relief of the present invention;

[0023] In the figure, 1-basic roof, 2-direct roof, 3-coal seam, 41-first floor rock layer, 42-second floor rock layer, 5-thick hard floor rock layer (blasting unloading rock layer); 6-mining tunnel; 7-coal pillar or lane-retaining filling body, 8-goaf, 9-coal seam side support pressure curve, 10-coal pillar or lane-retaining filling body side support pressure curve, 11-coal seam side sliding body, 12-coal pillar or lane-retaining filling body side sliding body, 13-blasting unloading area, 14-unloading borehole. DETAILED DESCRIPTION

[0024] To specifically demonstrate the purpose, technical solutions and advantages of the present invention, the present invention is further described below in conjunction with the accompanying drawings.

[0025] like Figure 1-3 As shown, the working conditions involved in the embodiment of the present invention are: the direct roof 2 and the basic roof 3 are arranged above the coal seam 3 in sequence, and the first floor rock layer 41, the second floor rock layer 42 and the thick hard floor rock layer 5 are arranged below the coal seam 3 in sequence; a mining tunnel 6 (golf-side tunneling) needs to be excavated along the goaf 7 in the coal seam, at which time the left side of the mining tunnel 6 is the coal seam side to be mined, and the right side is the coal pillar 7; or the mining tunnel 6 is the tunnel left when the previous working face is mined, at which time the left side of the mining tunnel 6 is the coal seam side to be mined, and the right side is the tunnel filling body 7 (golf-side tunneling); since the coal seam 6 is buried at a large depth, the floor heave problem is prone to occur. In this regard, the present invention proposes a method for preventing and controlling floor heave in coal mine tunnels based on floor blasting pressure relief, comprising the following steps:

[0026] S1: Determine the coal seam side support pressure curve 9 of the mining roadway 6 and the coal pillar or roadway retaining filling body side support pressure curve 10; introduce the Rankine soil pressure theory to analyze the stress characteristics of the mining roadway floor, and determine the range of the coal seam side sliding body 11 and the range of the coal pillar or roadway retaining filling body side sliding body 12; the specific determination method can refer to the master's thesis "Research on the Mechanism and Control Technology of the Floor Drum of the Gob-side Retaining Roadway in Thick Coal Seams in Gucheng Mine", China University of Mining and Technology, author Zheng Yu, Section 3.1.

[0027] S2: Determine the blasting decompression rock layer in the base plate

[0028] S21: First, determine the thick and hard bottom plate rock layer 5 in the bottom plate. The thick and hard bottom plate rock layer 5 can be determined based on the key layer theory, or based on experience to select a thick and hard rock layer;

[0029] S22: Next, a thick hard floor rock layer 5 which is closest to and does not intersect the coal seam side sliding body 11 and the coal pillar or lane retaining filling body side sliding body 12 is selected as the blasting pressure relief rock layer;

[0030] S3: Determine the scope of blasting pressure relief

[0031] S31: Calculate the area S of the coal seam side sliding body 11 1 and the area S of the side sliding body 12 of the coal pillar or the reserved lane filling body 2 ;

[0032] S32: Determine the energy E per unit area that can be released by the bottom heave deformation of the coal seam side sliding body 11 1 , determine the energy E per unit area that can be released by the side sliding body 12 bottom heave deformation of the coal pillar or the reserved filling body 2 ; Determine the capacity E that can be absorbed by the compression deformation of the unit area blasting pressure relief zone 13;

[0033] S33: Determine the area of ​​the blasting pressure relief zone 13 S = (E 1 ×S 1 +E 2 ×S 2 ) / E;

[0034] S34: Determine the boundary of the coal seam side of the blasting pressure relief zone 13, the boundary of the coal seam side should reach or exceed the peak position of the coal seam side support pressure curve 9 to the left; determine the boundary of the coal pillar or lane retaining filling body side of the blasting pressure relief zone 13, the boundary of the coal pillar or lane retaining filling body side should reach or exceed the peak position of the coal pillar or lane retaining filling body side support pressure curve 10 to the right; then determine the left and right widths of the blasting pressure relief zone 13, and the height of the blasting pressure relief zone 13 can be calculated according to the area S of the blasting pressure relief zone 13;

[0035] S35: determining the top boundary of the blasting pressure relief zone 13, wherein the top boundary is the top boundary of the blasting pressure relief rock layer, and the bottom boundary of the blasting pressure relief zone 13 can be obtained according to the height of the blasting pressure relief zone 13;

[0036] S4: Use blasting pressure relief drilling to blast the determined blasting pressure relief range

[0037] S41: constructing a pressure relief borehole 14 from the mining tunnel 6 to the blasting pressure relief area 13, charging the pressure relief borehole portion within the blasting pressure relief area 13, and sealing the pressure relief borehole portion between the blasting pressure relief area and the sliding body (the coal seam side sliding body 11 or the coal pillar or the roadway filling body side sliding body 12); and performing blasting;

[0038] S42: Grouting to reinforce the pressure relief drilling section in the coal seam side sliding body 11, coal pillar or lane retaining filling body side sliding body 12.

[0039] Although the present invention has been described above with preferred embodiments, it is not intended to limit the present invention. A person skilled in the art of the present invention may make various modifications and improvements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the definition of the claims.

Claims

1. A method for preventing and controlling floor heave in coal mine tunnels based on floor blasting and pressure relief, characterized in that: The steps include: S1: Determine the side support pressure curve of the coal seam of the mining roadway and the side support pressure curve of the coal pillar or the filling body of the retained roadway; introduce the Rankine earth pressure theory to analyze the stress characteristics of the bottom plate of the mining roadway, and determine the side sliding range of the coal seam and the side sliding range of the coal pillar or the filling body of the retained roadway; S2: Determine the blasting decompression rock layer in the bottom plate S21: First, determine the thick hard floor rock layer in the floor; S22: Secondly, a hard bottom rock layer which is closest to and does not intersect with the side sliding body of the coal seam and the side sliding body of the coal pillar or the retained roadway filling body is selected as the blasting pressure relief rock layer; S3: Determine the scope of blasting pressure relief S31: Calculate the side sliding area S1 of the coal seam and the side sliding area S2 of the coal pillar or the reserved filling body; S32: Determine the energy E1 that can be released by the bottom heave deformation of the side sliding body of the coal seam per unit area, determine the energy E2 that can be released by the bottom heave deformation of the side sliding body of the coal pillar or the reserved filling body per unit area; determine the capacity E that can be absorbed by the compression deformation of the blasting pressure relief area per unit area; S33: Determine the area of ​​the blasting pressure relief zone S = (E1×S1+E2×S2) / E; S34: Determine the boundary of the coal seam side of the blasting pressure relief zone, and the boundary of the coal seam side should reach or exceed the peak position of the support pressure curve of the coal seam side; determine the boundary of the coal pillar or the lane retaining filling body side of the blasting pressure relief zone, and the boundary of the coal pillar or the lane retaining filling body side should reach or exceed the peak position of the support pressure curve of the coal pillar or the lane retaining filling body side; then determine the left and right widths of the blasting pressure relief zone, and the height of the blasting pressure relief zone can be calculated according to the area S of the blasting pressure relief zone; S35: determining the top boundary of the blasting pressure relief zone, wherein the top boundary is the top boundary of the blasting pressure relief rock layer, and the bottom boundary of the blasting pressure relief zone can be obtained according to the height of the blasting pressure relief zone; S4: Use blasting pressure relief drilling to blast the determined blasting pressure relief range.

2. The method for preventing and controlling floor heave in coal mine tunnels according to claim 1, characterized in that: In step S21, the thick hard bottom plate rock layer is determined according to the key layer theory, or a rock layer with a larger thickness and a harder lithology is selected based on experience.

3. The method for preventing and controlling floor heave in a coal mine tunnel according to claim 1 or 2, characterized in that: Step S4 also includes S41: constructing a pressure relief borehole from the mining tunnel to the blasting pressure relief area, charging the pressure relief borehole portion within the blasting pressure relief area, and sealing the pressure relief borehole portion between the blasting pressure relief area and the sliding body; and performing blasting.

4. The method for preventing and controlling floor heave in coal mine tunnels according to claim 3, characterized in that: Step S4 also includes S42: grouting to reinforce the pressure relief drilled hole section in the side sliding body of the coal seam, the coal pillar or the side sliding body of the lane retaining filling body.

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