A method for determining the grouting hole location for grouting adjacent voids in a strip-filled mining face.

Abstract

This invention relates to a method for determining the location of grouting holes for grouting in adjacent voids in strip-filled mining faces. The method includes the following steps: determining the location and relevant parameters of the planned mining face; determining the location of the boundary of the coal pillar adjacent to the mining face; determining the filling rate of the filling face adjacent to the mining face, and obtaining the location of the boundary of the equivalent coal pillar of the filling face based on the filling rate; and obtaining the location of the grouting holes based on the obtained locations of the coal pillar boundary and the filling face boundary. The beneficial effects of this invention are: firstly, determining the area of ​​maximum development of void space in strip-filled mining processes; secondly, improving the effect of void grouting for reducing subsidence; and thirdly, deepening the research on void grouting for reducing subsidence under different conditions, providing a reference for subsequent operations.

Description

Technical Field

[0001] This invention relates to the field of coal mining technology, specifically to a method for determining the grouting hole location for grouting adjacent voids in a strip filling mining face. Background Technology

[0002] Currently, green development has become a consensus, and green mines have become a consensus among almost all mining enterprises. Mines in various regions are actively exploring ecological protection measures suitable for their own characteristics. Separation grouting technology has been favored by coal enterprises due to its unique advantages.

[0003] In traditional delamination grouting techniques, the coal pillars on both sides and the overlying key strata are typically fully utilized to form an overall subsidence reduction structure of "overlying key strata – isolation coal pillars – delamination compaction zone," with boreholes arranged in the middle of the two isolation coal pillars. However, with the increasing demand for surface subsidence reduction, the issue of delamination grouting in adjacent working faces is being raised more and more frequently, especially in the case of underground backfilling. How to arrange the boreholes is crucial to the success of delamination grouting and subsidence reduction.

[0004] The basic principle of existing delamination grouting is to use coal pillars on both sides to support the overlying key stratum, creating a delamination space between the key stratum and the underlying soft rock stratum due to the different settlement rates. Grouting filling technology is then used to fill this space with aggregates such as fly ash, compacting the goaf downwards and supporting the overlying rock stratum upwards, thereby achieving the goal of reducing surface subsidence. However, this technology is limited by the constraints of coal pillars on both sides. When facing a goaf or a previously backfilled mining face on one side, there is still no clear method for borehole layout. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for determining the grouting hole location in the adjacent void layer of a strip filling mining face, which aims to solve the problems in the prior art.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0007] A method for determining the grouting hole location for grouting adjacent voids in a strip-filling mining face includes the following steps:

[0008] S1: Determine the location and relevant parameters of the planned mining face;

[0009] S2: Determine the location of the boundary of the coal pillar adjacent to the mining face;

[0010] S3: Determine the filling rate of the backfill face adjacent to the mining face, and obtain the position of the boundary of the backfill equivalent coal pillar of the backfill face based on the filling rate;

[0011] S4: The position of the grouting hole is obtained based on the position of the coal pillar boundary obtained in S2 and the position of the filling surface boundary obtained in S3. The formula for calculating the distance between the position of the grouting hole and the coal pillar is as follows:

[0012] H n =[L×n+a×(n+1)+L×(1-v%)]÷2 (1)

[0013] In the formula,

[0014] n is the number of mining faces between the coal pillar and the backfill face; L is the width of the mining face (m); a is the width of the coal pillar in the roadway (m); ν% is the filling rate of the backfill face (%).

[0015] The beneficial effects of this invention are: the method of this invention is simple and can quickly determine the optimal location of the grouting hole. This method firstly determines the area of ​​maximum development of the delamination space in the strip mining process, secondly improves the effect of delamination grouting and settlement reduction, and thirdly deepens the research on delamination grouting and settlement reduction technology under different conditions, providing a reference for subsequent operations.

[0016] Based on the above technical solution, the present invention can be further improved as follows.

[0017] Furthermore, S2 specifically includes: determining the position of the coal pillar boundary and determining the distance between the mining face and the coal pillar, thereby determining the number n1 of the goaf between the mining face and the coal pillar and the width a of the roadway coal pillar.

[0018] The advantage of adopting the above-mentioned further scheme is that the method is simple and can quickly determine the number of goaf faces n1 between the mining face and the coal pillar and the width a of the roadway coal pillar, so as to provide data support for the subsequent determination of the grouting hole location.

[0019] Further, S3 specifically includes: determining the location of the filling face and the distance between the mining face and the filling face, thereby determining the number n2 of goaf faces between the mining face and the filling face and the width a of the roadway coal pillar; simultaneously, determining the location of the boundary of the equivalent coal pillar of the filling face based on the filling ratio of the filling face, wherein,

[0020] n = n1 + n2 + 1.

[0021] The advantage of adopting the above-mentioned further scheme is that the method is simple and can quickly determine the number of goaf faces n2 between the mining face and the filling face and the width of the roadway coal pillar a, so as to provide data support for the subsequent determination of the grouting hole location.

[0022] Furthermore, S1 specifically includes: determining the width L of the mining face.

[0023] The advantage of adopting the above-mentioned further scheme is that the method is simple and can quickly determine the width L of the mining face, so as to provide data support for the subsequent determination of the grouting hole position.

[0024] Furthermore, n in S4 is a natural number between 1 and n ≤ 5.

[0025] The advantage of adopting the above-mentioned further scheme is that the value range is based on the characteristics of the key layer's behavior, hardness, and thickness, and the value is reasonable. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the strip-type mining face layout in this invention;

[0027] Figure 2 This is a schematic diagram of the layout of a single goaf face after mining in this invention;

[0028] Figure 3 This is a schematic diagram of the arrangement of two goaf faces after mining in this invention;

[0029] Figure 4 This is a schematic diagram of the arrangement of three goaf faces after mining in this invention.

[0030] 1. Mining face; 2. Goaf face; 3. Coal pillar; 4. Filling face; 5. Filling equivalent coal pillar; 6. Grouting hole. Detailed Implementation

[0031] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0032] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0033] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0034] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0035] Example 1

[0036] like Figures 1 to 4 As shown in the figure, this embodiment provides a method for determining the grouting hole location for grouting adjacent voids in a strip filling mining face, specifically including the following steps:

[0037] S1: Determine the location and relevant parameters of planned longwall face 1;

[0038] S2: Determine the location of the boundary of the coal pillar 3 adjacent to the mining face 1;

[0039] S3: Determine the filling rate of the filling face 4 adjacent to the mining face 1, and obtain the position of the boundary of the filling equivalent coal pillar 5 of the filling face 4 based on the filling rate.

[0040] S4: The position of the grouting hole 6 is obtained based on the position of the coal pillar 3 boundary obtained in S2 and the position of the filling surface 4 boundary obtained in S3. The formula for calculating the distance between the position of the grouting hole 6 and the coal pillar 3 is as follows:

[0041] H n =[L×n+a×(n+1)+L×(1-v%)]÷2 (1)

[0042] In the formula,

[0043] n is the number of mining faces 1 between coal pillar 3 and filling face 4; L is the width of mining face 1 / m; a is the width of coal pillar 3 in the roadway / m; ν% is the filling rate of filling face 4 / %.

[0044] 1) Layout and problems of strip backfilling mining

[0045] Strip backfilling mining in coal mines generally employs a width-limited, skip-mining method, such as... Figure 1As shown, this method for coal mining can effectively control ground subsidence by setting reasonable working face width and underground filling rate. However, its disadvantages include a small working face width, mutual interference between underground filling and working face mining, resulting in low resource recovery efficiency. Moreover, when secondary mining is carried out on the remaining coal pillar 3, it will disturb the relative equilibrium state of the adjacent previous working faces, causing a secondary subsidence equivalent to full mining over a larger area. This makes it difficult to achieve the expected cumulative ground subsidence reduction effect, affecting the mine's ecological environment and economic benefits.

[0046] 2) Remedial measures for ground subsidence reduction in strip-fill mining

[0047] Overburden separation grouting for subsidence reduction involves injecting grout into the overburden space through boreholes on the surface to support the overlying strata and reduce ground subsidence. This process can be carried out in parallel with underground mining without interference. Therefore, when facing secondary ground subsidence caused by the mining of coal pillar 3 in strip-fill mining, surface separation grouting can be used as a remedial measure for ground subsidence reduction.

[0048] 3) Method for determining the optimal hole position

[0049] Because the overlying strata had already undergone subsidence and deformation in the early stages of the goaf work, and had formed a relatively stable state,

[0050] When there is no filling in the goaf, mining the adjacent coal pillar 3 will cause secondary subsidence of the upper strata in the goaf area;

[0051] When the goaf has been filled with gangue underground, and the overlying strata have undergone deformation, a structure of "gangue-filled support + overlying strata support" has been formed, equivalent to a certain range of supporting coal pillar 3. At this point, when mining adjacent coal pillar 3, the impact of the goaf is mainly the residual impact of the equivalent supporting coal pillar 3, the quantification ratio of which can be calculated with reference to the underground gangue filling rate. The optimal borehole location can be determined by the following method:

[0052] (1) One side of the mining face 1 is the coal pillar 3, and the other side is the filling face 4 (the goaf face 2 after mining, see...). Figure 2 ).

[0053] H1=[L+a×2+L×(1-v%)]÷2;

[0054] Where L is the width of the mining face / m; a is the width of the coal pillar 3 in the roadway / m; ν% is the filling rate of the filling face 4 / %; and H is the optimal distance between the grouting hole 6 and the coal pillar 3 / m.

[0055] (2) One side of the mining face 1 is the coal pillar 3, and the other side is the goaf face 2 + filling face 4 (two goaf faces 2 after mining, see...). Figure 3 ).

[0056] H2=[L×2+a×3+0+L×(1-v%)]÷2;

[0057] Where L is the width of the mining face / m; a is the width of the coal pillar 3 in the roadway / m; ν% is the filling rate of the filling face 4 / %; and H is the optimal distance between the grouting hole 6 and the coal pillar 3 / m.

[0058] (3) One side of the mining face 1 is the goaf face 2 + coal pillar 3, and the other side is the goaf face 2 + filling face 4 (the three goaf faces 2 after mining, see...). Figure 4 ).

[0059] H3=[L×3+a×4+L×(1-v%)]÷2;

[0060] Where L is the width of the mining face / m; a is the width of the coal pillar 3 in the roadway / m; ν% is the filling rate of the filling face 4 / %; and H is the optimal distance between the grouting hole 6 and the coal pillar 3 / m.

[0061] As can be seen from the above, when there are n (including the mining face 1) goaf faces 2 around the mining face 1, the optimal position of the grouting hole 6 and the distance between it and the coal pillar 3 are:

[0062] H n =[L×n+a×(n+1)+L×(1-v%)]÷2.

[0063] Where n is the number of mining faces 1 between coal pillar 3 and filling face 4; L is the width of mining face 1 / m; a is the width of coal pillar 3 in the roadway / m; ν% is the filling rate of filling face 4 / %.

[0064] The method described in this embodiment is simple and can quickly determine the optimal location of the grouting hole 6. This method has three advantages: first, it determines the area with the largest development of the separation space in the strip mining process; second, it improves the effect of separation grouting and settlement reduction; and third, it deepens the research on separation grouting and settlement reduction technology under different conditions, providing a reference for subsequent operations.

[0065] Example 2

[0066] Based on Example 1, in this example, S2 specifically includes: determining the position of the boundary of the coal pillar 3 and determining the distance between the mining face 1 and the coal pillar 3, thereby determining the number n1 of the goaf face 2 (equivalent to the mining face 1) between the mining face 1 and the coal pillar 3 and the width a of the roadway coal pillar 3.

[0067] This method is simple and can quickly determine the number n1 of goaf faces 2 between the mining face 1 and the coal pillar 3, as well as the width a of the roadway coal pillar 3, so as to provide data support for the subsequent determination of the location of the grouting hole 6.

[0068] Example 3

[0069] Based on Example 2, in this example, S3 specifically includes: determining the position of the filling surface 4 and determining the distance between the mining face 1 and the filling surface 4, thereby determining the number n2 of the goaf 2 (equivalent to the mining face 1) between the mining face 1 and the filling surface 4 and the width a of the roadway coal pillar 3; simultaneously, determining the position of the boundary of the filling equivalent coal pillar 5 according to the filling rate of the filling surface 4, wherein,

[0070] n = n1 + n2 + 1.

[0071] This method is simple and can quickly determine the number n2 of the goaf 2 between the mining face 1 and the filling face 4, as well as the width a of the roadway coal pillar 3, so as to provide data support for the subsequent determination of the location of the grouting hole 6.

[0072] Example 4

[0073] Based on the above embodiments, in this embodiment, S1 specifically includes: determining the width L of the mining face.

[0074] This method is simple and can quickly determine the width L of the mining face 1, providing data support for the subsequent determination of the location of the grouting hole 6.

[0075] Substituting the above data into equation (1) will confirm the location of grouting hole 6.

[0076] Example 5

[0077] Based on the above embodiments, in this embodiment, n in S4 is a natural number between 1 and n ≤ 5.

[0078] The range of values ​​is based on the characteristics of the critical layer's behavior, hardness, and thickness, and the values ​​are reasonable.

[0079] The steps for confirming the location of grouting hole 6 in this invention are as follows:

[0080] S1: Determine the location and relevant parameters of planned longwall face 1;

[0081] S2: Determine the location of the boundary of the coal pillar 3 adjacent to the mining face 1;

[0082] S3: Determine the filling rate of the filling face 4 adjacent to the mining face 1, and obtain the position of the boundary of the filling equivalent coal pillar 5 of the filling face 4 based on the filling rate.

[0083] S4: The position of the grouting hole 6 is obtained based on the position of the coal pillar 3 boundary obtained in S2 and the position of the filling surface 4 boundary obtained in S3. The formula for calculating the distance between the position of the grouting hole 6 and the coal pillar 3 is as follows:

[0084] H n =[L×n+a×(n+1)+L×(1-v%)]÷2.

[0085] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0086] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0087] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for determining the grouting hole location in the adjacent void layer of a strip-filled mining face, characterized in that, Specifically, the following steps are included: S1: Determine the location and relevant parameters of the planned mining face (1); S2: Determine the location of the boundary of the coal pillar (3) adjacent to the mining face (1); S3: Determine the filling rate of the filling face (4) adjacent to the mining face (1), and obtain the position of the boundary of the filling equivalent coal pillar (5) of the filling face (4) based on the filling rate; S4: The position of the grouting hole (6) is obtained based on the position of the coal pillar (3) boundary obtained in S2 and the position of the filling surface (4) boundary obtained in S3. The formula for calculating the distance between the position of the grouting hole (6) and the coal pillar (3) is as follows: H n =[L×n+a×(n+1)+L×(1-v%)]÷2 (1) In the formula, n is the number of mining faces (1) between the coal pillar (3) and the filling face (4); L is the width of the mining face (1) / m; a is the width of the roadway coal pillar (3) / m; ν% is the filling rate of the filling face (4) / %.

2. The method for determining the grouting hole location for grouting adjacent voids in a strip-filling mining face according to claim 1, characterized in that, The S2 specifically includes: determining the position of the boundary of the coal pillar (3) and determining the distance between the mining face (1) and the coal pillar (3), thereby determining the number n1 of the goaf face (2) between the mining face (1) and the coal pillar (3) and the width a of the roadway coal pillar (3).

3. The method for determining the grouting hole location for grouting adjacent voids in a strip-filling mining face according to claim 2, characterized in that, S3 specifically includes: determining the position of the filling face (4) and the distance between the mining face (1) and the filling face (4), thereby determining the number n2 of the goaf faces (2) between the mining face (1) and the filling face (4) and the width a of the roadway coal pillar (3); at the same time, determining the position of the boundary of the filling equivalent coal pillar (5) according to the filling rate of the filling face (4), wherein, n = n1 + n2 + 1.

4. The method for determining the grouting hole location for grouting adjacent voids in a strip-filling mining face according to any one of claims 1-3, characterized in that, S1 specifically includes: determining the width L of the mining face (1).

5. The method for determining the grouting hole location for grouting adjacent voids in a strip-filling mining face according to any one of claims 1-3, characterized in that: In S4, n is a natural number between 1 and n ≤ 5.

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