A method for selecting a material ratio for preventing and controlling rock burst based on a polymer filling

Abstract

The application discloses a kind of based on polymer filling prevention and cure rock burst material proportion selection method, comprising: obtaining the roof strata attribute of stoping working face, based on the roof strata attribute of stoping working face, obtain several goaf filling area;Based on the geological and mining information of the goaf filling area, obtain the influence factor of selecting polymer filling material proportion;Based on the influence factor, obtain the filling grade of the goaf filling area;Obtain the pH of goaf water, based on the filling grade and the pH of goaf water, obtain the polymer material proportion of the goaf filling area.The application not only can reduce the dynamic load disturbance formed by roof breakage movement, reduce the impact danger of working face, but also can inhibit goaf surface subsidence, protect the ecological environment of mining area, realize mine safety green mining.

Description

Technical Field

[0001] This invention belongs to the field of coal mining and coal mine safety technology, and particularly relates to a material proportioning and selection method based on polymer filling for preventing rockburst. Background Technology

[0002] During longwall mining, adjacent goaf areas are disturbed by the mining process, leading to increased roof movement. This dynamic load disturbance can easily affect the safe mining of the longwall face. Especially when the goaf contains thick, hard rock strata, the dynamic load disturbance increases exponentially, posing a further threat to safe mining. Current methods for reducing dynamic load disturbance in the goaf overlying rock mainly involve rock blasting. The purpose of blasting is to break up the rock strata, reducing the degree of dynamic load disturbance generated when the strata move again compared to before blasting. However, although the dynamic load disturbance is reduced, even minor dynamic load disturbances can still cause rockburst accidents when the longwall face reaches stress concentration areas. This is because this blasting pre-fracture method does not control the source of the dynamic load disturbance.

[0003] Furthermore, with the increasing scale of coal mining enterprises, integrated coal-power construction has become the main direction for future mine construction, leading to a significant increase in the production of solid waste such as fly ash generated during power generation. This solid waste not only impacts the ecological environment but also increases the processing costs for enterprises. Currently, some coal-fired power plants have begun exploring the feasibility of using fly ash polymers to fill goaf areas in mines. However, the proportioning of these polymer materials is not only unscientific but can also result in insufficient strength of the filler due to incorrect proportions, thus failing to achieve the desired filling effect.

[0004] Therefore, providing a method to scientifically and systematically formulate the proportion of fly ash polymer materials is one of the research directions in this industry. This method can not only achieve precise matching of filling in the goaf of the mine, suppress the breaking movement of the goaf roof, stop the generation of dynamic loads from the source, and prevent rockburst at the working face, but also enable the reuse of fly ash and reduce its impact on health and the environment. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a material proportioning and selection method based on polymer filling for preventing rockbursts. This method solves the technical problems existing in the prior art, can select polymer filling areas in adjacent goafs, identify the filling grade of adjacent goaf filling areas, and select polymer material proportions. It can reduce dynamic load disturbance caused by roof fracture movement, reduce the impact risk of working face, and inhibit surface subsidence in goafs, thus protecting the surface ecological environment of mining areas. This is a research direction in this industry.

[0006] To achieve the above objectives, the present invention provides a method for selecting the material proportions for preventing rockbursts based on polymer filling, comprising:

[0007] Obtain the properties of the roof strata of the longwall face, and based on the properties of the roof strata of the longwall face, obtain several goaf filling areas;

[0008] Based on the geological and mining information of the goaf filling area, the influencing factors of the selection of polymer filler material ratio are obtained;

[0009] Based on the aforementioned influencing factors, the filling grade of the goaf filling area is obtained;

[0010] The pH of the goaf water is obtained, and based on the filler grade and the pH of the goaf water, the polymer material ratio of the goaf filling area is obtained.

[0011] Optionally, obtaining the properties of the roof strata at the longwall face includes:

[0012] The adjacent goaf roadways of the longwall face are delineated by the dip width of the adjacent goaf areas to obtain several identification areas;

[0013] Based on half the dip width of the adjacent goaf, roof attribute detection holes are arranged perpendicular to the roof of the adjacent goaf roadway within the identification area.

[0014] Based on the top plate attribute detection holes, the drilling depth of the top plate attribute detection holes and the cumulative average thickness of the sandstone strata in the top plate attribute detection holes are obtained.

[0015] Optionally, the method for obtaining the drilling depth S of the top plate attribute detection hole is as follows:

[0016] S=k*H m

[0017] Among them, H m The average thickness of the coal seam is represented by ; k represents the depth coefficient.

[0018] Optionally, based on the properties of the roof strata of the mining face, several goaf filling areas are obtained, including:

[0019] Based on the borehole depth and the cumulative average thickness of the sandstone strata, the goaf filling coefficient of the identified area is obtained;

[0020] Based on the goaf filling coefficient, polymer filling areas of adjacent goaf areas are delineated to obtain several goaf filling areas.

[0021] Optionally, the factors influencing the proportion of selected polymer filler materials include: mining depth, hydrogeological type, coal seam thickness, goaf time, roof thickness reduction value, section coal pillar size, coal seam dip angle, and goaf temperature.

[0022] Optionally, obtaining the top plate thickness reduction value includes:

[0023] By arranging roof thickness detection holes perpendicular to the roof of the adjacent roadway within the goaf filling area, the thickness of the roof lithology within a certain range can be obtained.

[0024] Based on the thickness and reduction factor of the top lithology, the cumulative value of the rock layer thickness after reduction is obtained;

[0025] The cumulative value after reducing the thickness of the rock strata is the reduced value of the top plate thickness.

[0026] Optionally, the method for obtaining the filling grade of the goaf filling area is as follows:

[0027]

[0028] Where P represents the fill grade; j represents the influence factor number j = 1, 2, 3...N; p j This represents the weight assignment of the j-th influence factor; p jmax This represents the maximum value of the weight assigned to the j-th influence factor.

[0029] Optionally, obtaining the pH of the water in the goaf includes:

[0030] Based on the drilling depth of the top plate property detection hole, the depth of the goaf water collection hole is obtained;

[0031] Based on the dip angle of the coal seam, the elevation angle of the goaf water collection hole is obtained;

[0032] Based on the depth and elevation angle of the goaf water collection holes, the goaf water collection holes are arranged from the adjacent goaf roadway wall toward the adjacent goaf within the identification area.

[0033] The pH of the goaf water is obtained by collecting and measuring the goaf water in the goaf water collection holes.

[0034] Optionally, the method for obtaining the pH of the water in the goaf is as follows:

[0035]

[0036] Where R represents the average pH value of the water in the goaf, R r Let N represent the pH value of the water in the mined-out area of ​​each identification region collected in the r-th sampling. r This represents the number of times data was collected.

[0037] Technical advantages of this invention: This invention selects polymer-filled areas in adjacent goaf areas based on the characteristics of the roof of the longwall face, identifies the grade of goaf filling based on collected influencing factors, and, combined with the pH of the goaf water, achieves systematic selection of polymer material proportions. This method not only reduces dynamic load disturbance caused by roof fracture movement and decreases the risk of impact on the working face, but also inhibits surface subsidence in the goaf, protects the surface ecological environment of the mining area, and achieves safe and green mining. Attached Figure Description

[0038] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0039] Figure 1 This is a flowchart of the polymer material proportioning and selection method according to an embodiment of the present invention;

[0040] Figure 2 This is a schematic cross-sectional view of the drilling arrangement for top plate property detection in an embodiment of the present invention;

[0041] Figure 3 This is a schematic cross-sectional view of the arrangement of the top plate thickness detection holes in an embodiment of the present invention;

[0042] Figure 4 This is a schematic cross-sectional view of the water collection hole arrangement in the goaf area according to an embodiment of the present invention. Detailed Implementation

[0043] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0044] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0045] like Figure 1 As shown, this embodiment provides a material proportioning selection method for preventing rockbursts based on polymer filling, including:

[0046] S1. Delineate polymer filling areas in adjacent goaf areas based on the properties of the roof strata of the longwall face;

[0047] The specific definition of the polymer filling area in adjacent goaf areas in S1 is as follows:

[0048] S1.1. In the adjacent roadway of the longwall face, a goaf filling coefficient T identification area is defined every L meters, where L is the dip width of the adjacent goaf, and the width of the goaf perpendicular to the longwall face is the dip width of the adjacent goaf; in each identification area, a roof attribute detection hole is arranged every L / 2 meters.

[0049] S1.2, the drilling depth of the roof attribute detection hole is S, the drilling diameter is not less than 120mm, and the hole is arranged perpendicular to the roof of the adjacent tunnel. Figure 2 As shown;

[0050] S1.3. The depth S of the detection borehole is determined using formula (1);

[0051] S=k*H m (1)

[0052] In the formula, H m The average thickness of the coal seam being mined is represented by H; k represents the depth coefficient, when H... m When the distance is ≤3.0 meters, k is taken as 5; when the distance is 3.0 meters... <H m When H is ≤6.0 meters, k is taken as 8. m When the distance is greater than 6.0 meters, k is taken as 10.0.

[0053] S1.4 Record the cumulative average thickness S of sandstone strata in each top plate attribute detection borehole in the identification area for each filling coefficient T. s .

[0054] S1.5. Use formula (2) to determine the filling coefficient T of adjacent goaf areas;

[0055]

[0056] When T≥70%, it is determined that the adjacent goaf needs to be filled.

[0057] When T < 70%, it is determined that the adjacent goaf does not need to be filled.

[0058] S2. Based on the geological and mining information of the adjacent goaf filling area, collect the influencing factors for selecting the polymer filler material ratio;

[0059] The specific factors collected in S2 for selecting the influencing ratio of polymer filler materials are as follows:

[0060] S2.1 The influencing factors include: mining depth, hydrogeological type, coal seam thickness, goaf time, roof thickness reduction value, section coal pillar size, coal seam dip angle, and goaf temperature;

[0061] The mining depth is the average value D of the burial depth of the two roadways in the goaf.

[0062] The hydrogeological type is the hydrogeological type grade W given by the hydrogeological exploration of the coal mining face when the goaf is not mined.

[0063] The coal seam thickness is the average coal seam thickness H during working face mining. m ;

[0064] The goaf time is the time Y during which adjacent goaf areas are formed, and the goaf time is calculated from the time when the goaf area is fully formed.

[0065] The reduction value of the roof thickness is the cumulative value C of the rock strata thickness within 50m of the overlying surface of the longwall mining face after reduction.

[0066] The section coal pillar size is the isolation coal pillar size Z between the longwall face and the adjacent goaf.

[0067] The coal seam dip angle is the coal seam occurrence angle θ of the longwall mining face;

[0068] The temperature of the goaf is Q, which is the temperature measured by a mercury thermometer in an adjacent goaf.

[0069] S2.2, The cumulative value C after reducing the rock layer thickness is calculated as follows:

[0070] (1) In each goaf filling area of ​​the adjacent roadway, a roof thickness detection borehole is arranged, with a drilling depth of 50 meters and a borehole diameter of 60 mm. The borehole is arranged perpendicular to the roof of the adjacent roadway. Figure 3 As shown:

[0071] (2) Record the thickness h of the roof lithology of different probe holes. i ;

[0072] (3) Calculate the thickness reduction value C of the top plate using formula (3):

[0073]

[0074] In the formula, h i The thickness represents the thickness of different roof lithologies within a 50m range; i represents the stratum number, i = 1, 2, 3...n; λ represents the reduction factor, λ = 0.4 when the roof lithology is mudstone, λ = 0.6 when the roof lithology is sandy mudstone, λ = 0.3 when the roof lithology is coal, λ = 1.0 when the roof lithology is sandstone, and λ = 0.5 when the roof lithology is shale.

[0075] S3. Based on the collected influence factors, determine the filling grade of the filling area of ​​adjacent goaf areas;

[0076] The specific steps in S3 for determining the filling grade of adjacent goaf filling areas are as follows:

[0077] S3.1. Assign weight values ​​to each of the collected influencing factors according to Table 1.

[0078] S3.2. Use formula (4) to determine the filling grade of adjacent goaf filling areas:

[0079]

[0080] In the formula, P represents the fill grade; j represents the influence factor number j = 1, 2, 3...N; p j This represents the weight assignment of the j-th influence factor; p jmax This represents the maximum value of the weight assigned to the j-th influence factor.

[0081] When P≤0.2, the grade of the goaf filling is Grade I;

[0082] When 0.2 < P ≤ 0.4, the grade of the goaf filling is Grade II;

[0083] When 0.4 < P ≤ 0.6, the grade of the goaf filling is Grade III;

[0084] When 0.6 < P ≤ 0.8, the grade of the goaf filling is Grade IV;

[0085] When P > 0.8, the grade of the goaf filling is Grade V;

[0086] Table 1 shows the weighting of each influencing factor.

[0087] Table 1

[0088]

[0089] S4. Based on the filling grade of adjacent goaf areas and the pH of the goaf water, select the polymer material ratio; the pH determination of the goaf water in S4 specifically involves:

[0090] S4.1. Within each filling identification area, a goaf water collection hole is arranged every L / 4 meters, with a drilling depth S. L Meters, borehole diameter 50mm, borehole elevation angle Ψ with the horizontal plane, borehole arrangement from the adjacent goaf roadway wall towards the adjacent goaf area, such as Figure 4 As shown;

[0091] S4.2 Determine the depth S of the water collection hole in the goaf using formula (5). L ;

[0092]

[0093] S4.3. Use formula (6) to determine the elevation angle Ψ of the water collection hole in the goaf;

[0094] Ψ=90°-θ (6)

[0095] S4.4. Collect 100 mL of goaf water from each goaf water collection hole in each filling identification area every 8 hours, for a total of 9 times.

[0096] S4.5. Use precision pH test paper to measure the pH value of 9 samples collected from the water collection holes in each goaf area.

[0097] S4.6 Calculate the average pH value R of the goaf water in each identified area using formula (7);

[0098]

[0099] In the formula, R r Let N represent the pH value of the water in the mined-out area of ​​each identification region collected in the r-th sampling. r N represents the number of data collections. r =1,2,3...9.

[0100] S4.7 When R < 6.6, the water in the goaf is classified as Class I;

[0101] When 6.6≤R≤7.4, the water in the goaf is classified as Class II;

[0102] When R > 7.4, the water in the goaf is classified as Class III.

[0103] When the goaf water in the goaf filling area adjacent to the longwall face is Class I, the polymer material ratio is selected based on Table 2. Table 2 is the polymer material ratio table for Class I goaf water.

[0104] Table 2

[0105]

[0106]

[0107] When the goaf water in the goaf filling area adjacent to the longwall face is Class II, the polymer material ratio is selected based on Table 3. Table 3 is the polymer material ratio table for Class II goaf water.

[0108] Table 3

[0109] Level I 80.0％ 15.0％ 3.0％ 1.0％ 0.36％ 0.38％ 0.25％ 0.01％ Level II 77.5％ 16.0％ 5.0％ 1.0％ 0.19％ 0.15％ 0.15％ 0.01％ Level III 75.0％ 17.5％ 6.0％ 1.1％ 0.14％ 0.14％ 0.10％ 0.02％ Level IV 72.5％ 18.5％ 7.0％ 1.1％ 0.39％ 0.39％ 0.10％ 0.02％ Level V 70.0％ 20.0％ 8.0％ 1.2％ 0.33％ 0.36％ 0.08％ 0.03％

[0110] When the goaf water in the goaf filling area adjacent to the longwall face is Class III, the polymer material ratio is selected based on Table 4. Table 4 is the polymer material ratio table for Class III goaf water.

[0111] Table 4

[0112] Level I 80.0％ 15.0％ 3.0％ 1.0％ 0.46％ 0.45％ 0.08％ 0.01％ Level II 77.5％ 16.0％ 5.0％ 1.0％ 0.30％ 0.11％ 0.08％ 0.01％ Level III 75.0％ 17.5％ 6.0％ 1.1％ 0.14％ 0.14％ 0.10％ 0.02％ Level IV 72.5％ 18.5％ 7.0％ 1.1％ 0.39％ 0.39％ 0.10％ 0.02％ Level V 70.0％ 20.0％ 8.0％ 1.2％ 0.33％ 0.33％ 0.11％ 0.03％

[0113] This invention selects polymer-filled areas in adjacent goafs based on the characteristics of the roof of the longwall face, identifies the grade of goaf filling based on collected influencing factors, and systematically selects the polymer material ratio by combining the pH of the goaf water. This method not only reduces dynamic load disturbance caused by roof fracture and minimizes the risk of impact on the working face, but also inhibits surface subsidence in the goaf, protects the surface ecological environment of the mining area, and achieves safe and green mining.

[0114] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for selecting and proportioning materials for preventing rockbursts based on polymer filling, characterized in that, include: Obtain the properties of the roof strata of the longwall face, and based on the properties of the roof strata of the longwall face, obtain several goaf filling areas; Based on the geological and mining information of the goaf filling area, the influencing factors of the selection of polymer filler material ratio are obtained; Based on the aforementioned influencing factors, the filling grade of the goaf filling area is obtained; The pH of the goaf water is obtained, and based on the filler grade and the pH of the goaf water, the polymer material ratio of the goaf filling area is obtained.

2. The material proportioning and selection method for preventing rockbursts based on polymer filling as described in claim 1, characterized in that, Obtaining the properties of the roof strata in the longwall mining face includes: The adjacent goaf roadways of the longwall face are delineated by the dip width of the adjacent goaf areas to obtain several identification areas; Based on half the dip width of the adjacent goaf, roof attribute detection holes are arranged perpendicular to the roof of the adjacent goaf roadway within the identification area. Based on the top plate attribute detection holes, the drilling depth of the top plate attribute detection holes and the cumulative average thickness of the sandstone strata in the top plate attribute detection holes are obtained.

3. The material proportioning and selection method for preventing rockbursts based on polymer filling as described in claim 2, characterized in that, The method for obtaining the drilling depth S of the top plate attribute detection hole is as follows: ； in ， This represents the average thickness of the mined coal seam; k It is represented as a depth coefficient.

4. The material proportioning and selection method for preventing rockbursts based on polymer filling as described in claim 2, characterized in that, Based on the properties of the roof strata of the mining face, several goaf filling areas were obtained, including: Based on the borehole depth and the cumulative average thickness of the sandstone strata, the goaf filling coefficient of the identified area is obtained; Based on the goaf filling coefficient, polymer filling areas of adjacent goaf areas are delineated to obtain several goaf filling areas.

5. The material proportioning and selection method for preventing rockbursts based on polymer filling as described in claim 2, characterized in that, The factors influencing the proportion of selected polymer filler materials include: mining depth, hydrogeological type, coal seam thickness, goaf time, roof thickness reduction value, section coal pillar size, coal seam dip angle, and goaf temperature.

6. The material proportioning and selection method for preventing rockbursts based on polymer filling as described in claim 5, characterized in that, Obtaining the thickness reduction value of the top plate includes: The thickness of the roof lithology is obtained by arranging roof thickness detection holes perpendicular to the roof of the adjacent roadway within the goaf filling area. Based on the thickness and reduction factor of the top lithology, the cumulative value of the rock layer thickness after reduction is obtained; The cumulative value after reducing the thickness of the rock strata is the reduced value of the top plate thickness.

7. The material proportioning and selection method for preventing rockbursts based on polymer filling as described in claim 1, characterized in that, The method for obtaining the filling grade of the goaf filling area is as follows: ； in ，P Indicated as filler grade; j Represented as impact factor number j =1, 2, 3... N ; Represented as the first j Weight assignment for each influencing factor; Represented as the first j The maximum value of the weight assigned to each influencing factor.

8. The material proportioning and selection method for preventing rockbursts based on polymer filling as described in claim 5, characterized in that, Obtaining the pH of the water in the goaf includes: Based on the drilling depth of the top plate property detection hole, the depth of the goaf water collection hole is obtained; Based on the dip angle of the coal seam, the elevation angle of the goaf water collection hole is obtained; Based on the depth and elevation angle of the goaf water collection holes, the goaf water collection holes are arranged from the adjacent goaf roadway wall toward the adjacent goaf within the identification area. The pH of the goaf water is obtained by collecting and measuring the goaf water in the goaf water collection holes.

9. The material proportioning and selection method for preventing rockbursts based on polymer filling as described in claim 1, characterized in that, The method for obtaining the pH value of water in the goaf is as follows: ； Where R represents the average pH value of the water in the goaf. Let be the pH value of the water in the mined-out area of ​​each identified region collected in the r-th sampling. This represents the number of times data was collected.

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