A method for designing parameters of longwall cemented filling coal mining face

Abstract

The present application discloses a method for designing parameters of a longwall cemented backfill coal mining working face. The working face parameter design is completed by determining the width, length, spacing, filling pipeline layout, and filling rate parameters of the filling lanes. The width and length of the lanes are determined by the filling coal mining equipment and process, and the stability of the lanes. The spacing of the filling lanes is determined by the location of the mining stress concentration zone. The filling pipeline layout is determined by the shape of the lanes and the filling process. The filling rate is determined by the protection level of the surface buildings. The patented method of the present invention is of great significance to improving the safety factor of the working face, enhancing the production efficiency of the working face, and improving the management of the working face. At the same time, it improves the filling coal mining theory to achieve the purpose of safe and efficient mining. The method is simple to implement and has great promotion value.

Description

Technical Field

[0001] This invention belongs to the field of backfilling coal mining technology, specifically relating to a method for designing parameters of underground coal mining faces, and more specifically to a method for designing parameters of longwall cemented backfilling coal mining faces. Background Art

[0002] With the development of backfilling mining technology, longwall backfilling mining technology has also made significant progress. Using longwall backfilling mining allows for flexible arrangement of the working face, improving coal resource recovery rates and achieving better backfilling results. However, currently there is no complete method for designing working face parameters; most designs are based on specific examples analyzed under specific conditions, and technical operators lack a unified approach to working face parameter design. Therefore, determining a method for designing working face parameters is essential. Summary of the Invention

[0003] Technical problems to be solved:

[0004] To address the shortcomings of existing technologies, this application solves the problems of the lack of a complete working face parameter design method, the fact that most designs are based on specific examples analyzed according to specific circumstances, and the lack of a unified approach for working face parameter design among technical operators; it provides a parameter design method for longwall roadway cemented backfilling coal mining working faces, offering a set of design methods for backfilling coal mining working face parameter design.

[0005] Technical solution:

[0006] To achieve the above objectives, this application provides the following technical solution:

[0007] A parameter design method for longwall cemented backfilling coal mining faces includes the following steps:

[0008] The first step is to determine the width of the backfill roadway: this is determined by the model of the roadheader, tunneling and anchoring machine, or continuous mining machine, as well as the stability of the overlying strata of the backfill roadway.

[0009] The second step is to determine the length of the filling roadway: this is determined based on the size of the coal mining equipment, the filling process, the total width of the filling process circulation roadway, the length of the shuttle car, and the maximum transportation distance.

[0010] The third step is to determine the spacing of the filling roadways: this is determined based on the location of the mining stress concentration zone.

[0011] The fourth step is to determine the layout of the filling pipeline: based on the shape of the tunnel and the filling process;

[0012] The fifth step is to determine the filling ratio: this is determined based on the requirements for the protection of surface structures.

[0013] Furthermore, in the first step, the width of the filling roadway is determined based on the range served by the single excavation width of the coal mining equipment.

[0014] Based on the simplified mechanical model and

[0015] The stress above the working face filling roadway is obtained from the solution of the bending and sinking equation, thus yielding the specific width of the working face filling roadway.

[0016] Furthermore, in the second step, the length of the filling tunnel is determined according to the following calculation formula.

[0017] l1+l2+l3+l 梭max =l5+l6

[0018] In the formula: l1—width of the coal pillar left in the filling roadway, l2—length of the tunneling and anchoring machine body, l3—length of the shuttle car body.

[0019] l 梭max —Maximum shuttle car transport distance, l4—Total width of one cycle roadway, l5—Spacing between skips. l6—Maximum length of the filling tunnel;

[0020] Calculations show the maximum length of the filling tunnel.

[0021] Furthermore, in the third step, the spacing of the filling tunnels is determined using FLAC. 3D Numerical simulation software determines the stress distribution range, thereby determining the tunnel spacing.

[0022] Furthermore, in the fourth step, the arrangement of the filling pipeline is determined. Based on the working face conditions, the pipeline arrangement is divided into five types: single-inclination roadway filling pipeline arrangement (i.e., retaining wall on top); single-inclination roadway filling pipeline arrangement (i.e., coal pillar on top); horizontal roadway filling pipeline arrangement; undulating roadway filling pipeline arrangement (i.e., the highest point is at both ends of the roadway); and undulating roadway filling pipeline arrangement (i.e., the highest point is in the middle of the roadway).

[0023] Furthermore, in the fifth step, the filling rate is determined. Based on the requirements for the protection of surface buildings, the filling rate is determined to be 85% to 95%, and then the strength of the filling body is used to ensure that the filling rate requirement is met.

[0024] Beneficial effects:

[0025] This application provides a parameter design method for longwall roadway cemented backfilling coal mining faces, which has the following advantages compared with the prior art:

[0026] 1. This invention provides a complete method for designing parameters of longwall cemented backfilling coal mining faces, which helps technical operators quickly and accurately determine the key parameters of the working face for mines using the same or similar methods, thereby promoting safe and efficient mining.

[0027] 2. The design method of this invention is simple to operate and highly applicable. It can guide the actual engineering design and selection of key equipment on site, and has broad application prospects. Attached Figure Description

[0028] Figure 1 This is a flowchart illustrating the design process of the working surface parameters for this invention.

[0029] Figure 2 This is a simplified mechanical model diagram of the filling body-top plate system of the present invention. Figure 1 a The advancing length is half the working face. b The length of the coal pillar filling working face is given by k, where q is the uniformly distributed load borne by the overlying strata on the roof, and k is the length of the coal pillar filling working face. b denoted as the elastic foundation coefficient of the filling body, and w(x) is the deflection of the top plate.

[0030] Figure 3 This is a schematic diagram of coal mining in a backfilled tunnel according to the present invention. Detailed Implementation

[0031] The present invention will be further described below with reference to the accompanying drawings and the actual situation of a certain mine. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0032] Example 1:

[0033] The parameter design method for longwall cemented backfilling coal mining faces includes the following steps:

[0034] The first step is to determine the width of the filling tunnel: based on the model of the tunnel boring and anchoring machine and the service range of a single tunneling pass, the tunnel width is determined to be 5m; combined with... Figure 2 Simplified mechanical model, l in the figure a The advancing length is half the working face. b The length of the coal pillar filling working face is given by k, where q is the uniformly distributed load borne by the overlying strata on the roof, and k is the length of the coal pillar filling working face. b Let w(x) be the elastic subgrade coefficient of the infill body, and w(x) be the deflection of the top plate, according to the formula... Calculate the stress distribution and determine that the stress distribution of the overlying rock strata is consistent with the 5m width.

[0035] The second step is to determine the length of the filling roadway: Based on the working angle range of the roadheader, the angle between the excavated filling roadway and the working face roadway is determined to be 135°. Coal extraction is carried out using a skip-mining method, with every four filling roadways constituting one cycle. The transfer crusher and belt conveyor should be arranged after two cycles. Each filling roadway should have a 4.5m coal pillar as a filling retaining wall. Based on the aforementioned determination of the roadway length, the maximum transport distance of the selected shuttle car is 200m. Figure 3 The following calculation formula can be obtained:

[0036] If the maximum transport distance of the selected shuttle car is 200m, then the maximum length of the filling tunnel is calculated as follows:

[0037] l1+l2+l3+l 梭max =l5+l6

[0038] In the formula: l1—width of the coal pillar left in the filling roadway, 4.5m;

[0039] l2—Length of the tunneling and anchoring machine, 11.6m;

[0040] l3—Shuttle car body length, 9.14m;

[0041] l 梭max —Maximum transport distance of the shuttle car: 200m;

[0042] l4—The total width of a circular tunnel is 43.2m;

[0043] l5—Skip spacing Take 61.1m;

[0044] l6—Maximum length of the filling tunnel, in meters;

[0045] Calculations show that the maximum length of the filling tunnel is 164m;

[0046] The third step is to determine the spacing of the filling tunnels: using FLAC. 3D Numerical simulation software showed that after a single roadway was excavated, mining disrupted the original equilibrium state of the original rock stress field, creating a stress reduction zone in the roadway roof and floor. A certain range on both sides of the roadway became a support stress influence zone, resulting in stress concentration in the coal walls on both sides. The stress peak was reached at a distance of about 3.5m from the roadway side, with a support stress peak of 18.62MPa on the solid coal side and a peak stress concentration factor of 1.26. At a distance of 15m from the roadway side, the vertical stress decreased to 14.92-14.79MPa. The stress in the coal body outside the 15m range approached the original rock stress of 14.75MPa, indicating that the influence of the advance support pressure generated by the 5.0m roadway could be avoided at a distance of about 15m from the roadway side. Combined with the roadway-by-road cemented backfilling mining technology, the final determined roadway excavation spacing for backfilling roadways was 3 times the roadway width, i.e., 15.0m.

[0047] The fourth step is to determine the layout of the filling pipeline: The mine is a single inclined roadway with the retaining wall located at the bottom. Based on the working face, the pipeline layout is set as a single inclined roadway filling pipeline layout, that is, the retaining coal pillar is at the top.

[0048] The fifth step is to determine the filling rate: Based on the requirements for the protection of surface structures, and ensuring that the damage level is within Class I, the filling rate is determined to be 95% based on the expected surface subsidence, and the strength of the filling body is guaranteed to meet the filling rate requirements.

[0049] 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 technical principles 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 designing parameters of longwall cemented filling coal mining working face, characterized in that: The method for designing parameters of a longwall cemented filling coal mining working face comprises the following steps: The first step is to determine the width of the filling tunnel: it is determined by the model of the tunneling machine, anchoring machine or continuous mining machine, and the stability of the overlying rock formation of the filling tunnel; The second step is to determine the length of the filling tunnel: it is determined based on the size of the coal mining equipment, the filling process, the total width of the filling process circulation tunnel, the length of the shuttle car and the maximum transportation distance; The third step is to determine the spacing of the filling tunnels: it is determined according to the location of the mining stress concentration area; The fourth step is to determine the layout of the filling pipeline: according to the shape of the tunnel and the filling process; Step 5: Determine the filling rate: It is determined according to the protection requirements of surface buildings; In the first step, the width of the filling tunnel is determined according to the range of the single excavation width service of the coal mining equipment: According to the simplified mechanical model and The solution of the bending sinking equation can be used to obtain the stress above the working face filling tunnel, and thus the specific width of the working face filling tunnel can be obtained; In the second step, the length of the filling tunnel is determined according to the following calculation formula: l1+l2+l3+l 梭max ＝l5+l6 Where: l1 is the width of the coal pillar in the backfill tunnel, l2 is the length of the anchoring machine, l3 is the length of the shuttle car, l 梭max —The maximum transport distance of the shuttle car, l4—The total width of a circular lane, l5—The interval between skipping and mining, l6—maximum length of filling tunnel; Calculation shows that the maximum length of the filling tunnel.

2. The method for designing parameters of longwall cemented filling coal mining working face according to claim 1 is characterized by: In the third step, the spacing of the filling lanes is determined using FLAC 3D Numerical simulation software determines the stress distribution range and thus the tunnel spacing.

3. The method for designing parameters of longwall cemented filling coal mining working face according to claim 1 is characterized by: In the fourth step, the arrangement of the filling pipelines is determined. According to the conditions of the working face, the pipeline layout is divided into five types: single-inclined tunnel filling pipeline arrangement, i.e., the retaining wall is on top; single-inclined tunnel filling pipeline arrangement, i.e., the retaining coal pillar is on top; horizontal tunnel filling pipeline arrangement; undulating tunnel filling pipeline arrangement, i.e., the highest point is at both ends of the tunnel; undulating tunnel filling pipeline arrangement, i.e., the highest point is in the middle of the tunnel.

4. The method for designing parameters of longwall cemented filling coal mining working face according to claim 1 is characterized by: In the fifth step, the filling rate is determined to be 85% to 95% based on the surface building protection requirements, and the filling rate requirement is then ensured to be met by measuring the strength of the filling body.

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