Room-and-pillar goaf filling method

Abstract

The present invention relates to the technical field of goaf management, and provides a room-and-pillar goaf filling method, the method comprising determining filling boundary information and a maximum allowable collapse width corresponding to the room-and-pillar goaf; determining a goaf area to be filled from the room-and-pillar goaf according to the filling boundary information and the maximum allowable collapse width; and filling the goaf space of the goaf area to be filled with materials. The room-and-pillar goaf filling method provided by an embodiment of the present invention determines the filling boundary information and a maximum allowable collapse width corresponding to the room-and-pillar goaf, and then determines the goaf area to be filled in the room-and-pillar goaf, and fills the goaf space of the goaf area to be filled with materials, the maximum allowable collapse width represents the distance between adjacent goaf areas to be filled, thereby achieving partial filling of the room-and-pillar goaf, and being able to improve the stability of the room-and-pillar goaf after filling, thereby reducing the management engineering workload and cost.

Description

Technical Field

[0001] The invention relates to the technical field of goaf management, and in particular to a room-and-pillar goaf filling method. Background Art

[0002] Room-and-pillar goaf is a type of goaf in coal mines. It is the area left after the ore layer is mined by the room-and-pillar mining method. With the continuous development of economic construction and cities, a large number of railways and highways have to pass through room-and-pillar goafs, and some buildings and structures have to be built on room-and-pillar goafs. Under the influence of overburden stress, weathering and other factors, the effective size of the coal pillars in the room-and-pillar goafs is constantly reduced, making the local coal pillars unstable, which in turn leads to the collapse of the local roof of the room-and-pillar goaf. The scope of collapse changes from small to large, from low to high, until it develops to the surface, causing the surface to sink and deform, posing a threat to the safety of surface personnel and buildings (structures).

[0003] In order to prevent the room-and-pillar goaf from collapsing, the room-and-pillar goaf is treated by filling. However, the existing method is to fill all the fillable space in the room-and-pillar goaf, which results in a large amount of treatment work and high cost. Summary of the invention

[0004] The invention provides a room-and-pillar goaf filling method, which is used to solve the defects of large amount of treatment engineering and high cost in the prior art.

[0005] The present invention provides a room-and-pillar goaf filling method, comprising:

[0006] Determine the filling boundary information and maximum allowable collapse width corresponding to the room-and-pillar goaf;

[0007] Determine a goaf area to be filled from the room-and-pillar goaf according to the filling boundary information and the maximum allowable cave-in width;

[0008] The mined space of the mined area to be filled is filled with materials.

[0009] According to a room-and-pillar goaf filling method provided by an embodiment of the present invention, determining the maximum allowable collapse width corresponding to the room-and-pillar goaf includes:

[0010] Determine the collapse height and collapse angle corresponding to the room-and-pillar goaf;

[0011] The maximum allowable collapse width is determined based on the collapse height and the collapse angle.

[0012] According to a room-and-pillar goaf filling method provided by an embodiment of the present invention, determining the collapse height corresponding to the room-and-pillar goaf includes:

[0013] Determining key strata in the overburden structure based on the overburden structure above the room-and-pillar goaf;

[0014] The vertical distance between the bottom surface of the key layer and the top surface of the room-and-pillar goaf is determined as the collapse height.

[0015] According to a room-and-pillar goaf filling method provided by an embodiment of the present invention, the determining of the maximum allowable cave-in width based on the cave-in height and the cave-in angle comprises:

[0016] Determine the maximum allowable collapse width based on formula (1);

[0017] B=2qcotα (1)

[0018] Among them, B represents the maximum allowable collapse width, q represents the collapse height, and α represents the collapse angle.

[0019] According to a room-and-pillar goaf filling method provided by an embodiment of the present invention, the filling boundary information includes a local filling width, and the method of determining the filling boundary information corresponding to the room-and-pillar goaf includes:

[0020] Based on the ultimate strength theory and the maximum allowable collapse width, the local filling width corresponding to the room-and-pillar goaf is determined.

[0021] According to a room-and-pillar goaf filling method provided by an embodiment of the present invention, determining a local filling width corresponding to the room-and-pillar goaf includes:

[0022] Determine the local filling width based on formula (2);

[0023]

[0024] in, b=0.64σ 1 -γHk, c=-2γHkB, d=-γHkB 2 ;

[0025] A represents the local filling width, σ 1 represents the critical compressive strength, h represents the height of the room-and-pillar goaf, γ represents the average bulk density of the overburden in the room-and-pillar goaf, H represents the vertical distance between the top surface of the room-and-pillar goaf and the ground surface, k represents the stability safety factor, and B represents the maximum allowable collapse width.

[0026] According to a room-and-pillar goaf filling method provided by an embodiment of the present invention, determining a goaf area to be filled from the room-and-pillar goaf according to the filling boundary information and the maximum allowable cave-in width includes:

[0027] Determine a target local filling width and a target non-filling width according to the filling boundary information and the maximum allowable cave-in width, wherein the target local filling width is greater than or equal to the local filling width, and the target non-filling width is less than or equal to the maximum allowable cave-in width;

[0028] Based on the target local filling width and the target unfilled width, a plurality of goaf areas to be filled corresponding to the target local filling width are determined from the room-and-pillar goaf.

[0029] According to an embodiment of the present invention, a room-and-pillar goaf filling method is provided, wherein the room-and-pillar goaf includes a plurality of coal pillars evenly spaced apart, the goaf space being formed between adjacent coal pillars, and the goaf area to be filled includes at least one coal pillar and at least one goaf space adjacent to the at least one coal pillar.

[0030] According to a room-and-pillar goaf filling method provided by an embodiment of the present invention, the multiple goaf areas to be filled are distributed in a matrix.

[0031] According to a room-and-pillar goaf filling method provided by an embodiment of the present invention, the goaf space of the goaf area to be filled is filled with materials, comprising:

[0032] Arrange a plurality of injection holes in the treatment area above the goaf area to be filled;

[0033] The slurry is injected into the mined space of the mined area to be filled from the injection hole in the middle to the injection holes on the outside in sequence.

[0034] The room-and-pillar goaf filling method provided in the embodiment of the present invention determines the filling boundary information and the maximum allowable cave-in width corresponding to the room-and-pillar goaf, and then determines the goaf area to be filled in the room-and-pillar goaf, and fills the goaf space in the goaf area to be filled with materials. The maximum allowable cave-in width represents the distance between adjacent goaf areas to be filled, thereby achieving partial filling of the room-and-pillar goaf and improving the stability of the room-and-pillar goaf after filling, thereby reducing the amount and cost of governance engineering. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 It is one of the flow diagrams of the room-and-pillar goaf filling method provided in an embodiment of the present invention;

[0037] Figure 2 This is the second flow chart of the room-and-pillar goaf filling method provided in the embodiment of the present invention;

[0038] Figure 3 This is the third flow chart of the room-and-pillar goaf filling method provided by the embodiment of the present invention;

[0039] Figure 4 This is a fourth flow chart of the room-and-pillar goaf filling method provided in an embodiment of the present invention;

[0040] Figure 5 It is one of the structural schematic diagrams of the room-and-pillar goaf provided in the embodiment of the present invention;

[0041] Figure 6 This is the second structural schematic diagram of the room-and-pillar goaf provided in the embodiment of the present invention.

[0042] Reference numerals:

[0043] 1. Coal pillar; 2. Goaf space. DETAILED DESCRIPTION

[0044] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0045] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations on the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0046] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0047] In the embodiments of the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0048] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0049] Combine the following Figure 1-Figure 6 A room-and-pillar goaf filling method according to an embodiment of the present invention is described.

[0050] The embodiment of the present invention provides a room-and-pillar goaf filling method. Figure 1 One of the flow charts of the room-and-pillar goaf filling method provided by an embodiment of the present invention is illustrated, as shown in FIG. Figure 1 As shown, the room-and-pillar goaf filling method comprises the following steps:

[0051] Step 100: Determine the filling boundary information and the maximum allowable collapse width corresponding to the room-and-pillar goaf.

[0052] Step 200: Determine the goaf area to be filled in the room-and-pillar goaf according to the filling boundary information and the maximum allowable collapse width.

[0053] Step 300: Fill the goaf space of the goaf area to be filled with materials.

[0054] It can be understood that coal pillars are arranged inside the room-and-pillar goaf, and goaf spaces are formed between the coal pillars. In order to prevent the room-and-pillar goaf from collapsing, local areas of the room-and-pillar goaf are filled with materials, so that the materials and coal pillars filled in the goaf space between the coal pillars form a large pillar, which improves stability.

[0055] The area between the filling areas forms an unfilled area. If the original coal pillar in the unfilled area becomes unstable, its roof will collapse and cause surface subsidence. This embodiment first determines the filling boundary information and the maximum allowable collapse width corresponding to the room-and-pillar goaf area, and determines the goaf area to be filled from the room-and-pillar goaf area based on the filling boundary information and the maximum allowable collapse width. The stability of the goaf area to be filled can avoid the instability of the coal pillar in the unfilled area, thereby avoiding the problem of surface subsidence caused by the collapse of the roof of the unfilled area.

[0056] The room-and-pillar goaf filling method provided in the embodiment of the present invention determines the filling boundary information and the maximum allowable cave-in width corresponding to the room-and-pillar goaf, and then determines the goaf area to be filled in the room-and-pillar goaf, and fills the goaf space in the goaf area to be filled with materials. The maximum allowable cave-in width represents the distance between adjacent goaf areas to be filled, thereby achieving partial filling of the room-and-pillar goaf and improving the stability of the room-and-pillar goaf after filling, thereby reducing the amount and cost of governance engineering.

[0057] In one embodiment of the present invention, Figure 2 The second flow chart of the room-and-pillar goaf filling method provided by the embodiment of the present invention is illustrated as follows: Figure 2 As shown, in step 100, determining the maximum allowable collapse width corresponding to the room-and-pillar goaf may specifically include the following steps:

[0058] Step 101, determine the collapse height and collapse angle corresponding to the room-and-pillar goaf.

[0059] Step 102: determine the maximum allowable collapse width based on the collapse height and collapse angle.

[0060] It can be understood that the maximum allowable collapse width represents the unfilled width of the room-and-pillar goaf, and the unfilled width serves as a key technical indicator for local filling of the room-and-pillar goaf.

[0061] Optional, Figure 3 The third flow chart of the room-and-pillar goaf filling method provided by the embodiment of the present invention is illustrated as follows: Figure 3 As shown in the figure, the collapse height corresponding to the room-and-pillar goaf is determined by the following steps:

[0062] Step 1011: Determine the key strata in the overburden structure based on the overburden structure above the room-and-pillar goaf.

[0063] Step 1012: Determine the vertical distance between the bottom surface of the key layer and the top surface of the room-and-pillar goaf as the collapse height.

[0064] It can be understood that the collapse height of the unfilled area is determined based on the overburden structure of the roof above the room-and-pillar goaf, and the collapse angle is selected based on the lithology of the overburden structure; the maximum allowable collapse width is calculated based on the collapse height and collapse angle.

[0065] For example, Figure 5 As shown in the figure, according to the overburden structure of the room-and-pillar goaf roof, the key layer in the overburden structure above the room-and-pillar goaf is determined according to the key layer analysis method, the distance between the bottom surface of the key layer and the top surface of the room-and-pillar goaf is taken as the roof collapse height q of the unfilled area, and the collapse angle α is selected according to the lithology of the collapsed rock stratum, so as to calculate the maximum allowable collapse width B, and the unfilled width can be determined based on the obtained maximum allowable collapse width.

[0066] Further, step 102, determining the maximum allowable collapse width based on the collapse height and collapse angle, may specifically include the following contents:

[0067] Determine the maximum allowable collapse width based on formula (1);

[0068] B=2qcotα (1)

[0069] Among them, B represents the maximum allowable collapse width, q represents the collapse height, and α represents the collapse angle.

[0070] In one embodiment of the present invention, the filling boundary information includes a local filling width. In step 100, the filling boundary information corresponding to the room-and-pillar goaf is determined, which may specifically include the following contents:

[0071] Based on the ultimate strength theory and the maximum allowable collapse width, the local filling width corresponding to the room-and-pillar goaf is determined.

[0072] It can be understood that the filling boundary information can be the width of the filling area, based on which the width of the large pillar formed by the materials and coal pillars filled in the goaf can be determined.

[0073] It should be noted that the coal pillars in the room-and-pillar goaf are usually quadrilateral in structure, and the local filling width can represent the width along the two adjacent side directions of the coal pillar, so that the filling area has a square structure.

[0074] It can be understood that the local filling width, as a key technical indicator for local filling of room-and-pillar goaf, is specifically determined based on formula (2);

[0075]

[0076] in, b=0.64σ 1 -γHk, c=-2γHkB, d=-γHkB 2;

[0077] A represents the local filling width, σ 1 represents the critical compressive strength, h represents the height of the room-and-pillar goaf, γ represents the average bulk density of the overburden in the room-and-pillar goaf, H represents the vertical distance between the top surface of the room-and-pillar goaf and the ground surface, k represents the stability safety factor, and B represents the maximum allowable collapse width.

[0078] For example, the ultimate strength theory is based on the ultimate strength theory of coal pillar destruction. If the internal stress of the coal pillar reaches its allowable ultimate strength, the bearing capacity of the coal pillar will be reduced to zero and the coal pillar will be destroyed.

[0079] First, it is assumed that the pillars formed by the materials and coal pillars filling the empty space between the coal pillars are recorded as supporting coal pillars, and the safety factor of the stability of the supporting coal pillars is determined by formula (3);

[0080] k=σ p / σ (3)

[0081] Where k represents the stability safety factor;

[0082] σ represents the internal stress of the supporting coal pillar, in MPa, where σ is calculated by the following formula (4);

[0083]

[0084] Where γ represents the average bulk density of the overburden in the room-and-pillar goaf, in MN / m 3 , H represents the vertical distance between the top surface of the room-and-pillar goaf and the ground surface, that is, the burial depth of the goaf, in meters.

[0085] Among them, σ p It represents the ultimate compressive strength of the supporting coal pillar, in MPa.

[0086] It should be noted that σ p It is related to the strength of the coal pillar, as well as the size of the coal pillar, the geological structure inside the coal pillar, the contact conditions between the coal pillar and the top and bottom rock layers, and the lateral force of the coal pillar.

[0087] In this embodiment, σ p The linear coal pillar strength calculation formula proposed by Bieniawski is used for determination, which is specifically calculated by the following formula (5):

[0088]

[0089] Among them, σ 1 represents the critical compressive strength, which in this embodiment is the overall strength of the supporting coal pillar after the coal pillar and material filling, in MPa; A represents the local filling width, in m; h represents the height of the room-and-pillar goaf, in m.

[0090] Based on formula (3), formula (4) and formula (5), a cubic equation for calculating the local filling width A can be obtained, which is expressed as follows (6):

[0091]

[0092] By solving formula (6), the expression of the local filling width A can be obtained.

[0093] In this embodiment, the specific solution process of formula (6) is as follows:

[0094] Formula (6) is regarded as a cubic equation of one variable of the following formula (7);

[0095] ax 3 +bx 2 +cx+d=0 (7)

[0096] Using Cardin's general root-finding formula, let

[0097]

[0098] b=0.64σ 1 -γHk (9)

[0099] c=-2γHkB (10)

[0100] d=-γHkB 2 (11)

[0101]

[0102]

[0103]

[0104]

[0105] Based on the above formulas (8) to (15), the expression of the local filling width A can be obtained;

[0106]

[0107] It can be understood that based on the critical compressive strength σ 1 , the height h of the room-and-pillar goaf, the average bulk density γ of the overburden in the room-and-pillar goaf, the vertical distance H between the top surface of the room-and-pillar goaf and the ground surface, the stability safety factor k and the maximum allowable cave-in width B calculated above, calculate the local filling width A.

[0108] In one embodiment of the present invention, step 200, determining the goaf area to be filled from the room-and-pillar goaf according to the filling boundary information and the maximum allowable cave-in width, specifically comprises the following steps:

[0109] Step 201: Determine the target local filling width and the target unfilled width according to the filling boundary information and the maximum allowable collapse width.

[0110] Among them, the target local filling width is greater than or equal to the local filling width, and the target unfilled width is less than or equal to the maximum allowable collapse width.

[0111] It can be understood that the filling width represents the filling boundary information. The larger the filling width, the larger the width of the formed pillar and the better the stability. Therefore, the local filling width calculated above should be the minimum local filling width, and the target local width of the actual filling should be greater than or equal to the local filling width determined by the above calculation.

[0112] It can be understood that the maximum allowable collapse width represents the unfilled width of the room-and-pillar goaf. Therefore, in the actual filling process, the target unfilled width should be less than or equal to the maximum allowable collapse width, so that the filled room-and-pillar goaf can achieve higher stability.

[0113] Furthermore, the room-and-pillar goaf area includes a plurality of coal pillars evenly spaced apart, with goaf spaces formed between adjacent coal pillars. The goaf area to be filled should include at least one coal pillar and at least one goaf space adjacent to at least one coal pillar. Preferably, the boundary area of ​​each goaf area to be filled is a coal pillar.

[0114] Step 202: Based on the target local filling width and the target unfilled width, determine the goaf area to be filled corresponding to the target local filling width from the room-and-pillar goaf.

[0115] It can be understood that based on the determined target local filling width, the room-and-pillar goaf is divided into a plurality of goaf areas to be filled, and the interval distance between two adjacent goaf areas to be filled is the target unfilled width.

[0116] It can be understood that the goaf area to be filled is a quadrilateral, and the side length of the quadrilateral is equal to the target local filling width, and the goaf space between the coal pillars in the goaf area is filled with materials.

[0117] In one embodiment of the present invention, step 300, filling the goaf space of the goaf area to be filled with materials, may specifically include the following contents:

[0118] A plurality of injection holes are arranged in the treatment area above the goaf area to be filled, and the slurry is injected into the goaf space of the goaf area to be filled from the middle injection hole to the outer injection holes in sequence.

[0119] It can be understood that grouting holes are set in the management area above the mined-out area to be filled, and slurry is injected into the mined-out space of the mined-out area to be filled through the grouting holes, and the slurry is injected sequentially from the middle to the outside of the mined-out area to be filled. Under low pump pressure or gravity conditions, the diffusion range of the slurry can be effectively controlled, thereby avoiding the loss of slurry and saving costs.

[0120] In this embodiment, slurry is used to fill the mined space. Grouting holes can be drilled in the management area above the mined area to be filled. Slurry is injected into the mined space of the mined area to be filled through the grouting holes. The solidified slurry will form a large pillar together with several internal coal pillars, and the area between the large pillars (the non-filling area corresponding to the target non-filling width) will not be filled. It should be noted here that the stability of the large pillar is improved as the width of the large pillar increases relative to the original coal pillar. The larger the width, the higher the stability. The stability of the large pillar is sufficient to support the original coal pillar in the non-filling area. If the roof collapses due to instability, it will not cause surface collapse.

[0121] In a specific embodiment of the present invention, the coal mine goaf adopts the room-and-pillar mining method of mining 5m and leaving 7m, then the width of the coal pillar 1 is 5m, the width of the goaf space 2 between the coal pillars 1 is 7m, the vertical distance H between the top surface of the room-and-pillar goaf and the ground surface is 140.7m, and the height h (mining height) of the room-and-pillar goaf is 2.5m. Figure 4 The fourth flow chart of the room-and-pillar goaf filling method provided by the embodiment of the present invention is illustrated. Figure 4 As shown, the room-and-pillar goaf filling method specifically comprises the following steps:

[0122] Step 10: Determine the maximum allowable collapse width.

[0123] like Figure 5 As shown in the figure, according to the overburden structure above the room-and-pillar goaf and based on the key layer analysis method, the collapse height q is determined to be 50m, and the collapse angle α is determined to be 65° based on the lithology of the collapsed rock layer. Based on the above formula (1), the maximum allowable collapse width B is determined to be 46.63m.

[0124] Step 20: Determine the local filling width.

[0125] The safety stability coefficient of the coal (rock) pillar in the goaf is used as the criterion for determining the stability of the room-and-pillar goaf. The site stability grade is determined according to the safety stability coefficient of the coal (rock) pillar. See Table 1 for details.

[0126] Table 1 Determination of site stability grade according to safety factor of coal (rock) pillar stability

[0127] steady state Unstable Basic stability Stablize Stability safety factor k k≤1.2 1.2＜k≤2 k＞2

[0128] In this embodiment, the stability level of the room-and-pillar goaf after partial filling reaches stability, then the stability safety factor k is taken as 2, and the overall strength σ of the coal pillar 1 and the slurry bond is 1 The average bulk density of the overburden in the room-and-pillar goaf is γ0.025MN / m 3 , then based on the above formula (2), the local filling width A is determined to be 32.18m.

[0129] Step 30: Determine the goaf area to be filled in the room-and-pillar goaf according to the filling boundary information and the maximum allowable collapse width.

[0130] It can be understood that the coal pillar width L1 in the coal mine goaf is 5m, the goaf space width L2 is 7m, the target local filling width A1 should include an integer number of coal pillars 1 and an integer number of goaf space widths L2, and the target unfilled width B1 should also be an integer number of coal pillars 1 and an integer number of goaf space widths L2.

[0131] It can be understood that the target local filling width A1 is slightly larger than the local filling width, and in the target local filling width A1, along the side length direction of the coal pillar 1, the number of coal pillars 1 is one more than the number of goaf spaces 2, so that the two boundaries of the goaf area to be filled along the side length direction of the coal pillar 1 are coal pillars 1.

[0132] The target unfilled width B1 is slightly smaller than the maximum allowable collapse width. Along the side length direction of the coal pillar 1, the number of coal pillars 1 in the target unfilled width B1 is 1 less than the number of goaf spaces 2. Therefore, the two boundaries of the unfilled goaf area along the side length direction of the coal pillar 1 are goaf spaces 2.

[0133] In this embodiment, Figure 5 and Figure 6 As shown, the coal pillar width L1 is 5m, the goaf space width L2 is 7m, the local filling width A is 32.18m, and the maximum allowable collapse width B is 46.63m. The target local filling width A1 is 41m, and the target local filling width A1 includes four coal pillars 1 and three goaf spaces 2 located between the four coal pillars 1; the target unfilled width B1 is 43m, and the target unfilled width B1 includes four goaf spaces 2 and three coal pillars 1 located between the four goaf spaces 2.

[0134] Based on the target local filling width A1 and the target unfilled width B1, multiple goaf areas to be filled corresponding to the target local filling width A1 are determined from the room-and-pillar goaf area, and the room-and-pillar goaf area can be divided into multiple goaf areas to be filled.

[0135] Among them, multiple goaf areas to be filled are distributed in a matrix.

[0136] Step 40, filling the goaf space 2 of the goaf area to be filled with materials.

[0137] The grouting holes above the room-and-pillar goaf are used to fill the dispersed multiple goaf areas to be filled with slurry. After the solidification of the filling material in each goaf area to be filled, it will form a large coal pillar together with several coal pillars 1 inside it, and the area between the large coal pillars will not be filled, thereby completing the filling of the local area of ​​the room-and-pillar goaf.

[0138] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A room-and-pillar goaf filling method, characterized in that: include: Determine the filling boundary information and maximum allowable collapse width corresponding to the room-and-pillar goaf; Determine a goaf area to be filled from the room-and-pillar goaf according to the filling boundary information and the maximum allowable cave-in width; Filling the goaf space in the goaf area to be filled with materials; Wherein, the determination of the maximum allowable collapse width corresponding to the room-and-pillar goaf includes: Determine the collapse height and collapse angle corresponding to the room-and-pillar goaf; Determine the maximum allowable collapse width based on formula (1); B=2qcotα (1) Among them, B represents the maximum allowable collapse width, q represents the collapse height, and α represents the collapse angle; The filling boundary information includes a local filling width, and the filling boundary information corresponding to the room-and-pillar goaf is determined, including: Based on the ultimate strength theory and the maximum allowable collapse width, the local filling width corresponding to the room-and-pillar goaf is determined based on formula (2); in, c=-2γHkB,d=-γHkB 2 ; A represents the local filling width, σ1 represents the critical compressive strength, h represents the height of the room-and-pillar goaf, γ represents the average bulk density of the overburden in the room-and-pillar goaf, H represents the vertical distance between the top surface of the room-and-pillar goaf and the ground surface, k represents the stability safety factor, and B represents the maximum allowable collapse width.

2. The room-and-pillar goaf filling method according to claim 1, characterized in that: Determining the collapse height corresponding to the room-and-pillar goaf includes: Determining key strata in the overburden structure based on the overburden structure above the room-and-pillar goaf; The vertical distance between the bottom surface of the key layer and the top surface of the room-and-pillar goaf is determined as the collapse height.

3. The room-and-pillar goaf filling method according to claim 1, characterized in that: Determining a goaf area to be filled from the room-and-pillar goaf area according to the filling boundary information and the maximum allowable cave-in width includes: Determine a target local filling width and a target non-filling width according to the filling boundary information and the maximum allowable cave-in width, wherein the target local filling width is greater than or equal to the local filling width, and the target non-filling width is less than or equal to the maximum allowable cave-in width; Based on the target local filling width and the target unfilled width, a plurality of goaf areas to be filled corresponding to the target local filling width are determined from the room-and-pillar goaf.

4. The room-and-pillar goaf filling method according to claim 3, characterized in that: The room-and-pillar goaf area includes a plurality of coal pillars evenly spaced apart, the goaf space is formed between adjacent coal pillars, and the goaf area to be filled includes at least one coal pillar and at least one goaf space adjacent to the at least one coal pillar.

5. The room-and-pillar goaf filling method according to claim 3, characterized in that: The multiple goaf areas to be filled are distributed in a matrix.

6. The room-and-pillar goaf filling method according to any one of claims 1 to 2, characterized in that: The method of filling the goaf space of the goaf area to be filled with materials comprises: Arrange a plurality of injection holes in the treatment area above the goaf area to be filled; The slurry is injected into the mined space of the mined area to be filled from the injection hole in the middle to the injection holes on the outside in sequence.

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