A method for recovering gob-side entry retaining gangue support by pre-digging gangue recovery roadway

Abstract

The present invention discloses a method for recovering the gob-side entry retaining gob shield support by using a pre-dug gob shield recovery roadway, which comprises the following steps: S10. Obtain the parameters of the coal mining face; S20. Calculate the model, quantity and support range of the gob shield support required for the coal mining face; S30. Calculate the parameters of the gob shield recovery roadway, and the parameters of the gob shield recovery roadway include the length, width, height and support form of the gob shield recovery roadway; wherein, the opening of the gob shield recovery roadway is arranged in the withdrawal roadway, the gob shield recovery roadway is connected with the gob-side entry retaining roadway, and the trend of the gob shield recovery roadway is consistent with that of the gob-side entry retaining roadway; S40. Construct the gob shield recovery roadway, and during the construction, carry out the construction according to the scheme of tunneling while supporting. After the tunneling is completed, fill the whole section of the gob shield recovery roadway with mine inorganic foaming material; S50. After the coal mining of the coal mining face is completed, use the gob shield recovery roadway to recover the gob shield support. The present invention can recover the gob shield support in the gob-side entry retaining roadway through the gob shield recovery roadway, and can effectively ensure the safe and efficient coal mining of the working face.

Description

Technical Field

[0001] The present invention relates to the technical field of coal seam mining in coal mines, and particularly relates to a method for recovering the gob-side retaining gangue support by pre-driving a gangue recovery roadway. Background Art

[0002] In order to reduce the loss of sectional protective coal pillars, in recent years, China has been continuously promoting the non-pillar mining method. Gob-side entry retaining is one of the most commonly used methods in non-pillar mining. Gob-side entry retaining means that after the coal mining face is mined, the original gangue recovery roadway is maintained along the goaf edge. The gob-side entry retaining technology can effectively reduce the roadway driving volume, reduce the loss of the coal pillar for roadway protection, increase the resource recovery rate, and at the same time solve the problem of gas accumulation in the upper corner and avoid spontaneous combustion of the coal pillar in the goaf.

[0003] During the construction of gob-side entry retaining, erecting the gangue support is a necessary measure to ensure safe production. The safe recovery of the gangue support is of great significance. For the commonly used gangue support recovery method, when the working face advances 20 - 30 m from the withdrawal roadway, roof support is carried out on the working face. After the working face continues to advance, artificial support is carried out in the goaf to form a reserved space. The existing method has cumbersome construction procedures, high operation difficulty, and high risk factor, seriously restricting the normal connection of the working face and threatening the safe production of the coal mine. Summary of the Invention

[0004] The present invention aims to provide a method for recovering the gob-side retaining gangue support by pre-driving a gangue recovery roadway, and the gangue support in the gob-side entry retaining can be recovered through the gangue recovery roadway to effectively ensure the safe and efficient mining of the working face.

[0005] To achieve the above object, a method for recovering the gob-side retaining gangue support by pre-driving a gangue recovery roadway provided by the present invention includes the following steps:

[0006] S10. Obtain the parameters of the coal mining face, where the parameters of the coal mining face include the basic parameters of the working face and the basic parameters of the gob-side entry retaining;

[0007] S20. Calculate the model, quantity, and support range of the gangue support required for the coal mining face;

[0008] S30. Calculate the parameters of the gangue recovery roadway, where the parameters of the gangue recovery roadway include the length, width, height, and support form of the gangue recovery roadway;

[0009] Wherein, the opening of the gangue recovery roadway is arranged in the withdrawal roadway, the gangue recovery roadway is connected to the gob-side entry retaining, and the trend of the gangue recovery roadway is the same as that of the gob-side entry retaining;

[0010] S40. The construction of the waste rock retaining and recovery roadway is carried out according to the plan of tunneling and supporting simultaneously. After tunneling is completed, the whole cross-section of the waste rock retaining and recovery roadway is filled with inorganic foaming materials for mines.

[0011] S50. After coal mining in the coal mining face is completed, the waste rock retaining support is recovered by using the waste rock retaining and recovery roadway.

[0012] In the above technical solution, the present invention can also be improved as follows:

[0013] Preferably, in step S20, the calculation formula for the support strength required for gob-side entry retaining is:

[0014] q = KHγ×10 -5

[0015] Where: K—the ratio of the thickness of the overlying strata supported by the face support to the mining height, generally taking 4 - 8;

[0016] H—mining height, m;

[0017] γ—unit weight of roof rock, kN / m³;

[0018] q—required support strength, MPa;

[0019] In step S20, the calculation formula for the support strength of the waste rock retaining support is:

[0020] q 支 = P / F×10 -3 ) = P / 2AL×10 -3

[0021] Where: q 支 —support strength of the support, MPa;

[0022] P—resistance of the support at the working face, KN;

[0023] F—support area of the support, m 2 ;

[0024] A—center distance of a single group of supports, m;

[0025] L—length of the support roof beam, m.

[0026] The support strength of the waste rock retaining support needs to satisfy: q 支 ≥q;

[0027] According to the support strength required for gob-side entry retaining, the type, quantity and required support range of the waste rock retaining support are determined, and finally the quantity of the waste rock retaining support is determined: there are x rows and y columns in total, and the maximum height of the waste rock retaining support is h max .

[0028] Preferably, in step S30, the specifications of the waste rock retaining and recovery roadway are: length m, width n, height h, where

[0029] m=x*L*f

[0030] n=y*A*f

[0031] h=h max *f

[0032] Where, f is safety factor, which is 1.1-1.2;

[0033] A—center distance of a single set of brackets, m;

[0034] L—length of the top beam of the bracket, m;

[0035] h max - Maximum height of the rock retaining bracket, m;

[0036] x-number of rows of slag retaining brackets;

[0037] y- the number of columns of the slag retaining bracket.

[0038] Preferably, in step S40, an anti-extrusion embedded tray anchor rod is used to support the roof of the slag recovery tunnel.

[0039] Preferably, in step S40, (1) the formula for calculating the length of the anchor rod is:

[0040] L1=K2S+L2+L3

[0041] Where: L1—anchor length, m;

[0042] S—height of the falling arch, m;

[0043] K2—safety factor, generally K2=2;

[0044] L2—the depth of the anchor bolt into the stable rock formation, generally 0.5m;

[0045] L3—Exposed length of anchor rod in the tunnel, generally 0.1m;

[0046] Where: S = n / (2w)

[0047] n—width of the waste rock recovery tunnel; w—rock strength coefficient;

[0048] In step S40, (2) the spacing between anchor bolts is calculated. Usually, the spacing between bolts is equal to a:

[0049]

[0050] Where: a—row spacing, m;

[0051] Q—anchoring force, kN;

[0052] S—height of the falling arch, m;

[0053] γ—rock bulk density, kN / m 3 ;

[0054] K2—Safety factor.

[0055] Preferably, in step S40, the calculation formula for the usage of the mining inorganic foaming material is:

[0056] V=m*n*h

[0057] Where, V- volume of inorganic foaming material for mining, m 3 ;

[0058] m-the length of the waste recovery tunnel, m;

[0059] n-the width of the waste recovery tunnel, m;

[0060] h-the height of the slag recovery tunnel, m.

[0061] Preferably, the inorganic foaming material for mining is preferably Gainic inorganic self-foaming filling material.

[0062] Beneficial effects of this application:

[0063] This application adopts the method of pre-excavating a rock retaining recovery lane to recover the rock retaining supports along the goaf-retained lane. After obtaining the parameters of the coal mining working face and calculating the parameters of the rock retaining supports required for the coal mining working face, a rock retaining recovery lane connected to the goaf-retained lane is opened in the withdrawal channel. The rock retaining recovery lane adopts roof support and the entire section is filled with foam material. When the working face is mined through the rock retaining recovery lane, the coal mining machine cuts the coal body and filling materials, and the supported rock retaining recovery lane roof is intact. When the working face is through, the rock retaining supports are recovered through the rock retaining recovery lane. It is safe, fast and economical, and effectively ensures safe and efficient mining of the working face. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] In order to more clearly illustrate the specific implementation of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the specific implementation or the description of the prior art.

[0065] Figure 1 This is a schematic diagram of the arrangement of a rock retaining support for a rock retaining recovery lane along a gob-side retaining lane according to an embodiment of the present invention (partial mining has been carried out);

[0066] Figure 2 Schematic diagram of arrangement of rock retaining supports for a rock retaining recovery lane along a gob-side retaining lane according to an embodiment of the present invention (mining completed);

[0067] In the accompanying drawings,

[0068] Gob-side entry retaining 1, gangue retaining roadway 2, gangue retaining support 3, and retreat roadway 4. Detailed implementation manners

[0069] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present invention, but should not be construed as limiting the present invention.

[0070] Please refer to Figure 1 and Figure 2 , a method for recovering the gangue retaining support 3 of the gob-side entry retaining 1 by pre-digging the gangue retaining roadway 2, comprising the following steps:

[0071] S10. Obtain the parameters of the coal mining face. The parameters of the coal mining face include the basic parameters of the working face and the basic parameters of the gob-side entry retaining 1;

[0072] Among them, in step S10, the basic parameters of the working face and the basic parameters of the gob-side entry retaining 1 can be directly obtained through the coal mining face design, construction organization design, operation regulations, and construction drawings.

[0073] S20. Calculate the model, quantity, and support range of the gangue retaining support 3 required for the coal mining face;

[0074] In step S20, the calculation formula for the support strength required for the gob-side entry retaining 1 is:

[0075] q = KHγ × 10 -5

[0076] In the formula: K—the ratio of the thickness of the overlying strata supported by the working face support to the mining height, generally taking 4 - 8;

[0077] H—mining height, m;

[0078] γ—unit weight of roof rock, kN / m3;

[0079] q—required support strength, MPa.

[0080] In step S20, the calculation formula for the support strength of the gangue retaining support 3 is:

[0081] q 支 = P / F × 10 -3 ) = P / 2AL × 10 -3

[0082] In the formula: qsup—support strength of the support, MPa;

[0083] P—working face resistance of the support, KN;

[0084] F—the support area of the support, m 2 ;

[0085] A—the center distance of a single group of supports, m;

[0086] L—the length of the support roof beam, m.

[0087] The support strength of the gangue retaining support shall satisfy: q 支 ≥q;

[0088] According to the required support strength for the gob-side entry retaining, determine the model, quantity, and required support range of the gangue retaining support 3, and determine the number of supports: a total of x rows and y columns, and the maximum height h of the gangue retaining support 3 max .

[0089] S30. Calculate the parameters of the gangue recovery roadway 2. The parameters of the gangue recovery roadway 2 include the length, width, height, and support form of the gangue recovery roadway 2; the opening of the gangue recovery roadway 2 is located in the withdrawal roadway 4 and is connected to the gob-side entry retaining 1, and the trend of the gangue recovery roadway 2 is the same as that of the gob-side entry retaining 1;

[0090] In step S30, the specifications of the gangue recovery roadway 2 are: length m, width n, height h, where

[0091] m = x * L * f

[0092] n = y * A * f

[0093] h = h max * f

[0094] In the formula, f—the safety factor, taking 1.1 - 1.2;

[0095] A—the center distance of a single group of supports, m;

[0096] L—the length of the support roof beam, m;

[0097] h max —the maximum height of the gangue retaining support 3, m;

[0098] x—the number of rows of the gangue retaining support 3;

[0099] y—the number of columns of the gangue retaining support 3.

[0100] S40. Construct the gangue recovery roadway 2. During construction, it is carried out according to the plan of tunneling and supporting simultaneously. After tunneling is completed, the whole cross-section of the gangue recovery roadway 2 is filled with mine inorganic foaming materials;

[0101] In step S40, the roof of the gangue recovery roadway 2 is supported by anti-extrusion embedded tray bolts.

[0102] More specifically, in step S40,

[0103] Preferably, in step S40, (1) the calculation formula for the length of the bolt is:

[0104] L1 = K2S + L2 + L3

[0105] Where: L1—the length of the bolt, m;

[0106] S—the height of the caving arch, m;

[0107] K2—the safety factor, generally K2 = 2;

[0108] L2—the depth of the bolt anchored into the stable rock stratum, generally 0.5 m;

[0109] L3—the exposed length of the bolt in the roadway, generally 0.1 m;

[0110] Where: S = n / (2w);

[0111] n—the width of the gangue retaining roadway 2; w—the rock toughness coefficient;

[0112] In step S40, (2) the bolt spacing calculation, usually the spacing is taken to be equal as a:

[0113] (2) The bolt spacing calculation, usually the spacing is taken to be equal as a:

[0114]

[0115] In this embodiment, the mine inorganic foaming material is preferably the Garnick inorganic self-foaming filling material.

[0116] In step S40, the calculation formula for the usage amount of the mine inorganic foaming material is:

[0117] V = m * n * h

[0118] Where, V—the usage volume of the mine inorganic foaming material, m 3 ;

[0119] m—the length of the gangue retaining roadway 2, m;

[0120] n—the width of the gangue retaining roadway 2, m;

[0121] h—the height of the gangue retaining roadway 2, m;.

[0122] S50. After coal mining in the coal mining face is completed, the gangue retaining support 3 is recovered by using the gangue retaining roadway 2.

[0123] This application adopts the method of pre-excavating a rock retaining recovery lane to recover the rock retaining supports along the goaf-retained lane. After obtaining the parameters of the coal mining working face and calculating the parameters of the rock retaining supports 3 required for the coal mining working face, a rock retaining recovery lane 2 connected to the goaf-retained lane 1 is opened in the withdrawal channel 4. The rock retaining recovery lane 2 adopts roof support and the entire section is filled with foam material. When the working face is mined through the rock retaining recovery lane 2, the coal mining machine cuts the coal body and filling materials, and the supported rock retaining recovery lane 2 roof is intact. When the working face is through, the rock retaining supports 3 are recovered through the rock retaining recovery lane 2. It is safe, fast and economical, and effectively ensures safe and efficient mining of the working face.

[0124] The above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art will appreciate that the technical solutions of the present invention may be modified or replaced with equivalents without departing from the spirit and scope of the technical solutions of the present invention, and such modifications or equivalents shall be encompassed by the claims of the present invention. Any techniques, shapes, and structures not described in detail herein are well known.

Claims

1. A method for recovering gob-side entry retaining gangue support by pre-digging gangue recovery roadway, characterized in that It includes the following steps: S10. Obtain the parameters of the coal mining face, where the parameters of the coal mining face include the basic parameters of the working face and the basic parameters of gob-side entry retaining; S20. Calculate the model of the gob-side retaining support required for the coal mining face, the quantity of the gob-side retaining support, and the support range of the gob-side retaining support; In step S20, the calculation formula for the support strength required for gob-side entry retaining is: q = KHγ × 10 -5 In the formula: K—the ratio of the thickness of the overlying strata supported by the working face support to the mining height, generally taking 4 - 8; H—mining height, m; γ—unit weight of roof rock, kN / m³; q—required support strength, MPa; In step S20, the calculation formula for the support strength of the gob-side retaining support is: q 支 = P / F × 10 -3 = P / (2AL) × 10 -3 where: q 支 — support strength of the support, MPa; P—working face resistance of the support, KN; F—the support area of the support, m 2 ; A—center distance of a single set of supports, m; L—length of the support roof beam, m; The support strength of the waste rock support should meet: q 支 ≥q; According to the support strength required along the gob-side entry, determine the type, quantity of the gob-side support and the required support range, and finally determine the quantity of the gob-side support: there are x rows and y columns in total, and the maximum height of the gob-side support is h ma ; S30. Calculate the parameters of the gob-side recovery roadway, where the parameters of the gob-side recovery roadway include the length, width, height, and support form of the gob-side recovery roadway; Among them, the opening of the gob-side recovery roadway is arranged in the withdrawal roadway, the gob-side recovery roadway is connected with the gob-side entry retaining, and the trend of the gob-side recovery roadway is the same as that of the gob-side entry retaining; S40. Construct the gob-side recovery roadway. During construction, it is carried out according to the scheme of tunneling while supporting. After tunneling is completed, the whole cross-section of the gob-side recovery roadway is filled with mine inorganic foaming material; S50. After coal mining in the coal mining face is completed, use the gob-side recovery roadway to recover the gob-side retaining support.

2. A method for recovering the gob-side entry retaining gob shield by using a pre-dug gangue-retaining recovery roadway according to claim 1, characterized in that, In step S30, the specifications of the gob-side recovery roadway are: length m, width n, height h, where m = x * L * f n = y * A * f h = h max *f In the formula, f—safety factor, taking 1.1 - 1.2; A—center distance of a single set of supports, m; L—length of the support roof beam, m; h max - Maximum height of the gangue support, m; x—number of rows of gob-side retaining supports; y—number of columns of gob-side retaining supports.

3. A method for recovering a gob-side entry retaining gangue support by pre-digging a gangue-retaining recovery roadway according to claim 2, characterized in that, In step S40, use anti-extrusion embedded tray bolts to support the roof of the gob-side recovery roadway.

4. A method for recovering the gob-side entry retaining gangue support by pre-digging a gangue-retaining recovery roadway according to claim 3, characterized in that, In step S40, (1) the calculation formula for the length of the bolt is: L1 = K2S + L2 + L3 In the formula: L1—length of the bolt, m; S—height of the caving arch, m; K2—safety factor, generally taking K2 = 2; L2—depth of the bolt anchored into the stable rock stratum, generally taking 0.5 m; L3—exposed length of the bolt in the roadway, generally taking 0.1 m; In the formula: S = n / (2w); n—width of the gob-side recovery roadway; w—rock toughness coefficient; In step S40, (2) calculate the bolt spacing. Usually, the bolt spacing is taken to be equal as a: In the formula: a—bolt spacing, m; Q—anchoring force, KN; S—height of the caving arch, m; γ—Unit weight of rock, kN / m 3 ; K2—safety factor.

5. A method for recovering the gob-side entry retaining gangue support by pre-digging a gangue-retaining recovery roadway according to claim 4, characterized in that, In step S40, the calculation formula for the usage amount of the mine inorganic foaming material is: V = m * n * h In the formula, V is the volume of the inorganic foaming material for mine use, m 3 ; m—length of the gob-side recovery roadway, m; n—width of the gob-side recovery roadway, m; h—height of the gob-side recovery roadway, m.

6. A method for recovering the gob-side entry retaining gangue support by pre-digging a gangue-retaining recovery roadway according to claim 5, characterized in that, The mine inorganic foaming material is preferably Garnick inorganic self-foaming filling material.

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