A design method for a rotating through-and-withdrawal channel of a working face based on triangular stability

Abstract

The present invention provides a design method for a rotary through-withdrawal channel of a working face based on triangular stability, and the specific production geological conditions of the working face are investigated on site, and the core is taken on site and its physical and mechanical parameter characteristics are determined by laboratory standard processing; a mechanical model of a coal pillar is established and a critical width of stability is determined; based on the principle of reducing the support load and artificially controlling the segmented pressure, a reasonable tilt adjustment angle of the rotary through-withdrawal channel of the working face and the number of supports that simultaneously penetrate the working face and the withdrawal channel are determined; the process flow of the rotary through-withdrawal channel of the working face is determined according to the determined critical width of coal pillar stability, the critical tilt adjustment angle and the number of supports that simultaneously penetrate the withdrawal channel of the working face. This method can greatly reduce serious production safety problems such as large-area pressure from the roof and pressure on the working face caused by the parallel penetration of the supports through the withdrawal channel, can greatly improve the stress state of the surrounding rock of the withdrawal channel, can effectively reduce the risk of catastrophic instability of the surrounding rock of the withdrawal channel, and can ensure the safe and efficient withdrawal of the fully mechanized mining equipment.

Description

Technical Field

[0001] The invention belongs to the technical field of coal mining, and in particular relates to a design method for a rotating through-and-withdrawal channel of a working face based on triangular stability. Background Art

[0002] The withdrawal of equipment in the fully mechanized mining face is an important part of the coal mining process. At the same time, the safe and efficient withdrawal of fully mechanized mining face equipment has always been one of the key issues of coal production enterprises. In the current withdrawal process, the withdrawal channel is mostly pre-excavated near the stop mining line, so that the fully mechanized mining face equipment can be withdrawn in the withdrawal channel. During the penetration of the withdrawal channel, the catastrophic instability of the coal pillar between the working face and the withdrawal channel can easily induce safety problems such as large-scale "empty top" phenomenon and basic top advance breakage of the support of the working face and the withdrawal channel, which further leads to catastrophic instability of the surrounding rock such as sinking of the step of the withdrawal channel roof and serious coal wall spalling. At present, the fully mechanized mining face usually adopts the method of stopping mining to reduce the catastrophic risks such as the basic top advance breakage of the working face and the large-scale pressure of the roof. When advancing in parallel to the penetration of the withdrawal channel, the load of the working face support still has accidents such as excessive pressure and support crushing, which not only seriously reduces the mining speed of the working face, but also is not conducive to the safe and efficient withdrawal of the fully mechanized mining equipment. Therefore, a design method for a working face through-and-through withdrawal channel is needed to solve the above problems. Summary of the invention

[0003] In response to the problems existing in the above-mentioned prior art, the present invention provides a design method for a rotating through-withdrawal channel of a working face based on triangular stability. This method can greatly reduce serious production safety problems such as large-area pressure from the roof and pressure on the working face caused by the parallel penetration of the support through the withdrawal channel. It can ensure to a large extent that the working face is mined at a normal advancement speed, and can greatly improve the stress state of the surrounding rock of the withdrawal channel, which can effectively reduce the risk of catastrophic instability of the surrounding rock of the withdrawal channel, and can ensure the safe and efficient withdrawal of the comprehensive mining equipment.

[0004] In order to achieve the above object, the present invention provides a method for designing a rotating through-and-withdrawal channel of a working surface based on triangular stability, comprising the following steps:

[0005] Step 1: Conduct on-site investigation of the specific production geological conditions of the working face, take cores on-site and measure their physical and mechanical parameter characteristics through laboratory standard processing;

[0006] Step 2: Establish a mechanical model of the coal pillar and determine the critical width of stability;

[0007] S21: Determine the plastic zone width X1 of the coal pillar on the withdrawal channel side according to formula (1);

[0008]

[0009] Where m is the coal seam mining thickness, unit is m; A is the coal seam lateral pressure coefficient; k1 is the lateral stress concentration coefficient caused by tunneling; γ is the average bulk density of the overlying rock layer, unit is kN / m 3 ; H is the average buried depth of coal seam, unit is m; c0 is the cohesion of coal-rock interface, unit is MPa; is the internal friction angle of the coal-rock interface, unit: °; p' x The support strength of the anchor cable of the withdrawal channel on the coal seam, unit: MPa;

[0010] S22: Determine the width X3 of the plastic zone of the coal pillar on the working face according to formula (2);

[0011]

[0012] In the formula, ξ is the correction coefficient of plastic zone width. The mining of the working face has a great disturbance effect on the coal body in front of the coal wall, which is in a non-limit equilibrium state. Therefore, the width of the plastic zone needs to be corrected. R1 is the ultimate bearing strength of the coal body on the working face side, in MPa; R2 is the actual bearing strength of the coal body on the working face side, in MPa; k2 is the advanced stress concentration coefficient caused by mining at the working face; P x is the support strength of the working face support to the coal wall, unit: MPa;

[0013] S23: Determine the surplus amount X2 of the coal pillar width to be increased according to formula (3);

[0014] X2=0.2(X1+X3) (3);

[0015] S24: Determine the critical width B of the coal pillar to maintain stability according to formula (4);

[0016] B = X1 + X2 + X3 (4);

[0017] Step 3: Based on the principle of reducing the support load and artificially controlling the segmented pressure, determine the reasonable tilt angle of the working face rotation and penetration, the number of supports that the working face and the withdrawal channel penetrate at the same time each time, and the distance between the rotation fulcrum of the working face return air channel and the withdrawal channel;

[0018] S31: Based on the principle that the support resistance is equal and the number of supports through the withdrawal channel is the minimum, the range of the critical angle θ of the working face rotation through the withdrawal channel is determined according to formula (5);

[0019]

[0020] Wherein, L' is the minimum staggered distance of the bracket, in m; p is the rated working resistance of the bracket, in kN; q is the top plate load above the bracket, in MPa; L is the center distance of the bracket, in m; l is the top control distance of the bracket, in m;

[0021] S32: Based on the principle of minimizing the number of parallel through-brackets and artificially creating segmented pressure, the number of brackets n that the working surface and the retreat channel simultaneously penetrate each time is determined according to formula (6);

[0022]

[0023] S33: Determine the distance D between the rotation fulcrum of the return air lane of the working face and the retreat channel by determining the critical stable width B of the coal pillar, the rotation angle θ of the working face, and the length W of the working face;

[0024] Step 4: Determine the process flow of the withdrawal channel for rotating through the working face according to the determined critical width B of coal pillar stability, critical angle θ of inclination adjustment, and the number n of supports that simultaneously penetrate the withdrawal channel of the working face;

[0025] S41: Determine the final critical width of the coal pillar based on the working face advancement speed and the critical width B of the coal pillar to maintain stability; determine the final critical angle of inclination adjustment based on the range of the critical angle of inclination adjustment θ;

[0026] S42: When the working face is advanced parallel to the set tilt adjustment position D from the withdrawal channel, the tail of the scraper conveyor on the return air channel side of the working face is used as a fulcrum to make the head of the scraper conveyor on the transport channel side of the working face start to tilt and rotate to the position B from the withdrawal channel to the final critical width of the coal pillar, and ensure that the tilt adjustment angle is the final critical angle of tilt adjustment;

[0027] S43: After the inclination adjustment is completed, the working face begins to advance in parallel to the edge of the withdrawal channel at the mining side according to the predetermined final inclination adjustment critical angle, so that the head of the scraper conveyor on the transport lane side of the working face is first connected with the withdrawal channel;

[0028] S44: starting from the transport lane side, the working face supports are grouped into n-frame groups and numbered 1#, 2#, 3#, ... n# in sequence; and connected with the retreat channel in sequence according to the predetermined group numbers;

[0029] S45: After all the working face supports are fully connected with the withdrawal channel, start the withdrawal of the comprehensive mining equipment.

[0030] As a preferred embodiment, in step S33 of step three, the distance D is calculated according to formula (7);

[0031] D=B+Wtanθ (7).

[0032] As a preferred embodiment, in step 4 S41, the final tilt adjustment critical angle is the average value of the two end values ​​of the range of the tilt adjustment critical angle θ.

[0033] The present invention first determines the rock mass parameters on site, and then calculates the critical width of the coal pillar for stability, the reasonable tilt adjustment angle for the rotation and penetration of the working face, and the number of supports that penetrate the working face and the withdrawal channel at the same time each time; then, when the working face is advanced in parallel to the set tilt adjustment position, the tilt angle of the inclined scraper conveyor is adjusted, so that an oblique triangular area can be formed between the withdrawal channel and the working face during the inclined advancement of the working face, and then the stability of the self-stabilizing structure of the coal pillar in the triangular space can be used to avoid catastrophic instability of the coal pillar; further, on the basis of ensuring that the coal pillar can remain stable, based on the condition of equal support resistance, the minimum number of supports that penetrate the withdrawal channel at the same time is controlled, and after the supports are grouped, they are penetrated with the withdrawal channel in sequence in a predetermined order, and the risk of instability can be further reduced by artificially creating segmented pressure. Compared with the technology of stopping mining and letting pressure go, this method greatly reduces the risk of serious production safety problems such as large-area roof pressure, working face frame crushing, and support crushing accidents caused by the parallel penetration of the support through the withdrawal channel. It can ensure that the working face is mined at a normal advancement speed to a large extent, and greatly improve the stress state of the surrounding rock in the withdrawal channel. On the basis of ensuring the efficiency of mining, it effectively reduces the risk of catastrophic instability of the surrounding rock in the withdrawal channel, and ensures the safe and efficient withdrawal of the comprehensive mining equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the critical width of the coal pillar stability between the withdrawal channel and the working face of the present invention;

[0035] Figure 2 It is a schematic diagram of the working surface rotation and tilting through the withdrawal channel in the present invention;

[0036] Figure 3 It is a schematic diagram of normal advancement of the working face in the present invention;

[0037] Figure 4 It is a schematic diagram of the rotation and tilting of the working surface in the present invention;

[0038] Figure 5 It is a schematic diagram of the translational advancement of the working surface in the present invention;

[0039] Figure 6 It is a schematic diagram of the withdrawal channel beginning to penetrate in the present invention;

[0040] Figure 7 It is a schematic diagram of the retracement channel being connected in the present invention;

[0041] Figure 8 It is a schematic diagram showing that the withdrawal channel in the present invention is completely connected. DETAILED DESCRIPTION

[0042] The present invention will be further described below in conjunction with the accompanying drawings:

[0043] like Figures 1 to 8 As shown, the present invention provides a method for designing a rotating through-and-withdrawal channel of a working surface based on triangular stability, comprising the following steps:

[0044] Step 1: Conduct on-site investigation of the specific production geological conditions of the working face, take cores on-site and measure their physical and mechanical parameter characteristics through laboratory standard processing;

[0045] Step 2: Establish a mechanical model of the coal pillar and determine the critical width of stability;

[0046] S21: Determine the plastic zone width X1 of the coal pillar on the withdrawal channel side according to formula (1);

[0047]

[0048] Where m is the coal seam mining thickness, unit is m; A is the coal seam lateral pressure coefficient; k1 is the lateral stress concentration coefficient caused by tunneling; γ is the average bulk density of the overlying rock layer, unit is kN / m 3 ; H is the average buried depth of coal seam, unit is m; c0 is the cohesion of coal-rock interface, unit is MPa; is the internal friction angle of the coal-rock interface, unit: °; p' x The support strength of the anchor cable of the withdrawal channel on the coal seam, unit: MPa;

[0049] S22: Determine the width X3 of the plastic zone of the coal pillar on the working face according to formula (2);

[0050]

[0051] In the formula, ξ is the correction coefficient of plastic zone width. The mining of the working face has a great disturbance effect on the coal body in front of the coal wall, which is in a non-limit equilibrium state. Therefore, the width of the plastic zone needs to be corrected. R1 is the ultimate bearing strength of the coal body on the working face side, in MPa; R2 is the actual bearing strength of the coal body on the working face side, in MPa; k2 is the advanced stress concentration coefficient caused by mining at the working face; P x is the support strength of the working face support to the coal wall, unit: MPa;

[0052] S23: Determine the surplus amount X2 of the coal pillar width to be increased according to formula (3);

[0053] X2=0.2(X1+X3) (3);

[0054] S24: Determine the critical width B of the coal pillar to maintain stability according to formula (4);

[0055] B = X1 + X2 + X3 (4);

[0056] Step 3: Based on the principle of reducing the support load and artificially controlling the segmented pressure, determine the reasonable tilt angle of the working face rotation and penetration, the number of supports that the working face and the withdrawal channel penetrate at the same time each time, and the distance between the rotation fulcrum of the working face return air channel and the withdrawal channel;

[0057] After the working face is adjusted inclination, the spatial self-stabilizing structure stability of the triangular area formed by the oblique intersection of the withdrawal channel and the working face can be utilized to control the number of supports that simultaneously pass through the withdrawal channel, artificially create segmented pressure, change the force mode of the supports, and reduce the risks of working face support pressure, basic top advance breakage, etc.

[0058] S31: Based on the principle that the support resistance is equal and the number of supports through the withdrawal channel is the minimum, the range of the critical angle θ of the working face rotation through the withdrawal channel is determined according to formula (5);

[0059]

[0060] Wherein, L' is the minimum staggered distance of the bracket, in m; p is the rated working resistance of the bracket, in kN; q is the top plate load above the bracket, in MPa; L is the center distance of the bracket, in m; l is the top control distance of the bracket, in m;

[0061] S32: Based on the principle of minimizing the number of parallel through-brackets and artificially creating segmented pressure, the number of brackets n that the working surface and the retreat channel simultaneously penetrate each time is determined according to formula (6);

[0062]

[0063] S33: Determine the distance D between the rotation fulcrum of the return air lane of the working face and the retreat channel by determining the critical stable width B of the coal pillar, the rotation angle θ of the working face, and the length W of the working face;

[0064] Step 4: Determine the process flow of the withdrawal channel for rotating through the working face according to the determined critical width B of coal pillar stability, critical angle θ of inclination adjustment, and the number n of supports that simultaneously penetrate the withdrawal channel of the working face;

[0065] S41: Determine the final critical width of the coal pillar based on the working face advancement speed and the critical width B of the coal pillar to maintain stability; determine the final critical angle of inclination adjustment based on the range of the critical angle of inclination adjustment θ;

[0066] S42: When the working face is advanced parallel to the set tilt adjustment position D from the withdrawal channel, the tail of the scraper conveyor on the return air channel side of the working face is used as a fulcrum to make the head of the scraper conveyor on the transport channel side of the working face start to tilt and rotate to the position B from the withdrawal channel to the final critical width of the coal pillar, and ensure that the tilt adjustment angle is the final critical angle of tilt adjustment;

[0067] S43: After the inclination adjustment is completed, the working face begins to advance in parallel to the edge of the withdrawal channel at the mining side according to the predetermined final inclination adjustment critical angle, so that the head of the scraper conveyor on the transport lane side of the working face is first connected with the withdrawal channel;

[0068] S44: starting from the transport lane side, the working face supports are grouped into n-frame groups and numbered 1#, 2#, 3#, ... n# in sequence; and connected with the retreat channel in sequence according to the predetermined group numbers;

[0069] S45: After all the working face supports are fully connected with the withdrawal channel, start the withdrawal of the comprehensive mining equipment.

[0070] As a preferred embodiment, in step S33 of step three, the distance D is calculated according to formula (7);

[0071] D=B+Wtanθ (7).

[0072] As a preferred embodiment, in step 4 S41, the final tilt critical angle is the average value of the two end values ​​of the tilt critical angle θ. Of course, the calculated angle range can also be flexibly adjusted according to the on-site conditions of other working surfaces.

[0073] The present invention will be further described below in conjunction with embodiments:

[0074] Embodiment 1:

[0075] The average buried depth of the 9001 working face of the No. 9 coal seam in a certain mine is H = 440m, the working face length is 297m, the coal seam mining thickness is m = 3.5m, and the fully mechanized one-time mining method is adopted. The rated working resistance of the working face support is p = 9000kN, the support top control distance is l = 4.8m, the center distance is L = 1.75m, and the minimum support staggered distance is L' = 0.3m. The average bulk density of the overlying stratum is γ = 24.0kN / m 3 The cross-sectional dimensions of the pre-excavated retreat channel are: width × height = 5.2m × 3.5m, and the excavation adopts anchor net cable combined support.

[0076] The ultimate bearing strength of coal body measured in the laboratory and on site is R1 = 10.0MPa, the actual bearing strength is R2 = 2.0MPa, and the internal friction angle of the coal-rock interface is Cohesion c0 = 0.32MPa, coal seam lateral pressure coefficient A = 0.40, stress concentration coefficient k = 2.0, support strength P = 0.15Mpa.

[0077] The lateral stress concentration factor k1 caused by tunnel excavation is taken as 1.6, and the support strength p' of the anchor cable of the withdrawal channel on the coal side is taken as x=0.2Mpa, and according to formula (1), the width of the plastic zone of the coal pillar on the side of the withdrawal channel is determined to be 4.53m. The advanced stress concentration coefficient k2 caused by the mining of the working face is taken as 2.5, and the support strength P of the working face support to the coal wall is taken as x is 0.1Mpa, according to ξ is calculated, and then the plastic zone width X3 of the coal pillar on the withdrawal channel side is determined to be 7.11m according to formula (2). According to formula (3), the surplus amount X2 of the coal pillar width to be increased is determined to be 2.33m. According to formula (4), the critical width B for the coal pillar to remain stable is determined to be 13.97m. Considering the working face advancement speed of 5m / d, the final critical width of the coal pillar is determined to be 15m. That is: when the distance between the head of the scraper conveyor transport lane of the 9001 working face and the withdrawal channel is 15m, the working face should complete the tilt adjustment work, otherwise the coal pillar is very likely to suffer from catastrophic instability and other risks during the penetration period. In order to further improve the stability, the roof load is estimated by using the working face 8 times the mining height, taking q as 0.67MPa, and determining the critical angle range of the working face rotation through the withdrawal channel as 9.73°≤θ≤27.37° according to formula (5). After rounding, the tilt adjustment angle of the working face rotation through the withdrawal channel should be selected between 9° and 27°, and the average value of 18° is taken as the final tilt adjustment critical angle. According to formula (6), the number of supports n that the working face simultaneously passes through the withdrawal channel each time is determined to be 8. According to the working face length W = 297m, the final tilt adjustment critical angle θ = 18° and the final coal pillar critical width B = 15m, the distance D between the rotation fulcrum of the working face return air lane and the withdrawal channel is set to 110m. Therefore, the following working face rotation tilt adjustment through the withdrawal channel process is obtained:

[0078] (1) Figure 3 As shown in the figure, when the working face is parallel to the withdrawal channel 110m away, the working face return air channel side (scraper conveyor tail) is used as the fulcrum, and the working face transport channel side (scraper conveyor head) begins to tilt and rotate to a position 15m away from the withdrawal channel. The final tilt angle is 18°. Figure 4 As shown;

[0079] (2) After the inclination adjustment is completed, the working face begins to advance parallel to the edge of the withdrawal channel at a predetermined angle (18°), and the head of the scraper conveyor transport lane is first connected with the withdrawal channel. Figure 5 As shown;

[0080] (3) According to the principle of "minimum number of parallel through supports and artificially created segmented pressure", it is calculated that the number of supports that penetrate the withdrawal channel each time is 8. The working face supports are grouped into groups of 8 starting from the transport lane side and numbered 1#, 2#, 3#, ... 8# in sequence; according to the predetermined group numbers, they are connected with the withdrawal channel in sequence, such as Figure 6 and Figure 7 As shown;

[0081] (4) After all the working face supports are fully connected with the withdrawal channel, the withdrawal of the fully mechanized mining equipment is started. Figure 8 shown.

[0082] The present invention first determines the rock mass parameters on site, and then calculates the critical width of the coal pillar for stability, the reasonable tilt adjustment angle for the rotation and penetration of the working face, and the number of supports that penetrate the working face and the withdrawal channel at the same time each time; then, when the working face is advanced in parallel to the set tilt adjustment position, the tilt angle of the inclined scraper conveyor is adjusted, so that an oblique triangular area can be formed between the withdrawal channel and the working face during the inclined advancement of the working face, and then the stability of the self-stabilizing structure of the coal pillar in the triangular space can be used to avoid catastrophic instability of the coal pillar; further, on the basis of ensuring that the coal pillar can remain stable, based on the condition of equal support resistance, the minimum number of supports that penetrate the withdrawal channel at the same time is controlled, and after the supports are grouped, they are penetrated with the withdrawal channel in sequence in a predetermined order, and the risk of instability can be further reduced by artificially creating segmented pressure. Compared with technologies such as stopping mining and letting pressure go, this method greatly reduces the risk of serious production safety problems such as large-area roof pressure and working face frame crushing caused by parallel penetration of supports, and the risk of supports crushing to death. It can ensure that the working face is mined at a normal advancement speed to a large extent, and greatly improve the stress state of the surrounding rock in the withdrawal channel. On the basis of ensuring the efficiency of mining, it effectively reduces the risk of catastrophic instability of the surrounding rock in the withdrawal channel, and ensures the safe and efficient withdrawal of the comprehensive mining equipment.

Claims

1. A method for designing a rotating through-and-withdrawal channel for a working surface based on triangular stability, characterized in that: The steps include: Step 1: Conduct on-site investigation of the specific production geological conditions of the working face, take cores on-site and measure their physical and mechanical parameter characteristics through laboratory standard processing; Step 2: Establish a mechanical model of the coal pillar and determine the critical width of stability; S21: Determine the plastic zone width X1 of the coal pillar on the withdrawal channel side according to formula (1); Where m is the coal seam mining thickness, unit is m; A is the coal seam lateral pressure coefficient; k1 is the lateral stress concentration coefficient caused by tunneling; γ is the average bulk density of the overlying rock layer, unit is kN / m 3 ; H is the average buried depth of coal seam, unit is m; c0 is the cohesion of coal-rock interface, unit is MPa; is the internal friction angle of the coal-rock interface, unit: °; p' x The support strength of the anchor cable of the withdrawal channel on the coal seam, unit: MPa; S22: Determine the width X3 of the plastic zone of the coal pillar on the working face according to formula (2); In the formula, ξ is the correction coefficient of plastic zone width. The mining of the working face has a great disturbance effect on the coal body in front of the coal wall, which is in a non-limit equilibrium state. Therefore, the width of the plastic zone needs to be corrected. R1 is the ultimate bearing strength of the coal body on the working face side, in MPa; R2 is the actual bearing strength of the coal body on the working face side, in MPa; k2 is the advanced stress concentration coefficient caused by mining at the working face; P x is the support strength of the working face support to the coal wall, unit: MPa; S23: Determine the surplus amount X2 of the coal pillar width to be increased according to formula (3); X2=0.2(X1+X3) (3); S24: Determine the critical width B of the coal pillar to maintain stability according to formula (4); B = X1 + X2 + X3 (4); Step 3: Based on the principle of reducing the support load and artificially controlling the segmented pressure, determine the reasonable tilt angle of the working face rotation and penetration, the number of supports that the working face and the withdrawal channel penetrate at the same time each time, and the distance between the rotation fulcrum of the working face return air channel and the withdrawal channel; S31: Based on the principle that the support resistance is equal and the number of supports through the withdrawal channel is the minimum, the range of the critical angle θ of the working face rotation through the withdrawal channel is determined according to formula (5); Wherein, L' is the minimum staggered distance of the bracket, in m; p is the rated working resistance of the bracket, in kN; q is the top plate load above the bracket, in MPa; L is the center distance of the bracket, in m; l is the top control distance of the bracket, in m; S32: Based on the principle of minimizing the number of parallel through-brackets and artificially creating segmented pressure, the number of brackets n that the working surface and the retreat channel simultaneously penetrate each time is determined according to formula (6); S33: Determine the distance D between the rotation fulcrum of the return air lane of the working face and the retreat channel by determining the critical stable width B of the coal pillar, the rotation angle θ of the working face, and the length W of the working face; Step 4: Determine the process flow of the withdrawal channel for rotating through the working face according to the determined critical stable width B of the coal pillar, the critical angle θ for adjusting the inclination, and the number n of supports that simultaneously penetrate the withdrawal channel of the working face; S41: Determine the final critical width of the coal pillar based on the working face advancement speed and the critical width B of the coal pillar to maintain stability; determine the final critical angle of inclination adjustment based on the range of the critical angle of inclination adjustment θ; S42: When the working face is advanced parallel to the set tilting position D from the withdrawal channel, the tail of the scraper conveyor on the return air channel side of the working face is used as a fulcrum to make the head of the scraper conveyor on the transport channel side of the working face start to tilt and rotate to the position where the distance from the withdrawal channel reaches the final coal pillar critical width B, and ensure that the tilting angle is the final tilting critical angle; S43: After the inclination adjustment is completed, the working face begins to advance in parallel to the edge of the withdrawal channel at the mining side according to the predetermined final inclination adjustment critical angle, so that the head of the scraper conveyor on the transport lane side of the working face is first connected with the withdrawal channel; S44: starting from the transport lane side, the working face supports are grouped into n-frame groups and numbered 1#, 2#, 3#, ... n# in sequence; and connected with the retreat channel in sequence according to the predetermined group numbers; S45: After all the working face supports are fully connected with the withdrawal channel, start the withdrawal of the comprehensive mining equipment.

2. A method for designing a rotating through-and-withdrawal channel for a working surface based on triangular stability according to claim 1, characterized in that: In step 3, in S33, the distance D is calculated according to formula (7); D=B+Wtanθ (7).

3. A method for designing a rotating through-and-withdrawal channel for a working surface based on triangular stability according to claim 1 or 2, characterized in that: In step 4 S41, the final tilt adjustment critical angle is the average value of the two end values ​​of the range of the tilt adjustment critical angle θ.

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