Shallow-burial-depth fully-mechanized caving mining grouting filling control mining space deformation method

Abstract

The invention belongs to the field of filling mining, and discloses a shallow-burial-depth fully-mechanized caving mining grouting filling control mining space deformation method which comprises the steps that a mining space is divided into a main control auxiliary filling space and an auxiliary control main filling space, and double-hole grouting filling drill holes are formed in the ground at intervals. A high-strength quick-setting material and a fly ash-based reinforcing material in the main control and auxiliary filling space are grouted and filled, the two materials are bonded with the fractured rock mass to form a cemented combined bearing body, movement of a key layer is retarded, and the existence time of the auxiliary control and main filling space is prolonged; the auxiliary control and main filling space is filled with coal gangue slurry in a grouting mode, the supporting and cementing combined bearing body synergistically assists in controlling the key layer, and the two layers of spaces synergistically achieve shallow-burial-depth fully-mechanized caving mining solid waste high-quantity disposal and surface subsidence protection. According to the method, the mining space control effect is safe and reliable, the green low-carbon targets of further controlling surface subsidence, protecting water resources and the like can be achieved while the mining space control is achieved, and the method has wide practicability in shallow-burial deep fully-mechanized caving filling and solid waste disposal.

Description

Technical Field

[0001] The present invention belongs to the field of filling mining, and is particularly suitable for use in mining scenarios such as coal mine solid waste disposal, green mining on mines, surface subsidence control, and water-saving coal mining under shallow-depth high-intensity mining conditions. It specifically relates to a method for controlling mining space deformation by grouting filling in shallow-depth fully-mechanized caving mining. Background Art

[0002] Energy security and environmental protection in the western region have become an important part of green mine construction. However, coal seams in the west are characterized by shallow burial, thick coal seams, and fast mining speed. The rapid change speed of the shallow burial depth mining space restricts the efficient disposal of gangue. Traditional gangue solid waste disposal methods are difficult to meet the production and solid waste disposal needs of modern large-scale mines.

[0003] Traditional delamination grouting filling has no delamination space under shallow buried comprehensive top-caving mining conditions; underground solid filling has no post-frame filling space under shallow buried coal seam conditions; subsequent filling under shallow buried deep comprehensive top-caving mining conditions has a fast closure speed of the mining space, which limits the amount and timing of solid waste disposal, and even causes hazards such as ground slurry bursting; therefore, it is urgent to propose a mining space control method for shallow buried deep comprehensive top-caving mining filling, which does not affect the normal production conditions of the working face, and realizes the method of coordinated solid waste disposal and surface subsidence protection through mining space control. The operation is simple, the engineering is safe and reliable, and it has extremely high engineering application value. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the present invention provides a method for controlling the deformation of the mining space by grouting filling in shallow deep comprehensive top-caving mining. By filling the main control auxiliary filling space and the auxiliary control main filling space with different filling materials, the fracture and deformation of the key layer are collaboratively controlled. The mining space control effect of the method is safe and reliable. While achieving mining space control, green and low-carbon goals such as surface subsidence and water resource protection can be further controlled. It has wide practicality in shallow deep comprehensive top-caving filling and solid waste disposal.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] A method for controlling mining space deformation by grouting in shallow-buried deep fully-mechanized caving mining, the method comprising:

[0007] The mining space is divided into main control auxiliary filling space and auxiliary control main filling space, double-hole grouting filling drill holes are arranged at intervals on the ground, and different filling materials are used in the two-layer space to coordinately control the deformation of the mining space, so as to realize high-volume disposal of solid waste in shallow buried and deep comprehensive mining; wherein, the main control auxiliary filling space is filled with high-strength quick-setting materials and fly ash-based reinforcement materials by grouting, and the two materials are bonded with the broken rock mass to form a bonded composite bearing body, which blocks the movement of the key layer and extends the auxiliary control main filling space; the auxiliary control main filling space is filled with coal gangue slurry by grouting, and the supporting bonded composite bearing body coordinates with the auxiliary control key layer.

[0008] Preferably, the main controlled auxiliary filling space is the space between the key layer above the collapse zone and below, which restricts 60% to 80% of the mining space movement and is filled with and disposed of 20% to 30% of fly ash solid waste.

[0009] Preferably, the auxiliary control main filling space is the collapse zone space, which limits the movement of the mining space by more than 20% to 40%, and disposes and fills 70% to 80% of the coal gangue solid waste.

[0010] The present invention also provides a method for controlling mining space deformation by grouting in shallow-buried deep fully-mechanized caving mining, the method comprising:

[0011] S1: Drilling holes on the ground at the exploration drilling point, located one square meter in the advance direction and in the middle of the working face in the vertical advancement direction; two main control exploration holes K are arranged adjacent to the exploration drilling point t1 , Auxiliary control detection hole K t2 , where K t1 The final hole layer burial depth H t1 Located at the bottom of the key layer, at the top of the main control and auxiliary charging space; K t2 The final hole layer burial depth H t2 Located in the upper part of the collapse zone, at the top of the auxiliary control main filling space;

[0012] S2: Main control probe hole K t1 , Auxiliary control detection hole K t2 Carry out water injection to maintain pressure and record the working face advancement main control exploration hole K t1 The starting time when the injection pressure continues to decrease T t1 And the corresponding lag working surface distance S t1 , auxiliary control detection hole K t2 The starting time when the injection pressure continues to decrease T t2 And the corresponding lag working surface distance S t2 , giving the spacing D of the grouting filling drilling points t ;

[0013] S3: Grouting starts in the exploration hole, and the exploration hole K is controlled in time t1 , Auxiliary control detection hole K t2 Respectively in Tt1 , T t2 Grouting starts at 1:00, and the main control drilling hole K t1 , auxiliary control drilling K t2 Respectively on the lagging working surface S t1 , S t2 Start grouting at

[0014] S4: The orifice pressure of the main control hole is greater than the maximum grouting pressure P zmax , the orifice pressure of the auxiliary control hole is greater than P fmax Stop grouting when

[0015] S5: Before the working face is mined, the ground is arranged with grouting filling holes. The distance D between the holes is based on the advancing direction of the arrangement points. t Arrange in sequence, in the middle of the working surface in the vertical advancement direction; two drilling main control drilling holes K are arranged adjacent to each other at a single arrangement point za , auxiliary control drilling K fa , where K za The final hole layer burial depth H za Located at the bottom of the key layer, at the top of the main control and auxiliary charging space; K fa The final hole layer burial depth H fa Located in the upper part of the collapse zone, at the top of the auxiliary control main filling space;

[0016] S6: Two drilling master drilling K za , auxiliary control drilling K fa Carry out water injection to maintain pressure and record the main control drilling hole K of the working face advancement za The starting time when the injection pressure continues to decrease T za And the corresponding lag working surface distance S za , auxiliary control drilling K fa The starting time when the injection pressure continues to decrease T fa And the corresponding lag working surface distance S fa ;

[0017] S7: Grouting starts at the grouting hole, and the main control drilling hole K za , auxiliary control drilling K fa Respectively in T za , T fa Grouting starts at 1:00, and the main control drilling hole K za , auxiliary control drilling K fa Respectively on the lagging working surface S za , S fa Start grouting at

[0018] S8: Circular grouting, different grouting arrangement points, as the working face advances, the grouting process is circulated in sequence until the grouting of the working face is completed.

[0019] Preferably, in S2, the spacing D between the grouting filling holes is t , according to the master drilling K z Lagging working surface distance S z Subtract auxiliary control drilling K f Lagging working surface distance S f The calculation formula is: D = S z -S f .

[0020] Preferably, in said S3, grouting starts at the exploration hole, and the exploration hole K is controlled in time. t1 , Auxiliary control detection hole K t2 Respectively in T t1 , T t2 Grouting starts at 1:00, and the main control drilling hole K t1 , auxiliary control drilling K t2 Respectively on the lagging working surface S t1 , S t2 Grouting starts at:

[0021] S31: Construction of cemented composite bearing body, when the orifice pressure of the main control hole is less than 30% of the minimum orifice pressure of the main control hole P zmin When the orifice pressure of the main control hole is greater than 30% of the minimum orifice pressure P of the main control hole, high-strength quick-setting material is used for grouting and filling to bond the rock mass and solidify and seal the mining cracks. zmin When constructing, fly ash-based reinforcement materials are used to solidify the key support layers and coordinate the disposal of fly ash solid waste;

[0022] S32: auxiliary control main filling space grouting, auxiliary control hole injects coal gangue slurry;

[0023] Among them, the minimum orifice pressure P zmin For: P zmin =H za (γ-γ 1 ), where H za is the grouting layer of the main control hole, γ is the comprehensive specific gravity of the formation, 1 is the specific gravity of fly ash-based reinforcement material.

[0024] Preferably, in S4, the maximum orifice pressure P of the main control hole is zmax To control the mining space, the maximum grouting pressure should be less than the grouting layer H of the main control hole. za With coal seam burial depth H 煤 The formation pressure between the main control hole grouting layer H za 、Deepness of coal seam H 煤 And the main control hole grouting layer H za The comprehensive gravity of the strata above the coal seam below γ 2 Related, the calculation formula is: P zmax=k(H 煤 -H za )γ 2 , K is the safety factor of 1.1 to 1.3.

[0025] Preferably, in S4, the minimum orifice pressure P of the auxiliary control hole is fmin The goal is to coordinate the control of the sinking and breaking of the overlying key layer. The minimum grouting pressure needs to be greater than the self-gravity of the overlying rock. fa The above stratum comprehensive gravity γ 3 And the specific gravity of coal gangue slurry γ 3 Related, the calculation formula is: P fmin =H fa (γ f -γ 3 ); Maximum orifice pressure of auxiliary control hole P fmax It is 1.1 to 1.3 times the minimum orifice pressure.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The present invention controls the fracture and deformation of key layers by filling different filling materials in the main control auxiliary filling space and the auxiliary control main filling space. The mining space control effect is safe and reliable, the engineering construction is simple, the operation indicators are clear, and while achieving mining space control, it can further control green and low-carbon goals such as surface subsidence and water resource protection, and has wide practicality in this technical field. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0029] Figure 1 This is a flow chart of a method for controlling mining space deformation by grouting in shallow-buried deep fully-mechanized caving mining according to the present invention;

[0030] Figure 2 This is a cross-sectional view of the arrangement of grouting and filling drilling holes for shallow-buried deep fully-mechanized caving mining according to the present invention;

[0031] Figure 3 It is a plan view of the arrangement of grouting and filling drilling holes for shallow-buried deep fully-mechanized caving mining of the present invention;

[0032] In the figure: 1-main control auxiliary filling space, 2-auxiliary control main filling space, 3-key layer, 4-high strength quick setting material, 5-fly ash based reinforcement material, 6-cemented composite bearing body, 7-coal gangue slurry, 8-main control drilling hole (when it is an exploration hole, it is the main control exploration hole K t1, when it is a grouting hole, it is K za ), 9- auxiliary control drilling hole (when it is an exploration hole, it is an auxiliary control exploration hole K t2 , when it is a grouting hole, it is K zb ), 10-the buried depth of the main control borehole (when it is an exploration hole, it is the main control exploration hole H t1 , when it is a grouting hole, it is H za ), 11-the buried depth of the auxiliary hole (when it is an exploration hole, it is the H of the auxiliary control exploration hole t2 , when it is a grouting hole, it is H zb ), 12- coal seam burial depth H 煤 , 13- Main control probe hole K t1 , 14- auxiliary control detection hole K t2 , 15- master drilling K za , 16- auxiliary control drilling K fa , 17-square length of the working surface, 18-grouting filling drilling point spacing D t . DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] Embodiment 1

[0036] Taking a shallow-buried and fully mechanized top-caving coal mine in the west as an example, the specific implementation steps are as follows:

[0037] The present invention provides a method for controlling the deformation of mining space by grouting filling in shallow deep fully mechanized caving mining, which divides the mining space into a main control auxiliary filling space 1 and an auxiliary control main filling space 2. Figure 2 , Figure 3 As shown, double-hole grouting filling boreholes are arranged at intervals on the ground, and different filling materials are used in the two-layer space to coordinately control the deformation of the mining space, so as to achieve high-volume disposal of solid waste from shallow buried deep comprehensive mining.

[0038] In this embodiment, the main controlled auxiliary filling space 1 is the space between the key layer 3 above the collapse zone and below, which restricts 60% to 80% of the mining space movement and is filled with and disposed of 20% to 30% of fly ash solid waste.

[0039] In this embodiment, the auxiliary control main filling space 2 is a collapse zone space, which limits the movement of the mining space by more than 20% to 40%, and disposes and fills 70% to 80% of coal gangue solid waste.

[0040] In this embodiment, the main control auxiliary filling space 1 is filled with high-strength quick-setting material 4 and fly ash-based reinforcement material 5 by grouting. The two materials are bonded with the broken rock mass to form a cemented composite bearing body 6, which blocks the movement of the key layer 3 and extends the auxiliary control main filling space 2.

[0041] In this embodiment, the auxiliary control main filling space 2 is filled with coal gangue slurry 7 by grouting, and the supporting and bonding composite bearing body 6 cooperates with the auxiliary control key layer 3.

[0042] Furthermore, if Figure 1 As shown, a method for controlling mining space deformation by grouting in shallow deep fully mechanized caving mining includes the following steps:

[0043] S1: Exploration hole arrangement, drilling holes on the ground at the exploration drilling point, one square meter ahead of the cutting eye in the advancement direction, that is, Figure 2 Middle 17, located in the middle of the working face in the vertical advancement direction. Two main control exploration holes K are arranged adjacent to the exploration drilling point t1 13. Auxiliary control detection hole K t2 14. K t1 The final hole layer burial depth H t1 Located at the bottom of the key layer, at the top of the main control and auxiliary charging space; K t2 The final hole layer burial depth H t2 Located at the upper part of the collapse zone, at the top of the auxiliary control main filling space.

[0044] S2: Water injection test of exploration hole, main control exploration hole K t1 13. Auxiliary control detection hole K t2 14 Carry out water injection to maintain pressure and record the main control exploration hole K of the working face advancement t1 The starting time when the injection pressure of 13 continues to decrease T t1 And the corresponding lag working surface distance S t1 , auxiliary control detection hole K t2 14 The starting time when the water injection pressure continues to decrease T t2 And the corresponding lag working surface distance S t2 . Give the spacing D of the grouting filling drilling points t 18 that is Figure 2 Middle 18.

[0045] S3: Grouting starts in the exploration hole, and the exploration hole K is controlled in time t1 13. Auxiliary control detection hole K t2 14 respectively in T t1 , T t2 Grouting starts at 1:00, and the main control drilling hole Kt1 , auxiliary control drilling K t2 Respectively on the lagging working surface S t1 , S t2 Start grouting.

[0046] Specifically, S31: The cemented composite carrier 6 is constructed, when the orifice pressure of the main control hole is less than 30% of the minimum orifice pressure P of the main control hole zmin When the orifice pressure of the main control hole is greater than 30% of the minimum orifice pressure P of the main control hole, high-strength quick-setting material 4 is used for grouting and filling to bond the rock mass and solidify and block the mining cracks. zmin When using fly ash-based reinforcement materials 5, solidify the key support layer 3, and coordinate the disposal of fly ash solid waste.

[0047] Among them, the constructed cemented composite bearing body is a mixed rock mass formed by sealing and reinforcing the broken rock mass in the main control auxiliary filling space (the space between the key layer above the collapse zone and below) through high-strength quick-setting materials and fly ash-based materials. The bearing performance, adhesion and tensile strength of the improved rock mass are better than those of the original broken rock mass, so it is called a cemented composite bearing body.

[0048] S32: Grouting of auxiliary control main filling space 2, and injection of coal gangue slurry 7 into the auxiliary control hole. The grouting process is to prepare slurry according to the designed ratio, and then grouting is carried out in the auxiliary hole main filling through a grouting pump, and the grouting pressure is monitored at any time. After the drilling and grouting is completed, the grouting is closed.

[0049] S4: Stop grouting, the orifice pressure of the main control hole is greater than the maximum grouting pressure P zmax , the orifice pressure of the auxiliary control hole is greater than P fmax Stop grouting.

[0050] S5: Grouting filling drilling arrangement. Grouting filling drilling is arranged on the ground before the working face is mined. The arrangement points are advanced in the direction according to the spacing D between the drilling points. t Arrange in sequence, in the middle of the working surface in the vertical advancement direction. Two drilling main control drilling holes K are arranged adjacent to each other at a single arrangement point za , auxiliary control drilling K fa . K za The final hole layer burial depth H za Located at the bottom of the key layer, at the top of the main control and auxiliary charging space; K fa The final hole layer burial depth H fa Located at the upper part of the collapse zone, at the top of the auxiliary control main filling space.

[0051] S6: Water injection test parameter monitoring, two boreholes master control borehole K za 15. Auxiliary control drilling K fa 16Inject water to maintain pressure and record the main control drilling hole K of the working face advancement za 15 The starting time when the water injection pressure continues to decrease Tza And the corresponding lag working surface distance S za , auxiliary control drilling K fa The starting time when the injection pressure of 16 continues to decrease T fa And the corresponding lag working surface distance S fa .

[0052] S7: Grouting starts at the grouting hole, and the main control drilling hole K za 15. Auxiliary control drilling K fa 16 respectively in T za , T fa Start grouting at 1500 s, and control the drilling hole K in space za 15. Auxiliary control drilling K fa 16 respectively on the lagging working surface S za , S fa Start grouting.

[0053] Repeat steps S31 to S4. (The process of grouting the grouting hole is the same as the process of grouting the exploration hole, except that the names of the holes are different in different time periods according to their functions).

[0054] S8: cyclic grouting (in terms of time, the same hole, according to the change of function, first becomes an exploration hole (water injection to maintain pressure) and then a grouting hole (injecting slurry); in terms of space, with the impact of the advancement of the working face as the boundary, as the working face is mined, the exploration hole is injected with water to maintain pressure before mining, and after mining, due to the generation of cracks, the parameters monitored by the exploration are obtained, and the exploration hole becomes a grouting hole), with different grouting arrangement points, as the working face advances, the grouting process is cyclically carried out in sequence until the grouting of the working face is completed.

[0055] In this embodiment, the spacing D between the grouting filling drilling holes in S2 is t 18. According to the master control drilling K z Lagging working surface distance S z Subtract auxiliary control drilling K f Lagging working surface distance S f The grouting is started at the point where the grouting is obtained, as shown in formula (1)

[0056] D t =S z -S f (1)

[0057] In this embodiment, the minimum orifice pressure P of the main control hole in S31 is zmin The goal is to control the sinking and breaking of the overlying key layer 3. The minimum grouting pressure needs to be greater than the self-gravity of the overlying rock, and the grouting layer position H of the main control hole za The above-mentioned stratum comprehensive specific gravity γ and the specific gravity γ of the fly ash-based reinforcement material 5 1 The calculation is shown in Equation 2.

[0058] P zmin =H za (γ-γ 1 ) (2)

[0059] In this embodiment, the maximum grouting pressure in S4 includes the maximum orifice pressure P of the main control hole. zmax and the maximum orifice pressure P of the auxiliary control hole fmax .

[0060] Among them, the maximum orifice pressure of the main control hole is P zmax To control the mining space, the maximum grouting pressure should be less than the grouting layer H of the main control hole. za With coal seam burial depth H 煤 The formation pressure between the main control hole grouting layer H za 、Deepness of coal seam H 煤 And the main control hole grouting layer H za The comprehensive gravity of the strata above the coal seam below γ 2 Correlation, calculation is shown in formula 3

[0061] P zmax =k(H 煤 -H za )γ 2 (3)

[0062] Among them, K is the safety factor of 1.1 to 1.3, and the minimum orifice pressure of the auxiliary control hole is P fmin , with the goal of collaboratively controlling the sinking and breaking of the overlying key layer 3, the minimum grouting pressure needs to be greater than the self-gravity of the overlying rock, and the auxiliary control hole grouting layer H fa The above stratum comprehensive gravity γ 3 and the specific gravity of the gangue slurry 7 γ 3 The calculation is shown in formula 4.

[0063] P fmin =H fa (γ f -γ 3 ) (4)

[0064] Maximum orifice pressure P of auxiliary control hole fmax It is 1.1 to 1.3 times the minimum orifice pressure.

[0065] In this embodiment, the high-strength quick-setting material 4 is a water glass-cement double-liquid slurry, and the volume ratio of water glass to cement slurry is 0.6:1, wherein the cement slurry includes 70-90 parts of cement and 100-120 parts of water in terms of mass.

[0066] In this embodiment, the fly ash-based reinforcement material 5 includes 40 parts of fly ash, 25 parts of cement, 3 parts of accelerating agent and 32 parts of water in terms of mass fractions.

[0067] In this embodiment, the gangue slurry includes 70 parts of coal gangue aggregate and 30 parts of water in terms of mass fraction.

[0068] In this embodiment, the gangue slurry is characterized in that the particle size of the gangue aggregate is not higher than 20 mm.

[0069] In this technical solution, high-strength quick-setting material 4 and fly ash-based reinforcement material 5 are used to bond with the broken rock mass in the main control auxiliary filling space 1 to form a cemented composite bearing body 6, thereby blocking the movement of the key layer 3 and extending the auxiliary control main filling space 2. Filling space and filling time are provided for the auxiliary control main filling space 2, which is conducive to solving the problem of large-scale treatment of waste rock in shallow buried deep comprehensive mining. Moreover, since the system is arranged on the ground and does not affect safe and efficient mining underground, parallel mining and filling can be achieved. This method has reasonable logic, strong applicability, simple operation, obvious effect, and has wide application value.

[0070] The embodiments described above are only descriptions of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for controlling mining space deformation by grouting in shallow deep fully mechanized caving mining, characterized in that: The method comprises: The mining space is divided into main control auxiliary filling space and auxiliary control main filling space, double-hole grouting filling drill holes are arranged at intervals on the ground, and different filling materials are used in the two-layer space to coordinately control the deformation of the mining space, so as to realize high-volume disposal of solid waste in shallow buried and deep comprehensive mining; wherein, the main control auxiliary filling space is filled with high-strength quick-setting materials and fly ash-based reinforcement materials by grouting, and the two materials are bonded with the broken rock mass to form a bonded composite bearing body, which blocks the movement of the key layer and prolongs the existence time of the auxiliary control main filling space; the auxiliary control main filling space is filled with coal gangue slurry by grouting, and the supporting bonded composite bearing body coordinates with the auxiliary control of the key layer.

2. The method according to claim 1, characterized in that The main controlled auxiliary filling space is the space between the key layer above the collapse zone and below, which limits the movement of the mining space by 60% to 80% and is filled with and disposed of 20% to 30% of fly ash solid waste.

3. The method according to claim 1, characterized in that The auxiliary control main filling space is the collapse zone space, which limits the movement of the mining space by more than 20% to 40%, and disposes and fills 70% to 80% of the coal gangue solid waste.

4. A method for controlling mining space deformation by grouting in shallow deep fully mechanized caving mining, characterized in that: The method comprises: S1: Drilling holes on the ground at the exploration drilling point, located one square meter in the advance direction and in the middle of the working face in the vertical advancement direction; two main control exploration holes K are arranged adjacent to the exploration drilling point t1 , Auxiliary control detection hole K t2 , where K t1 The final hole layer burial depth H t1 Located at the bottom of the key layer, at the top of the main control and auxiliary charging space; K t2 The final hole layer burial depth H t2 Located in the upper part of the collapse zone, at the top of the auxiliary control main filling space; S2: Main control probe hole K t1 , Auxiliary control detection hole K t2 Carry out water injection to maintain pressure and record the working face advancement main control exploration hole K t1 The starting time when the injection pressure continues to decrease T t1 And the corresponding lag working surface distance S t1 , auxiliary control detection hole K t2 The starting time when the injection pressure continues to decrease T t2 And the corresponding lag working surface distance S t2 , giving the spacing D of the grouting filling drilling points t ; S3: Grouting starts in the exploration hole, and the exploration hole K is controlled in time t1 , Auxiliary control detection hole K t2 Respectively in T t1 , T t2 Grouting starts at 1:00, and the main control drilling hole K t1 , auxiliary control drilling K t2 Respectively on the lagging working surface S t1 , S t2 Start grouting at S4: The orifice pressure of the main control hole is greater than the maximum grouting pressure P zmax , the orifice pressure of the auxiliary control hole is greater than P fmax Stop grouting when S5: Before the working face is mined, the ground is arranged with grouting filling holes. The distance D between the holes is based on the advancing direction of the arrangement points. t Arrange in sequence, in the middle of the working surface in the vertical advancement direction; two drilling main control holes K are arranged adjacent to each other at a single arrangement point za , auxiliary control drilling K fa , where K za The final hole layer burial depth H za Located at the bottom of the key layer, at the top of the main control and auxiliary charging space; K fa The final hole layer burial depth H fa Located in the upper part of the collapse zone, at the top of the auxiliary control main filling space; S6: Two drilling master drilling K za , auxiliary control drilling K fa Inject water to maintain pressure and record the main control drilling hole K of the working face advancement za The starting time when the injection pressure continues to decrease T za And the corresponding lag working surface distance S za , auxiliary control drilling K fa The starting time when the injection pressure continues to decrease T fa And the corresponding lag working surface distance S fa ; S7: Grouting starts at the grouting hole, and the main control drilling hole K za , auxiliary control drilling K fa Respectively in T za , T fa Grouting starts at 1:00, and the main control drilling hole K za , auxiliary control drilling K fa Respectively on the lagging working surface S za , S fa Start grouting at S8: Circular grouting, different grouting arrangement points, as the working face advances, the grouting process is circulated in sequence until the grouting of the working face is completed.

5. The method according to claim 4, characterized in that In S2, the spacing D between the grouting filling holes is t , according to the master drilling K z Lagging working surface distance S z Subtract auxiliary control drilling K f Lagging working surface distance S f The calculation formula is: D = S z -S f .

6. The method according to claim 4, characterized in that In S3, the exploration hole starts grouting, and the exploration hole K is controlled in time. t1 , Auxiliary control detection hole K t2 Respectively in T t1 , T t2 Grouting starts at 1:00, and the main control drilling hole K t1 , auxiliary control drilling K t2 Respectively on the lagging working surface S t1 , S t2 Grouting starts at: S31: Construction of cemented composite bearing body, when the orifice pressure of the main control hole is less than 30% of the minimum orifice pressure of the main control hole P zmin When the orifice pressure of the main control hole is greater than 30% of the minimum orifice pressure P of the main control hole, high-strength quick-setting material is used for grouting and filling to bond the rock mass and solidify and seal the mining cracks. zmin When constructing, fly ash-based reinforcement materials are used to solidify the key support layers and coordinate the disposal of fly ash solid waste; S32: auxiliary control main filling space grouting, auxiliary control hole injects coal gangue slurry; Among them, the minimum orifice pressure P zmin For: P zmin =H za (γ-γ1), where H za is the grouting layer of the main control hole, γ is the comprehensive specific gravity of the formation, and γ1 is the specific gravity of the fly ash-based reinforcement material.

7. The method according to claim 4, characterized in that In S4, the maximum orifice pressure P of the main control hole zmax To control the mining space, the maximum grouting pressure should be less than the grouting layer H of the main control hole. za With coal seam depth H 煤 The formation pressure between the main control hole grouting layer H za 、Deepness of coal seam H 煤 And the main control hole grouting layer H za The stratum comprehensive specific gravity γ2 above the coal seam below is related to the calculation formula: zmax =k(H 煤 -H za )γ2, K is the safety factor of 1.1 to 1.

3.

8. The method according to claim 4, characterized in that In S4, the minimum orifice pressure P of the auxiliary control hole fmin The goal is to coordinate the control of the sinking and breaking of the overlying key layer. The minimum grouting pressure needs to be greater than the self-gravity of the overlying rock. fa The above-mentioned formation comprehensive specific gravity γ3 and the specific gravity γ3 of coal gangue slurry are related, and the calculation formula is: P fmin =H fa (γ f -γ3); Maximum orifice pressure of auxiliary control hole P fmax It is 1.1 to 1.3 times the minimum orifice pressure.

Images