A method for repairing surface cracks in coal mining subsidence areas

Abstract

The present invention discloses a method for repairing surface cracks in a coal mining subsidence area, comprising the following steps: S01: before mining, obtaining the physical and mechanical parameters of the stratum structure of the mining area; S02: before mining, constructing a three-dimensional similarity simulation model to simulate coal seam mining; S03: during mining, using an unmanned aerial vehicle to monitor the surface layer of the mining area; S04: after mining, using geophysical prospecting and drilling to determine moderate cracks and severe cracks that need to be repaired; S05: using a segmented method to gradually repair the moderate cracks and severe cracks, dividing the surface cracks in the subsidence area into mild cracks, moderate cracks and severe cracks, and using different repair methods to improve efficiency, thereby achieving effective repair of surface layer cracks.

Description

Technical Field

[0001] The invention relates to the technical field of mining engineering, and in particular to a method for repairing surface fissures in a coal mining subsidence area. Background Art

[0002] During the coal mining process, goafs will be formed. Some parts of the overlying rock layer above each layer will fall into the goaf, causing the upper rock layer and surface layer to collapse, and eventually some cracks will be formed in the surface layer. These cracks are generally divided into tensile cracks and collapse cracks.

[0003] Tensile cracks are caused by horizontal tensile deformation of the ground surface during coal mining. The crack width is generally small and the development depth is generally shallow. They mainly develop in the surface layer. Under certain conditions, such as the release of geological stress or the stabilization of surface settlement, tensile cracks may heal themselves.

[0004] Collapse fissures are formed during coal mining as the overburden above the coal seam collapses, often lagging behind the working face. Such fissures are relatively wide and deep, so the possibility of self-healing is relatively small. In most cases, collapse fissures need to be repaired by engineering measures.

[0005] In the prior art, generally, tensile cracks do not need to be treated, but rely on their own healing, and collapse cracks are repaired by filling, grouting, etc. However, since collapse cracks are generally wide and deep, more surface soil is required. Some wider collapse cracks are very deep, and some reach the aquifer. If such collapse cracks are not separated, and a single method or a combination of grouting filling, filler filling, and surface soil filling is directly adopted, the slurry, filler surface soil, etc. will enter the aquifer and affect the ecology of the aquifer. In addition, since the slurry, filler, and surface soil will always flow into the aquifer and leave the collapse cracks, it is difficult to fill the collapse cracks, which takes a long time, has low efficiency, and consumes a lot of materials. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for repairing surface cracks in a coal mining subsidence area. The method divides the surface cracks in the subsidence area into mild cracks, moderate cracks and severe cracks, and adopts different repair means accordingly. Mild cracks rely on the self-healing of the surface layer, moderate cracks are repaired by filling repair fillers with surface soil, and severe cracks are repaired by constructing a barrier layer and filling the surface soil. This will not affect the underlying aquifer, saves surface soil, improves efficiency, and achieves effective repair of surface cracks.

[0007] The technical solution of the present invention provides a method for repairing surface cracks in a coal mining subsidence area, comprising the following steps:

[0008] S01: Before mining, physical and mechanical parameters of the surface layer, rock layer, aquifer, impermeable layer, overburden rock layer and coal seam of the mining area are obtained by means of geophysical exploration and drilling;

[0009] S02: Before mining, a three-dimensional similarity simulation model is constructed to simulate the collapse area of ​​the surface layer and the surface fissures formed in the collapse area during coal seam mining, and the surface fissures are divided into light fissures, medium fissures and severe fissures according to their width and depth; wherein the maximum development depth of the medium fissures reaches the rock layer, and the maximum development depth of the severe fissures reaches the aquifer below the rock layer;

[0010] S03: During mining, the surface layer of the mining site is monitored by using a drone, and the areas where the moderate cracks and the severe cracks have appeared or are likely to appear are determined through monitoring images;

[0011] S04: After mining, geophysical exploration and drilling are used to determine the moderate cracks and severe cracks that need to be repaired;

[0012] S05: gradually repairing the moderate cracks and the severe cracks in a segmented manner;

[0013] The repair method of the moderate fissure includes: filling the moderate fissure with a repair filler to a preset height, and then filling the surface layer soil above the repair filler to the upper surface of the surface layer;

[0014] The repair method of the severe cracks includes: constructing a barrier layer at a preset depth of the severe cracks, and then filling the surface layer soil above the barrier layer to the upper surface of the surface layer.

[0015] In one of the optional technical solutions, the method for repairing the moderate cracks includes: filling the repair filler into the moderate cracks in the rock formation and filling it to the interface between the rock formation and the surface layer.

[0016] In one of the optional technical solutions, the method for repairing the severe cracks includes: the isolation layer is constructed in the severe cracks of the rock formation, and the top of the isolation layer is located at the interface between the rock formation and the surface layer.

[0017] In one of the optional technical solutions, the repair method of the severe cracks includes: using a barrier layer construction device to construct the barrier layer;

[0018] The insulation layer construction device comprises at least one set of insulation layer construction tooling, wherein the insulation layer construction tooling comprises a tooling base having a grouting flow channel, a grouting pipe head connected to the tooling base and communicating with the grouting flow channel, and a grouting lifting pipe detachably connected to the grouting pipe head;

[0019] A receiving groove is arranged around the tooling base, a rubber bag is arranged in the receiving groove, an inlet of the rubber bag is communicated with the grouting flow channel, and the rubber bag is extended out of the receiving groove and connected to the wall surface of the severe crack by grouting;

[0020] The grouting pipe head is provided with a radially extending grouting nozzle, and the grouting nozzle is located above the tooling base, and the isolation layer is formed above the rubber bladder and the tooling base through grouting.

[0021] In one of the optional technical solutions, the construction method of the isolation layer includes:

[0022] Using the grouting lifting tube, the tooling base is placed into the severe crack to a preset depth;

[0023] Injecting grout into the grouting and pulling tube, so that the grout enters the rubber bladder and expands the rubber bladder to contact the wall surface of the severe crack;

[0024] After a first preset time, the grouting is stopped, and the grouting is started again after the slurry in the rubber bag solidifies, and the slurry is sprayed into the severe cracks through the grouting nozzle and is above the rubber bag and the tooling base;

[0025] After the second preset time has passed, the grouting is stopped, and after the slurry on the rubber bag and the tooling base solidifies to form the isolation layer, the grouting pulling tube is taken out.

[0026] In one of the optional technical solutions, the tooling base is slidably provided with anchor claws on both sides along the width direction, and the anchor claws are located below the rubber bag;

[0027] The grouting pipe head is pivotally connected to the tooling base and can be driven to rotate by the grouting lifting pipe;

[0028] A driving transmission assembly is connected between the lower end of the grouting pipe head and the anchor claw;

[0029] As the grouting pipe head rotates, the driving transmission assembly drives the anchor claw to extend so as to be inserted into the wall surface of the severe crack to fix the tooling base.

[0030] In one of the optional technical solutions, a cavity is provided in the tooling base, and the lower end of the grouting pipe head is located in the cavity.

[0031] Channels communicating with the outside are provided on both sides of the cavity, and the flukes are slidably mounted in the channels;

[0032] The driving transmission assembly includes a driving gear mounted at the lower end of the grouting pipe head and two transmission racks mounted on opposite sides of the driving gear, and the two transmission racks are respectively connected to the anchor claws on both sides;

[0033] As the grouting pipe head rotates, the driving transmission assembly can drive the anchor claws on both sides to extend synchronously.

[0034] In one of the optional technical solutions, a pair of oppositely arranged lifting tube protrusions are provided at the lower end of the grouting lifting tube;

[0035] An annular groove for accommodating the lifting tube protrusion is provided in the grouting pipe head above the grouting nozzle;

[0036] The inner surface of the pipe head wall of the grouting pipe head is provided with a pair of guide grooves arranged opposite to each other, the upper ends of the guide grooves are located on the top surface of the pipe head wall, the lower ends of the guide grooves are connected to the annular groove, and the lifting tube protrusion can enter and exit the annular groove through the guide grooves;

[0037] The inner surface of the tube head wall is provided with a pair of oppositely arranged straight groove sections above the annular groove, the pair of straight groove sections and the pair of guide grooves are arranged alternately, and the lifting tube protrusion can enter the straight groove sections through the annular groove;

[0038] When the lifting tube protrusion is in the straight groove section, the grouting lifting tube can lift the grouting tube head and can rotate the grouting tube head.

[0039] In one of the optional technical solutions, the front and rear ends of the tooling base are provided with vertically extending base baffles for limiting the thickness of the partition layer.

[0040] In one of the optional technical solutions, the partition layer construction device includes a plurality of sets of the partition layer construction tools arranged in a front-to-back interval, and two adjacent tool bases are hinged;

[0041] When constructing the partition layer, the rubber bags in the extended state of the front and rear tooling bases are connected.

[0042] The above technical solution has the following beneficial effects:

[0043] The method for repairing surface cracks in coal mining subsidence areas provided by the present invention simulates the areas where light cracks, moderate cracks and severe cracks may appear through similar simulation tests before mining; uses drone monitoring during mining to determine the areas where moderate cracks and severe cracks appear; and determines the areas where moderate cracks and severe cracks appear through geophysical prospecting and drilling after mining; and then adopts different repair means corresponding to light cracks, moderate cracks and severe cracks, wherein light cracks rely on the self-healing of the surface layer, moderate cracks are repaired by filling repair fillers and surface soil, and severe cracks are repaired by constructing a barrier layer and filling the surface soil, which will not affect the underlying aquifer, saves surface soil, improves efficiency, and realizes effective repair of surface cracks. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The disclosure of the present invention will become more easily understood with reference to the accompanying drawings. It should be understood that these drawings are only for illustrative purposes and are not intended to limit the scope of protection of the present invention. In the drawings:

[0045] Figure 1 A schematic diagram of the steps of a method for repairing surface fissures in a coal mining subsidence area provided by an embodiment of the present invention;

[0046] Figure 2 It is a schematic diagram of simulating coal seam mining using a three-dimensional similarity simulation model;

[0047] Figure 3 Schematic diagram of constructing a barrier layer at a preset depth of a severe crack and then filling the surface soil above the barrier layer;

[0048] Figure 4 The main view of the tooling for the partition layer;

[0049] Figure 5 for Figure 4 A cross-sectional view along the length direction;

[0050] Figure 6 for Figure 5 A schematic diagram showing the rubber bladder expanding and extending out of the tooling base;

[0051] Figure 7 Side view of tooling for the partition layer;

[0052] Figure 8 for Figure 7 A cross-sectional view along the width direction;

[0053] Fig. 9 for Figure 8 A schematic diagram showing the anchor claw extending outward from the tooling base;

[0054] Fig.10 for Figure 8-9A schematic diagram showing the rubber bladder expanding and extending out of the tooling base;

[0055] Fig.11 A top view of a pair of flukes cooperating with a drive transmission assembly, wherein the pair of flukes are in a retracted state;

[0056] Fig.12 for Fig.11 A top view of a pair of flukes shown in an extended state;

[0057] Fig.13 A stereoscopic diagram showing a pair of lifting tube protrusions provided at the lower end of the grouting lifting tube;

[0058] Fig.14 It is a top view of the upper end of the grouting pipe head;

[0059] Fig.15 for Figure 7 Section view along AA direction;

[0060] Fig.16 for Fig.15 Cross-sectional view along BB direction;

[0061] Fig.17 for Fig.15 Sectional view along CC;

[0062] Fig.18 Schematic diagram of placing the tooling base into a severe crack, the anchor claws extending out and inserting into the wall of the severe crack, and the rubber bladder expanding out and extending out of the tooling base and connecting with the wall of the severe crack;

[0063] Fig.19 It is a schematic diagram of injecting grout onto the tooling base and the rubber bag through a grouting nozzle to form a partition layer;

[0064] Fig. 20 A schematic diagram of removing the grouting lifting pipe after forming the isolation layer;

[0065] Fig.21 The schematic diagram is for filling the surface soil above the isolation layer;

[0066] Fig. 22 A schematic diagram of a partition layer construction device including multiple sets of partition layer construction tooling;

[0067] Fig.23 It is a schematic diagram of the rubber bladders of the front and rear tooling bases being in a connected state when in an extended state;

[0068] Fig.24 This is a schematic diagram of constructing a partition layer above the front and rear tooling bases and the rubber bladder. DETAILED DESCRIPTION

[0069] The specific embodiments of the present invention are further described below in conjunction with the accompanying drawings. The same components are represented by the same reference numerals. It should be noted that the words "front", "rear", "left", "right", "upper" and "lower" used in the following description refer to directions in the accompanying drawings, and the words "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

[0070] like Figure 1-3 As shown, a method for repairing surface cracks in a coal mining subsidence area provided by an embodiment of the present invention comprises the following steps:

[0071] S01: Before mining, physical and mechanical parameters of the surface layer 100, rock layer 200, aquifer 300, impermeable layer 400, overlying rock layer 500 and coal seam 600 of the mining area are obtained by means of geophysical prospecting and drilling.

[0072] S02: Before mining, a three-dimensional similarity simulation model is constructed to simulate the collapse area of ​​the surface layer 100 and the surface fissures formed in the collapse area when the coal seam 600 is mined, and the surface fissures are divided into light fissure 1, medium fissure 2 and severe fissure 3 according to the width and depth of the surface fissures. Among them, the maximum development depth of the medium fissure 2 reaches the rock layer 200, and the maximum development depth of the severe fissure 3 reaches the aquifer 300 below the rock layer 200.

[0073] S03: During mining, the surface layer 100 of the mining site is monitored using a drone, and the areas where moderate fissures 2 and severe fissures 3 have appeared or are likely to appear are determined through monitoring images.

[0074] S04: After mining, geophysical exploration and drilling are used to determine the moderate fractures 2 and severe fractures 3 that need to be repaired.

[0075] S05: Use a segmented approach to gradually repair moderate cracks 2 and severe cracks 3.

[0076] Among them, the repair method of the moderate crack 2 includes: filling the moderate crack 2 with repair filler to a preset height, and then filling the surface soil 101 above the repair filler to the upper surface of the surface layer 100.

[0077] The repair method of the severe fissure 3 includes: constructing a barrier layer 4 at a preset depth of the severe fissure 3 , and then filling the surface soil 101 above the barrier layer 4 to the upper surface of the surface layer 100 .

[0078] The method for repairing surface fissures in coal mining subsidence areas provided by the present invention is used to repair surface fissures formed by surface layer collapse caused by coal mining. After the surface fissures are repaired, the integrity of the surface layer of the mining area can be maintained for reclamation, planting of vegetation, etc.

[0079] The stratum structure is generally divided into the surface layer 100, the rock layer 200, the aquifer 300, the impermeable layer 400, the overburden rock layer 500 and the coal seam 600 from top to bottom. Of course, some strata may contain multiple layers of coal seams 600. When the coal seam 600 is mined, as the coal mining face advances, a goaf 700 will be formed behind it, and the overburden rock layer 500 above the coal seam roof will fall into the goaf 700, which in turn affects the area corresponding to the surface layer 100 to collapse, thereby generating some cracks.

[0080] Some cracks are generated by the stretching of the surface layer. They are narrow and shallow. They are mainly generated in the surrounding areas of the surface collapse area. They are generally several centimeters wide and mainly developed in the surface layer 100. These cracks are generally called tensile cracks. After the geological stress is released or the surface settlement is stabilized, the tensile cracks can heal themselves. Therefore, these tensile cracks generally do not need special treatment. In the present invention, the tensile cracks are called mild cracks 1.

[0081] Some cracks are caused by the collapse of the surface layer 100, mainly in the surface collapse area. They are wide and deep. Some cracks are as wide as tens of centimeters or even more than half a meter. Their development depth can generally reach the rock layer 200, and some even reach the aquifer 300. These cracks are generally called collapse cracks, which cannot heal automatically and require special treatment.

[0082] The specific width and depth of the above-mentioned tensile cracks and collapse cracks depend on the physical and mechanical properties of the geological structure of the mining area and the coal mining method.

[0083] In order to more reasonably manage the collapse fissures, the present invention further classifies the collapse fissures and adopts different repair methods. Generally, the wider the collapse fissures, the deeper their development depth. In the present invention, the collapse fissures are divided into moderate fissures 2 and severe fissures 3. The maximum development depth of the moderate fissures 2 can reach the rock layer 200, and the maximum development depth of the severe fissures 3 can reach the aquifer 300. The width of the severe fissures 3 is generally greater than the width of the moderate fissures 2.

[0084] The method for repairing surface cracks in coal mining subsidence areas provided by the present invention comprises the following specific steps:

[0085] Step 1: Before mining the coal seam 600, physical and mechanical parameters of the surface layer 100, rock layer 200, aquifer 300, impermeable layer 400, overburden rock layer 500 and coal seam 600 of the mining area are obtained by geophysical exploration and drilling. The thickness, position, hardness, depth, etc. of each layer are detected to provide guidance for the subsequent determination of the occurrence area of ​​surface fissures and the division of surface fissures.

[0086] Step 2: Before mining the coal seam 600, a three-dimensional similarity simulation model is constructed, which includes the surface layer 100, the rock layer 200, the aquifer 300, the impermeable layer 400, the overburden rock layer 500 and the coal seam 600, and simulates the overburden rock layer 500 falling into the goaf 700 when the coal seam 600 is mined, so as to form a subsidence area in the surface layer 100 and a surface fissure formed in the subsidence area. Thus, according to the width and depth of the surface fissures, light fissures 1, moderate fissures 2 and severe fissures 3 are divided, and it can guide the areas, fissure widths, fissure depths, etc. of light fissures 1, moderate fissures 2 and severe fissures 3 in the mining field during the actual mining process, and which areas may have moderate fissures 2 and severe fissures 3, etc.

[0087] Step 3: When mining the coal seam 600, use a drone to monitor the surface layer 100 of the mining site, and determine the areas where moderate fissures 2 and severe fissures 3 have appeared and may appear through monitoring images. The camera of the drone is connected to the control equipment (e.g., computer) of the mining site through a wireless signal, and the captured images, videos, etc. are transmitted to the control equipment for the user to watch on the screen. By watching the images and videos, the existing fissures can be roughly determined. If the width of some fissures is wide, reaching more than 10 cm, it is judged that the area is the area where moderate fissures 2 and severe fissures 3 are generated. It is also possible to roughly determine the areas where moderate fissures 2 and severe fissures 3 may appear in the future based on their generation rules, so as to provide guidance for the subsequent geophysical exploration and drilling to determine the location of moderate fissures 2 and severe fissures 3.

[0088] Step 4: After mining the coal seam 600 and the collapse of the surface layer 100 is completed, the medium cracks 2 and severe cracks 3 that need to be repaired are determined by geophysical exploration and drilling according to the area determined in the above steps. For example, tools can be used to measure the width and depth of the cracks, determine the rock properties and water content at the bottom of the cracks, and determine whether the cracks are medium cracks 2 or severe cracks 3. If the bottom of a surface crack develops to the middle and lower part of the rock layer 200, or even to the aquifer 300, the surface crack is judged to be a severe crack 3. If the bottom of a surface crack develops to the middle and upper part of the rock layer 200, the surface crack is judged to be a medium crack 2. The reason why the standard is positioned in the middle of the rock layer 200 is that once the crack develops below the middle of the rock layer 200, the small cracks around it are more likely to be connected to the aquifer 300.

[0089] Step 5: Use segmented method to gradually repair the moderate cracks 2 and the severe cracks 3. The segmented method referred to here refers to segmented repair along the length direction of the moderate cracks 2 and the severe cracks 3.

[0090] The repair method of the moderate fissure 2 is: fill the repair filler into the moderate fissure 2 to a preset height. The repair filler can be concrete or a mixture of sand and solidifying materials. The solidifying material can be a microbial solidifying material for solidifying the sand. The microbial solidifying material can be Bacillus pasteurianus, etc., which conducts metabolic activities in a nutrient salt environment rich in calcium ions and nitrogen sources to induce the deposition of calcium carbonate. These microorganisms convert dissolved calcium ions and carbon dioxide into calcium carbonate through metabolism, and deposit them on the surface and gaps of sand particles to form a stable cement, thereby enhancing the mechanical properties and stability of the sand. The repair filler is mainly used to fill the part where the moderate fissure 2 develops into the rock stratum 200. After the repair filler solidifies in the fissure, the structure is stable and compatible with the surrounding rock stratum 200. It can also adhere to the surrounding rock stratum 200 to improve the repair effect of the rock stratum part.

[0091] After the repair filler is filled and solidified, the surface soil 101 is filled above the repair filler to the upper surface of the surface layer 100 to complete the repair of the surface cracks. Since the surface soil 101 is completely filled in the moderate cracks 2 in the surface layer 100, the soil in the crack part is basically the same as the surrounding soil after the repair. The surface soil 101 can be dug from the surface of the mining site. By first filling the repair filler to repair the moderate cracks 2 in the rock layer 200, and then filling the surface soil 101 to repair the moderate cracks 2 in the surface layer 100, on the one hand, the effect of repairing the rock cracks can be improved, and on the other hand, the surface soil 101 can be saved.

[0092] The method for repairing the severe fissures 3 is as follows: first, a barrier layer 4 is constructed at a preset depth of the severe fissures 3. The barrier layer 4 isolates the severe fissures 3 along the width direction, and the lower part thereof is no longer filled, which plays the role of filling the foundation and can also prevent the filler from entering the aquifer 300. The barrier layer 4 is constructed in the severe fissures 3 of the rock layer 200, and then the surface soil 101 is filled above the barrier layer 4 to the upper surface of the surface layer 100. Since the surface soil 101 is completely filled in the severe fissures 3 of the surface layer 100, after the repair, the soil in the fissure part is basically the same as the surrounding soil, and there is no difference. By first constructing the barrier layer 4 in the severe fissures 3 in the rock layer 200, and then filling the surface soil 101 to repair the severe fissures 3 in the surface layer 100, the problem of filler entering the aquifer 300 and causing waste of filler in the existing method can be avoided.

[0093] There are two ways to form the isolation layer 4:

[0094] The first method is to drill a plurality of transverse grouting pipes arranged side by side along the length direction of the severe cracks 3 , the transverse grouting pipes pass through the severe cracks 3 along the width direction, and concrete slurry is injected into the transverse grouting pipes to form a barrier layer 4 in the severe cracks 3 .

[0095] The second method is to use the barrier layer construction device mentioned in the following embodiment to construct the barrier layer 4.

[0096] In summary, the method for repairing surface cracks in coal mining subsidence areas provided by the present invention simulates the areas where light cracks 1, moderate cracks 2 and severe cracks 3 may appear through similar simulation tests before mining. During mining, drone monitoring is used to determine the areas where moderate cracks 2 and severe cracks 3 appear. After mining, the areas of moderate cracks 2 and severe cracks 3 are determined by geophysical prospecting and drilling. Then, different repair methods are used for light cracks 1, moderate cracks 2 and severe cracks 3. Light cracks 1 rely on the self-healing of the surface layer 100, moderate cracks 2 are repaired by filling, and severe cracks 3 are repaired by constructing a barrier layer 4 and filling. It will not affect the aquifer 300 below, saves fillers, improves efficiency, and realizes effective repair of cracks in the surface layer 100.

[0097] In one embodiment, the repair method of the medium cracks 2 includes: filling the repair filler in the medium cracks 2 of the rock layer 200 and filling it to the interface between the rock layer 200 and the surface layer 100, so as to ensure that the repair filler completely fills the medium cracks 2 in the rock layer 200, and ensure that the surface layer soil 101 is used to fill the medium cracks 2 in the surface layer 100. The height of the repair filler can be determined by estimating the volume or by on-site detection.

[0098] In one embodiment, the repair method of the severe cracks 3 includes: a barrier layer 4 is constructed in the severe cracks 3 of the rock layer 200, and the top of the barrier layer 4 is located at the interface between the rock layer 200 and the surface layer 100, so as to ensure that the barrier layer 4 is constructed in the severe cracks 3 in the rock layer 200, and ensure that the surface layer soil 101 is used to fill the severe cracks 3 in the surface layer 100. The height of the barrier layer 4 can be determined by on-site detection.

[0099] In one embodiment, if Figure 4-10 and Figure 18-21 As shown, the repair method of the severe crack 3 includes: constructing the isolation layer 4 using an isolation layer construction device.

[0100] The barrier layer construction device includes at least one barrier layer construction tool 5, which includes a tool base 51 with a grouting channel 511, a grouting pipe head 52 connected to the tool base 51 and communicated with the grouting channel 511, and a grouting pulling pipe 53 detachably connected to the grouting pipe head 52.

[0101] A receiving groove 512 is provided around the tooling base 51, and a rubber bag 54 is provided in the receiving groove 512. The inlet of the rubber bag 54 is connected to the grouting channel 511. Through grouting, the rubber bag 54 extends out of the receiving groove 512 and connects with the wall of the severe crack 3.

[0102] A radially extending grouting nozzle 522 is provided on the grouting pipe head 52 . The grouting nozzle 522 is located above the tooling base 51 . Grouting is performed to form a partition layer 4 above the rubber bladder 54 and the tooling base 51 .

[0103] The method of drilling and installing a transverse grouting pipe is relatively inefficient. In this embodiment, a special barrier layer construction device is used to construct the barrier layer 4.

[0104] The barrier layer construction device comprises at least one set of barrier layer construction tools 5 , each set of barrier layer construction tools 5 can be used to construct the barrier layer 4 , and the number of barrier layer construction tools 5 can be selected according to the length of the barrier layer 4 currently required to be constructed.

[0105] The isolation layer construction tool 5 includes a tool base 51 , a grouting pipe head 52 , a grouting pulling pipe 53 and a plurality of rubber bags 54 .

[0106] The tooling base 51 is substantially rectangular and can be formed by connecting a plurality of modules in sequence along the width direction, so that the width of the tooling base 51 can be changed according to the width of the severe crack 3 .

[0107] The tool base 51 has a grouting flow channel 511, and the grouting flow channel 511 can adopt a plurality of linear flow channels. The middle part of the tool base 51 has a mounting hole for mounting a grouting pipe head 52. The grouting flow channel 511 extends from the mounting hole to the peripheral edge of the tool base 51.

[0108] A receiving groove 512 is provided around the tool base 51. Specifically, a receiving groove 512 is provided on both sides of the tool base 51 in the width direction. One or more rubber bladders 54 are provided in the receiving groove 512, and the entrance of each rubber bladder 54 is connected to the grouting flow channel 511. In normal state, the rubber bladder 54 is accommodated in the receiving groove 512, so when the tool base 51 is placed in the severe fissure 3, the rubber bladder 54 will not touch the wall or rock of the severe fissure 3. When slurry is injected into the rubber bladder 54, it will expand and extend from the receiving groove 512 to connect with the wall of the severe fissure 3, playing the role of sealing the gap between the side of the tool base 51 and the wall of the severe fissure 3, so as to receive the slurry injected from the grouting pipe head 52 above, and avoid or reduce the slurry from flowing down from the gap between the side of the tool base 51 and the wall of the severe fissure 3. Since the rubber bag 54 is a flexible bag, it can adapt to the wall surface of the severe crack 3 and deform, and has a good connection effect with the wall surface of the severe crack 3.

[0109] The grouting pipe head 52 has a grouting channel, and the lower end of the grouting channel is closed. The lower end of the grouting pipe head 52 is connected to the mounting hole of the tooling base 51, and the upper end of the grouting pipe head 52 extends above the tooling base 51. The middle and lower part of the grouting pipe head 52 has a grouting outlet 521 connected to the grouting channel, and the grouting outlet 521 is located at the lower end of the grouting channel. The grouting inlet of each grouting flow channel 511 is connected to the grouting outlet 521. The grouting pipe head 52 is provided with a plurality of grouting nozzles 522 connected to the grouting channel, and the grouting nozzles 522 are located above the tooling base 51 and extend radially along the grouting pipe head 52.

[0110] Specifically, a connecting sleeve is provided on the top of the tooling base 51, and the lower end of the grouting pipe head 52 is connected to the mounting hole via the connecting sleeve, and the grouting pipe head 52 is located above the connecting sleeve.

[0111] Grouting is performed through the grouting nozzle 522 to form a partition layer 4 above the rubber bladder 54 and the tooling base 51 .

[0112] The lower end of the grouting lifting tube 53 is detachably connected to the grouting pipe head 52, for example, by means of threads, etc. So that after the construction of the isolation layer 4 is completed, the grouting lifting tube 53 can be removed and reused. The grouting lifting tube 53 is used to lift the tooling base 51 so as to place the tooling base 51 into a designated position in the severe crack 3. The grouting lifting tube 53 has a grouting channel for connecting to the grouting equipment for grouting. The grouting channel of the grouting lifting tube 53 is connected to the grouting channel of the grouting pipe head 52. The grouting lifting tube 53 can adopt a telescopic structure so as to adjust the depth of the tooling base 51 into the severe crack 3.

[0113] The grouting slurry mentioned in this embodiment can be concrete slurry. The length of the tooling base 51 is greater than the width of the severe crack 3, and the width of the tooling base 51 is less than the width of the severe crack 3. The gap between the two needs to meet the rubber bag 54 to be able to connect to the wall of the severe crack 3 after being extended.

[0114] When the tooling 5 is constructed using a partition layer, the tooling base 51 is placed into the severe fissure 3 to a preset depth using a grouting pull-up tube 53, and then grouting is injected into the grouting pull-up tube 53 for a period of time. Since the grouting channel 511 is below the grouting nozzle 522 and at the lower end of the grouting channel, the slurry is first injected into the rubber bladder 54 through the grouting channel 511 to expand it. According to the time counted in advance experiments, after the first period of grouting, the grouting is ended, and the slurry in the rubber bladder 54 is waited to solidify to keep the rubber bladder 54 in contact with the wall of the severe fissure 3. During the first stage of grouting, the slurry will basically not be ejected from the grouting nozzle 522. Since the volume of the rubber bladder 54 is limited, the grouting pressure is low during the first grouting period. For example, the first stage grouting pressure is set to F. As needed, a pressure stop valve can be set in the grouting nozzle 522. When the grouting pressure in the grouting channel is greater than F, the pressure stop valve opens and the grouting nozzle 522 starts grouting. This ensures that the slurry will not spray out from the grouting nozzle 522 during the first stage of grouting.

[0115] After the slurry in the rubber bag 54 solidifies to form a support layer, the second stage of grouting begins. At this time, since the rubber bag 54 and the grouting flow channel 511 are both solid structures, the slurry will be sprayed out from the upper grouting nozzle 522 and fall on the upper part of the extended rubber bag 54 and the upper part of the tooling base 51. After the second period of time, the grouting is stopped and the slurry is waited for to solidify, thereby forming a barrier layer 4, which is connected to the wall of the severe fissure 3. After the barrier layer 4 is formed, the grouting lifting pipe 53 is taken out, and the surface soil 101 can be filled above the barrier layer 4.

[0116] In one embodiment, if Figure 4-10 and Figure 18-21 As shown, the construction method of the isolation layer 4 includes:

[0117] The tooling base 51 is placed into the severe crack 3 to a preset depth using the grouting lifting tube 53 .

[0118] Grout is injected into the grouting and pulling tube 53 , and the grout enters the rubber bladder 54 and causes the rubber bladder 54 to expand so as to contact the wall surface of the severe crack 3 .

[0119] After the first preset time, the grouting is stopped, and the grouting is started again after the slurry in the rubber bag 54 solidifies. The slurry is sprayed into the severe cracks 3 through the grouting nozzle 522 and is above the rubber bag 54 and the tooling base 51.

[0120] After the second preset time has passed, the grouting is stopped, and after the slurry on the rubber bag 54 and the tooling base 51 solidifies to form the isolation layer 4, the grouting pulling tube 53 is taken out.

[0121] In one embodiment, if Figure 8-10 and Figure 18-21 As shown, the tooling base 51 is slidably provided with anchor claws 55 on both sides along the width direction, and the anchor claws 55 are located below the rubber bag 54.

[0122] The grouting pipe head 52 is pivotally connected to the tooling base 51 and can be driven to rotate by the grouting lifting pipe 53 .

[0123] A driving transmission assembly 56 is connected between the lower end of the grouting pipe head 52 and the anchor claw 55 .

[0124] As the grouting pipe head 52 rotates, the driving transmission assembly 56 drives the anchor claw 55 to extend so as to be inserted into the wall surface of the severe crack 3 for fixing the tooling base 51 .

[0125] In this embodiment, retractable anchor claws 55 are arranged on the left and right sides of the tooling base 51, and the number of anchor claws 55 can be set as needed. For example, if multiple anchor claws 55 are arranged on each side, the multiple anchor claws 55 on each side are installed on a connecting plate 551. The anchor claws 55 are located below the rubber bag 54, and are used to extend and insert into the wall surface of the severe crack 3 to fix the tooling base 51.

[0126] The grouting pipe head 52 is pivotally connected to the tooling base 51 , and the grouting pipe head 52 can be driven to rotate by the grouting lifting pipe 53 .

[0127] In this embodiment, the grout outlet 521 of the grouting pipe head 52 is annular to maintain communication with the inlet of the grouting flow channel 511. When the annular grout outlet 521 rotates, the portion not connected with the inlet of the grouting flow channel 511 will be sealed by the hole wall of the mounting hole. The grouting pipe head 52 can be connected to the hole wall of the mounting hole by a bearing, a rotating ring, etc., or connected to a connecting sleeve.

[0128] A drive transmission assembly 56 is connected between the lower end of the grouting pipe head 52 and the anchor claw 55. The drive transmission assembly 56 can be acted upon by the rotating grouting pipe head 52 to drive the drive transmission assembly 56 to drive the anchor claw 55 to extend, thereby inserting it into the wall surface of the severe crack 3 for fixing the tooling base 51.

[0129] In the present invention, for the convenience of description, the length direction of the tooling base 51 is defined as the front-to-back direction, and the width direction thereof is defined as the left-to-right direction.

[0130] As required, the anchor claw 55 can be extended before grouting into the rubber bag 54. Specifically, after the tooling base 51 is put into the severe crack 3, the grouting lifting pipe 53 is rotated to drive the grouting pipe head 52 to rotate. At the beginning, the tooling base 51 will be driven to swing at a certain angle under the action of friction, and its front and rear ends will contact the wall surface of the severe crack 3. Then the grouting lifting pipe 53 is continued to be rotated, and the grouting pipe head 52 drives the driving transmission component 56 to operate, driving the anchor claw 55 to extend. When the anchor claw 55 is extended, the anchor claws 55 at the front and rear ends will automatically align the tooling base 51. For example, if the tooling base 51 is in a swinging state with the front end leaning to the left and the rear end leaning to the right, then when the anchor claws 55 are extended, the anchor claws 55 on the left side of the front end and the anchor claws 55 on the right side of the rear end first contact the wall surface of the severe crack 3, and the tooling base 51 is straightened through the reaction force of the anchor claws 55 on the left side of the front end and the anchor claws 55 on the right side of the rear end, and finally the anchor claws 55 on the left and right sides of the tooling base 51 can be inserted into the wall surface of the severe crack 3.

[0131] In one embodiment, if Figure 5-6 and Figure 8-12 As shown, a cavity 513 is provided in the tooling base 51, and the lower end of the grouting pipe head 52 is located in the cavity 513.

[0132] Channels 515 communicating with the outside are provided on both sides of the cavity 513 , and the flukes 55 are slidably assembled in the channels 515 .

[0133] The driving transmission assembly 56 includes a driving gear 561 mounted on the lower end of the grouting pipe head 52 and two transmission racks 562 mounted on opposite sides of the driving gear 561. The two transmission racks 562 are respectively connected to the anchor claws 55 on both sides.

[0134] As the grouting pipe head 52 rotates, the driving transmission assembly 56 can drive the anchor claws 55 on both sides to extend synchronously.

[0135] In this embodiment, a cavity 513 is provided in the tooling base 51, and a lower end cover 514 is detachably provided at the bottom of the cavity 513 to install the components in the cavity 513. The lower ends of the drive transmission assembly 56 and the grouting pipe head 52 are both in the cavity 513.

[0136] The left and right sides of the cavity 513 are provided with channels 515 communicating with the outside, and the flukes 55 are slidably assembled in the channels 515. Specifically, the multiple flukes 55 on each side are mounted on a connecting plate 551, and the connecting plate 515 can enter the cavity 513 and can also slide along the channels 515 to drive the flukes 55 to extend.

[0137] The driving transmission assembly 56 includes a driving gear 561 and a pair of transmission racks 562. The driving gear 561 is mounted on the lower end of the grouting pipe head 52 and is driven to rotate by the grouting pipe head 52. A pair of transmission racks 562 are arranged on the front and rear sides of the driving gear 561 and mesh with the driving gear 561. The two transmission racks 562 are respectively connected to the two connecting plates 551. As the grouting pipe head 52 rotates, the driving gear 561 drives the two transmission racks 562 to move synchronously, and then drives the anchor claws 55 on both sides to extend synchronously through the two connecting plates 551.

[0138] In one embodiment, if Figure 13-17 As shown, a pair of lifting tube protrusions 531 arranged opposite to each other are provided at the lower end of the grouting lifting tube 53.

[0139] An annular groove 523 for accommodating the lifting tube protrusion 531 is provided in the grouting pipe head 52 above the grouting nozzle 522 .

[0140] The inner surface of the pipe head wall of the grouting pipe head 52 is provided with a pair of relatively arranged guide grooves 524, the upper ends of the guide grooves 524 are located on the top surface of the pipe head wall, and the lower ends of the guide grooves 524 are connected to the annular groove 523, and the pulling tube protrusion 531 can enter and exit the annular groove 523 through the guide grooves 524.

[0141] The inner surface of the tube head wall is provided with a pair of oppositely arranged straight groove sections 525 above the annular groove 523 . The pair of straight groove sections 525 are alternately arranged with a pair of guide grooves 524 . The lifting tube protrusion 531 can enter the straight groove section 525 through the annular groove 523 .

[0142] When the lifting tube protrusion 531 is in the straight groove section 525 , the grouting lifting tube 53 can lift the grouting tube head 52 and can rotate the grouting tube head 52 .

[0143] In this embodiment, when assembling the lower end of the grouting lifting tube 53 with the grouting pipe head 52, first align the lifting tube protrusion 531 with the guide groove 524 of the grouting pipe head 52, and then insert the lower end of the grouting lifting tube 53 into the grouting pipe head 52 until the lifting tube protrusion 531 enters the annular groove 523. Then rotate the grouting lifting tube 53 by a certain angle, such as 90°, so that the lifting tube protrusion 531 is aligned with the straight groove section 525. Lift the grouting lifting tube 53 upward, so that the lifting tube protrusion 531 enters the straight groove section 525, and the grouting lifting tube 53 can drive the grouting pipe head 52 to rotate. When the grouting lifting tube 53 needs to be disassembled, the grouting lifting tube 53 is dropped, the lifting tube protrusion 531 enters the annular groove 523, and the grouting lifting tube 53 is rotated in the opposite direction by a certain angle so that the lifting tube protrusion 531 is aligned with the guide groove 524, and the grouting lifting tube 53 is lifted.

[0144] In one embodiment, if Figure 4 As shown, the front and rear ends of the tooling base 51 are provided with base baffles 57 extending vertically to limit the thickness of the partition layer 4 .

[0145] In one embodiment, if Figure 22-24 As shown, the partition layer construction device includes a plurality of partition layer construction tooling 5 arranged at intervals in front and back, and two adjacent tooling bases 51 in front and back are hinged.

[0146] When the partition layer 4 is constructed, the rubber bags 54 of the two front and rear tooling bases 51 in the extended state are connected.

[0147] In this embodiment, in order to increase the length of the barrier layer 4 constructed at one time, the barrier layer construction device uses multiple sets of barrier layer construction tools 5, and two adjacent tool bases 51 are hinged to adapt to the bending of the heavy crack 3 in the length direction. Of course, if the curvature of the heavy crack 3 is too large or too sharp, it needs to be handled according to the situation.

[0148] In this embodiment, the front and rear ends of the tooling base 51 are also provided with accommodating grooves 512, which can be connected to or separated from the accommodating grooves 512 on the side. Rubber bags 54 are also provided in the accommodating grooves 512 on the front and rear ends, which are separated from the rubber bags 54 on the side to avoid mutual interference.

[0149] When constructing the partition layer 4, the rubber bags 54 in the extended state of the front and rear tooling bases 51 are connected to each other, so as to form a support layer between the front and rear tooling bases 51 for receiving the slurry injected from the grouting pipe head 52 above, thereby avoiding or reducing the slurry from flowing down from the gap between the two tooling bases 51.

[0150] Ear plates may be provided at the front and rear ends of the tooling base 51, and the front and rear adjacent ear plates are connected via a rotating shaft.

[0151] In this embodiment, a base baffle 57 may be provided at the front end of the frontmost tooling base 51 and the rear end of the rearmost tooling base 51 to limit the thickness of the partition layer 4 .

[0152] As needed, the above technical solutions can be combined to achieve the best technical effect.

[0153] The above are only the principles and preferred embodiments of the present invention. It should be noted that, for those skilled in the art, several other modifications can be made based on the principles of the present invention, which should also be considered as the protection scope of the present invention.

Claims

1. A method for repairing surface fissures in coal mining subsidence areas, characterized in that: The steps include: S01: Before mining, physical and mechanical parameters of the surface layer, rock layer, aquifer, impermeable layer, overburden rock layer and coal seam of the mining area are obtained by means of geophysical exploration and drilling; S02: Before mining, a three-dimensional similarity simulation model is constructed to simulate the collapse area of ​​the surface layer and the surface fissures formed in the collapse area during coal seam mining, and the surface fissures are divided into light fissures, medium fissures and severe fissures according to their width and depth; wherein the maximum development depth of the medium fissures reaches the rock layer, and the maximum development depth of the severe fissures reaches the aquifer below the rock layer; S03: During mining, the surface layer of the mining site is monitored by using a drone, and the areas where the moderate cracks and the severe cracks have appeared or are likely to appear are determined through monitoring images; S04: After mining, geophysical exploration and drilling are used to determine the moderate cracks and severe cracks that need to be repaired; S05: gradually repairing the moderate cracks and the severe cracks in a segmented manner; The repair method of the moderate fissure includes: filling the moderate fissure with a repair filler to a preset height, and then filling the surface layer soil above the repair filler to the upper surface of the surface layer; The repair method of the severe cracks includes: constructing a barrier layer at a preset depth of the severe cracks, and then filling the surface layer soil above the barrier layer to the upper surface of the surface layer; The method for repairing the severe cracks includes: constructing the isolation layer using an isolation layer construction device; The insulation layer construction device comprises at least one set of insulation layer construction tooling, wherein the insulation layer construction tooling comprises a tooling base having a grouting flow channel, a grouting pipe head connected to the tooling base and communicating with the grouting flow channel, and a grouting lifting pipe detachably connected to the grouting pipe head; A receiving groove is arranged around the tooling base, a rubber bag is arranged in the receiving groove, an inlet of the rubber bag is communicated with the grouting flow channel, and the rubber bag is extended out of the receiving groove and connected to the wall surface of the severe crack by grouting; The grouting pipe head is provided with a radially extending grouting nozzle, and the grouting nozzle is located above the tooling base, and the isolation layer is formed above the rubber bladder and the tooling base through grouting.

2. The method for repairing surface fissures in coal mining subsidence areas according to claim 1, characterized in that: The repair method of the moderate cracks includes: the repair filler is filled in the moderate cracks of the rock formation and filled to the interface between the rock formation and the surface layer.

3. The method for repairing surface fissures in coal mining subsidence areas according to claim 1, characterized in that: The repair method of the severe cracks includes: the isolation layer is constructed in the severe cracks of the rock layer, and the top of the isolation layer is located at the interface between the rock layer and the surface layer.

4. The method for repairing surface fissures in coal mining subsidence areas according to claim 1, characterized in that: The construction method of the isolation layer includes: Using the grouting lifting tube, the tooling base is placed into the severe crack to a preset depth; Injecting grout into the grouting and pulling tube, so that the grout enters the rubber bladder and expands the rubber bladder to contact the wall surface of the severe crack; After a first preset time, the grouting is stopped, and the grouting is started again after the slurry in the rubber bag solidifies, and the slurry is sprayed into the severe cracks through the grouting nozzle and is above the rubber bag and the tooling base; After the second preset time has passed, the grouting is stopped, and after the slurry on the rubber bag and the tooling base solidifies to form the isolation layer, the grouting pulling tube is taken out.

5. The method for repairing surface fissures in coal mining subsidence areas according to claim 1, characterized in that: The tooling base is slidably provided with anchor claws on both sides along the width direction, and the anchor claws are located below the rubber bag; The grouting pipe head is pivotally connected to the tooling base and can be driven to rotate by the grouting lifting pipe; A driving transmission assembly is connected between the lower end of the grouting pipe head and the anchor claw; As the grouting pipe head rotates, the driving transmission assembly drives the anchor claw to extend so as to be inserted into the wall surface of the severe crack to fix the tooling base.

6. The method for repairing surface fissures in coal mining subsidence areas according to claim 5, characterized in that: A cavity is provided in the tooling base, and the lower end of the grouting pipe head is located in the cavity. Channels communicating with the outside are provided on both sides of the cavity, and the flukes are slidably mounted in the channels; The driving transmission assembly includes a driving gear mounted at the lower end of the grouting pipe head and two transmission racks mounted on opposite sides of the driving gear, and the two transmission racks are respectively connected to the anchor claws on both sides; As the grouting pipe head rotates, the driving transmission assembly can drive the anchor claws on both sides to extend synchronously.

7. The method for repairing surface fissures in coal mining subsidence areas according to claim 5, characterized in that: A pair of oppositely arranged lifting tube protrusions are provided at the lower end of the grouting lifting tube; An annular groove for accommodating the lifting tube protrusion is provided in the grouting pipe head above the grouting nozzle; The inner surface of the pipe head wall of the grouting pipe head is provided with a pair of guide grooves arranged opposite to each other, the upper ends of the guide grooves are located on the top surface of the pipe head wall, the lower ends of the guide grooves are connected to the annular groove, and the lifting tube protrusion can enter and exit the annular groove through the guide grooves; The inner surface of the tube head wall is provided with a pair of oppositely arranged straight groove sections above the annular groove, the pair of straight groove sections and the pair of guide grooves are arranged alternately, and the lifting tube protrusion can enter the straight groove sections through the annular groove; When the lifting tube protrusion is in the straight groove section, the grouting lifting tube can lift the grouting tube head and can rotate the grouting tube head.

8. The method for repairing surface fissures in coal mining subsidence areas according to claim 1, characterized in that: The front and rear ends of the tooling base are provided with base baffles extending vertically, which are used to limit the thickness of the partition layer.

9. The method for repairing surface fissures in coal mining subsidence areas according to claim 1, characterized in that: The partition layer construction device comprises a plurality of sets of the partition layer construction tools arranged in a front-to-back interval, and two adjacent tool bases are hinged; When constructing the partition layer, the rubber bags in the extended state of the front and rear tooling bases are connected.

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