CN116816436A - Stable control method suitable for narrow coal pillar gob-side entry driving surrounding rock - Google Patents
Stable control method suitable for narrow coal pillar gob-side entry driving surrounding rock Download PDFInfo
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- 239000003245 coal Substances 0.000 title claims abstract description 133
- 239000011435 rock Substances 0.000 title claims abstract description 102
- 238000000034 method Methods 0.000 title claims abstract description 48
- 238000005422 blasting Methods 0.000 claims abstract description 77
- 230000002787 reinforcement Effects 0.000 claims abstract description 41
- 230000000694 effects Effects 0.000 claims abstract description 33
- 238000005520 cutting process Methods 0.000 claims abstract description 30
- 238000010276 construction Methods 0.000 claims abstract description 23
- 230000003014 reinforcing effect Effects 0.000 claims abstract description 16
- 238000005553 drilling Methods 0.000 claims description 54
- 238000007789 sealing Methods 0.000 claims description 20
- 239000002002 slurry Substances 0.000 claims description 12
- 238000002347 injection Methods 0.000 claims description 9
- 239000007924 injection Substances 0.000 claims description 9
- 239000007787 solid Substances 0.000 claims description 8
- 230000000087 stabilizing effect Effects 0.000 claims description 8
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- 230000004048 modification Effects 0.000 description 13
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- 238000013461 design Methods 0.000 description 6
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- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
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- 238000000605 extraction Methods 0.000 description 3
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Abstract
The application discloses a surrounding rock stability control method suitable for narrow coal pillar gob-side entry driving, which belongs to the field of surrounding rock stability control and comprises the following steps: acquiring the structural characteristics of the overlying strata of the narrow coal pillar gob-side entry driving, and optimally designing the key parameters of the pre-splitting blasting of the overlying strata; obtaining a presplitting blasting roof-cutting pressure relief construction effect based on the key parameters of the cover rock presplitting blasting; grouting reinforcement is carried out on the narrow coal pillars of the gob-side entry driving based on the roof-cutting pressure relief construction effect, so that a grouting reinforcement effect of the narrow coal pillars is obtained; and dynamically reinforcing and supporting key parts of the gob-side entry driving roadway based on the roof-cutting pressure relief construction effect and the narrow coal pillar grouting reinforcement effect. The application can optimize the stress environment of the narrow coal pillar, effectively enhance the overall strength and bearing capacity of the narrow coal pillar, further inhibit the deformation and damage of the roadway through dynamic reinforcement support, and greatly reduce the support cost.
Description
Technical Field
The application belongs to the technical field of surrounding rock stability control, and particularly relates to a surrounding rock stability control method suitable for narrow coal pillar gob-side entry driving.
Background
About 92% of coal mines in China are underground mining, and in order to improve the coal resource mining rate, a narrow coal pillar gob-side entry driving technology is adopted at present. The narrow coal pillar gob-side entry driving refers to a driving mode that a new roadway is driven out along the edge of a goaf where the last adjacent working face has been collapsed by a mode of reserving a small coal pillar as a stoping roadway of the next working face. In order to relieve the situation of the tension of mine excavation succession, the heading of the next section working face is not advanced to carry out roof cutting pressure relief or section coal pillar treatment on the stoping tunnel of the next section working face before stoping or during stoping, and the stoping tunnel of the next section working face is finished. Under the engineering background, the section coal pillar between the upper section and the lower section faces the lateral supporting pressure influence during the stoping of the working face of the last section, the tunneling influence of the section, the advanced supporting pressure and the lateral supporting pressure influence during the stoping of the working face of the section, so that the narrow coal pillar is poor in stress environment, the problems of roof caving, large upper part moving amount, large bottom bulging amount and the like are easily caused, the stability control difficulty of the surrounding rock of the tunnel is increased, and serious threat is brought to the safe and efficient production of the coal mining working face.
The existing stoping roadway mainly adopts the supporting scheme of anchor net spraying supporting, anchor net spraying supporting and the like. When the anchor rod/anchor cable with excessive rigidity and small deformation amount faces the large deformation of the surrounding rock of the roadway, the anchor rod/anchor cable cannot ensure that larger elongation deformation is cooperatively generated in the supporting process, and the problem that the anchor rod/anchor cable breaks off and loses the supporting capacity is solved; the concrete spraying layer also has the problem of easy cracking and falling. The traditional support mode is poor in stress environment, and when surrounding rock deformation is large in the gob-side entry, the expected support effect is difficult to achieve. Meanwhile, the roadway side on the side of the upper section is easily influenced by the goaf water of the working surface of the upper section, so that the mechanical property of the surrounding rock of the section coal pillar is obviously deteriorated, the strength of the narrow coal pillar is low, and the narrow coal pillar is easily caused to be locally unstable under the mining influence of the working surface.
In the prior art, a single or multiple supporting control method is mostly adopted for the stability control of surrounding rock of a tunneling roadway along the sky. When a single surrounding rock stability control method is used, the stability of surrounding rock of a gob-side roadway with more complex geological environment and stress environment is difficult to ensure, so that the gob-side roadway is subjected to repeated repair caused by the problem of strong mine pressure during stoping, and safe and efficient mining is restricted; when the multiple surrounding rock stabilization control method is blindly used, the problems of low supporting efficiency, resource waste and the like are caused by complex working procedures and more supporting materials.
Disclosure of Invention
The application provides a stable control method suitable for surrounding rock of a narrow coal pillar gob-side entry driving, which mainly aims at the problems that a next section of stoping roadway is driven along the edge of a goaf of a previous section, and roof cutting pressure relief or section coal pillar treatment is not adopted in advance before or during stoping of the previous section, so as to solve the technical problems in the prior art.
In order to achieve the above purpose, the application provides a stable control method suitable for narrow coal pillar gob-side entry driving surrounding rock, which comprises the following steps:
acquiring the structural characteristics of the cover rock of the narrow coal pillar gob-side entry driving roadway, optimally designing key parameters of cover rock presplitting blasting, including drilling elevation angle, azimuth angle, blasthole distance, presplitting blasting control height, presplitting blasting implementation time, presplitting blasting level and the like, presplitting blasting is carried out on the cover rock of the narrow coal pillar gob-side entry driving roadway based on the cover rock presplitting blasting parameters, so that roof pressure relief of the cover rock of the narrow coal pillar is realized, and stress regulation is realized;
grouting reinforcement is carried out on the narrow coal pillars based on the implementation effect of the cover rock presplitting blasting roof cutting pressure relief of the narrow coal pillar gob-side entry driving roadway, so that the mechanical properties of the narrow coal pillars are improved, and the bearing capacity of the coal pillars is improved;
and dynamically reinforcing and supporting key parts of the gob-side entry based on the implementation effect of the cover rock presplitting blasting roof cutting pressure relief of the gob-side entry driving tunnel and the grouting reinforcement effect of the narrow coal pillar.
Preferably, the process of obtaining the cover rock pre-splitting blasting parameters comprises the following steps:
basic parameters of a coal face of an upper section and the section, geological data of the coal face, support data of a stoping roadway and the like are obtained, geological conditions of a narrow coal pillar gob-side entry driving roadway, overlying strata parameters, ground stress distribution of roadway surrounding rocks and the like are analyzed, overlying strata structural characteristics are clarified, pre-splitting blasting drilling key parameters are designed according to the overlying strata structural characteristics, and the overlying strata pre-splitting blasting parameters are optimally designed based on the drilling key parameters.
Preferably, the drilling key parameters include: the drilling device comprises an orifice position, a drilling length, a drilling angle and a drilling interval, wherein the orifice position is kept on a straight line along the direction of the roadway, the drilling length is determined according to the orifice position, the cover rock presplitting blasting level and the drilling angle, and the drilling angle does not exceed a preset angle value.
Preferably, the process of pre-splitting blasting the narrow coal pillar along the gob-side entry driving comprises the following steps:
based on the designed cover rock presplitting blasting parameters, the presplitting blasting drilling holes are charged in a forward charging mode, and the presplitting blasting is carried out on the narrow coal pillar gob-side entry driving in a serial blasting network mode, so that the roof cutting pressure relief of the narrow coal pillar is realized.
Preferably, before the pre-splitting blasting of the overlying strata of the gob-side entry driving roadway is carried out, the method further comprises the following steps:
based on the pre-splitting blasting drilling, the grouting pipe and the slurry returning pipe are implanted into the drilling holes to the designed positions, and the hole sealing and grouting are realized by adopting a hole sealing mode of 'one plug and one injection' or 'two plugs and one injection', and matching with cement slurry.
Preferably, the method further comprises the following steps before grouting, reinforcing and modifying the narrow coal pillar:
and peeping different positions of the narrow coal pillar based on monitoring equipment such as a drilling peeping instrument to obtain the development condition of cracks of the coal pillar, and determining the grouting reinforcement range and reinforcement time of the narrow coal pillar based on the distribution characteristics of the cracks.
Preferably, the process of grouting reinforcement is carried out on the narrow coal pillar gob-side entry driving coal pillar:
through grouting hole making, hole sealing and grouting, adopting a hole-by-hole repeated grouting mode to circularly grouting and reinforcing the narrow coal pillar gob-side entry driving coal pillar;
and constructing grouting drilling holes at the position where the narrow coal pillar needs grouting reinforcement, connecting grouting solid pipes, hole sealing devices, grouting flower pipes and other devices, starting a grouting pump, and moving to the next grouting hole for grouting after single-hole grouting is finished.
Preferably, the process of dynamically reinforcing and supporting the key parts of the gob-side entry driving roadway comprises the following steps:
based on the implementation effect of the cover rock presplitting blasting roof cutting pressure relief of the narrow coal pillar gob-side entry driving roadway and the grouting reinforcement modification effect of the narrow coal pillar, the anchor injection integrated flexible anchor rod, the hollow grouting anchor rod, the hydraulic prop, the point pillar and the like are adopted to dynamically reinforce and support key parts such as shoulder pits, bottom corners, top plates and the like of the gob-side entry driving roadway.
Compared with the prior art, the application has the following advantages and technical effects:
the application is suitable for a stable control method of the surrounding rock of the gob-side entry driving of the narrow coal pillar, which is a systematic control method of the surrounding rock of the roadway by the roof cutting and pressure relief of the presplitting blasting, the grouting reinforcement modification of the narrow coal pillar and the dynamic reinforcement support of the key part, firstly, the advanced/lateral support pressure propagation path is cut off by the roof cutting and pressure relief mode of presplitting blasting, the stress environment of the narrow coal pillar is improved, and the surrounding rock of the gob-side entry driving roadway is positioned in an unloading area; secondly, grouting reinforcement modification is carried out on the narrow coal pillar according to the implementation effect of roof cutting and pressure relief of the cover rock presplitting blasting, so that the mechanical property of the narrow coal pillar is improved, and the self bearing capacity of the coal pillar is improved; and thirdly, according to the implementation effect of roof cutting and pressure relief of the cover rock presplitting blasting and the grouting reinforcement modification effect of the narrow coal pillars, the stability of the roadway is further enhanced by dynamically reinforcing and supporting key parts of the excavation roadway along the sky, and consolidating the construction effects of roof cutting and pressure relief and grouting reinforcement modification.
The method has the beneficial effects that the gob-side entry driving tunnel can be controlled gradually, the gob-side entry driving tunnel belongs to a layer-by-layer progressive relationship, and the surrounding rock of the gob-side entry driving tunnel can be controlled more flexibly.
Drawings
The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the application. In the drawings:
FIG. 1 is a flow chart of a method for controlling stability of surrounding rock according to an embodiment of the present application;
FIG. 2 is a schematic view of a face-inclined cross-section blasthole layout in accordance with an embodiment of the present application;
FIG. 3 is a schematic diagram of the arrangement of grouting holes of narrow coal pillars with different heights according to an embodiment of the application;
FIG. 4 is a schematic diagram of narrow coal pillar side grouting reinforcement according to an embodiment of the present application;
FIG. 5 is a schematic cross-sectional view of a dynamically reinforced roadway support design in accordance with an embodiment of the present application;
fig. 6 is a schematic cross-sectional view of a dynamically reinforced support design for a roadway anchoring and grouting integrated flexible anchor rod according to an embodiment of the application.
Detailed Description
It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other. The application will be described in detail below with reference to the drawings in connection with embodiments.
It should be noted that although a logical order is depicted in the flowchart, in some cases the steps depicted or described may be performed in a different order than presented herein.
Example 1
As shown in fig. 1, the embodiment provides a method for stabilizing and controlling surrounding rock of a gob-side entry driving of a narrow coal pillar, which comprises the following steps:
acquiring the structural characteristics of the cover rock of the narrow coal pillar gob-side entry driving roadway, optimally designing key parameters of cover rock presplitting blasting, including drilling elevation angle, azimuth angle, blasthole distance, presplitting blasting control height, presplitting blasting implementation time, presplitting blasting level and the like, presplitting blasting is carried out on the cover rock of the narrow coal pillar gob-side entry driving roadway based on the cover rock presplitting blasting parameters, so that roof pressure relief of the cover rock of the narrow coal pillar is realized, and stress regulation is realized;
grouting reinforcement is carried out on the narrow coal pillars based on the implementation effect of the cover rock presplitting blasting roof cutting pressure relief of the narrow coal pillar gob-side entry driving roadway, so that the mechanical properties of the narrow coal pillars are improved, and the bearing capacity of the coal pillars is improved;
and dynamically reinforcing and supporting key parts of the gob-side entry based on the implementation effect of the cover rock presplitting blasting roof cutting pressure relief of the gob-side entry driving tunnel and the grouting reinforcement effect of the narrow coal pillar.
A method for performing presplitting blasting roof cutting pressure relief, grouting, reinforcement modification and dynamic reinforcement support on a narrow coal pillar; the specific method comprises the following steps:
in the embodiment, the gateway tunneling on the working face A of the coal seam of a certain mine is used as an engineering background, the thickness of the coal seam a is 1.8m, the gateway on the A is tunneled along the goaf of the working face B, and an 8m coal pillar is reserved between the working face A and the working face B. During the process of the gateway tunneling on the working face A and the stoping of the working face A, the stress concentration of a narrow coal pillar between the working face A and the working face B is caused by the influence of the lateral supporting pressure of the working face B, the mine pressure is obvious, the surrounding rock deformation of the gateway on the working face A is large, and the safety production of the working face is threatened. In order to realize stable control of the surrounding rock of the cis-slot on the working face A, firstly, the cis-slot on the working face A is provided for implementing cover rock presplitting blasting roof cutting pressure relief.
(1) Cover rock presplitting blasting implementation time: the implementation of the cover rock presplitting blasting is carried out after the end of the gateway tunneling on the working face A, the construction is completed before the working face A is stoped or the construction is carried out during the working face A stoping, when the working face A is constructed during the stoping, the distance D between the cover rock presplitting blasting construction and the coal wall of the working face A is more than or equal to L+S based on the advanced supporting pressure and the characteristics of the cover rock presplitting blasting construction, wherein: l is the bearing pressure influence range of the working face A, and S is the working face A pushing distance during the construction period of the cover rock presplitting blasting.
(2) Cover rock presplitting blasting horizon: minimum effective height H of presplitting blasting min ＝M/K p -1, wherein: m is the mining height of working face A, K p The volume expansion coefficient of the crushed rock is 1.2 to 1.3.
And comprehensively analyzing and determining the cover rock presplitting blasting horizon by adopting a research method such as a key layer theory, numerical simulation and the like according to parameters such as mining thickness of the working face A, lithology of the roof and the like. The effective layer of the cover rock presplitting blasting generally needs to cut off the hard rock stratum in the cover rock of the working face A, and the maximum height of the presplitting blasting is reasonably determined according to the layer of the hard rock stratum in the cover rock, the drilling construction difficulty and other factors.
(3) Roof angle of cover rock presplitting blasting: the roof cutting direction of the cover rock presplitting blasting is biased to one side of the goaf on the working face B, the included angle between the drilling hole and the vertical direction is 10-15 degrees, and the included angle between the drilling hole and the axial direction of the crossheading roadway on the working face A is 75-90 degrees.
(4) Drilling hole position: and the cover rock presplitting blasting drilling hole is selected to be at the position of the gateway shoulder nest on the working face A or at the position of the roof plate which is 0.5-1 m away from the gateway side on the working face A.
(5) Drilling length: and determining the drilling length through a trigonometric function relation according to the position of the drilling hole opening of the cover rock presplitting blasting, the cover rock presplitting blasting layer position and the drilling angle.
(6) Drilling pitch: according to the selected explosive specification (the coal mine gas extraction water gel grain with phi 63mm or phi 75mm can be selected), and meanwhile, the drilling spacing is determined according to parameters such as the simulation result of the deep hole pre-splitting blasting fracturing numerical value of the coal mine gas extraction water gel grain, the period of the working face A, the step pressing distance and the like, and the drilling spacing is designed to be 6-8 m.
(7) Drilling diameter: and according to the specification of the selected explosive, the diameter of the drilled hole is 75-113 mm.
And (3) performing cover rock pre-splitting blasting construction, wherein the hole sealing length is 25% -40% of the length of the blast hole. In the embodiment, the selected coal mine gas extraction water gel grain with the explosive specification of phi 63mm is controlled at 22m from the top plate of the coal seam a, specific parameters are listed in table 1, and a drilling arrangement schematic diagram is shown in fig. 2.
TABLE 1
Based on the designed cover rock pre-splitting blasting parameters, the method is implemented on a gateway on the working face A, the distance between the opening position and the gateway side on the working face A is selected to be 0.5m, all drilling opening positions keep a straight line along the direction of the gateway on the working face A, the pre-splitting blasting drilling holes are charged in a forward charging mode, the hole sealing and grouting are realized by adopting a 'one-plug one-injection' hole sealing mode and matching with single-liquid cement slurry (cement ratio=0.6-0.7:1), after the single-liquid cement slurry is solidified for 24-48 h, the pre-splitting blasting is carried out in a serial blasting network mode, and the number of the pre-splitting blasting holes is less than or equal to 8 at one time.
In the embodiment of the application, the roof cutting construction of the cover rock pre-splitting blasting is carried out on the gate roof on the working face A in the direction of approaching the goaf on the working face B, after the cover rock pre-splitting blasting, the restraint degree between the gate roof of the goaf on the working face B and the gate on the working face A is reduced, the stress transmission between the rock strata of the roof is weakened, and the stress environment of the narrow coal pillar is optimized.
In order to improve the stability control effect of the surrounding rock of the gob-side entry driving of the narrow coal pillar, grouting reinforcement modification is carried out on the narrow coal pillar according to the implementation effect of the presplitting blasting roof cutting pressure relief of the covering rock of the gob-side entry driving of the narrow coal pillar.
In order to improve the strength of surrounding rock of a roadway and prevent the surface of a coal side of a narrow coal pillar from seepage and leakage, the positions of the coal side and a top plate are sprayed with slurry before grouting, reinforcing and modifying the narrow coal pillar. The thickness of the spraying slurry is not less than 50mm, the strength is not less than C20 based on no leakage of the slurry, the spraying slurry range is larger than the grouting range, and the slurry is prevented from leaking from the front of the grouting section.
Any one or a combination of a plurality of cement paste, inorganic composite grouting materials, chemical materials or other applicable grouting materials is selected, grouting hole depth is 4m, and hole spacing is 2m. Different arrangements of the coal pillars with different thicknesses are adopted when the grouting holes are arranged, as shown in fig. 3. As shown in FIG. 3 (a), the thickness of the coal seam a is 1.8m, the grouting holes are arranged in a single row, the drilling phi is 42mm, the grouting holes are arranged in the middle of the coal seam, and the distance between the grouting holes and the top plate and the bottom plate of the coal seam is 0.9m. The grouting holes are internally provided with grouting flower pipes and grouting solid pipes (the inner section is a grouting flower pipe, the outer section is a grouting solid pipe), and the middle is fixedly connected by adopting a 300mm long mining hole packer; and (3) positioning and sealing by adopting a grouting hole packer, wherein the sealing position is 1m away from the orifice.
The repeated grouting mode is adopted hole by hole, and the specific position can be properly adjusted according to the condition of the on-site pipeline in order to facilitate construction. The construction steps of the grouting reinforcement modification process of the narrow coal pillar are as follows: and (3) constructing grouting holes in the range to be grouting reinforcement, installing grouting flower pipes, hole sealing devices, grouting solid pipes and the like, positioning and sealing holes through the hole sealing devices, and requiring that the distance between the tail ends of the grouting flower pipes and the bottoms of the grouting holes is 0.5m, as shown in fig. 4. And (3) opening a grouting pump to seal holes and grouting, wherein the standard grouting pressure is not less than 5MPa, the pump is stopped after the pressure is stabilized for 3-5 min, and the single-hole grouting is finished. And sequentially carrying out next drilling grouting.
Considering the working face stoping advanced influence range, the narrow coal pillar grouting reinforcement modification construction needs to be performed in advance of the working face coal wall construction of more than or equal to 120m during the working face stoping period.
Parameters that need to be determined prior to construction for narrow coal pillar grouting reinforcement modification techniques include, but are not limited to:
(1) Determining grouting reinforcement treatment range;
(2) Grouting hole design technical requirements;
(3) Grouting process design requirements.
Grouting hole design specifications, including but not limited to:
(1) When the coal thickness is 1.5-2.5 m, the grouting holes are arranged in a single row, when the coal thickness is more than or equal to 2.5m, the grouting holes are not less than two rows, and the upper row and the lower row adopt a staggered stubble arrangement mode;
(2) The distance between the upper row and the lower row of the grouting holes is no more than 1m in principle, and the distance between the grouting holes is no more than 3m.
(3) The grouting hole phi is 42mm, and the hole depth is 1/2 of the width of the narrow coal pillar.
(4) Grouting pressure is not less than 5MPa, and grouting standard is stabilized for 3-5 min.
Grouting process design specifications, including but not limited to:
(1) Grouting mode: repeating grouting hole by hole;
(2) Grouting material: selecting any one or a combination of a plurality of cement paste, inorganic composite grouting materials, chemical materials or other applicable grouting materials;
(3) The hole sealing mode comprises the following steps: the hole adopts a grouting flower pipe and a grouting solid pipe (the inner section is the grouting flower pipe, the outer section is the grouting solid pipe), the middle is fixedly connected with a 300mm mining hole packer, the grouting hole packer is used for positioning hole sealing, the hole sealing position is not less than 2m away from the hole opening, and the tail end of the grouting flower pipe is 0.5m away from the bottom of the grouting hole.
The grouting reinforcement modification construction process comprises the following steps: grouting drilling, connecting grouting solid pipes, hole packer, grouting pipe and other devices, and performing several procedures of pump opening, hole sealing, grouting, pump stopping and the like.
The grouting hole length, radius, hole sealing length and grouting pressure in the application are research methods such as site industrial test, numerical simulation and the like for reinforcing site by grouting of a site narrow coal pillar, the slurry diffusion condition is analyzed, and the grouting technology and technological parameters are reasonably determined.
The application is mainly used for the narrow coal pillar along the air with the coal thickness more than or equal to 1.5 m. The grouting position is preferably a crack development area, the surrounding rock stress tends to be balanced, and grouting reinforcement should be performed as early as possible. And (3) using monitoring equipment such as a drilling peeping instrument and the like to peep different positions of the narrow coal pillar so as to obtain the development condition of cracks of the coal pillar, and determining the grouting reinforcement range and reinforcement time of the narrow coal pillar based on the observed crack distribution characteristics.
Based on the stable control effect of the stable control of surrounding rock of the gob-side entry driving roadway by the pre-splitting blasting roof cutting pressure relief of the gateway cover rock on the working face A and the grouting reinforcement modification of the narrow coal pillar, the key parts of the gateway shoulder pit, the bottom angle and the top plate on the working face A, which are easy to be instable and damaged, are reinforced and supported. Referring to fig. 5, a reinforcing support manner for deformation of the shoulder fossa of the crossheading on the working face a is provided. Referring to fig. 6, on the basis of the original support, an anchor injection integrated flexible anchor rod reinforcing support is adopted for the shoulder hole part, the flexible anchor rod has the specification of phi 21.8 multiplied by 6300mm, a grouting stop plug is matched for use, a grouting pipe of a grouting pump is connected with a grouting elbow pipe of the grouting plug, and the grouting pump is started to complete full-length anchor injection within the range of a flexible anchor rod body.
After the roof-cutting pressure relief measures of the cover rock pre-splitting blasting are implemented on the working face A, the stress environment of the narrow coal pillar is optimized, and the pressure relief effect is realized; on the basis, grouting reinforcement modification is carried out along the hollow narrow coal pillar, so that the effect of enhancing the bearing performance of the surrounding rock of the narrow coal pillar is achieved; after dynamic reinforcement is adopted on the key part in the gateway along the empty roadway on the working face A, the deformation of the gateway shoulder nest part on the working face A is controlled, the deformation of the surrounding rock of the roadway is reduced, and the stability of the surrounding rock is further enhanced.
The present application is not limited to the above-mentioned embodiments, and any changes or substitutions that can be easily understood by those skilled in the art within the technical scope of the present application are intended to be included in the scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.
Claims (8)
1. The method for stably controlling the surrounding rock of the gob-side entry driving of the narrow coal pillar is characterized by comprising the following steps of:
acquiring the cover rock structural characteristics of the narrow coal pillar gob-side entry driving roadway, optimally designing cover rock pre-splitting blasting parameters based on the drilling key parameters of the cover rock structural characteristics, and pre-splitting blasting the cover rock of the narrow coal pillar gob-side entry driving roadway based on the cover rock pre-splitting blasting parameters to realize the roof cutting and pressure relief of the cover rock of the narrow coal pillar, realize the stress regulation and control, and obtain the roof cutting and pressure relief construction effect;
grouting reinforcement is carried out on the narrow coal pillars of the gob-side entry driving based on the roof-cutting pressure relief implementation effect, so that a grouting reinforcement effect of the narrow coal pillars is obtained;
and dynamically reinforcing and supporting the key parts of the roadway based on the roof-cutting pressure relief construction effect and the narrow coal pillar grouting reinforcement effect.
2. The method for stabilizing and controlling the surrounding rock of the gob-side entry driving of the narrow coal pillar according to claim 1, wherein the process for optimally designing the presplitting blasting parameters of the cover rock comprises the following steps:
according to basic parameters of working surfaces of upper and lower sections of the gob-side entry driving roadway, geological data and stoping roadway support data, analyzing geological conditions of the gob-side entry driving roadway, overlying rock parameters and roadway surrounding rock ground stress distribution of a narrow coal pillar, defining structural characteristics, designing pre-splitting blasting drilling key parameters according to the overlying rock structural characteristics, and optimally designing the overlying rock pre-splitting blasting parameters based on the drilling key parameters.
3. The method for stabilizing and controlling the surrounding rock of the gob-side entry driving of the narrow coal pillar according to claim 2, wherein the drilling key parameters comprise: the drilling device comprises an orifice position, a drilling length, a drilling angle, a drilling diameter and a drilling interval, wherein the orifice position is kept on a straight line along the direction of the roadway, the drilling length is determined according to the orifice position, the cover rock presplitting blasting horizon and the drilling angle, and the drilling angle does not exceed a preset angle value.
4. The method for stabilizing and controlling the surrounding rock of the gob-side entry driving roadway of the narrow coal pillar according to claim 1, wherein the process of presplitting blasting on the covering rock of the gob-side entry driving roadway of the narrow coal pillar comprises the following steps:
based on the designed cover rock presplitting blasting parameters, the presplitting blasting drilling holes are charged in a forward charging mode, and presplitting blasting is carried out on the narrow coal pillar gob-side entry driving in a serial blasting network mode, so that the roof cutting pressure relief construction effect is obtained.
5. The method for stabilizing and controlling the surrounding rock of the gob-side entry driving of the narrow coal pillar according to claim 3, wherein before the roof-cutting pressure relief construction effect is obtained, the method further comprises the following steps:
based on the pre-splitting blasting drilling, the grouting pipe and the slurry returning pipe are implanted into the drilling holes to the designed positions, and the hole sealing and grouting are realized by adopting a hole sealing mode of 'one plug and one injection' or 'two plugs and one injection', and matching with cement slurry.
6. The method for stabilizing and controlling the surrounding rock of the gob-side entry driving of the narrow coal pillar according to claim 1, wherein before grouting and reinforcing the narrow coal pillar of the gob-side entry driving, the method comprises the following steps:
and peeping different positions of the narrow coal pillar based on monitoring equipment such as a drilling peeping instrument to obtain the development condition of cracks of the coal pillar, and determining the grouting reinforcement range and reinforcement time of the narrow coal pillar based on the distribution characteristics of the cracks.
7. The method for stabilizing and controlling the surrounding rock of the gob-side entry driving of the narrow coal pillar according to claim 1, wherein the process of grouting and reinforcing the narrow coal pillar of the gob-side entry driving is characterized in that:
through grouting hole making, hole sealing and grouting, adopting a hole-by-hole repeated grouting mode to circularly grouting and reinforcing the narrow coal pillar gob-side entry driving coal pillar;
and constructing grouting drilling holes at the position where the narrow coal pillar needs grouting reinforcement, connecting a grouting solid pipe, a hole packer and a grouting pipe device, starting a grouting pump, and moving to the next grouting hole for grouting after single-hole grouting is finished.
8. The method for stabilizing and controlling the surrounding rock of the gob-side entry driving of the narrow coal pillar according to claim 1, wherein the process of dynamically reinforcing and supporting the key part of the gob-side entry driving comprises the following steps:
based on the roof-cutting pressure relief construction effect and the narrow coal pillar grouting reinforcement effect, an anchor injection integrated flexible anchor rod is adopted to dynamically reinforce and support key parts of the gob-side entry driving, wherein the key parts are easy-deformation parts of the gob-side entry driving.
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| CN107701188A (en) * | 2017-10-25 | 2018-02-16 | 太原理工大学 | One kind cuts top destressing method for the mined out side static state spalling of gob side entry driving thin coal pillar |
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| CN113107488A (en) * | 2021-04-21 | 2021-07-13 | 淮南矿业(集团)有限责任公司 | Method for treating roof of fully mechanized coal mining face of coal mine |
| CN115182729A (en) * | 2022-08-02 | 2022-10-14 | 安徽理工大学 | Inclined coal seam small coal pillar penetrating deep cutting shallow pouring gangue blocking roadway protection technology and top cutting position determination method |
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| CN107701188A (en) * | 2017-10-25 | 2018-02-16 | 太原理工大学 | One kind cuts top destressing method for the mined out side static state spalling of gob side entry driving thin coal pillar |
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| CN112832768A (en) * | 2021-02-01 | 2021-05-25 | 中国矿业大学(北京) | Roadway protection method based on small coal pillars |
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