Advanced pre-grouting method for coal roadway driving face

Abstract

The invention relates to the technical field of coal seam mining, in particular to an advanced pre-grouting method for a coal roadway driving face. The advanced pre-grouting method comprises the steps that S1, a coal seam roof of a tunneling roadway is explored, and the section shape of the roadway and the crushing degree of the coal seam roof are determined; s2, a grouting hole arrangement scheme and a grouting process are designed according to the section shape of the roadway and the breaking degree of the coal seam roof; s3, according to the grouting hole arrangement scheme, drilling construction is conducted on the coal roadway driving working face; and S4, slurry is injected into the coal roadway driving working face according to the grouting technology, and normal advancing of the coal roadway driving working face is ensured. According to the method, by designing the grouting hole arrangement scheme for the coal roadway driving working face before mining operation, the diffusion radius of slurry can be increased, the total slurry injection amount can be increased, the cohesiveness of top coal can be better improved, the self-bearing capacity of the top coal can be improved, wall caving, roof caving and human injury can be avoided, and the mining efficiency can be improved. And the efficient and safe propulsion of the coal roadway tunneling operation is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of coal seam mining, in particular to an advance pre-grouting method for a coal tunnel excavation working face. Background Art

[0002] Comprehensively-mechanized top-coal caving is one of the main coal mining methods used in mining extra-thick coal seams. The notable features of the mining tunnels in the fully-mechanized top-coal caving working face are large cross-section, top coal retention along the bottom, and a coal seam as the tunnel roof, which makes mining more difficult.

[0003] At present, during the process of tunneling thick coal seams underground in coal mines, due to the weak bearing capacity of the top coal itself, it is sometimes affected by mining or the deterioration of geological conditions, which is prone to accidents such as rock spalling and roof collapse, greatly affecting the normal advancement of the coal tunneling working face and may pose a threat to the safety of construction workers. Therefore, there is an urgent need for a solution to improve the stability of the top coal in the coal tunneling working face. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the related art. To this end, the present invention proposes an advance pre-grouting method for coal roadway excavation working face, so as to achieve bonding of the soft and broken coal body of the coal roadway excavation working face before excavation operation, so as to achieve the purpose of improving the bearing capacity of the coal body, strengthening the roadway and ensuring the efficient and safe excavation operation.

[0005] The present invention provides an advance pre-grouting method for a coal tunneling working face, the advance pre-grouting method comprising: step S1, exploring the coal seam roof of the tunneling tunnel to determine the tunnel cross-sectional shape and the degree of coal seam roof fragmentation; Step S2, designing a grouting hole arrangement scheme and a grouting process according to the tunnel cross-sectional shape and the degree of coal seam roof fragmentation; Step S3, drilling construction is performed on the coal roadway excavation working face according to the grouting hole arrangement plan; Step S4, injecting slurry into the coal roadway excavation working face according to the grouting process to ensure the normal advancement of the coal roadway excavation working face.

[0006] According to an advance pre-grouting method for a coal roadway excavation working face provided by the present invention, the grouting hole arrangement scheme is as follows: Three grouting holes are opened at the coal roadway excavation working face, distributed in upper and lower layers and arranged in an inverted triangle, with the grouting holes in the upper layer and the grouting holes in the lower layer spaced 1 meter apart in the vertical direction; Alternatively, five grouting holes are opened at the coal roadway excavation working face, distributed in upper and lower layers and arranged in an inverted trapezoid, with the grouting holes on the upper layer and the grouting holes on the lower layer spaced 1 meter apart in the vertical direction.

[0007] According to an advance pre-grouting method for a coal tunnel excavation working face provided by the present invention, the drilling construction at the coal tunnel excavation working face comprises: The grouting holes are drilled in an upward inclined direction. The length of the grouting holes is 10 meters, the diameter of the grouting holes is 40 mm, and the angle between the extension direction of the grouting holes and the horizontal plane is between 10° and 15°.

[0008] According to the present invention, a method for pre-grouting in coal tunnel excavation working face is provided, wherein the grouting process comprises: completing the slurry injection operation in sequence from low to high according to the position height of the grouting hole, so as to ensure that each grouting hole is filled with slurry.

[0009] According to an advance pre-grouting method for a coal tunnel excavation working face provided by the present invention, during the process of injecting slurry into the grouting hole, the grouting pressure is always between 2 MPa and 5 MPa.

[0010] According to an advance pre-grouting method for a coal tunnel excavation working face provided by the present invention, when injecting slurry, the grouting pressure gradually increases with the increase of the filling ratio.

[0011] According to an advance pre-grouting method for a coal tunnel excavation working face provided by the present invention, before injecting slurry into the grouting hole, a grouting facility is prepared, and the specific steps include: The first step is to insert a grouting pipe into the grouting hole. The length of the grouting pipe is half a meter less than that of the grouting hole. The second step is to connect the grouting pipe with the grouting pipe at the mouth of the grouting hole, and then fill the mouth of the grouting hole with cement to seal the grouting hole. The third step is to connect the grouting pipe to the grouting pump and transport the slurry through the grouting pump.

[0012] According to the advance pre-grouting method for coal tunnel excavation working face provided by the present invention, the grouting pump adopts ZBQS-15 / 6 two-component pneumatic grouting pump, and during the slurry injection process, the output pressure and flow rate can be controlled by adjusting the air inlet valve; The working parameters of the grouting pump are: working air pressure between 0.4MPa and 0.8Mpa, compressed air flow rate greater than or equal to 5m3 / min, output pressure between 20Mpa and 25Mpa, and maximum grouting flow rate of 25L / min.

[0013] According to an advance pre-grouting method for coal tunneling working face provided by the present invention, the grouting material is: a composite Marisan polymer chemical grouting material formed by mixing conventional A-type Marisan and B-type modified resin in a volume ratio of 1:1.

[0014] According to a method for advance pre-grouting in a coal tunnel excavation working face provided by the present invention, advance pre-grouting and excavation operations are carried out alternately in the coal tunnel excavation working face, and advance pre-grouting is carried out every 10 meters along the extension direction of the coal tunnel excavation working face. Excavation operations are carried out after the grouting is completed, and the excavation distance is equal to the interval of advance pre-grouting.

[0015] The above one or more technical solutions in the present invention have at least one of the following technical effects: By designing grouting holes for the coal roadway excavation working face before mining operations, the diffusion radius of the slurry can be increased, the total amount of slurry injected into the coal seam can be increased, the adhesion of the top coal can be better increased, and the self-bearing capacity of the top coal can be significantly improved, thereby avoiding spalling, roof falls and personal accidents, and ensuring the efficient and safe advancement of coal roadway excavation operations.

[0016] In addition to the technical problems solved by the present invention, the technical features of the technical solutions constituted, and the advantages brought about by the technical features of these technical solutions described above, other technical features of the present invention and the advantages brought about by these technical features will be further explained in conjunction with the accompanying drawings or will be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the drawings required for use in the embodiments or related technical descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A schematic diagram of the distribution of grouting holes for a coal tunnel excavation working face provided in an embodiment of the present invention.

[0019] Figure 2 A schematic diagram of the extension of a grouting hole in a coal seam provided in an embodiment of the present invention.

[0020] Reference numerals: 1. Grouting hole; 11. The first grouting hole; 12. The second grouting hole; 13. The third grouting hole; 2. The extension path of the grouting holes; 3. The cross section of the tunnel; 4. The excavation tunnel; 5. The coal seam. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations on the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0023] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0024] In the embodiments of the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0025] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0026] In the present invention, the coal tunneling working face refers to a specific area used to advance the tunnel during coal mining. The tunnel section refers to the cross section of the tunnel in an underground mine.

[0027] Fully mechanized top coal caving is one of the main mining methods used in mining extra-thick coal seams. The notable features of the mining tunnels in the fully mechanized top coal caving working face are large cross-sections, top coal left along the bottom, and the top of the tunnel is a coal seam, which makes mining difficult. In the process of tunneling along the bottom of thick coal seams in coal mines, due to the weak bearing capacity of the top coal itself, sometimes affected by mining or deteriorating geological conditions, it is easy to cause accidents such as spalling and roof collapse, which greatly affects the normal advancement of the coal tunnel excavation working face and may threaten the safety of construction workers. Therefore, there is an urgent need for a solution to improve the stability of the top coal in the coal tunnel excavation working face.

[0028] In order to achieve the purpose of bonding the soft and broken coal body at the coal roadway excavation working face before excavation operation, so as to improve the bearing capacity of the coal body, strengthen the roadway, and ensure the efficiency and safety of excavation operation.

[0029] In an embodiment of the present invention, an advance pre-grouting method for a coal roadway excavation working face is introduced.

[0030] The advance pre-grouting method comprises: step S1, exploring the coal seam roof of the tunnel to determine the cross-sectional shape of the tunnel and the degree of crushing of the coal seam roof.

[0031] Step S2, designing a grouting hole arrangement plan and a grouting process according to the tunnel cross-sectional shape and the degree of coal seam roof fragmentation.

[0032] Step S3, drilling construction is performed on the coal roadway excavation working face according to the grouting hole arrangement plan.

[0033] Step S4, injecting slurry into the coal roadway excavation working face according to the grouting process to ensure the normal advancement of the coal roadway excavation working face.

[0034] Furthermore, after all the grouting holes have been grouted, the deformation of the tunnel section is tested to ensure that the cracks in the broken coal body are densely filled and firmly bonded. Otherwise, the above steps need to be repeated and another advance pre-grouting is performed.

[0035] In this embodiment, by designing grouting holes for the coal roadway excavation working face before the mining operation, the diffusion radius of the slurry can be increased, the total amount of slurry injected into the coal seam can be increased, the adhesion of the top coal can be better increased, and the self-bearing capacity of the top coal can be significantly improved, thereby avoiding spalling, roof falls and personal accidents, and ensuring the efficient and safe advancement of the coal roadway excavation operation.

[0036] On the basis of the above-mentioned embodiment, in another embodiment of the present invention, an advance pre-grouting method for coal roadway excavation working face is introduced.

[0037] The grouting hole arrangement plan is: open 3 grouting holes in the coal roadway excavation working face, distribute them according to the upper and lower layers and arrange them in an inverted triangle, and the grouting holes on the upper layer and the grouting holes on the lower layer are 1 meter apart in the vertical direction.

[0038] Specifically, Figure 1 As shown, three grouting holes are arranged in an inverted triangle on the tunnel section 3. The grouting holes located in the upper layer are, from left to right, the first grouting hole 11 and the second grouting hole 12. The grouting hole located in the lower layer is the third grouting hole 13.

[0039] like Figure 2 As shown, the grouting hole 1 extends from the cross section of the tunnel 4 upwardly and obliquely into the coal seam 5. Moreover, the length of the grouting hole 1 is 10 meters. The angle between the extension path 2 of the grouting hole and the horizontal line is 10°.

[0040] Alternatively, five grouting holes are opened at the coal roadway excavation working face, distributed in upper and lower layers and arranged in an inverted trapezoid, with the grouting holes on the upper layer and the grouting holes on the lower layer spaced 1 meter apart in the vertical direction.

[0041] On the basis of the above-mentioned embodiment, in another embodiment of the present invention, an advance pre-grouting method for coal roadway excavation working face is introduced.

[0042] The drilling construction at the coal tunnel excavation working face includes: drilling a grouting hole in an upwardly inclined direction. The length of the grouting hole is 10 meters. The diameter of the grouting hole is 40 mm. The angle between the extension direction of the grouting hole and the horizontal plane is between 10° and 15°.

[0043] On the basis of the above-mentioned embodiment, in another embodiment of the present invention, an advance pre-grouting method for coal roadway excavation working face is introduced.

[0044] The grouting process includes: completing the slurry injection operation in order from low to high according to the position height of the grouting hole, so as to ensure that each grouting hole is filled with slurry. Performing the slurry injection operation in order from low to high can prevent the slurry in the grouting hole of the upper layer from leaking downward.

[0045] On the basis of the above-mentioned embodiment, in another embodiment of the present invention, an advance pre-grouting method for coal roadway excavation working face is introduced.

[0046] During the process of injecting slurry into the grouting hole, the grouting pressure is always between 2Mpa and 5Mpa.

[0047] Furthermore, when injecting the slurry, the grouting pressure gradually increases with the increase of the filling ratio.

[0048] On the basis of the above-mentioned embodiment, in another embodiment of the present invention, an advance pre-grouting method for coal roadway excavation working face is introduced.

[0049] Before injecting slurry into the grouting hole, prepare the grouting facilities. The specific steps include: The first step is to insert a grouting pipe into the grouting hole, the length of which is half a meter shorter than the length of the grouting hole; the second step is to connect the grouting pipe with the grouting pipe at the opening of the grouting hole, and then fill the opening of the grouting hole with cement to seal the grouting hole; the third step is to connect the grouting pipe to the grouting pump and transport the slurry through the grouting pump. Moreover, the distance between the grouting pump and the grouting hole should preferably be within 10 meters.

[0050] Furthermore, the grouting pump adopts a ZBQS-15 / 6 two-component pneumatic grouting pump. During the slurry injection process, the output pressure and flow rate can be controlled by adjusting the air inlet valve.

[0051] The working parameters of the grouting pump are: working air pressure between 0.4MPa and 0.8Mpa, compressed air flow rate greater than or equal to 5m3 / min, output pressure between 20Mpa and 25Mpa, and maximum grouting flow rate of 25L / min.

[0052] Furthermore, the grouting material is a composite Marisan polymer chemical grouting material prepared by mixing conventional A-type Marisan and B-type modified resin in a volume ratio of 1:1.

[0053] Composite Marisan polymer chemical grouting material has the characteristics of high strength after curing, flame retardancy, low reaction temperature and strong applicability.

[0054] On the basis of the above-mentioned embodiment, in another embodiment of the present invention, an advance pre-grouting method for coal roadway excavation working face is introduced.

[0055] Advance pre-grouting and excavation operations are carried out alternately in the coal roadway excavation working face. Advance pre-grouting is carried out every 10 meters along the extension direction of the coal roadway excavation working face. Excavation operations are carried out after the grouting is completed, and the excavation distance is equal to the interval of advance pre-grouting.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0057] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for pre-grouting in advance for coal tunneling working face, characterized in that: Step S1, exploring the coal seam roof of the tunnel to determine the tunnel cross-sectional shape and the degree of coal seam roof fragmentation; Step S2, designing a grouting hole arrangement scheme and a grouting process according to the tunnel cross-sectional shape and the degree of coal seam roof fragmentation; Step S3, drilling construction is performed on the coal roadway excavation working face according to the grouting hole arrangement plan; Step S4, injecting slurry into the coal roadway excavation working face according to the grouting process to ensure the normal advancement of the coal roadway excavation working face.

2. The advance pre-grouting method for coal roadway excavation working face according to claim 1 is characterized in that: The grouting hole arrangement scheme is as follows: Three grouting holes are opened at the coal roadway excavation working face, distributed in upper and lower layers and arranged in an inverted triangle, with the grouting holes in the upper layer and the grouting holes in the lower layer spaced 1 meter apart in the vertical direction; Alternatively, five grouting holes are opened at the coal roadway excavation working face, distributed in upper and lower layers and arranged in an inverted trapezoid, with the grouting holes on the upper layer and the grouting holes on the lower layer spaced 1 meter apart in the vertical direction.

3. The advance pre-grouting method for coal roadway excavation working face according to claim 2 is characterized in that: The drilling construction at the coal roadway excavation working face includes: The grouting holes are drilled in an upward inclined direction. The length of the grouting holes is 10 meters, the diameter of the grouting holes is 40 mm, and the angle between the extension direction of the grouting holes and the horizontal plane is between 10° and 15°.

4. The advance pre-grouting method for coal roadway excavation working face according to any one of claims 1 to 3, characterized in that: The grouting process includes: completing the slurry injection operation in sequence from low to high according to the position height of the grouting hole, so as to ensure that each grouting hole is filled with slurry.

5. The advance pre-grouting method for coal roadway excavation working face according to claim 4 is characterized in that: During the process of injecting slurry into the grouting hole, the grouting pressure is always between 2Mpa and 5Mpa.

6. The advance pre-grouting method for coal roadway excavation working face according to claim 5, characterized in that: When injecting slurry, the grouting pressure gradually increases with the increase of filling ratio.

7. The advance pre-grouting method for coal roadway excavation working face according to claim 6, characterized in that: Before injecting slurry into the grouting hole, prepare the grouting facilities. The specific steps include: The first step is to insert a grouting pipe into the grouting hole. The length of the grouting pipe is half a meter less than that of the grouting hole. The second step is to connect the grouting pipe with the grouting pipe at the mouth of the grouting hole, and then fill the mouth of the grouting hole with cement to seal the grouting hole. The third step is to connect the grouting pipe to the grouting pump and transport the slurry through the grouting pump.

8. The advance pre-grouting method for coal roadway excavation working face according to claim 7, characterized in that: The grouting pump adopts ZBQS-15 / 6 two-component pneumatic grouting pump. During the slurry injection process, the output pressure and flow rate can be controlled by adjusting the air inlet valve; The working parameters of the grouting pump are: working air pressure is between 0.4MPa and 0.8Mpa, and the compressed air flow rate is greater than or equal to 5m 3 / min, the output pressure is between 20Mpa and 25Mpa, and the maximum grouting flow rate is 25L / min.

9. The advance pre-grouting method for coal roadway excavation working face according to claim 4, characterized in that: The grouting material is a composite Marisan polymer chemical grouting material prepared by mixing conventional A-type Marisan and B-type modified resin in a volume ratio of 1:

1.

10. The advance pre-grouting method for coal roadway excavation working face according to any one of claims 1 to 3, characterized in that: Advance pre-grouting and excavation operations are carried out alternately in the coal roadway excavation working face. Advance pre-grouting is carried out every 10 meters along the extension direction of the coal roadway excavation working face. Excavation operations are carried out after the grouting is completed, and the excavation distance is equal to the interval of advance pre-grouting.

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