Gob-side entry retaining method for fully mechanized caving face of soft coal thick coal seam

Abstract

The invention provides a gob-side entry retaining method for a fully mechanized caving face of a soft coal thick coal seam, which comprises the following steps of: tunneling a mining roadway of the fully mechanized caving face needing gob-side entry retaining along a coal seam roof, excavating a roadway bottom plate in sections to form a to-be-filled section and a slope section, and keeping a certain distance between the to-be-filled section and mining of the mining face, the slope section extends to a bottom plate of the original mining roadway through the inclined slope surface; a filling platform is constructed on the to-be-filled section, a filling bag is placed between the filling platform and the immediate roof, and an anchorage device is arranged to penetrate through the filling bag and then is anchored to the immediate roof; filling materials are poured into the filling bags, the filling bags are made to be tightly attached to the top side and the two sides of the roadway after being expanded, filling bodies are formed after the filling materials are solidified, a top plate of the gob-side entry retaining is formed through the filling bodies, then gob-side entry retaining work is carried out, and the mining working face is pushed forwards; advanced bottom falling is carried out before mining, top filling is carried out, and therefore the gob-side entry retaining technology of the fully mechanized caving face of the soft coal thick coal seam is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of coal mining, and in particular relates to a method for retaining lanes along the gob in a fully mechanized caving working face in a soft coal thick seam. Background Art

[0002] Gob-side lane-retaining technology, especially top-cutting lane-retaining technology, is a pillar-free mining technology that can improve the coal recovery rate of the working face, reduce the tunnel excavation rate, and achieve Y-type ventilation, which is beneficial to the gas control of the working face. It has been widely promoted and applied in medium and thick coal seams, and has achieved good promotion and application results. However, it is difficult to be effectively promoted in soft coal and thick coal seam mines, mainly due to the following constraints:

[0003] (1) The coal seam is thick, weak and broken, with a high gas content. It is difficult to excavate along the bottom of the top coal, and there are great risks of roof and gas. The mining tunnel of the fully mechanized caving working face generally needs to be excavated along the bottom, otherwise the triangular coal resources at the end of the working face will be greatly lost. When the top coal is excavated, the roof is soft coal, the strength of the tunnel roof is low, and the tunnel support is difficult. During excavation, the top coal is also easy to fall, which is very likely to cause gas over-limit and roof and gas accidents during excavation.

[0004] (2) The mining roadway of the fully-mechanized caving working face in soft and thick coal seams is excavated along the bottom. The maintenance of the mining roadway is difficult during use, and it is even more difficult to leave a roadway along the goaf. The mining roadway of the fully-mechanized caving working face in soft and thick coal seams is excavated with the top coal. During the mining of the working face, the advance support pressure is relatively large, and the advancing speed of the fully-mechanized caving working face is stirred. The mining roadway of the working face has a large deformation during use, and even needs to be repaired many times. When leaving a roadway along the goaf, the mining roadway needs to experience two dynamic pressure effects, and the mine pressure is more intense, which can easily cause the top coal to break, the roof to sink a lot, form a net bag, and even cause the roof to fall, posing a major safety hazard.

[0005] (3) The thickness of coal seams in most mining areas is unstable, making anchor net support difficult. The mining tunnel of the fully mechanized caving working face is excavated along the bottom plate. When the thickness of the coal seams is unstable, the anchor net support parameters are difficult to determine. Some mining areas even need to leave nearly 10m of top coal. The anchor cable needs to pass through the coal seam and anchor it in the hard rock layer, making anchor net support difficult.

[0006] Therefore, it is necessary to provide an improved technical solution to address the above-mentioned deficiencies in the prior art. Summary of the invention

[0007] The purpose of the present invention is to overcome the deficiencies in the above-mentioned prior art, and the present invention provides a method for retaining lanes along the goaf in a fully mechanized caving working face in a soft coal thick seam.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] A method for retaining lanes along the gob in a fully mechanized caving working face in a soft coal thick seam comprises the following steps:

[0010] Step S1, the fully mechanized caving working face needs to be excavated along the coal seam roof along the mining roadway with gob-retained lanes, and the roof of the area in front of the working face is pre-splitting blasted in the original mining roadway;

[0011] Step S2, excavating the tunnel floor in sections to form a section to be filled and a slope section, wherein the section to be filled and the mining face are kept at a certain distance, and the slope section extends to the floor of the original mining tunnel through an inclined slope;

[0012] Step S3, constructing a filling platform at the section to be filled, placing a filling bag between the filling platform and the direct top, and setting an anchor to pass through the filling bag and then anchor it to the direct top;

[0013] Step S4, pouring filling material into the filling bag, so that the filling bag is inflated and close to the top and sides of the roadway, so as to form a filling body after the filling material solidifies, and the top plate of the gob-side roadway is formed by the filling body, and then the gob-side roadway retention work is carried out and the mining working face is advanced forward;

[0014] Step S5, repeating steps S2-S4 according to the recovery progress of the mining face until the coal seam excavation in the area to be mined is completed.

[0015] Preferably, depending on the recovery progress of the mining face, filling is carried out every 2-3 days, with each filling step being 4-6m.

[0016] Preferably, a filling platform is formed by supporting a π-shaped beam or an anchor cable hanging beam with a hydraulic single column, and the elevation of the lower surface of the filling platform is in the same plane as the elevation of the top plate of the gob-side entry retention;

[0017] Anchors are set directly on the top, and the filling bag is placed on the π-shaped beam. The filling bag is provided with holes corresponding to the anchors. The anchors pass downward through the filling bag and are fixed on the π-shaped beam.

[0018] Preferably, the anchor is directly anchored on the direct top, and the filling bag is provided with a through hole corresponding to the anchor. The anchor is passed downward through the filling bag and then connected to the suspension beam to form a filling platform. The elevation of the lower surface of the filling platform is in the same plane as the elevation of the top plate of the gob-retained tunnel.

[0019] Preferably, in step S1, an anchor net is installed on the roof of the original mining tunnel for support.

[0020] Preferably, the filling bag is made of elastic material, and elastic cuffs corresponding to the anchors are provided at the perforations of the top plate and the bottom plate of the filling bag;

[0021] A filling port and an exhaust port are provided on one side of the filling bag corresponding to the mining direction.

[0022] Preferably, air is supplied into the filling bag through the filling port to inflate it, so that the elastic cuffs of the top plate and the bottom plate of the filling bag slide along the anchor to the top plate of the tunnel and the filling platform.

[0023] Preferably, the free surface of the filling bag is sealed by a template and a steel mesh.

[0024] Preferably, the elastic cuff is a rubber ring, which is fixed concentrically with the perforation of the filling bag by hot melting or gluing, and the inner diameter of the rubber ring is smaller than the outer diameter of the anchor, thereby forming an interference fit with the anchor.

[0025] Preferably, the pouring filling material is a two-component quick-setting material, and the setting time is 20 minutes to 40 minutes.

[0026] Beneficial effects: This application designs a top-advancing technology for the fully-mechanized caving working face in soft and thick coal seams, which carries out advance bottoming and top filling before mining, thereby realizing the technology of leaving lanes along the goaf for the fully-mechanized caving working face in soft and thick coal seams. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. Among them:

[0028] Figure 1 A schematic diagram of the distribution of the fully mechanized caving working face in the coal seam in the specific embodiment provided by the present invention;

[0029] Figure 2 A schematic diagram of the segmented excavation of the bottom plate in a specific embodiment provided by the present invention;

[0030] Figure 3 This is a schematic diagram of anchoring of a filling section in a specific embodiment provided by the present invention;

[0031] Figure 4 This is a simplified diagram of the filling bag structure in a specific embodiment provided by the present invention.

[0032] In the figure: 1. Goaf; 2. Mining working face; 3. Mining tunnel; 4. Section to be filled; 5. Advanced bottoming area; 6. Coal seam; 7. Anchor suspension beam; 8. Original support anchor; 9. Cutting top line; 10. Filling bag; 11. Anchor; 12. Filling port; 13. Exhaust port; 14. Elastic cuff. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0034] In the description of the present invention, the terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and do not require that the present invention must be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the present invention. The terms "connected" and "connected" used in the present invention should be understood in a broad sense. For example, they can be fixed connections or detachable connections; they can be directly connected or indirectly connected through intermediate components. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0035] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0036] In order to realize gob-side tunneling in fully mechanized caving working face in soft coal thick seam, the present invention designs a technical solution of tunneling along the top, advancing the bottom and filling the top in fully mechanized caving working face in soft coal thick seam, such as Figure 1 As shown, there are mining tunnels 3 on both sides of the mining face 2. As the mining face 2 advances, the goaf 1 needs to be backfilled, and the original mining tunnels 3 are maintained along the edge of the goaf 1 behind the coal mining face. The purpose of this practice is to recycle the protective coal pillars left in the traditional mining method, so as to re-support the mining tunnel 3 of the previous section and leave it for the next section. In this implementation, according to the advancement progress of the mining face 2, the bottom plate of the mining tunnel 3 is advanced to form a goaf-retained tunnel, and a filling section is set after the advanced bottoming. The filling section is always located in front of the mining face 2, and the bottom is filled as the mining face 2 advances, thereby realizing the goaf-retained tunnel of the fully mechanized caving face of the soft coal thick seam 6, and ensuring the safety and stability of the construction.

[0037] like Figure 2As shown, firstly, the roof of the original mining tunnel 3 is anchored and supported by anchor nets or steel plates, and then filled according to the mining progress. The advanced bottoming area 5 is set as a slope section, which extends to the bottom of the original mining tunnel 3 through the inclined slope, and a section to be filled 4 is set between the filled area and the advanced bottoming area 5. The section to be filled 4 is filled with a roof by setting a filling platform, and the space between the filling platform and the direct roof is filled and reinforced to form a new roof of the mining tunnel 3, thereby ensuring the stability of the advancement of the next cycle working face.

[0038] like Figure 3 As shown, the filling section is fixed on the direct roof by a filling platform and an anchor 11, and the two sides of the filling bag 10 are respectively restricted by the two sides of the goaf-retaining lane. Specifically, the two sides of the goaf-retaining lane are the filling material in the goaf area 1 and the thick coal seam 6, respectively. The direct roof is reserved when the goaf area 1 is mined, so that the direct roof extends into the goaf area 1 through the inclined surface, thereby forming a goaf-retaining lane along the goaf for the next cycle of coal seam 6 mining.

[0039] like Figure 4 As shown, the filling material is constrained by the filling bag 10 and the filling platform, so as to form a filling area that fits the top and the two sides. The main body of the filling bag 10 is a square rubber bag, and 6 rubber sheets can be formed into a rectangular structure corresponding to the area to be filled by hot melting or gluing. Anchors 11 are provided on the filling platform. The anchors 11 can be anchor rods or anchor cables, preferably anchor cables. The upper end of the anchors 11 is anchored directly on the top, and the lower end is correspondingly connected to the filling platform to form a bottom mold to support the filling bag 10. The filling bag 10 is provided with a plurality of perforations corresponding to the anchors 11, and the perforations are arranged on the top plate and the bottom plate of the filling bag 10, so that the anchors 11 can penetrate the filling bag 10 in the longitudinal direction. The perforations of the filling bag 10 are slidably sealed with the anchors 11, so as to avoid leakage of the filling material during the filling process. The free end of the filling bag 10 is sealed with a steel pipe and a template in combination with a steel mesh, so that it swells and fits tightly to the top and the two sides of the tunnel after filling with the filling material.

[0040] In an optional embodiment, the present application also provides a method for leaving lanes along the goaf in a fully-mechanized caving working face of soft coal and thick coal seam 6, comprising the following steps: Step S1, the mining tunnel 3 of the fully-mechanized caving working face that needs to leave lanes along the goaf is excavated along the roof of the coal seam 6. At this time, the roof of the tunnel is a stable rock layer, and bottom coal is left in the tunnel. The excavation and support of the mining tunnel 3 is easy, the excavation efficiency is high, and there are basically no roof and gas hazards; in the mining section of the working face, pre-splitting blasting is performed on the roof of the area in front of the working face in the original mining tunnel 3.

[0041] Step S2, then excavate the bottom plate, the excavation depth can be determined according to the thickness of the coal at the bottom of the tunnel, and for the convenience of pedestrians, the excavation can be carried out in stages and a slope surface can be formed, so that the bottom plate is excavated in sections to form a section to be filled 4 and a slope section. The bottom plate of the section to be filled 4 is excavated to the elevation of the bottom plate of the tunnel left along the air. The excavation process can adopt various forms such as tunnel repair machine, bucket machine or manual excavation.

[0042] The section to be filled 4 and the mining face are kept at a certain distance. The slope section extends to the bottom of the original mining tunnel 3 through the inclined slope. The filling height is determined according to the bottom height and the height of the goaf. After filling, the section to be filled 4 forms the top plate of the goaf.

[0043] Step S3, before filling, a filling platform needs to be constructed first. The filling platform can be constructed by using anchor cable suspension beams 7, or by using hydraulic single columns and π-shaped beams. The filling platform is used to support the filling bag 10 and is connected to the anchor 11 to form an anchoring structure to ensure the stability of the filling material. The filling bag 10 is placed between the filling platform and the direct top, and the anchor 11 is set to pass through the filling bag 10 and anchor it to the direct top.

[0044] Step S4, after the filling platform is built, the filling bag is inflated by compressed air, and then the filling material is poured into the filling bag 10, so that the filling bag 10 is inflated and close to the top and two sides of the tunnel, so that a filling body is formed after the filling material solidifies, and the top plate of the tunnel along the air is formed by the filling body, and then the tunnel along the air is retained work is carried out and the mining working face is pushed forward.

[0045] Step S5, repeating steps S2-S4 according to the recovery progress of the mining face until the excavation of the coal seam 6 in the area to be mined is completed.

[0046] In an optional embodiment, the space to be filled can be determined according to the progress of the working face recovery. Generally, according to the normal mining progress, the space is filled once every 2-3 days, and the step distance of each filling is 4-6m. The filling height is determined according to the bottom starting height and the height of the tunnel left along the air.

[0047] In an optional embodiment, the specific construction method is adjusted according to the selected filling platform. Specifically: when the filling platform is formed by supporting the π-shaped beam through hydraulic single columns, the elevation of the lower surface of the filling platform is in the same plane as the elevation of the top plate of the gob-retained tunnel; an anchor 11 is set on the direct top, and the filling bag 10 is placed on the π-shaped beam. The filling bag 10 is provided with a perforation corresponding to the anchor 11. The anchor 11 passes downward through the filling bag 10 and is fixed on the π-shaped beam. The hydraulic single column is removed after the filling material solidifies.

[0048] When a filling platform is formed by a suspended beam, the anchor 11 is directly anchored on the direct top, and a hole corresponding to the anchor 11 is provided on the filling bag 10. The anchor 11 is passed downward through the filling bag 10 and then connected to the suspended beam to form a filling platform. The elevation of the lower surface of the filling platform is in the same plane as the elevation of the top plate of the gob-retained tunnel.

[0049] Furthermore, a steel mesh needs to be laid above the supporting π-shaped beam or suspension beam to increase the supporting strength.

[0050] In step S1, anchor nets are installed on the top plate of the original mining tunnel 3 for support. Specifically, anchor rods or anchor cables are installed on the top plate of the original mining tunnel 3, the anchor rods or anchor cables extend upward into the old top, and then anchor nets and steel guard plates are set on the anchor rods or anchor cables for reinforcement.

[0051] In an optional embodiment, the filling bag 10 is made of an elastic material, such as rubber material, and is formed by fixing 6 pieces to each other to form a rectangular structure corresponding to the area to be filled. Elastic cuffs 14 corresponding to the anchor 11 are arranged at the perforations of the top plate and the bottom plate of the filling bag 10. The elastic cuff 14 is a rubber ring having a thickness. The rubber ring is fixed concentrically with the perforation of the filling bag 10 by hot melting or gluing. The inner diameter of the rubber ring is smaller than the outer diameter of the anchor 11, thereby forming an interference fit with the anchor 11, thereby forming a sliding sealing structure without affecting the sliding. Preferably, an elastic cuff 14 is respectively arranged on both sides of the top plate and the bottom plate of the filling bag 10.

[0052] A filling port 12 and an exhaust port 13 are provided on one side of the filling bag 10 corresponding to the mining direction. The filling port 12 is used for inflation and pouring filling material. Air is supplied to the filling bag 10 through the filling port 12 to inflate it. When the filling bag 10 swells, the elastic cuffs 14 of the top and bottom plates of the filling bag 10 are driven by the air pressure to slide along the anchor 11 to the top plate and the filling platform of the tunnel, thereby forming a rectangular structure. At this time, even if the wind pressure is not supplied, the filling bag 10 will not become deflated under the action of the elastic cuffs 14. Then, the filling material is poured through the filling port 12. In order to form the filling area during the pouring process, the free surface of the filling bag 10 is sealed by a template and a steel mesh.

[0053] In an optional embodiment, the pouring filling material is generally a quick-setting material with a setting time of about 20 minutes to 40 minutes, which can reduce the pressure on the filling mold bag and prevent the bag from swelling and slurry leakage; the material strength can be adjusted according to the surrounding rock conditions of the tunnel.

[0054] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are within the scope of protection of the pending claims of the present invention.

Claims

1. A method for retaining lanes along the gob in a fully mechanized caving working face in a soft coal thick seam, characterized in that: The following steps are involved: Step S1, the fully mechanized caving working face needs to be excavated along the coal seam roof along the mining roadway with gob-retained lanes, and the roof of the area in front of the working face is pre-splitting blasted in the original mining roadway; Step S2, excavating the tunnel floor in sections to form a section to be filled and a slope section, wherein the section to be filled and the mining face are kept at a certain distance, and the slope section extends to the floor of the original mining tunnel through an inclined slope; Step S3, constructing a filling platform at the section to be filled, placing a filling bag between the filling platform and the direct top, and setting an anchor to pass through the filling bag and then anchor it to the direct top; Step S4, pouring filling material into the filling bag, so that the filling bag is inflated and close to the top and sides of the roadway, so as to form a filling body after the filling material solidifies, and the top plate of the gob-side roadway is formed by the filling body, and then the gob-side roadway retention work is carried out and the mining working face is advanced forward; Step S5, repeating steps S2-S4 according to the recovery progress of the mining face until the coal seam excavation in the area to be mined is completed.

2. The method for retaining lanes along the gob in a fully mechanized caving working face in a soft coal thick seam according to claim 1 is characterized in that: Depending on the recovery progress of the mining face, filling is carried out every 2-3 days, with each filling step being 4-6m.

3. The method for retaining lanes along the gob in a fully mechanized caving working face in a soft coal thick seam according to claim 1 is characterized in that: A filling platform is formed by supporting a π-shaped beam or an anchor cable hanging beam with a hydraulic single column, and the lower surface elevation of the filling platform is in the same plane as the top elevation of the gob-side entry retention; Anchors are set directly on the top, and the filling bag is placed on the π-shaped beam. The filling bag is provided with holes corresponding to the anchors. The anchors pass downward through the filling bag and are fixed on the π-shaped beam.

4. The method for retaining lanes along the gob in a fully mechanized caving working face in a soft coal thick seam according to claim 1, characterized in that: Anchor the anchor directly on the direct top, the filling bag is provided with a perforation corresponding to the anchor, the anchor is passed downward through the filling bag and connected to the suspension beam to form a filling platform, and the elevation of the lower surface of the filling platform is in the same plane as the elevation of the top plate of the gob-retained tunnel.

5. The method for retaining lanes along the gob in a fully mechanized caving working face in a soft coal thick seam according to claim 1, characterized in that: In step S1, anchor nets are installed on the roof of the original mining tunnel for support.

6. The method for retaining lanes along the gob in a fully mechanized caving working face in a soft coal thick seam according to claim 1, characterized in that: The filling bag is made of elastic material, and elastic cuffs corresponding to the anchors are arranged at the perforations of the top plate and the bottom plate of the filling bag; A filling port and an exhaust port are provided on one side of the filling bag corresponding to the mining direction.

7. The method for retaining lanes along the gob in a fully mechanized caving working face in a soft coal thick seam according to claim 6, characterized in that: Air is supplied into the filling bag through the filling port to inflate it, so that the elastic cuffs of the top plate and the bottom plate of the filling bag slide along the anchor to the top plate of the tunnel and the filling platform.

8. The method for retaining lanes along the gob in a fully mechanized caving working face in a soft coal thick seam according to claim 7, characterized in that: The free surface of the filling bag is sealed by a template and a steel mesh.

9. The method for retaining lanes along the gob in a fully mechanized caving working face in a soft coal thick seam according to claim 6, characterized in that: The elastic cuff is a rubber ring, which is concentrically fixed to the perforation of the filling bag by hot melting or gluing. The inner diameter of the rubber ring is smaller than the outer diameter of the anchor, thereby forming an interference fit with the anchor.

10. The method for retaining gob-side entry in a fully-mechanized caving working face in a soft coal thick seam according to claim 1, characterized in that: The pouring filling material is a two-component quick-setting material with a setting time of 20 to 40 minutes.

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