A method for collaborative support of a mining roadway in a three-soft coal seam

Abstract

This invention belongs to the field of coal resource mining, and specifically discloses a method for coordinated support of mining roadways in soft coal seams. This invention utilizes anchor cables, irregular supports, and individual props for coordinated support in mining roadways in soft coal seams. Targeted backing materials are selected to fit the surrounding rock and avoid empty sides and roofs. Precise anchor cable placement ensures strong anchoring force, improving the overall bearing capacity of the roadway and effectively controlling surrounding rock deformation. Material selection and anchor cable placement can be adjusted as needed, reducing construction difficulty and improving efficiency.

Description

Technical Field

[0001] This invention relates to the field of coal resource mining, and in particular to a method for coordinated support of mining roadways in three soft coal seams. Background Technology

[0002] In the field of coal mining, the support of mining roadways in soft coal seams (soft roof, soft floor, and soft coal seam) has always been a difficult problem for mining engineers. During the mining process, the soft coal seams (soft roof, soft floor, and soft coal seam) have low strength and poor stability, and are easily softened when exposed to water, which exacerbates the complexity of roadway support.

[0003] Existing technologies, such as conventional rock bolt support and conventional steel shed support, have significant shortcomings when dealing with soft coal seams. Conventional rock bolt support struggles to maintain anchoring force in soft, fractured surrounding rock, easily leading to bolt failure and excessive surface deformation of the roadway. Conventional steel shed support, due to its structural and connection limitations, cannot adapt to the irregular cross-sectional changes of roadways with large deformations. Under high stress, the shed structure is prone to twisting and breakage, failing to effectively control the deformation of the surrounding rock. Furthermore, traditional backing materials and mesh connections are also insufficient to achieve tight fit and effective protection against the surrounding rock under these complex geological conditions, easily resulting in open walls and roofs, leading to a decrease in overall roadway stability and seriously threatening coal mine safety and mining efficiency. Therefore, there is an urgent need to develop a targeted and adaptable support solution to address the challenges of roadway support in soft coal seams, ensuring roadway safety and stability and efficient coal mining. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a method for coordinated support of mining roadways in three soft coal seams.

[0005] To achieve the above objectives, the present invention is implemented according to the following technical solution:

[0006] A method for coordinated support in mining roadways of three soft coal seams includes the following steps:

[0007] S1. Several types of U-shaped steel sheds are erected at intervals in the three soft coal seam mining roadway to form a steel shed, and a single pillar is set between each type of U-shaped steel shed and the bottom plate of the three soft coal seam mining roadway for support.

[0008] S2. Install the side protection net and back plate in sequence on the surrounding rock wall of the three soft coal seam mining roadway. The back plate passes through the U-shaped steel frame at both ends and fits tightly against the surrounding rock.

[0009] S3. After the steel canopy is erected, several anchor cables are installed in the surrounding rock of the roadway between every two adjacent U-shaped steel canopies, through the plastic protective netting and back plate, to improve the overall bearing capacity of the roadway and suppress the deformation of the surrounding rock.

[0010] Furthermore, the U-shaped steel canopy includes a first arc-shaped canopy leg, a second arc-shaped canopy leg, a first arc-shaped top beam, a horizontal top beam, and a second arc-shaped top beam. The bottoms of the first and second arc-shaped canopy legs are fixed within the floor of the three-soft coal seam mining roadway. The top of the first arc-shaped canopy leg overlaps with the lower end of the first arc-shaped top beam and is fixed with multiple cable clamps. The top of the first arc-shaped top beam overlaps with one end of the horizontal top beam and is fixed with multiple cable clamps. The other end of the horizontal top beam overlaps with the top of the second arc-shaped top beam and is fixed with multiple cable clamps. The lower end of the second arc-shaped top beam overlaps with the top of the second arc-shaped canopy leg and is fixed with multiple cable clamps. The radius of curvature of the first arc-shaped canopy leg is smaller than that of the second arc-shaped canopy leg, and the radius of curvature of the first arc-shaped top beam is larger than that of the second arc-shaped top beam.

[0011] Furthermore, the spacing between the U-shaped steel sheds is 700 mm.

[0012] Furthermore, the protective netting includes a plastic protective netting and a diamond-shaped netting, with the protective netting placed in the inner layer tightly against the surrounding rock and the diamond-shaped netting in the outer layer.

[0013] Furthermore, an anchor cable is installed between the clamping cables at both ends of the horizontal top beam, and an anchor cable is installed 200mm from the outermost clamping cable at both ends of the horizontal top beam. An anchor cable is installed 200mm above the uppermost clamping cable at the lower end of the first arc-shaped top beam and the uppermost clamping cable at the lower end of the second arc-shaped top beam. An anchor cable is installed 200mm below the lowermost clamping cable at the lower end of the first arc-shaped top beam and the uppermost clamping cable at the lower end of the second arc-shaped top beam. An anchor cable is installed 400mm above each end of the bottom plate.

[0014] Furthermore, the overlap length between the first arc-shaped canopy leg and the first arc-shaped top beam, the first arc-shaped top beam and the horizontal top beam, the horizontal top beam and the second arc-shaped top beam, and the second arc-shaped top beam and the second arc-shaped canopy leg is at least 400 mm.

[0015] Furthermore, each U-shaped steel shed is equipped with two individual support columns, one of which is connected to the bottom of the top of the first arc-shaped top beam, and the other is connected to the bottom of the top of the second arc-shaped top beam.

[0016] Compared with existing technologies, this invention is designed for mining roadways in soft coal seams. It uses anchor cables, irregular supports, and individual props for coordinated support, selects targeted backing materials to fit the surrounding rock, and avoids open sides and roofs. The precise anchor cable arrangement provides strong anchoring force, improves the overall bearing capacity of the roadway, and effectively controls the deformation of the surrounding rock. The material selection and anchor cable arrangement can be adjusted as needed, reducing construction difficulty and improving efficiency. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the support structure of the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. The specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention.

[0019] like Figure 1 As shown in the figure, this embodiment exemplarily demonstrates a method for coordinated support in a three-soft coal seam mining roadway, including the following steps:

[0020] S1. Several types of U-shaped steel frames 6 are erected at intervals in the three-soft coal seam mining roadway to form a steel shed, and a single pillar 3 is installed between each type of U-shaped steel frame 6 and the floor of the three-soft coal seam mining roadway for support; this embodiment uses U 36 The steel profiles are processed into a steel shed. The U-shaped steel shed frame 6 includes a first arc-shaped shed leg 61, a second arc-shaped shed leg 65, a first arc-shaped top beam 62, a horizontal top beam 63, and a second arc-shaped top beam 64. The bottoms of the first arc-shaped shed leg 61 and the second arc-shaped shed leg 65 are fixed within the floor of the three-soft coal seam mining roadway. The top of the first arc-shaped shed leg 61 overlaps with the lower end of the first arc-shaped top beam 62 and is fixed with multiple cable clamps 2. The top of the first arc-shaped top beam 62 overlaps with one end of the horizontal top beam 63 and is fixed with multiple cable clamps 2. The other end of the horizontal top beam 63 overlaps with the top of the second arc-shaped top beam 64 and is fixed with multiple cable clamps 2. The lower end of the second arc-shaped top beam 64 overlaps with the top of the second arc-shaped shed leg 65 and is fixed with multiple cable clamps 2. The radius of curvature of the first arc-shaped shed leg 61 is smaller than that of the second arc-shaped shed leg 65, and the radius of curvature of the first arc-shaped top beam 62 is larger than that of the second arc-shaped top beam 64. Figure 1 As shown, the entire steel shed is an irregular U-shaped steel shed; the overlap length between the first arc-shaped shed leg 61 and the first arc-shaped top beam 62, the first arc-shaped top beam 62 and the horizontal top beam 63, the horizontal top beam 63 and the second arc-shaped top beam 64, and the second arc-shaped top beam 64 and the second arc-shaped shed leg 65 is at least 400 mm. This overlap length design enhances the overall structural integrity of the shed. Three sets of cable clamps 2 (with limiting cable clamps at the ends) are used to connect the joints, and one set of cable clamps 2 is installed 700mm above the bottom plate to optimize the connection method. The spacing between the U-shaped steel canopy frames 6 is 700mm, and the torque of the cable clamp bolts is 300N·m to ensure a tight connection. The depth of the column socket is 400mm to enhance the stability of the steel canopy foundation. In addition, each U-shaped steel canopy frame 6 is equipped with two individual support columns 3. The top of one individual support column 3 is connected to the bottom of the top of the first arc-shaped top beam 62, and the top of the other individual support column is connected to the bottom of the top of the second arc-shaped top beam 64 to construct a stable support frame. This allows the steel canopy to remain stable under high stress environment and effectively resist the deformation pressure of the roadway.

[0021] S2. In the three-soft coal seam mining roadway, a protective mesh 5 and a backing plate 4 are installed sequentially on the surrounding rock wall. The backing plate 4 passes through a U-shaped steel frame 6 at both ends, tightly fitting the surrounding rock. In this embodiment, the protective mesh 5 includes a plastic protective mesh (9000×900mm, can be cut as needed), a diamond mesh (Φ8mm, 5000×900mm, 2000×900mm), and an iron backing plate (50mm wide, 1000mm long, U-shaped). 36 (Steel profile processing). Plastic protective mesh is placed in the inner layer, and diamond mesh in the outer layer. When material supply is insufficient, multiple alternative solutions are set up to ensure construction continuity. The back panels are spaced 300mm apart at the top and 400mm apart at the sides. The top and two side panels are parallel to the centerline of the roadway, and steel beams pass through both ends to tightly fit the surrounding rock, avoiding empty sides and roofs, and achieving all-round protection of the roadway surrounding rock.

[0022] S3. Anchor Cable Reinforcement Support: After the steel canopy is erected, several anchor cables are installed in the surrounding rock of the roadway between every two adjacent U-shaped steel canopies, penetrating the side protection net 5 and the back plate 4. Specifically, an anchor cable 1 is installed between the clamping cables 2 at both ends of the horizontal top beam 63, an anchor cable 1 is installed 200mm from the outermost clamping cable at both ends of the horizontal top beam 63, an anchor cable 1 is installed 200mm above the uppermost clamping cable at the lower end of the first arc-shaped top beam 62 and the uppermost clamping cable at the lower end of the second arc-shaped top beam 64, an anchor cable 1 is installed 200mm below the lowermost clamping cable at the lower end of the first arc-shaped top beam 62 and the uppermost clamping cable at the lower end of the second arc-shaped top beam 64, and an anchor cable 1 is installed 400mm above both ends of the bottom plate. Φ28.6×8300mm anchor cables are used, along with one K3050 and two Z3050 anchoring agents. 400×400×20mm manganese steel anchor cable trays are used. The anchor cable preload reaches 300kN, and the exposed length is controlled between 150 and 250mm. The roof anchor cables closely follow the face anchor cables, and the side anchor cables lag behind by no more than 5 frames. Through precise anchor cable layout and parameter settings, the overall bearing capacity of the roadway is greatly improved, and the deformation of the surrounding rock is suppressed.

[0023] The technical solutions of the present invention are not limited to the specific embodiments described above. Any technical modifications made in accordance with the technical solutions of the present invention fall within the protection scope of the present invention.

Claims

1. A method for coordinated support in roadways for mining three soft coal seams, characterized in that, Includes the following steps: S1. Several types of U-shaped steel sheds are erected at intervals in the three soft coal seam mining roadway to form a steel shed, and a single pillar is set between each type of U-shaped steel shed and the bottom plate of the three soft coal seam mining roadway for support. S2. Install the side protection net and back plate in sequence on the surrounding rock wall of the three soft coal seam mining roadway. The back plate passes through the U-shaped steel frame at both ends and fits tightly against the surrounding rock. S3. After the steel canopy is erected, several anchor cables are installed in the surrounding rock of the roadway between every two adjacent U-shaped steel canopies, through the plastic protective netting and back plate, to improve the overall bearing capacity of the roadway and suppress the deformation of the surrounding rock.

2. The method for coordinated support of three-soft coal seam mining roadways according to claim 1, characterized in that: The U-shaped steel canopy includes a first arc-shaped canopy leg, a second arc-shaped canopy leg, a first arc-shaped top beam, a horizontal top beam, and a second arc-shaped top beam. The bottoms of the first and second arc-shaped canopy legs are fixed inside the floor of the three-soft coal seam mining roadway. The top of the first arc-shaped canopy leg overlaps with the lower end of the first arc-shaped top beam and is fixed with multiple cable clamps. The top of the first arc-shaped top beam overlaps with one end of the horizontal top beam and is fixed with multiple cable clamps. The other end of the horizontal top beam overlaps with the top of the second arc-shaped top beam and is fixed with multiple cable clamps. The lower end of the second arc-shaped top beam overlaps with the top of the second arc-shaped canopy leg and is fixed with multiple cable clamps. The radius of curvature of the first arc-shaped canopy leg is smaller than that of the second arc-shaped canopy leg, and the radius of curvature of the first arc-shaped top beam is larger than that of the second arc-shaped top beam.

3. The method for coordinated support of three-soft coal seam mining roadways according to claim 1 or 2, characterized in that, The spacing between the U-shaped steel sheds is 700 mm.

4. The method for coordinated support of three-soft coal seam mining roadways according to claim 1, characterized in that: The protective netting includes a plastic protective netting and a diamond-shaped netting. The plastic protective netting is placed in the inner layer, closely attached to the surrounding rock, while the diamond-shaped netting is in the outer layer.

5. The method for coordinated support of three-soft coal seam mining roadways according to claim 2, characterized in that: An anchor cable is installed between the cable clamps at both ends of the horizontal top beam. An anchor cable is installed 200mm from the outermost cable clamp at both ends of the horizontal top beam. An anchor cable is installed 200mm above the uppermost cable clamp at the bottom of the first arc-shaped top beam and the uppermost cable clamp at the bottom of the second arc-shaped top beam. An anchor cable is installed 200mm below the lowermost cable clamp at the bottom of the first arc-shaped top beam and the uppermost cable clamp at the bottom of the second arc-shaped top beam. An anchor cable is installed 400mm above each end of the bottom plate.

6. The method for coordinated support of three-soft coal seam mining roadways according to claim 2, characterized in that: The overlap length between the first arc-shaped canopy leg and the first arc-shaped top beam, the first arc-shaped top beam and the horizontal top beam, the horizontal top beam and the second arc-shaped top beam, and the second arc-shaped top beam and the second arc-shaped canopy leg is at least 400 mm.

7. The method for coordinated support of three-soft coal seam mining roadways according to claim 2, characterized in that: Each U-shaped steel shed is equipped with two individual support columns. The top of one individual support column is connected to the bottom of the top of the first arc-shaped top beam, and the top of the other individual support column is connected to the bottom of the top of the second arc-shaped top beam.

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