A method for reinforcing mudstone slope systems in coal-bearing strata

Abstract

This invention discloses a method for reinforcing mudstone slope systems in coal-bearing strata, comprising four steps: zoned surface drainage, electrochemical drainage, intermittent retaining wall isolation, and passive anchor cable traction. This invention provides zoned slope treatment, facilitating tailored solutions for each area. Electrochemical drainage, combined with crack filling, achieves continuous reinforcement of local slopes, moving away from the previous one-size-fits-all approach. Multiple V-shaped reinforcement triangles are used to achieve a cluster effect, enabling coordinated treatment from multiple points. Segmented retaining walls block mutual influence between upper and lower zones, binding adjacent zones together and providing effective support. Passive anchor cable traction continuously reinforces weak and marginal areas, achieving comprehensive systemic treatment with no blind spots and targeted reinforcement in key areas.

Description

Technical Field

[0001] This invention relates to a slope system reinforcement method, specifically a method for reinforcing a mudstone slope system in coal-bearing strata. Background Technology

[0002] Coal-bearing strata refer to a series of sedimentary rocks containing coal seams and exhibiting genetic coherence, formed through continuous deposition over a specific geological period. Mudstone is a common lithology in coal-bearing strata of open-pit coal mines. Due to its characteristics such as low strength, high water absorption, easy softening upon contact with water, strong disintegration, and extremely poor weathering resistance, mudstone is highly susceptible to slope deformation and instability when used as an open-pit mine slope. The softening nature of mudstone renders traditional reinforcement methods such as drainage and dewatering ineffective. Furthermore, the well-developed internal fissures of the slope hinder effective drainage and dewatering, and the complex geological conditions make individual reinforcement methods insufficient. Therefore, there is an urgent need to develop a reinforcement method that offers effective drainage and dewatering and enables comprehensive, systematic management. Summary of the Invention

[0003] To address the problems existing in the prior art, this invention provides a method for reinforcing mudstone slope systems in coal-bearing strata, which has good drainage and desiccation effects and improves slope stability.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a method for reinforcing mudstone slope systems in coal-bearing strata, comprising four steps: zoned surface drainage, electrochemical drainage, intermittent retaining wall isolation, and passive traction of anchor cables;

[0005] Zonal surface drainage: The coal-bearing mudstone slope is divided into several continuous treatment zones from top to bottom. Drainage channels connecting the designated water storage area of ​​the mining area are constructed at the top and middle of each treatment zone. Drainage channels are also constructed at the bottom of the treatment zone located at the bottom.

[0006] Electrochemical drainage: Within each treatment zone, multiple rows of central dewatering wells are horizontally arranged along the slope inclination direction, with the depth of the central dewatering wells extending to the bedrock of the slope. The central dewatering wells in adjacent rows are arranged horizontally in a staggered manner. The central dewatering wells have an embedded conductive steel inner wall that connects to the cathode of the power source, with several holes arranged in the inner wall. The depth of the conductive steel inner wall is 2-3m greater than the thickness of the mudstone of the slope. With the central dewatering well as the center, peripheral dewatering wells are arranged in an array around the central dewatering wells, with the depth of the peripheral dewatering wells extending to the bedrock. The peripheral dewatering wells have an embedded conductive steel inner wall that connects to the anode of the power source, with several holes arranged in the inner wall. The depth of the conductive steel inner wall is 2-3m greater than the thickness of the mudstone of the slope. An electrolyte solution is injected into each peripheral dewatering well. When the water content in the slope cracks reaches the average water content in the slope cracks during the non-rainy season, solidified electrolyte is added to the peripheral dewatering wells. The solidified electrolyte gradually solidifies and fills the internal cracks of the slope.

[0007] Intermittent retaining wall isolation: At the boundary edge of two adjacent management zones on the same column, a retaining wall is constructed along the edge direction; at the middle position of the boundary between two adjacent management zones on the same row, a connecting retaining wall is constructed along the perpendicular boundary direction.

[0008] Passive traction of anchor cables: In the edge areas of the treatment zones not covered by the three steps of zoned surface drainage, electrochemical drainage, and intermittent retaining wall isolation, reinforcement boreholes are drilled, anchor cables are installed in the reinforcement boreholes, and grout is injected at the bottom of the boreholes to anchor the roots of the anchor cables, forming an anchoring section.

[0009] Furthermore, both the barrier walls and connecting walls adopt rock-embedded foundations and are constructed using a drilling and casting method, with the foundations reaching directly to the bedrock.

[0010] Furthermore, the retaining wall is 20-50m long and spaced 30-50m apart.

[0011] Furthermore, the distance between two adjacent central drainage wells in the same row is 30-90m. When the mechanical properties of the mudstone on the slope are poor, the smaller value is taken, and vice versa.

[0012] Furthermore, the conductive steel inner wall extends 1-2m beyond the slope surface and rolls outward.

[0013] Furthermore, the diameter of the central dewatering well is 2-4m, and the diameter of the peripheral dewatering well is 0.2-0.4m.

[0014] Compared with existing technologies, this invention provides zoned slope management, facilitating tailored solutions for each area; electrochemical drainage combined with crack filling achieves continuous reinforcement of local slopes, changing the previous one-time solution approach; multiple V-shaped reinforcement triangles are used to achieve a cluster effect, enabling coordinated management from multiple points; segmented retaining walls prevent mutual influence between upper and lower zones, achieving binding between adjacent zones and providing effective support for each zone; passive anchor cable traction continuously reinforces weak and marginal areas, achieving a comprehensive system management goal of universal treatment without blind spots and reinforcement of key areas. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the reinforcement location in this invention;

[0016] Figure 2 This is a schematic diagram of the reinforcement method of the present invention;

[0017] Figure 3 This is a schematic diagram of the reinforcement unit structure of the present invention;

[0018] In the diagram: 1-coal-bearing mudstone slope; 2-treatment zone; 3-drainage ditch; 4-central dewatering well; 5-edge dewatering well; 6-reinforcement column; 7-V-shaped reinforced triangular area; 8-zone boundary; 9-barrier wall; 10-connecting wall; 11-reinforcement borehole. Detailed Implementation

[0019] The invention will now be further described with reference to the accompanying drawings.

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] This invention provides a technical solution, a method for reinforcing mudstone slope systems in coal-bearing strata, comprising four steps: zoned surface drainage, electrochemical drainage, intermittent retaining wall isolation, and passive traction of anchor cables.

[0022] Zoning surface drainage:

[0023] like Figure 1 As shown, the open-pit coal-bearing mudstone slope 1 requiring treatment is divided into several continuous treatment zones 2 from top to bottom. The division criteria should be that the mudstone properties, structure, settlement, and other engineering mechanical structures and parameters within each treatment zone 2 are similar, facilitating subsequent targeted treatment based on the specific conditions of each zone; for example... Figure 2 As shown, drainage channels 3 are constructed at the top and middle of each treatment zone 2 to connect the designated water storage area of ​​the mining area. The treatment zone 2 at the bottom also has a drainage channel 3 constructed at the bottom. During rainfall, the drainage channels 3 are used to drain surface runoff and prevent excessive precipitation from seeping into the coal-bearing mudstone slope 1.

[0024] Electrochemical drainage:

[0025] like Figure 2 and Figure 3As shown, within each treatment zone 2, multiple rows of central dewatering wells 4 with diameters of 2-4m are horizontally arranged along the slope inclination direction. The depth of the central dewatering wells 4 extends to the bedrock of the slope. The central dewatering wells 4 in adjacent rows are arranged horizontally in a staggered manner. The distance between two adjacent central dewatering wells 4 in the same row is between 30-90m. When the mechanical properties of the slope mudstone are poor, a smaller value is taken, and vice versa. The central dewatering wells 4 have an embedded conductive steel inner wall that connects to the cathode of a power source. The conductive steel inner wall has several holes, and the depth of the conductive steel inner wall is greater than that of the slope mudstone. The rock thickness is 2-3m, and the inner wall extends 1-2m beyond the slope surface and rolls outward to provide support. Around each central drainage well 4 with a radius of 15m, peripheral drainage wells 5 with a diameter of 0.2-0.4m are arranged in an array. The depth of the peripheral drainage wells 5 reaches the bedrock. The peripheral drainage wells 5 have an embedded conductive steel inner wall that connects to the anode of the power supply. The conductive steel inner wall has several holes and its depth is 2-3m greater than the thickness of the mudstone on the slope. The inner wall extends 1-2m beyond the slope surface and rolls outward to provide support.

[0026] Electrolyte solution is injected into each edge drainage well 5. The electrolyte solution penetrates deep into the slope through the pores in the inner wall and dissolves in the internal water. The attraction of the electrolyte solution by the electric field electrochemically modifies the mudstone, causing the water inside the slope to gradually flow from the positive end (i.e., inside the edge drainage well 5) to the negative end (i.e., inside the central drainage well 4), thereby reducing the amount of water inside the slope. When the water content in the slope cracks reaches the average water content in the slope cracks during the non-rainy season, solidified electrolyte is added to the edge drainage well 5 (i.e., the positive end). As the electrolyte moves towards the central drainage well 4 (i.e., the negative end), it gradually solidifies and fills the cracks inside the slope, thereby improving the stability of the slope.

[0027] Based on rainfall infiltration and groundwater recharge, electro-osmotic drainage is carried out in a timely manner, and the dewatering wells are periodically pumped out. Each central dewatering well 4 and the surrounding edge dewatering wells 5 form a reinforcement unit. After electro-osmotic drainage, the slope properties within each reinforcement unit are improved. Reinforcement columns 6 are formed in a local area centered on the reinforcement unit. Three reinforcement columns 6 staggered between two adjacent rows form a V-shaped reinforcement triangle area 7. Multiple sets of V-shaped reinforcement triangle areas 7 work together to achieve a group column reinforcement effect and perform combined reinforcement of the slope.

[0028] Intermittent retaining wall barrier:

[0029] At the boundary 8 of two adjacent treatment zones 2 in the same column, a retaining wall 9 is constructed along the edge direction. The retaining wall 9 adopts a rock-embedded base and is constructed by drilling and casting, with the base reaching the bedrock to ensure that the retaining wall 9 has strong tensile strength and can play a supporting and blocking role to prevent slope deformation. The retaining wall 9 between zones in the same column is used to block the mutual influence between the upper and lower zones within the column and to provide support for the zones within the column. At the middle position of the boundary of two adjacent treatment zones 2 in the same row, a connecting retaining wall 10 is constructed along the perpendicular boundary direction to connect the left and right treatment zones 2. The connecting retaining wall 10 also adopts a rock-embedded base and is constructed by drilling and casting, with the base reaching the bedrock to ensure that the connecting retaining wall 10 has good shear resistance and can realize the binding of the two adjacent zones to prevent them from being misaligned, thereby providing mutual support. The length of the barrier retaining wall 9 and the connecting retaining wall 10 is 20-50m, and the interval is 30-50m. The length and interval of the retaining wall are selected according to the geological conditions of the interval. When the geological conditions of the interval are poor, a long retaining wall and a small interval are used, and vice versa. At the same time, when the electrochemical drainage and column reinforcement effect is good, a short retaining wall and a large interval can also be used to reduce construction costs.

[0030] Anchor cable passive traction:

[0031] In the edge areas of treatment zone 2 that are not covered in the three steps of surface drainage, electrochemical drainage, and intermittent retaining wall isolation, or in other areas of treatment zone 2 that require stronger reinforcement, reinforcement boreholes 11 are drilled. The depth of reinforcement boreholes 11 extends to the relatively stable rock strata of the slope. Anchor cables are installed in reinforcement boreholes 11, and grout is injected at the bottom of the borehole to anchor the roots of the anchor cables, forming an anchoring section to enhance the reinforcement effect.

[0032] The parameters involved in this invention can be adjusted according to the conditions within different zones, and it is not necessary to use the same set of parameters in different zones. Moreover, this invention consists of various sub-projects forming an overall reinforcement system. The parameters of the projects affect each other, and a single project cannot achieve slope reinforcement. Therefore, it is not advisable to decompose each sub-project and evaluate it separately.

[0033] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0034] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any minor modifications, equivalent substitutions, and improvements made to the above embodiments based on the technical essence of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for reinforcing mudstone slope systems in coal-bearing strata, characterized in that, It includes four steps: zoned surface drainage, electrochemical drainage, intermittent retaining wall isolation, and passive anchor cable traction. Zoning surface drainage: The coal-bearing mudstone slope (1) is divided into several continuous treatment zones (2) from top to bottom. Drainage channels (3) connecting the designated water storage area of ​​the mining area are constructed at the top and middle of each treatment zone (2). Drainage channels (3) are also constructed at the bottom of the treatment zone (2) located at the bottom. Electrochemical drainage: Within each treatment zone (2), multiple rows of central dewatering wells (4) are horizontally arranged along the slope inclination direction. The depth of the central dewatering wells (4) extends to the bedrock of the slope, and the central dewatering wells (4) in adjacent rows are arranged horizontally in an alternating manner. The central dewatering wells (4) have an embedded conductive steel inner wall that connects to the cathode of the power supply. Several holes are arranged in the inner wall, and the depth of the conductive steel inner wall is 2-3m greater than the thickness of the mudstone of the slope. With the central dewatering well (4) as the center, peripheral dewatering wells (4) are arranged in an array around the central dewatering well (4). Dry well (5), the edge dewatering well (5) reaches the bedrock. The edge dewatering well (5) is embedded with a conductive steel inner wall that connects to the anode of the power supply. Several holes are arranged in the inner wall. The depth of the conductive steel inner wall is 2-3m greater than the thickness of the mudstone on the slope. Electrolyte solution is injected into each edge dewatering well (5). When the water content in the slope cracks reaches the average water content in the slope cracks during the non-rainy season, solidified electrolyte is added to the edge dewatering well (5). The solidified electrolyte gradually solidifies and fills the cracks inside the slope. Intermittent retaining wall barrier: At the boundary (8) of two adjacent governance zones (2) in the same column, a barrier wall (9) is constructed along the edge direction; at the middle position of the boundary of two adjacent governance zones (2) in the same row, a connecting barrier wall (10) is constructed along the perpendicular boundary direction. Anchor cable passive traction: In the edge area of ​​the treatment zone (2) that is not involved in the three steps of surface drainage, electrochemical drainage and intermittent retaining wall isolation, a reinforcement borehole (11) is opened, an anchor cable is installed in the reinforcement borehole (11), and the anchor cable root is anchored by grouting at the bottom of the borehole to form an anchoring section.

2. The method for reinforcing mudstone slope systems in coal-bearing strata according to claim 1, characterized in that: Both the barrier wall (9) and the connecting wall (10) adopt rock-embedded foundations and are constructed by drilling and casting, with the foundations reaching the bedrock.

3. The method for reinforcing mudstone slope systems in coal-bearing strata according to claim 1, characterized in that: The retaining wall is 20-50m long and spaced 30-50m apart.

4. The method for reinforcing mudstone slope systems in coal-bearing strata according to claim 1, characterized in that: The distance between two adjacent central drainage wells (4) in the same row is 30-90m. When the mechanical properties of the mudstone on the slope are poor, the smaller value is taken, and vice versa.

5. The method for reinforcing mudstone slope systems in coal-bearing strata according to claim 1, characterized in that: The conductive steel inner wall extends 1-2m beyond the slope surface and rolls outward.

6. The method for reinforcing a mudstone slope system in coal-bearing strata according to claim 1, characterized in that: The diameter of the central dewatering well (4) is 2-4m, and the diameter of the peripheral dewatering well (5) is 0.2-0.4m.

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