A gob steep slope roadbed reinforcing structure

Abstract

This utility model relates to the field of reinforcement engineering technology, specifically disclosing a reinforcement structure for steep slope subgrade in mining subsidence areas. It includes a foundation reinforcement structure, a slope support structure, and pavement structure reinforcement. The foundation reinforcement structure comprises one or more steel pipes, the inner side of which is hollow, and grout is injected inside to form a grout-reinforced body. This utility model utilizes steel pipes arranged in a staggered, quincunx pattern, with grout injection forming a diffused grout-reinforced body. This, combined with the steel pipes, forms a reinforcement structure that fills ground voids, improves foundation density and integrity, effectively increases the vertical bearing capacity of the foundation, and reduces uneven settlement. The vertical arrangement of steel pipe piles inside the slope, with a welded beam crown forming an integral frame at the top, enhances the synergistic effect of multiple steel pipe piles, significantly improving the lateral anti-sliding capacity of the slope and preventing slope slippage.

Description

Technical Field

[0001] This utility model relates to the field of reinforcement engineering technology, specifically a reinforcement structure for steep slope roadbeds in mining subsidence areas. Background Technology

[0002] Underground mining activities such as coal and metal mining create goaf areas, which can lead to foundation subsidence and slope slippage, threatening the long-term stability and safety of transportation infrastructure such as highways and railways. Therefore, it is necessary to reinforce the steep slope roadbeds in goaf areas.

[0003] Existing solutions, such as grouting reinforcement and pile foundation support, each have their own shortcomings, for example: Grouting reinforcement method: This method involves injecting grout into the subgrade through steel pipes to improve the bearing capacity of the foundation and reduce uneven settlement. However, the strata in the goaf are mostly broken rock and soil, which makes the grout easy to lose or spread unevenly, thus limiting the reinforcement range.

[0004] Pile foundation support method: This method uses bored piles to improve the overall stability of the slope and resist lateral slippage. However, this method has high construction costs, large pile volume, and poor deformation resistance, making it difficult to adapt to the continuous settlement of the mining subsidence area.

[0005] The prior art discloses a construction method for single-hole composite grouting reinforcement of base course and subgrade of road with defects (Chinese Patent Publication No.: CN109763391A). The method is as follows: In steep slope subgrades in mining areas, there are problems such as low grouting pressure, limited diffusion radius, uneven distribution of reinforced body, insufficient grouting depth, lack of lateral anti-slip ability, poor structural integrity, and easy occurrence of differential settlement.

[0006] Based on this, this application provides a roadbed reinforcement structure for steep slopes in mining subsidence areas. Utility Model Content

[0007] To address the shortcomings of existing technologies, this utility model provides a reinforcement structure for steep slope roadbeds in mining subsidence areas, which solves the problems of single measures, poor structural coordination, and insufficient adaptation of reinforcement parameters in the treatment of steep slope roadbeds in mining subsidence areas.

[0008] This utility model discloses a subgrade reinforcement structure for steep slopes in mining subsidence areas, comprising a foundation reinforcement structure, a slope support structure, and pavement structure reinforcement, including: A foundation reinforcement structure, comprising one or more steel pipes, wherein the inner side of the steel pipes is hollow and grout is injected inside to form a grout-reinforced body; A slope support structure, comprising one or more steel pipe piles, each steel pipe pile comprising a pipe body, with a beam crown on the top of the steel pipe pile located on the outer side of the pipe body, and the multiple steel pipe piles arranged vertically inside the slope and intersecting with the grouting body. The road reinforcement structure includes a graded crushed stone layer, a cement-stabilized crushed stone layer, a tack coat, and an asphalt concrete layer, which are arranged sequentially from bottom to top.

[0009] As a further improvement of this utility model, the top of the beam crown is welded to form an integral frame, and multiple steel pipe piles are fixed to enhance the lateral anti-slip capability.

[0010] As a further improvement of this utility model, the foundation reinforcement structure is set inside the foundation of the goaf area for the purpose of reinforcing the goaf area.

[0011] As a further improvement of this utility model, one or more overflow holes are provided on the outer side of the steel pipe constituting the foundation reinforcement structure for grout to overflow and diffuse to form a connecting reinforcement body, thereby improving the vertical bearing capacity of the foundation reinforcement structure. As a further improvement of this utility model, the steel pipes are arranged in a staggered quincunx pattern to form a grouting reinforcement body, which, together with the steel pipes, forms a reinforced structure.

[0012] As a further improvement of this utility model, the grouting reinforcement body, steel pipe pile and beam cap are spatially intersecting and / or connected to form an overall reinforcement frame to enhance the integrity and durability of the steep slope subgrade in the mining area.

[0013] As a further improvement of this utility model, the outer diameter of the steel pipe is 40-55mm, the length is 8-10m, the diameter of the overflow hole opened on the outer side of the steel pipe is 10-15mm, the spacing between every two steel pipes is 0.8-1.2m, and the diffusion radius of the grouting solid is greater than or equal to 1.5m.

[0014] As a further improvement of this utility model, the diameter of the steel pipe pile is 150-200mm, the length is 12-16m, and the spacing between every two steel pipe piles is 1.0-1.5m.

[0015] As a further improvement of this utility model, the thickness of the graded crushed stone layer is 12-16cm, the thickness of the cement-stabilized crushed stone layer is 12-16cm, and the thickness of the asphalt concrete layer is 5-8cm.

[0016] Compared with the prior art, the beneficial effects of this utility model are as follows: This utility model uses steel pipes arranged in a staggered quincunx pattern to form a diffused grouting reinforcement body through grouting. This, combined with the steel pipes, forms a reinforced structure that fills the voids in the strata, improves the density and integrity of the foundation, effectively increases the vertical bearing capacity of the foundation, and reduces uneven settlement. By vertically arranging steel pipe piles inside the slope and forming an integral frame at the top with a welded beam crown, the synergistic effect of multiple steel pipe piles is enhanced, significantly improving the lateral anti-sliding capacity of the slope and preventing slope slippage. The steel pipe grouting reinforcement body, steel pipe piles and beam caps intersect and / or connect with each other in space to form an overall reinforcement framework, which further enhances the integrity of the steep slope subgrade in the mining area, enabling it to maintain stability better when facing complex geological conditions and external forces. For road surface reinforcement, a road reinforcement structure is adopted, with graded crushed stone layers and cement-stabilized crushed stone layers arranged sequentially from bottom to top. This layer-by-layer reinforcement from the road foundation to the surface improves the strength, integrity, and durability of the road surface, enabling it to withstand vehicle loads and natural environmental erosion over a long period. Through the coordinated reinforcement of the foundation, slope, and road surface, a complete reinforcement system is formed, effectively resisting the impact of complex geological conditions and natural disasters in mining subsidence areas. This ensures the long-term stable operation of transportation infrastructure and extends the service life of the roadbed. Compared with the traditional pile foundation support method, this reinforcement structure reduces construction costs and improves resource utilization efficiency while ensuring reinforcement effects. It is adaptable to different mining subsidence conditions and has strong versatility and adaptability. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of the vertical structure of the steel flower pipe of this utility model; Figure 2 This is a top view schematic diagram of the combined steel pipe pile and beam cap structure of this utility model; Figure 3 This is a schematic diagram of the vertical structure of the steel pipe pile of this utility model; Figure 4 This is a schematic diagram of the combined structure of the steel pipe, steel pipe pile, and beam crown of this utility model; Figure 5 This is a schematic diagram of the combined structure of the beam cap and steel pipe pile of this utility model; Figure 6 This is a front view structural diagram of the steel pipe of this utility model; Figure 7 This is a schematic diagram of the beam cap and steel pipe pile structure of this utility model; Figure 8 This is a schematic diagram of the beam cap and steel pipe pile structure of this utility model; Figure 9 This is a schematic diagram of the end face structure of the steel pipe pile of this utility model; Figure 10 This is a schematic diagram of the road surface reinforcement structure and the steel pipe combination structure of this utility model.

[0018] In the diagram: 1. Steel pipe; 2. Grout overflow hole; 3. Beam cap; 4. Steel pipe pile; 5. Road surface reinforcement structure; 41. Pipe body; 42. Pouring port; 51. Asphalt concrete layer; 52. Prime coat; 53. Graded crushed stone layer; 54. Cement-stabilized crushed stone layer; 55. Original base course. Detailed Implementation

[0019] The following illustrations will reveal several embodiments of the present invention. For clarity, many physical details will be described in the following description. However, it should be understood that these physical details should not be used to limit the present invention. That is, in some embodiments of the present invention, these physical details are not essential. Furthermore, for the sake of simplicity, some conventional structures and components will be shown in a simple schematic manner in the illustrations.

[0020] Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0021] Please see Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 7 The subgrade reinforcement structure for steep slopes in mining areas provided in this application includes a foundation reinforcement structure, a slope support structure, and a pavement structure reinforcement.

[0022] The foundation reinforcement structure includes one or more steel pipes 1, the inner side of which is hollow, and grout is injected inside to form a grouting reinforcement body; The slope support structure includes one or more steel pipe piles 4, each steel pipe pile 4 including a pipe body 41, the top of which is provided with a beam crown 3, and the multiple steel pipe piles 4 are arranged vertically inside the slope and intersect with the grouting reinforcement body. The road surface reinforcement structure 5 includes a graded crushed stone layer 53, a cement-stabilized crushed stone layer 54, a tack coat 52, and an asphalt concrete layer 51.

[0023] Following underground mining activities in coal mines, metal mines, and other areas, steep slope subgrades in goaf areas face severe problems. The cavities created by underground mining lead to uneven settlement of the foundation, while the stability of the slope soil decreases, making it prone to slippage. These problems seriously threaten the safety of transportation infrastructure such as highways and railways, rendering existing reinforcement technologies inadequate for practical needs. Existing grouting reinforcement methods are limited in scope due to the fractured strata in goaf areas, easy loss or uneven diffusion of grout, and high construction costs, coupled with poor pile resistance to deformation, making them unsuitable for the continuous settlement of goaf areas. Therefore, a more effective reinforcement structure is needed to address these issues.

[0024] Specifically, the foundation reinforcement structure is the basic part of the steep slope roadbed reinforcement in the entire mining subsidence area. Its main function is to improve the bearing capacity of the foundation and reduce uneven settlement.

[0025] In the foundation of steep slope roadbeds in goaf areas, one or more steel perforated pipes 1 are laid out according to the actual situation. After the steel perforated pipes 1 are installed, grout is injected into the steel perforated pipes 1 using specialized grouting equipment. The grout is determined according to the geological characteristics of the goaf area. For goaf areas with a lot of fractured rock and soil, cement grout with good fluidity and cohesion can be selected. During the grouting process, the grouting pressure and grouting speed must be controlled. If the grouting pressure is too low, the grout will not be able to diffuse sufficiently; if the grouting pressure is too high, it may lead to stratum fracturing or grout loss. The grouting speed also needs to be moderate to ensure that the grout can evenly fill the voids inside and around the steel perforated pipes 1. When the grout fills the inside of the steel perforated pipes 1 and diffuses within a certain range in the surrounding strata, a grouting solid is formed. The grouting solid is tightly bonded to the surrounding strata, improving the overall strength and stability of the foundation. Therefore, grouting is generally carried out by staged pressure injection. The pressure for staged grouting is: initial pressure 0.3MPa, final pressure 0.6MPa. After drilling, steel pipe 1 is inserted, and grout is injected in stages using a grouting pump, causing the grout to form a diffuser in the fractured rock strata. The grout body integrates with the surrounding rock and soil, improving the bearing capacity of the foundation.

[0026] The slope support structure is mainly used to enhance the stability of the slope and resist lateral slippage. One or more steel pipe piles 4 are arranged vertically inside the slope. The spacing between the multiple steel pipe piles 4 should be reasonably set to ensure that they can work together to resist the lateral slippage of the slope.

[0027] A beam cap 3 is installed on top of the steel pipe pile 4. The beam cap 3 is usually made of reinforced concrete. The function of the beam cap 3 is to connect multiple steel pipe piles 4 into a whole so that they can better play their supporting role. The connection between the beam cap 3 and the steel pipe pile 4 must be firm, and welding or bolt connection can be used.

[0028] Furthermore, a pouring port 42 is provided at the top of the pipe body 41, so that the steel pipe pile 4 and the beam crown 3 can be better connected after pouring through the pouring method. Multiple steel pipe piles 4 are vertically arranged inside the slope and intersect with the grouting reinforcement body in the foundation reinforcement structure, making the foundation reinforcement structure and the slope support structure an organic whole, jointly bearing the load of the steep slope subgrade in the mining area. During construction, it is necessary to ensure that the steel pipe piles 4 intersect accurately with the grouting reinforcement body to ensure the synergistic effect of the structure.

[0029] The road surface reinforcement structure 5 is mainly designed to improve the strength and durability of the road surface and adapt to the deformation of the roadbed in the mining subsidence area.

[0030] Specifically, a graded crushed stone layer 53 is laid on the roadbed surface. The thickness of the graded crushed stone layer 53 is generally determined according to the road design requirements and the geological conditions of the mining subsidence area, and appropriate compaction equipment such as road rollers should be used for compaction to ensure that it has sufficient density.

[0031] Furthermore, a cement-stabilized crushed stone layer 54 is laid on top of the graded crushed stone layer 53. The cement-stabilized crushed stone layer 54 is made of cement, crushed stone and water mixed in a certain proportion. After laying, it must be properly cured to ensure the performance of the cement-stabilized crushed stone layer 54.

[0032] After laying the cement-stabilized crushed stone layer 54, a tack coat 52 is sprayed onto its surface. The purpose of the tack coat 52 is to better bond the asphalt concrete layer 51 to the cement-stabilized crushed stone layer 54. The selection of the tack coat 52 should be determined based on the surface properties of the cement-stabilized crushed stone layer 54 and the type of asphalt concrete. When spraying the tack coat 52, the spraying amount and uniformity should be carefully controlled.

[0033] Finally, an asphalt concrete layer 51 is laid on top of the tack coat 52. When laying the asphalt concrete, the construction temperature and compaction should be controlled to ensure the flatness and compaction quality of the asphalt concrete layer 51.

[0034] The grouting reinforcement structure in the foundation reinforcement structure improves the bearing capacity of the foundation and reduces uneven settlement. The steel pipe piles 4 and beam caps 3 in the slope protection structure work together to resist lateral slippage of the slope, enhancing its stability. The pavement reinforcement structure 5 improves the strength and durability of the pavement, adapting to the deformation of the subgrade in the mining subsidence area. The foundation reinforcement structure and the slope protection structure form a unified whole through the intersection of the steel pipe piles 4 and the grouting reinforcement structure, jointly bearing the load of the steep slope subgrade in the mining subsidence area. The pavement reinforcement structure 5 is laid on top of the foundation and slope reinforcement structures, further improving the stability and safety of the entire subgrade. This comprehensive reinforcement structure can simultaneously solve the problems of foundation settlement and slope slippage in steep slope subgrades in mining subsidence areas, providing a reliable guarantee for the long-term stable operation of transportation infrastructure.

[0035] Please see Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 The top of the beam crown 3 is welded to form an integral frame, which fixes multiple steel pipe piles 4 to enhance the lateral anti-slip capability.

[0036] The foundation reinforcement structure is installed on the inner side of the foundation of the goaf area and is used to reinforce the goaf area.

[0037] The outer side of the steel pipe 1 that makes up the foundation reinforcement structure is provided with one or more overflow holes 2 for grout to overflow and diffuse to form a connecting reinforcement body, which is used to improve the vertical bearing capacity of the foundation reinforcement structure. The graded crushed stone layer 53, cement-stabilized crushed stone layer 54, tack coat 52, and asphalt concrete layer 51 are arranged sequentially from bottom to top.

[0038] In the slope protection structure, the beam cap 3 is set on top of the steel pipe piles 4, and its top is connected by welding. Through welding, the beam cap 3 is connected into an integral frame. This integral frame can firmly fix multiple steel pipe piles 4 together, enabling them to work together. When the slope is subjected to lateral forces, the beam cap 3 can evenly transfer the force to each steel pipe pile 4, thereby enhancing the lateral anti-sliding capacity of the entire slope protection structure.

[0039] A stable support system is formed by multiple steel pipe piles 4 arranged vertically inside the slope and fixed by the beam cap 3. The connection between the beam cap 3 and the steel pipe piles 4 is tight and stable through welding, so that they can exert maximum effectiveness in resisting the lateral slippage of the slope. Under the condition of increased lateral pressure, the support system composed of the beam cap 3 and the steel pipe piles 4 can effectively prevent the slope from slipping and ensure the safety of the roadbed.

[0040] The foundation reinforcement structure is set inside the foundation of the goaf. Its main purpose is to reinforce the goaf in sections. When determining the specific location of the foundation reinforcement structure, it is necessary to conduct a detailed survey and analysis of the geological conditions of the goaf.

[0041] The steel perforated pipe 1, which forms the foundation reinforcement structure, has one or more overflow holes 2 on its outer side. During the grouting process, the grout overflows from the overflow holes 2 through the hollow part inside the steel perforated pipe 1. Since the strata in the goaf are mostly broken rock and soil, the overflowing grout can diffuse in the surrounding strata and fully mix with the broken rock and soil particles to form a grouting solid. This solid fills the voids in the strata, improves the density and integrity of the foundation, and thus significantly improves the vertical bearing capacity of the foundation reinforcement structure. For example, in some goaf areas, after grouting to form a grouting solid, the vertical bearing capacity of the foundation can be improved, effectively reducing uneven settlement of the foundation.

[0042] Furthermore, the road reinforcement structure 5 consists of a graded crushed stone layer 53, a cement-stabilized crushed stone layer 54, a tack coat 52, and an asphalt concrete layer 51 arranged sequentially from bottom to top, as follows: The graded crushed stone layer 53 in the road reinforcement structure 5 is laid on the original base layer 55 and is the basic layer of the road structure. During the laying process, appropriate compaction equipment is used to compact it to ensure that it has sufficient density. The graded crushed stone layer 53 can play the role of spreading load and improving the stress condition of the subgrade.

[0043] The cement-stabilized crushed stone layer 54 is laid on top of the graded crushed stone layer 53. The cement-stabilized crushed stone layer 54 is composed of cement, crushed stone, and water mixed in a certain proportion. The amount of cement used is determined according to the properties of the crushed stone and the load-bearing requirements of the road surface.

[0044] After paving, proper curing is necessary to ensure the performance of the cement-stabilized crushed stone layer 54. This layer can further improve the strength and integrity of the pavement.

[0045] After the cement-stabilized crushed stone layer 54 is laid, a tack coat 52 is sprayed on the surface. The purpose of the tack coat 52 is to better bond the asphalt concrete layer 51 to the cement-stabilized crushed stone layer 54. The asphalt concrete layer 51 is finally laid on top of the tack coat 52. During the laying process, the construction temperature and compaction are controlled to ensure the smoothness and compaction quality of the asphalt concrete layer 51. The asphalt concrete layer 51 can provide a smooth and anti-skid road surface, improving driving comfort and safety.

[0046] The foundation reinforcement structure, through the grouting of steel pipe 1 to form a connecting solid body, improves the vertical bearing capacity of the foundation and reduces uneven settlement. The slope support structure, through the synergistic effect of beam cap 3 and steel pipe pile 4, enhances the lateral anti-sliding capacity of the slope. The pavement reinforcement structure 5 reinforces the pavement layer by layer from the foundation to the surface, improving the strength, integrity, and durability of the pavement. These three reinforcement structures work together to form a complete roadbed reinforcement system for steep slopes in mining subsidence areas, effectively solving the problems of foundation settlement and slope slippage in steep slopes of mining subsidence areas, and ensuring the long-term stable operation of transportation infrastructure.

[0047] Please see Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Figure 9 as well as Figure 10 The steel pipes 1 are arranged in a staggered quincunx pattern to form a grouting reinforcement body, which, together with the steel pipes 1, forms a reinforced structure.

[0048] The grouting reinforcement body, steel pipe pile 4 and beam cap 3 are spatially intersecting and / or connected to form an overall reinforcement frame to enhance the integrity and durability of the steep slope subgrade in the mining area.

[0049] The outer diameter of the steel pipe 1 is 40-55mm, the length is 8-10m, the diameter of the overflow hole 2 opened on the outer side of the steel pipe 1 is 10-15mm, the spacing between every two steel pipes 1 is 0.8-1.2m, and the diffusion radius of the grouting solid is greater than or equal to 1.5m.

[0050] The steel pipe pile 4 has a diameter of 150-200mm and a length of 12-16m, and the spacing between every two steel pipe piles 4 is 1.0-1.5m.

[0051] The thickness of the graded crushed stone layer 53 and the cement-stabilized crushed stone layer 54 is 12-16 cm, and the thickness of the asphalt concrete layer 51 is 5-8 cm.

[0052] The steel perforated pipes 1 are arranged in a staggered, quincunx pattern on the inner side of the foundation in the goaf. This ensures the pipes are evenly distributed in space, maximizing their reinforcing effect. The inner side of each steel perforated pipe 1 is hollow. After installation, graded pressurized grout is injected into its interior using specialized grouting equipment. As the grout is injected, it overflows from the overflow holes 2 on the outer side of the steel perforated pipes 1, spreading throughout the surrounding strata. Due to the staggered arrangement of the steel perforated pipes 1, the overflowing grout connects with each other, forming a grouting reinforced body. This grouting reinforced body is tightly bonded to the steel perforated pipes 1, together forming a reinforced structure. This reinforced structure fills the voids in the strata, improving the density and integrity of the foundation, thereby enhancing its vertical bearing capacity.

[0053] The outer diameter of the steel pipe 1 is 40-55mm and the length is 8-10m. The overflow hole 2 opened on the outside of the steel pipe 1 has a diameter of 10-15mm, which can ensure that the slurry overflows smoothly, while avoiding the slurry loss too quickly due to the excessively large hole diameter.

[0054] The spacing between every two steel pipes is 0.8 to 1.2 meters. This spacing allows the grouting reinforcement bodies to connect with each other and form an effective reinforcement system. The diffusion radius of the grouting reinforcement bodies is greater than or equal to 1.5 meters, ensuring that the reinforcement range can cover the key areas of the goaf and improve the reinforcement effect of the foundation.

[0055] The steel pipe piles 4 in the slope support structure are arranged vertically inside the slope. The diameter of the steel pipe piles 4 is 150-200mm and the length is 12-16m, so as to ensure that the steel pipe piles 4 have sufficient strength and deformation resistance, and can effectively resist the lateral sliding of the slope. Generally, rotary drilling rigs are used for construction. Steel pipe piles 4 are inserted and cement mortar is poured in. After the beam cap 3 is poured on top of the steel pipe piles 4, the steel pipe piles 4 are connected into a whole.

[0056] The spacing between every two steel pipe piles 4 is 1.0–1.5 m. This reasonable spacing allows the steel pipe piles 4 to work together and jointly bear the lateral forces of the slope. A beam cap 3 is installed on top of the steel pipe piles 4. The top of the beam cap 3 is formed into an integral frame by welding or other methods, fixing multiple steel pipe piles 4 together. The beam cap 3 connects the steel pipe piles 4 into a whole, enabling them to work together better in resisting lateral slippage of the slope. When the slope is subjected to lateral forces, the beam cap 3 can evenly transfer the force to each steel pipe pile 4, enhancing the lateral anti-slip capacity of the entire slope support structure.

[0057] The grouting reinforcement body (steel pipe 1), steel pipe piles (4), and beam caps (3) intersect and / or connect spatially. For example, the steel pipe piles (4) intersect with the grouting reinforcement body, forming an organic whole between the foundation reinforcement structure and the slope support structure. This integrated reinforcement frame can effectively distribute and transfer loads, enhancing the integrity and durability of the steep slope subgrade in the mining area. In the event of natural disasters such as earthquakes and rainstorms, the integrated reinforcement frame can better resist external forces, ensuring the safety of the subgrade.

[0058] The pavement reinforcement structure 5 consists of a graded crushed stone layer 53, a cement-stabilized crushed stone layer 54, a tack coat 52, and an asphalt concrete layer 51 arranged sequentially from bottom to top. The thickness of both the graded crushed stone layer 53 and the cement-stabilized crushed stone layer 54 is 12–16 cm. The graded crushed stone layer 53, laid on the subgrade surface, helps to distribute loads and improve the stress condition of the subgrade. The cement-stabilized crushed stone layer 54, placed on top of the graded crushed stone layer 53, is a mixture of cement, crushed stone, and water in a specific ratio, further enhancing the pavement's strength and integrity. The tack coat 52 is sprayed onto the surface of the cement-stabilized crushed stone layer 54. The asphalt concrete layer 51 is laid within 24 hours of the tack coat 52's application, forming a flexible-rigid composite pavement system. This system effectively disperses differential settlement while ensuring structural integrity, with an interlayer bond strength ≥0.4 MPa, allowing the asphalt concrete layer 51 and the cement-stabilized crushed stone layer 54 to bond together better. The asphalt concrete layer 51 has a thickness of 5-8 cm, which can provide a smooth and anti-skid road surface, improving driving comfort and safety.

[0059] Through the synergistic effect of the foundation reinforcement structure, slope support structure, and pavement reinforcement structure 5, a complete roadbed reinforcement system for steep slopes in mining subsidence areas is formed. The foundation reinforcement structure improves the vertical bearing capacity of the foundation and reduces uneven settlement; the slope support structure enhances the lateral anti-sliding capacity of the slope and prevents slope slippage; and the pavement reinforcement structure 5 improves the strength and durability of the pavement. The various structural components work together to effectively solve the safety problems of steep slope roadbeds in mining subsidence areas, ensuring the long-term stable operation of transportation infrastructure.

[0060] See also Figure 4 The dashed lines represent the boundary between soil and rock and the boundary between weathering, while the solid lines represent the current ground level area.

[0061] The above description is merely an embodiment of this utility model and is not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this utility model should be included within the scope of the claims of this utility model.

Claims

1. A subgrade reinforcement structure for steep slopes in mining subsidence areas, comprising a foundation reinforcement structure, a slope support structure, and a pavement reinforcement structure (5), characterized in that: it comprises: A foundation reinforcement structure, the foundation reinforcement structure including one or more steel pipes (1), the inner side of the steel pipe (1) is hollow, and grout is injected inside to form a grouting reinforcement body; The slope support structure includes one or more steel pipe piles (4), the steel pipe pile (4) includes a pipe body (41), the outer side of the pipe body (41) is provided with a steel pipe pile (4) and the top of the steel pipe pile (4) is provided with a beam crown (3), and the multiple steel pipe piles (4) are arranged vertically inside the slope and intersect with the grouting body; The road reinforcement structure (5) includes a graded crushed stone layer (53), a cement-stabilized crushed stone layer (54), a prime coat (52), and an asphalt concrete layer (51), which are arranged sequentially from bottom to top.

2. The subgrade reinforcement structure for steep slopes in mining areas according to claim 1, characterized in that: The top of the beam crown (3) is welded to form an integral frame, and multiple steel pipe piles (4) are fixed to enhance the lateral anti-slip ability.

3. The subgrade reinforcement structure for steep slopes in mining areas according to claim 1, characterized in that: The foundation reinforcement structure is installed on the inner side of the foundation of the goaf area and is used to reinforce the goaf area.

4. The subgrade reinforcement structure for steep slopes in mining areas according to claim 1, characterized in that: The steel pipe (1) that makes up the foundation reinforcement structure has one or more overflow holes (2) on its outer side, which are used for grout to overflow and spread to form a connecting reinforcement body, thereby improving the vertical bearing capacity of the foundation reinforcement structure.

5. The subgrade reinforcement structure for steep slopes in mining areas according to claim 1, characterized in that: The steel pipes (1) are arranged in a quincunx pattern to form a grouting reinforcement body, which, together with the steel pipes (1), forms a reinforced structure.

6. The subgrade reinforcement structure for steep slopes in mining areas according to claim 1, characterized in that: The grouting reinforcement body, steel pipe pile (4) and beam cap (3) intersect and / or connect with each other in space to form an overall reinforcement frame to enhance the integrity and durability of the steep slope subgrade in the mining area.

7. The subgrade reinforcement structure for steep slopes in mining areas according to claim 1, characterized in that: The outer diameter of the steel pipe (1) is 40-55 mm and the length is 8-10 m. The diameter of the overflow hole (2) opened on the outer side of the steel pipe (1) is 10-15 mm. The distance between each two steel pipes (1) is 0.8-1.2 m. The diffusion radius of the grouting solid is greater than or equal to 1.5 m.

8. The subgrade reinforcement structure for steep slopes in mining areas according to claim 1, characterized in that: The diameter of the steel pipe pile (4) is 150-200mm and the length is 12-16m. The spacing between every two steel pipe piles (4) is 1.0-1.5m.

9. The subgrade reinforcement structure for steep slopes in mining areas according to claim 1, characterized in that: The thickness of the graded crushed stone layer (53) is 12-16 cm, the thickness of the cement-stabilized crushed stone layer (54) is 12-16 cm, and the thickness of the asphalt concrete layer (51) is 5-8 cm.

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