A flexible retaining structure for mine ecological restoration

Abstract

The present invention provides a flexible retaining structure for use in a mine ecological restoration area, including a highway arranged outside a rock slope, a retaining structure arranged inside the highway, a first drainage ditch, a slope repair area, a progressive retaining structure, and a second drainage ditch arranged from inside to outside between the rock slope and the highway, wherein the first drainage ditch is close to the cliff of the rock slope; the outer slope surface of the progressive retaining structure intersects with the top surface of the slope repair area, and the intersection area serves as the highest point of the progressive retaining structure. The flexible retaining structure provided by the present invention not only has the advantages of good retaining and water retaining effects, but also has a stable and reliable structure. More importantly, it can effectively regulate the direction of water flow, cleverly disperse the retaining pressure and rainwater pressure, and can smoothly drain larger rainwater into the groove of the concrete ditch body during use; it also has the advantages of simple materials, low cost, strong adaptability, good overall stability, low hardening rate, and more ecological and environmental protection.

Description

Technical Field

[0001] The invention belongs to the technical field of mine ecological restoration, and in particular relates to a flexible retaining structure for mine ecological restoration. Background Art

[0002] Small and medium-sized open-pit mines of limestone, sandstone, etc. in hilly and mountainous areas are often located next to a single highway. After the mine is closed, the ecological restoration of the mine is implemented and nearby residents rely on a rural road to carry out exchanges with the outside world for various mineral products, daily necessities, etc. Due to the limitations of terrain conditions, the width of the road is very limited, and it is not uncommon to see winding mountain roads with a slope on one side and a cliff on the other. When carrying out ecological restoration of mines in the later stage, due to restrictions on transportation, terrain, investment, etc., after carrying out conventional terrain and landform remediation, soil recovery is generally carried out in the form of paving soil. Areas with conditions will design dry block stones, mortar block stones, etc. to intercept the soil at the edge of the restoration area, but most areas with small scale and general road accessibility have less consideration of soil interception facilities. On the one hand, it leads to serious soil erosion in the region. On rainy days, water carrying a large amount of sediment flows freely on the road, making the road slippery and the overall environment poor. It increases the difficulty of passing and the rate of collisions between vehicles, and increases the cost of road cleaning and maintenance. On the other hand, the soil stability of the paved road is very poor, and the soil water retention time is very short, resulting in poor ecological restoration effect. Summary of the invention

[0003] At least to solve the technical problems mentioned in the background technology, the purpose of the present invention is to provide a flexible retaining structure for mine ecological restoration. The flexibility described in the present invention should at least be understood as the following effects: first, the material is flexible, and the traditional hard retaining wall such as exposed mortar masonry and dry masonry is not used; second, the structural flexibility can effectively control the direction of water flow, cleverly disperse the retaining pressure and rainwater pressure, and achieve stability, low price and ecological benefits.

[0004] The present invention adopts the following technical solution.

[0005] A flexible retaining structure for mine ecological restoration comprises a highway arranged outside a rock slope, a retaining structure arranged inside the highway, a first drainage ditch, a slope repair area, a progressive retaining structure, and a second drainage ditch arranged from inside to outside between the rock slope and the highway, wherein the first drainage ditch is close to the cliff of the rock slope; the outer slope surface of the progressive retaining structure intersects with the top surface of the slope repair area, and the intersection area serves as the highest point of the progressive retaining structure; wherein the angle between the top surface of the slope repair area and the horizontal plane is not greater than 6°, the angle between the outer slope surface of the progressive retaining structure and the vertical plane is 45±3°, and the low point of the slope repair area is located at the first drainage ditch.

[0006] In order to further improve the stability of the flexible retaining structure and better prevent soil erosion, the progressive retaining structure includes: the inner ditch wall of the second drainage ditch, the compacted soil slope and the concave area arranged on the top of the inner ditch wall, the concave area is provided with herbaceous plants, the outer edge of the concave area forms a retaining edge that is inclined upward, the inner edge of the concave area coincides with the outer slope surface, the compaction degree of the compacted soil slope is not less than 90%, and the top surface slope of the compacted soil slope is consistent with the top surface slope of the slope repair area; the compacted soil slope is used as the primary retaining structure, and the retaining edge, the top wall of the inner ditch wall and the compacted soil slope are jointly enclosed to form a secondary retaining structure.

[0007] In order to further improve the stability of the flexible retaining structure, the second drainage ditch includes a concrete bottom plate, an inner ditch wall and an outer ditch wall. The concrete bottom plate is arranged on the original soil rammed layer, the top wall of the outer ditch wall adopts a C20 cast-in-place concrete top pressure structure, and the inner ditch wall and the outer ditch wall are both made of mortar-laid block stones.

[0008] Furthermore, the bottom wall of the concave area has a horizontal area and a slope area, and the angle between the slope area and the horizontal plane is no greater than 15°.

[0009] In order to further improve the stability and service life of the flexible retaining structure, the outer wall of the retaining edge presents a continuous concave-convex structure along the cross section of the retaining edge, and the height of the retaining edge is no more than 5 cm.

[0010] In order to better carry out ecological restoration, the compacted soil slope, the boundary area between the slope restoration area and the original soil layer are basically at the same height as the bottom of the concave area.

[0011] Preferably, the top of the inner groove wall is higher than the top of the outer groove wall.

[0012] Preferably, the inner groove wall and the outer groove wall are arranged vertically.

[0013] Preferably, the cross section of the first drainage ditch is an inverted trapezoidal structure.

[0014] Beneficial effects: In the present invention, with its specific flexible retaining structure, the "R"-shaped pressure on the back of the retaining wall structure is cleverly decomposed. The sloped repair area and the progressive retaining structure jointly bear the "drum-shaped" part with larger retaining pressure. The progressive retaining structure intercepts part of the overflowing water and soil, and can increase the upwelling or infiltration pressure of the initial bottom pore water in the repair area, and bears the "pedestrian" part of the retaining pressure, which plays a good role in ensuring the stability of the overall structure, and can effectively prevent the second drainage ditch from becoming unstable. In the present invention, the concave area and the retaining edge are the basis for promoting the progressive retaining structure to play a role, and the stability of the progressive retaining structure and the overall structure is guaranteed by appropriate interception force, and the key elements necessary for growth such as water retention and fertilizer retention are provided, playing an important role in retaining water and fertilizer, maintaining stability, etc. The flexible retaining structure provided by the present invention not only has the advantages of good soil and water retaining effects, but also has a stable and reliable structure. More importantly, it can effectively regulate the direction of water flow, cleverly disperse the soil retaining pressure and rainwater pressure, and can smoothly drain larger rainwater into the groove of the concrete ditch body during use; it also has the advantages of simple materials, low cost, strong adaptability, good overall stability, low hardening rate, and more ecological and environmental protection.

[0015] By adopting the flexible retaining structure provided by the present invention, under the action of light or medium rain, no obvious surface runoff will be generated, and rainwater will continue to increase the soil moisture content mainly in the form of infiltration. After the rainwater infiltrates to the bottom, the excess rainwater forms micro-runoff and flows along the direction of the highway. With the help of the progressive retaining structure, the water flow speed can be significantly reduced, and the water accumulation at the bottom of the slope repair area is guaranteed by physical interception, so that the soil moisture content is maintained at a high level, and the duration is increased by about 2-3 times compared with the direct paved soil structure; under the action of heavy rain, obvious surface runoff is generated, and the rainwater flows at a slower speed along the inner side of the slope repair area, which slows down the convergence speed to the maximum extent, reduces the sediment rate carried away by rainwater by about 60%, and ensures that the rainwater can penetrate vertically downward to avoid the phenomenon of "the soil is still dry after the heavy rain", ensuring that the soil can reach the maximum saturated moisture content, and at the same time, the infiltrated water forms a virtuous cycle through the joint action of the slope repair area and the progressive retaining structure, so that the soil water can be maintained at a high level, and the duration of soil water is increased by about 2~2.5 times (compared with the paved soil structure). BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the flexible retaining structure in the embodiment;

[0017] Figure 2 A schematic diagram of a progressive retaining structure of a flexible retaining structure in an embodiment;

[0018] Figure 3 for Figure 1 Enlarged view of area A in the middle. DETAILED DESCRIPTION

[0019] The technical solution of the present invention is described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example

[0020] Combination Figures 1 to 3 As shown, a flexible retaining structure for mine ecological restoration includes a highway 12 arranged on the outside of a rock slope 11, a retaining structure arranged on the inside of the highway 12, and a first drainage ditch 13, a slope repair area 14, a progressive retaining structure, and a second drainage ditch 17 arranged from the inside to the outside between the rock slope 11 and the highway 12, wherein the first drainage ditch 13 is close to the cliff of the rock slope 11; the outer slope surface 8 of the progressive retaining structure intersects with the top surface 9 of the slope repair area 14, and the intersection area serves as the highest point of the progressive retaining structure; wherein the soil cover thickness of the slope repair area 14 is ≥40 cm, the angle between the top surface 9 of the slope repair area 14 and the horizontal plane is not greater than 6°, the angle between the outer slope surface 8 of the progressive retaining structure and the vertical plane is 45°, and the low point of the slope repair area 14 is located at the first drainage ditch 13.

[0021] In this embodiment, the progressive retaining structure is as follows Figure 2 As shown, it includes: the inner ditch wall 2 of the second drainage ditch 17, the compacted soil slope 5 and the inner concave area 3 set on the top of the inner ditch wall 2, the soil thickness in the inner concave area 3 is 5 cm, the inner concave area 3 is provided with herbaceous plants (perennial dwarf evergreen plants), the outer edge of the inner concave area 3 forms a retaining edge 4 that is tilted upward, the inner edge of the inner concave area 3 coincides with the outer slope surface 8, the compaction degree of the compacted soil slope 5 is not less than 90%, and the top surface slope of the compacted soil slope 5 is consistent with the slope of the top surface 9 of the slope repair area 14; the compacted soil slope 5 is used as the primary retaining structure, and the retaining edge 4, the top wall of the inner ditch wall 2 and the compacted soil slope 5 together form a secondary retaining structure.

[0022] In this embodiment, the second drainage ditch 17 includes a 100 mm thick concrete base plate 6, a 300 mm wide inner ditch wall 2 and a 300 mm wide outer ditch wall 7. The outer ditch wall 7 is 400 mm high. The concrete base plate 6 is arranged on the original soil rammed layer 15. The top wall of the outer ditch wall 7 adopts a 50 mm thick C20 cast-in-place concrete top pressure structure. Both the inner ditch wall 2 and the outer ditch wall 7 are made of mortar-laid block stones.

[0023] In this embodiment, the bottom wall of the concave area 3 has a horizontal area 20 and a slope area 21, and the angle between the slope area 21 and the horizontal plane is 15°; along the cross section of the retaining edge 4, the outer wall of the retaining edge 4 presents a continuous concave-convex structure, and the height of the retaining edge 4 is not more than 5 cm.

[0024] In this embodiment, the compacted soil slope 5, the slope repair area 14 and the boundary area 10 of the original soil layer are basically at the same height as the bottom of the inner concave area 3; the top of the inner ditch wall 2 is higher than the top of the outer ditch wall 7; the inner ditch wall 2 and the outer ditch wall 7 are both arranged vertically; the cross-section of the first drainage ditch 13 is an inverted trapezoidal structure.

[0025] Construction plan: earth excavation; earth compaction; construction of concrete ditch bottom and ditch wall, ditch wall C20 on one side of highway 12 is pressed 5cm, and the side of the slope repair area 14 is set to an arc ditch wall top of ≤15° (that is, the angle between the slope area 21 and the horizontal plane is ≤15°), and 5-10cm of cultivated soil is spread; 3-5 kinds of perennial dwarf evergreen suitable mixed grass seeds are sown on the soil layer of the concave area 3, and the sowing density should be 20-30g / m2; the outer slope surface 8 of the slope repair area 14 is patted and compacted with a shovel to a compactness of more than 90%, the repair plot is set to be low inside and high outside, and the overall table slope is controlled within 6°. The first drainage ditch 13 uses an earth ditch according to the size of the catchment area; engineering management and vegetation management.

[0026] During use, part of the rainwater flows inward (left side in the figure) along the top surface 9 of the compacted soil slope 5 and the slope repair area 14, and the other part of the rainwater flows outward along the outer slope 8 of the compacted soil slope 5 to the concave area 3; when the rainwater is small, the rainwater flowing to the concave area 3 will penetrate into the compacted soil slope 5 and the original soil layer, and part of the rainwater will be retained in the concave area 3; when the rainwater is large, the rainwater flowing to the concave area 3 will further climb over the retaining edge 4 and flow into the groove of the concrete ditch body, and this part of the rainwater flows to the following direction: Figure 3 Indicated by the arrow.

[0027] This solution uses simple materials and has low cost. Ordinary construction materials such as cement, mortar, and stone blocks can meet the needs of the project. The process is simple and uses less materials, using about 2 / 3 less materials than ordinary mortar-laid block stone retaining ridges. It has strong adaptability and good overall stability, and is especially suitable for various scenarios such as hilly and mountainous areas near transportation roads, production roads, and field roads. The relatively stable slope ratio plus the isolation grass strip will transition the restoration area to a mature farming area after 2-3 farming periods, and the overall isolation and retaining effect will tend to be stable. The hardening rate is low and more ecological and environmentally friendly. Compared with conventional mortar-laid block stones and dry-laid block stones, the hardening rate is low, which reduces carbon emissions while increasing soil carbon sinks. The overall solution is more ecological and environmentally friendly.

[0028] In this scheme, with its specific flexible retaining structure, the "R"-shaped pressure on the back of the retaining wall structure is cleverly decomposed. The sloped repair area and the progressive retaining structure jointly bear the "drum-shaped" part with larger retaining pressure. The progressive retaining structure intercepts part of the overflowing water and soil, and can increase the initial bottom pore water upwelling or lower layer pressure in the repair area, and bears the "pedestrian" part of the retaining pressure, which plays a good role in ensuring the stability of the overall structure, and can effectively prevent the second drainage ditch from becoming unstable. In the present invention, the concave area and the retaining edge are the basis for promoting the progressive retaining structure to play a role, with appropriate interception force to ensure the stability of the progressive retaining structure and the overall structure, provide key elements necessary for growth such as water retention and fertilizer retention, and play an important role in retaining water and fertilizer, maintaining stability, etc.

[0029] The flexible retaining structure provided by the present invention not only has the advantages of good soil and water retaining effects, but also has a stable and reliable structure. More importantly, it can effectively regulate the direction of water flow, cleverly disperse the soil retaining pressure and rainwater pressure, and can smoothly drain larger rainwater into the groove of the concrete ditch body during use.

[0030] By adopting the flexible retaining structure provided by the present invention, under the action of light or medium rain, no obvious surface runoff will be generated, and rainwater will continue to increase the soil moisture content mainly in the form of infiltration. After the rainwater infiltrates to the bottom, the excess rainwater forms micro-runoff and flows along the direction of the highway. With the help of the progressive retaining structure, the water flow speed can be significantly reduced, and the water accumulation at the bottom of the slope repair area is guaranteed by physical interception, so that the soil moisture content is maintained at a high level, and the duration is increased by about 2-3 times compared with the direct paved soil structure; under the action of heavy rain, obvious surface runoff is generated, and the rainwater flows at a slower speed along the inner side of the slope repair area, which slows down the convergence speed to the maximum extent, reduces the sediment rate carried away by rainwater by about 60%, and ensures that the rainwater can penetrate vertically downward to avoid the phenomenon of "the soil is still dry after the heavy rain", ensuring that the soil can reach the maximum saturated moisture content, and at the same time, the infiltrated water forms a virtuous cycle through the joint action of the slope repair area and the progressive retaining structure, so that the soil water can be maintained at a high level, and the duration of soil water is increased by about 2~2.5 times (compared with the paved soil structure).

Claims

1. A flexible retaining structure for mine ecological restoration, comprising a road (12) arranged outside a rock slope (11), and a retaining structure arranged inside the road (12), characterized in that: A first drainage ditch (13), a slope repair area (14), a progressive retaining structure, and a second drainage ditch are arranged from the inside to the outside between the rock slope (11) and the highway (12), wherein the first drainage ditch (13) is close to the cliff of the rock slope (11); the outer slope surface (8) of the progressive retaining structure intersects with the top surface (9) of the slope repair area (14), and the intersection area serves as the highest point of the progressive retaining structure; wherein the angle between the top surface (9) of the slope repair area (14) and the horizontal plane is not greater than 6°, the angle between the outer slope surface (8) of the progressive retaining structure and the vertical plane is 45±3°, and the lowest point of the slope repair area (14) is located at the first drainage ditch (13); The progressive retaining structure comprises: an inner ditch wall (2) of a second drainage ditch, a compacted soil slope (5), and an inner concave area (3) arranged at the top of the inner ditch wall (2), the inner concave area (3) being provided with herbaceous plants, the outer edge of the inner concave area (3) forming a retaining edge (4) that tilts upward, the inner edge of the inner concave area (3) coincides with the outer slope surface (8), the compaction degree of the compacted soil slope (5) is not less than 90%, and the top surface slope of the compacted soil slope (5) is consistent with the top surface (9) slope of the slope repair area (14); the compacted soil slope (5) is used as a primary retaining structure, and the retaining edge (4), the top wall of the inner ditch wall (2) and the compacted soil slope (5) together form a secondary retaining structure; The bottom wall of the inner concave area (3) has a horizontal area (20) and a slope area (21), and the angle between the slope area (21) and the horizontal plane is not greater than 15 degrees; along the cross section of the retaining edge (4), the outer wall of the retaining edge (4) presents a continuous concave-convex structure, and the height of the retaining edge (4) is not greater than 5 cm; the boundary area (10) between the compacted soil slope body (5), the slope repair area (14) and the original soil layer is substantially at the same height as the bottom of the inner concave area (3).

2. The flexible retaining structure according to claim 1, characterized in that: The second drainage ditch comprises a concrete bottom plate (6), an inner ditch wall (2) and an outer ditch wall (7); the concrete bottom plate (6) is arranged on the original soil rammed layer (15); the top wall of the outer ditch wall (7) adopts a C20 cast-in-place concrete top pressure structure; and both the inner ditch wall (2) and the outer ditch wall (7) adopt a mortar-laid block stone structure.

3. The flexible retaining structure according to claim 2, characterized in that: The top of the inner groove wall (2) is higher than the top of the outer groove wall (7).

4. The flexible retaining structure according to claim 3, characterized in that: The inner groove wall (2) and the outer groove wall (7) are both arranged vertically.

5. The flexible retaining structure according to claim 4, characterized in that: The cross section of the first drainage ditch (13) is an inverted trapezoidal structure.

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