Methods and apparatus for ecological restoration and protection of steep slopes in open-pit mining sites

Abstract

This solution addresses the problems in conventional technologies where regrowth is difficult and the stability of the regrowth structure is low on steep, rocky slopes remaining in mining areas after the operation of open-pit mines. [Solution] Belonging to the field of slope or inclined land stabilization technology, the present invention provides a method and apparatus for ecological restoration and protection of steep slopes in open-pit mines. The method for ecological restoration and protection of steep slopes in open-pit mines includes a steep slope in an open-pit mine that includes multiple layers of stair units, with the stair units sequentially arranged vertically to include gentle slopes and steep slopes. The method includes direct regreening of the gentle slopes, spraying a base layer on the bottom layer, spraying a surface layer on the top layer, and sowing mixed seeds in the surface layer. The method includes solidifying and regreening of the steep slopes, evaluating the stability of the gentle slopes and steep slopes, protecting the steep slopes based on the evaluation results, and then regreening the steep slopes. Overall, by combining this method with the present apparatus, not only is the regreening efficiency increased, but the safety of the slope and the ecological restoration effect are also guaranteed.

Description

Technical Field

[0001] The present invention belongs to the technical field of slope or inclined land stabilization, and particularly relates to a method and device for ecological restoration and protection of steep slopes in open-pit mines.

Background Art

[0002] In the mined-out mining area, there may remain steep exposed rocky slopes. The surfaces of these slopes are mainly hard rocks, lacking soil and moisture, making it difficult for vegetation to recover under natural conditions and causing serious damage to the ecological environment. To solve this problem, it is necessary to carry out ecological restoration on these slopes.

[0003] However, there are various difficulties in the ecological restoration of steep rocky slopes. In the conventional soil covering restoration method, collapse and landslides are likely to occur due to bad weather and geological conditions at the slope soil quality and the boundary between soil and rock. The landslide of the surface layer soil covering not only leads to the failure of slope restoration but also poses potential safety risks. On the other hand, how to stably maintain the ecological slope protection layer over a long period, promote the growth of plants, and achieve maintenance-free in the later stage is a technical difficulty.

Summary of the Invention

Problems to be Solved by the Invention

[0004] Therefore, it is necessary to use more scientific and reasonable engineering measures and technical means to realize the ecological restoration of steep rocky slopes in combination with the specific situation and environmental conditions of the steep rocky slopes in open-pit mines.

Means for Solving the Problems

[0005] In view of the above-mentioned drawbacks of the prior art, the object of the present invention is to provide a method and device for ecological restoration and protection of steep slopes in open-pit mines, and to solve the problems in the prior art that it is difficult to revegetate the steep rocky slopes left in the mining area after mining in open-pit mines and the structural stability of revegetation is low.

[0006] To achieve the above-mentioned objectives and other related objectives, the present invention provides a method and apparatus for ecological restoration and protection of steep slopes in open-pit mining sites.

[0007] A method for ecological restoration and protection of steep slopes in an open-pit mine, wherein the steep slope of the open-pit mine includes multiple layers of stair units, each stair unit includes sequentially connected gentle slopes and steep slopes, the gentle slopes include direct regreening, spraying a base layer on the bottom layer, spraying a surface layer on the top layer, and sowing mixed seeds in the surface layer, and the steep slopes include solidifying regreening, evaluating the stability of the gentle slopes and steep slopes, protecting the steep slopes based on the evaluation results, and then regreening the steep slopes.

[0008] Preferably, protection against steep slopes includes structural protection and surface protection. Structural protection involves forming multiple anchor points on the slope of the steep section using injection-type anchor rods, laying a steel-plastic geogrid on the slope of the steep section, and installing frame-shaped connecting reinforcing bars between each anchor point. Surface protection involves laying a protective net on the slope of the steep section and spraying a base layer.

[0009] Preferably, restoring greenery to a steep slope involves spraying a topsoil onto the bottomsoil of the steep slope, sowing mixed seeds within the topsoil, planting downward-growing climbing plants at the top of the steep slope, and planting upward-growing climbing plants at the bottom of the steep slope.

[0010] Preferably, replanting on a steep slope involves using a drilling machine to drill multiple planting holes 50 to 100 cm deep at a downward angle of 30 to 60° on the slope, the diameter of each planting hole (110) includes at least one enlarged section, and multiple rooting holes are drilled in each of the planting holes, the inside of which the rooting holes communicate with the planting holes and penetrate radially into the slope, and after filling the planting holes with an ecological substrate, dwarf shrubs (6) are transplanted to replant.

[0011] Preferably, the seeds include seeds of herbaceous plants, dwarf shrubs, and climbing plants, with a germination rate of 90% or higher. Seeds that are difficult to germinate are treated with a germination-promoting agent before use, and the seeds further include plant seeds collected from the surrounding environment of slopes.

[0012] Preferably, before laying the protective net, horizontal straw bundles are placed on the slope at regular height intervals, and the horizontal straw bundles are fixed with anchor rods. After laying the protective net, the straw bundles and the protective net are tied together again, and the protective net is made of covered plastic netting.

[0013] Preferably, the rooting holes are located in the tunnel entrance area of ​​the slope and are covered with straw bundles, the straw bundles are fixed to the slope, and the sprayed base layer and surface layer are covered with the straw bundles.

[0014] Preferably, the sprayed thickness of the base layer is 7 to 10 cm, and the base layer contains P32.5 cement at a mass ratio of 5%.

[0015] Preferably, the base layer sprayed per square meter is 0.06 to 0.08 m³ of planting soil. 3 It contains 2-3 kg of fiber, 80 g of adhesive, 30-40 g of PAM, 60-80 g of water-retaining agent, and 50 g of compound fertilizer.

[0016] Preferably, the surface layer sprayed per square meter is 0.06 to 0.04 m³ of planting soil. 3 It contains 1.6-1.8 kg of rice hulls, 1.6-1.8 kg of rice straw fragments, 0.8-1 kg of wood fiber, 15 g of adhesive, 8-10 g of PAM, 8-10 g of water-retaining agent, 6-8 kg of organic fertilizer, 30 g of compound fertilizer, and 55 g of seeds.

[0017] The apparatus for ecological restoration and protection of steep slopes in open-pit mining sites is used to drill the rooting holes and includes a drill rod, a drill bit, and an axis adjustment device. The drill bit is connected to the end of the drill rod, and the axis adjustment device is rotatably sleeve-mounted on the drill rod. The diameter of the drill bit is greater than the diameter of the drill rod, and the initial outer diameter of the axis adjustment device is smaller than the diameter of the drill bit. The inner ring surface of the axis adjustment device is rotatably fitted with the drill rod, and the outer ring surface is provided with three radial expansion and contraction structures. When the radial expansion and contraction structures are extended, the area of ​​the axis adjustment device exceeds the diameter range of the drill bit.

[0018] Preferably, the radially expanding structure includes a guide groove, an expandable body, and an expandable power source, wherein the guide groove includes two structural plates fixedly connected to the outer ring surface, the expandable body is slidably mounted between the two structural plates, the sliding direction is along the radial direction of the drill rod, and the expandable power source is mounted between the outer ring surface and the expandable body to provide sliding power.

[0019] Preferably, the drill bit includes a body, roller cutters and a nozzle, the tail end of the body is connected to the drill rod, the head end of the body is a disc-shaped end face, three roller cutters are mounted on the disc-shaped end face in a circular arrangement at equal intervals, the axes of the roller cutters are parallel to the axis of the drill bit body, roller teeth are installed on the circumferential surface of the roller cutters, the roller teeth of two cutters are fitted together in adjacent regions of any two cutters, the nozzle is positioned outside the intermediate region between two adjacent cutters and is directed toward the roller tooth fitting region inside the two adjacent cutters. [Effects of the Invention]

[0020] As described above, the method and apparatus for ecological restoration and protection of steep slopes in open-pit mining sites according to the present invention have at least the following beneficial effects: For the special structure of the steep slopes in open-pit mines, a method of directly revegetating the gentle slope sections is proposed. By spraying the bottom base layer and the surface base layer and further sowing and irrigating mixed seeds, the stability of the slope base material is effectively enhanced, the rooting and growth of vegetation are promoted, and the ecological restoration effect and stability of the slope are significantly strengthened. For the steep slope sections, after evaluating the stability and providing protection in advance, the same revegetation method as that of the gentle slope sections is adopted to ensure the stability and effectiveness of the revegetation structure and solve the problem of difficulty in revegetating the steep sections. Generally speaking, not only the revegetation efficiency is improved, but also the safety of the slope and the ecological restoration effect are guaranteed.

Brief Description of the Drawings

[0021] [Figure 1] Shows a schematic diagram of the revegetation of the staircase unit of the present invention. [Figure 2] Shows a schematic diagram of the steep slope in an open-pit mine. [Figure 3] Shows a partial enlarged view of part A in FIG. 1 of the present invention. [Figure 4] Shows a schematic diagram of the protection structure for the steep section of the present invention. [Figure 5] Shows a schematic diagram of the drill rod side of the repair device of the present invention. [Figure 6] Shows a schematic diagram of the drill head side of the repair device of the present invention. [Figure 7] Is a schematic diagram showing a state of the diameter expansion operation of the present invention. [Figure 8] Is a schematic diagram showing another state of the diameter expansion operation of the present invention. [Figure 9] Is a schematic diagram showing the bottom base layer component table of the present invention. [Figure 10] Is a schematic diagram showing the surface base layer component table of the present invention.

Embodiments for Carrying Out the Invention

[0022] Hereinafter, the implementation manners of the present invention will be described based on specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention according to the content disclosed in this specification.

[0023] Refer to Figures 1 to 10. The structures, proportions, sizes, etc. shown in the appendices of this specification are all used to correspond to the disclosures of the specification and are merely aids for understanding and interpretation by those familiar with the art, and are not limiting conditions that restrict the implementation of the present invention, and therefore have no substantial technical significance. Any modification of structure, change in proportion relationships, or adjustment of size is included within the scope of the disclosed technical content of the present invention, provided that it does not affect the effects produced by the present invention and the purposes achieved. At the same time, terms such as “up,” “down,” “left,” “right,” “middle,” and “one” used herein are for descriptive convenience and do not limit the scope of the present invention. Changes or adjustments of their relative relationships are considered to be included within the scope of the present invention, provided that they do not substantially change the technical content.

[0024] The following embodiments are for illustrative purposes only. The embodiments can be combined with each other and are not limited to those shown in the following single embodiments.

[0025] Refer to Figures 1 to 4. This is one embodiment of the method for ecological restoration and protection of steep slopes in open-pit quarries provided by the present invention. As shown in Figure 2, the structure of the steep slope of the open-pit quarry includes a multi-layered staircase unit 1, where under normal conditions, the height of each staircase layer is approximately 30 m and the width is 10 to 15 m, and the staircase unit 1 includes a gently sloping section 10 and a steeply sloping section 11 that are sequentially connected vertically. The steeply sloping section 11 is mainly rocky, the maximum inclination angle of the rocky slope is 65 to 70°, the rock layers are relatively intact, the degree of weathering is low, and the rock is hard.

[0026] The steep section 11 has a large incline, and the surface is made of exposed rock. The rock layer is hard and complete, making it difficult for plants to take root on the slope and hindering reforestation. Existing technologies exist for slope reforestation using soil cover, but considering the actual technical challenges of the present invention, the steep incline of the rocky slope presents two problems. Firstly, the soil cover is not stable on the slope, resulting in low stability of the soil reforestation structure. In particular, during the rainy season from May to October, if soil cover is applied to the slope using conventional methods, localized collapses and slides may occur, not only resulting in reforestation failure but also posing a significant safety risk. Secondly, it is difficult for reforesting plants to take root in the rock layer. Surface soil cover on rocky slopes has low water retention capacity, making it difficult for plants to survive during hot periods, and requiring long-term maintenance work such as artificial irrigation.

[0027] In this invention, considering the special step structure of the steep, rocky slope of the open-pit quarry, regreening is directly applied to the gently sloping section 10. Specifically, this involves spraying a base layer 20 on the lower layer, spraying a top layer 21 on the upper layer, and sowing a mixed seed in the top layer 21. Sowing means sowing and watering, and sowing can be done by spraying. The spraying thickness of the base layer is 5 cm or more, and the spraying thickness of the top layer is 2 cm or more. The base layer 20 and the top layer 21 are collectively called the base layer, and the base layer material mainly consists of local planting loam, with the addition of mixed materials that are advantageous for the bonding of the ecological dam layer and plant growth, such as fibers, clay, PAM, water-retaining agents, compound fertilizers, rice hulls, and organic fertilizers. Furthermore, the base layer 20 uses a substrate with a certain viscosity and strength, effectively adhering to the slope, ensuring the stability of the reforestation structure, preventing the erosion and collapse of the base layer, and providing a solid support base for the surface layer. This ensures the sustainability and safety of the entire reforestation process. On the other hand, the surface layer 21 uses a substrate with a certain viscosity and vegetation potential, firmly adhering to the base layer while simultaneously providing an environment suitable for plant growth. This ensures that seeds are effectively fixed to the slope, allowing for smooth germination and growth, promoting vegetation formation, and enhancing the ecological restoration effect and stability of the slope.

[0028] In the above embodiment, a method is adopted in which a base layer 20 is sprayed on the lower layer, a surface base layer 21 is sprayed on the upper layer, and mixed seeds are sown in the surface base layer 21. This significantly improves the stability of the slope substrate, promotes the rooting and growth of vegetation, effectively reduces the erosion of the base layer material, and ensures ecological restoration and greening effects on the slope.

[0029] The reinforcement and re-greening of the steep slope section 11 includes evaluating the stability of the gentle slope section 10 and the steep slope section 11, and then performing re-greening on the steep slope section 11 after providing protection based on the evaluation results. The re-greening method is the same as for the gentle slope section 10, and includes spraying the base layer 20, spraying the surface base layer 21, and sowing mixed seeds in the surface base layer 21. Because the steep slope section 11 has a large incline and the rock layer is hard, the stability and effectiveness of direct re-greening are difficult to guarantee. Therefore, by installing a protective structure in advance, the stability of the base layer 20 and surface base layer 21 sprayed afterward is increased, creating favorable conditions for subsequent re-greening work and ensuring the stability and effectiveness of the re-greening structure.

[0030] Furthermore, as shown in Figures 3 and 4, protection against the steep slope 11 includes structural protection and surface protection. Structural protection involves forming multiple anchor points in the steep slope 11 using injection-type anchor rods 30, laying a steel-plastic geogrid 31 in the steep slope 11, and installing frame-shaped connecting reinforcing bars 32 between each anchor point. The anchor rods may be made of Φ20 reinforcing bars with a spacing of 3m x 3m and a length of 0.5 to 1.0m. The connecting reinforcing bars should be made of Φ14 reinforcing bars with a spacing of 3m x 3m. The quantity and spacing of the injection-type anchor rods 30 and geogrid 31 on the slope depend on the evaluation results for the steep slope 11; if the slope is steep, the spacing of the anchors and geogrid should be reduced. The inside of the anchor holes should be filled to 8-9cm with vegetable adhesive or cement milk, and the exposed parts should be coated with rust-preventive paint. The injection-type anchor rods 30 form multiple anchor points in the steep section 11, and by connecting with the steel-plastic geogrid 31 and connecting reinforcing bars 32, a stable solidification network is formed, thereby improving the slip resistance and overall stability of the slope of the base layer having a certain viscosity and strength.

[0031] For surface protection, a protective net is laid on the slope of the steep section 11, and the base layer 20 is sprayed onto it. The protective net is specified as #14, with a mesh size of 40mm x 40mm. Before spraying, loose rocks on the slope where the protective net will be installed and at the top of the slope are cleaned, the base layer is sprayed first, and then the surface layer is sprayed. The protective net is attached to anchors and secured at the connection points with the anchors, and the ends of the protective net at the top and bottom of the slope are fixed to ensure that the protective net is in close contact with the slope, minimizing voids and gaps, and ensuring that the protective net provides sufficient support to protect the vegetation base layer material. The protective net and the base layer work together to protect the slope, ensuring that the slope ecological protection layer remains stable even under heavy rain, prolonged rain, and earthquake conditions.

[0032] Structural protection, surface protection, and the combined action of shrubs and grasses growing within the substrate reduce erosion of the surface and base layer due to heavy rainfall, ensuring plant establishment. After the shrubs and grasses have grown and proliferated and stabilized (approximately 2 years later), maintenance becomes unnecessary, enabling a longer-term natural ecological recovery process.

[0033] Furthermore, as shown in Figure 1, replanting of the steep slope 11 involves spraying a topsoil layer 21 onto the bottom soil layer 20 on the slope of the steep slope 11 and sowing mixed seeds in the topsoil layer 21. Based on the environmental conditions of the target mining area, the replanting plant community will start with herbaceous plants and climbing plants as the main components, with shrubs as supplementary plants, and as the vegetation community evolves, it will eventually form a community that is mainly shrubs with herbaceous plants and climbing plants as supplementary plants. The plant species of the mixed seeds to be sowed will mainly be those native to the area, and the following plant species can be selected: Herbaceous plants: Bermuda grass, dock, tall fescue, cosmos, etc.

[0034] Shrub plants: Leucaena leucocephala, Sophora xanthantha, Pyracantha, Crotalaria, etc.

[0035] Climbing plants: Virginia creeper (planting seedlings), Casuarina equisetifolia, Pueraria lobata, and other types of vines (planting seedlings).

[0036] Plant downward-growing climbing plants 4 at the top of the steep slope 11.

[0037] Upward-growing climbing plants 5 are planted at the base of the steep slope section 11.

[0038] As shown in Figure 1, this embodiment involves restoring greenery to a steep slope 11 by drilling multiple planting holes 110 with a depth of 50 to 100 cm at a downward angle of 30 to 60° to the slope using a drilling machine, with the specific drilling angle determined according to the rock conditions of the slope, taking into consideration the ease of construction and the growth angle of the plantings, the diameter of the planting holes 110 including at least one enlarged section, drilling multiple rooting holes 111 into each planting hole 110, the inside of the rooting holes 111 communicating with the planting holes 110 and penetrating the slope radially, filling the planting holes 110 with an ecological substrate, and then transplanting shrubs 6 to restore greenery.

[0039] In the above embodiment, the planting holes 110 play an extremely important role in ecological restoration work, and are even more crucial on steep, rocky slopes. The main purpose of the planting holes is to provide a growing environment for the root systems of shrubs and to enhance slope stability by utilizing the natural growth characteristics of the shrubs. Compared to the conventional anchor rod reinforcement method, ecological restoration using shrubs is not only more environmentally friendly but also promotes the natural recovery of the ecosystem and realizes a more harmonious coexistence between humans and nature.

[0040] However, planting shrubs on rocky slopes is not easy. Because the rock is hard and the slope is steep, the shrub root system has difficulty penetrating deeply and establishing a stable root system. To solve this problem, the planting hole 110 is designed with a specially widened section. This design cleverly expands the internal space of the hole, allowing more ecological substrate to be filled and providing the shrub root system with more space to grow. As a result, the shrub root system can grow freely within the hole, and the widened section forms a root system position limiting structure. When faced with adverse conditions such as strong winds or slope erosion, the root system and the widened section work together to firmly fix the shrub within the hole and effectively maintain the stability of the slope.

[0041] In addition to increasing internal space, the radial design of the root holes 111 is also a major feature of this technology. These holes radiate from the plant holes 110 into the slope and connect with the base layer sprayed onto the slope, providing the shrub root system with more abundant growth space. The root system penetrates the slope surface along these root holes 111, firmly gripping the rock and further strengthening the anchoring effect between the shrub and the rock body by closely connecting with the slope base layer soil. This design not only improves the shrub's resistance to uprooting but also allows the shrub to better absorb water and nutrients from the slope surface, resulting in healthy growth.

[0042] Furthermore, a clever feature is that the rooting holes 111 also serve a drainage function. Because the permeability of the rock layer is low, if only the planting holes 110 were used, a large amount of rainwater would accumulate in the holes during the rainy season, making it difficult for the water to penetrate into the rock layer. This not only restricts the growth space of the root system but can also cause the root system to be submerged in water and rot, potentially affecting the survival rate of the shrubs. The design of the rooting holes 111 allows water to be drained from the holes, thus avoiding this problem. This ensures the normal growth and development of the shrubs and creates a fixation effect.

[0043] In summary, the design of the planting holes 110 and rooting holes 111 skillfully solves the challenges of planting shrubs on steep, rocky slopes. This not only provides a good growing environment for shrubs but also strengthens the stability of the slope and promotes the restoration and development of the ecosystem. Such ecological restoration methods are not only more environmentally friendly and sustainable but also more stable.

[0044] Furthermore, the seeds include those of herbaceous plants, shrubs, and climbing plants. Before use, plant seeds undergo germination rate tests, and only those with a germination rate of 90% or higher are used. Seeds that are difficult to germinate are treated to induce germination before use. The seeds also include plant seeds collected from the surrounding environment of the slope. In the specific construction process, plant seeds are collected on-site and added to ensure that the restored slope harmonizes with the surrounding environment as much as possible.

[0045] As shown in Figure 4, in this embodiment, before laying the protective net, horizontal straw bundles 34 are installed at regular intervals along the slope. They may be installed at 1m intervals, and the straw bundles 34 are fixed with anchor rods. After laying the protective net, the straw bundles 34 and the protective net are tied together again. The straw bundles are made by bundling rice straw and are installed horizontally inside the protective net on top of the anchor rods. The central part of the straw bundles between adjacent anchor rods is tied to the protective net. The purpose of the straw bundles 34 is to prevent the base material from sliding off during spraying work. A PVC-coated plastic net is used for the protective net, and its purpose is to achieve corrosion protection durability of 10 to 20 years. The rooting holes 111 are located in the tunnel entrance (exit) area of ​​the slope and are covered with straw bundles 34. The straw bundles 34 are fixed to the slope, and the sprayed base layer 20 and surface layer 21 cover the straw bundles 34.

[0046] In the above-described embodiment, the shrub root system in the planting hole 110 can grow from the rock to the base layer on the slope surface through the rooting hole 111. However, in order to increase the strength of the base layer, 5% by mass of P32.5 cement may be mixed into the base layer 20, which is unfavorable for the growth of the shrub root system. The root system may require more time to penetrate the base layer 20 and reach the surface base layer to absorb water and nutrients. Therefore, if the area located at the entrance of the rooting hole 111 on the slope is covered with straw bundles 34, even if the sprayed base layer 20 contains a certain mass ratio of cement, the shielding and covering effect of the straw bundles 34 allows the shrub root system to penetrate the base layer 20 at high speed through the straw bundles 34 and reach the surface base layer 21. The straw bundles 34 help the shrub root system penetrate and provide a humus environment favorable for the development of the root system.

[0047] Furthermore, as shown in Figure 3, the sprayed thickness of the base layer 20 is 7-10 cm, and the adhesion between the base layer and the slope is enhanced by incorporating 5% P32.5 cement by mass into the base layer 20. Tests on the adhesion of the base layer showed no peeling even after scouring by heavy rain for two days. The sprayed thickness of the surface layer is 3-5 cm. In areas with high temperatures and high water evaporation, it is desirable that the overall thickness of the base material not be less than 12 cm, and even in localized areas, it is desirable that it not be less than 10 cm. When spraying, work from bottom to top, spraying the base of the slope first, then spraying the slope, and repeating this process to ensure the base material thickness is achieved.

[0048] In this embodiment, the base layer 20 sprayed per square meter contains 0.06 to 0.08 cubic meters of planting loam, 2 to 3 kg of fiber, 80 g of binder, 30 to 40 g of PAM, 60 to 80 g of water-retaining agent, and 50 g of compound fertilizer. The top layer 21 sprayed per square meter contains 0.06 to 0.04 cubic meters of planting loam, 1.6 to 1.8 kg of rice hulls, 1.6 to 1.8 kg of rice straw fragments, 0.8 to 1 kg of wood fiber, 15 g of binder, 8 to 10 g of PAM, 8 to 10 g of water-retaining agent, 6 to 8 kg of organic fertilizer, 30 g of compound fertilizer, and 55 g of seeds. For specific components, refer to Figure 9, which is the base layer component table.

[0049] The base layer composition improves the physicochemical properties and ecological functions of slope soils, enhances slope stability and vegetation growth conditions, and provides a solid foundation for slope restoration and ecological recovery.

[0050] The topsomal layer composition not only effectively enhances the water retention, nutrient retention, and structural stability of slope soils, but also enables rapid reforestation and restoration of biodiversity through the incorporation of diverse herbaceous seeds. This provides an economical, environmentally friendly, long-term, and effective solution for slope protection. For specific components of the topsomal layer, please refer to Figure 10, which is a table of topsomal layer components.

[0051] In the above-described embodiment, after the completion of ecological restoration and protection work on the steep slopes of the open-pit mining site, it is necessary to periodically monitor and maintain the process.

[0052] The monitoring includes the growth status of greening plants and the stability of the base layer. If a rainy season occurs, the erosion of the base layer by rainwater will be inspected in detail, and drainage pipes will be installed vertically at locations where erosion marks from flowing water are observed on the slope, or at locations where grooves have been formed by slope erosion. At the boundary between gentle and steep slopes, a water collection weir or drainage ditch will be formed by spraying base layer soil, and a trumpet-shaped opening will be provided. The drainage pipes will be positioned along the vertical erosion grooves and fixed to the slope using anchor rods. The water intake at the top of the drainage outlet will be located at the trumpet-shaped opening of the drainage ditch. When additional base layer soil is sprayed, the drainage pipes will be covered. This will allow the drainage pipes to discharge water from the slope surface, reducing the effects of erosion.

[0053] The care includes regularly irrigating the slope during the germination period of grass seeds in the base layer. A dedicated micro-irrigation system is installed to ensure that the watered area is evenly distributed across the slope and that the reforested area is completely covered, thereby ensuring the growth of the slope greenery. Once the slope greenery has grown stably, the micro-irrigation system may be removed, and care will cease, transitioning to a natural restoration phase.

[0054] As shown in Figures 5 to 8, an embodiment of the ecological restoration and protection device for steep slopes of open-pit quarries provided by the present invention is used for drilling the planting holes 110. The ecological restoration and protection device for steep slopes of open-pit quarries includes a drill rod 7, a drill bit 8, and an axis adjustment device 9. The drill bit 8 is connected to the end of the drill rod 7, and the axis adjustment device 9 is rotatably sleeve-mounted on the drill rod 7. The diameter of the drill bit 8 is greater than the diameter of the drill rod 7, and the initial outer diameter of the axis adjustment device 9 is smaller than the diameter of the drill bit 8. The axis adjustment device 9 has an inner ring surface that is rotatably fitted with the drill rod 7, and an outer ring surface provided with three radial extension structures 91. When the radial extension structures 91 are extended, the area corresponding to the axis adjustment device 9 exceeds the diameter range of the drill bit 8.

[0055] Comparing Figures 7 and 8, the three sets of radial contraction structures 91 are evenly arranged around the outer circumference of the drill rod 7, with a spacing of 120° between them. By controlling the amount of expansion and contraction of each radial contraction structure 91, the offset between the axis of the drill rod 7 and the axis of the planting hole 110 can be adjusted. This allows the drill bit 8 to expand the edge of the planting hole 110 as the drill rod 7 rotates the drill bit 8, thereby creating an enlarged diameter section within the planting hole 110. This increases the internal diameter of the planting hole 110 while keeping the main hole diameter small, allowing more substrate to be filled and facilitating the rooting and growth of the shrub. Subsequently, the root system and the enlarged diameter section form a positional limiting structure, increasing the shrub's resistance to uprooting and enhancing the regenerative structure's resistance to storms and slope sliding.

[0056] Furthermore, the radial contraction structure 91 includes a guide groove 911, an extendable body 912, and an extendable power source 913. The guide groove 911 includes two structural plates fixedly connected to the outer ring surface, and the extendable body 912 is positioned between the two structural plates, with its sliding direction aligned with the radial direction of the drill rod 7. The extendable power source 913 is provided between the outer ring surface and the extendable body 912 and provides power for sliding. The extendable power source 913 can use an electric or hydraulic extendable cylinder, and a plurality of protruding cones are provided on the end face of the extendable body 912 facing the hole wall side of the planting hole 110. When the three sets of extendable bodies 912 extend and contact the hole wall of the planting hole 110, the protruding cones securely maintain contact, allowing for smooth diameter expansion work with the drill bit.

[0057] The drill bit 8 also includes a main body 80, a roller cutter 81, and a nozzle 82.

[0058] The tail end of the main body 80 is connected to the drill rod 7, the head end of the main body 80 is a disc-shaped end face, and three roller cutters 81 are mounted on the disc-shaped end face in a circular arrangement at equal intervals, the axis of the roller cutters 81 is parallel to the axis of the drill bit 8 main body 80, and roller teeth are installed on the circumferential surface of the roller cutters 81.

[0059] As the drill bit 8 rotates, the roller cutter 81 cuts its roller teeth into the rock, creating radial cracks on the rock surface. Simultaneously, thrust is applied to the roller cutter by extending the radial contraction structure 91 on the opposite side of the enlarged diameter section. As the roller cutter continuously compacts and crushes the rock, the cracks in the rock extend and penetrate, and rock fragments collapse, resulting in rock breakage. After rock breakage is complete, numerous cracks may remain in the rock of the borehole wall that did not fall out in the enlarged diameter section. When matrix is ​​filled in, moisture and nutrients in the matrix penetrate these cracks to a certain extent, and the root system of the shrub can also enter the cracks to some extent. This further strengthens the bond between the shrub root system and the cracks, improving the wind resistance and uprooting ability of the shrub.

[0060] In the adjacent regions of any two cutters 81, the roller teeth of the two cutters 81 are engaged with each other, and the nozzle 82 is positioned outside the intermediate region between the two adjacent cutters 81 and directed towards the inner roller tooth engagement region of the two adjacent cutters 81.

[0061] During the hole enlargement process, abrasive material or cooling water can be sprayed from the nozzle 82, thereby increasing the efficiency of hole enlargement.

[0062] In summary, the present invention effectively overcomes various shortcomings of existing technologies, produces beneficial technical effects, and possesses remarkable inventiveness.

[0063] The embodiments described above are illustrative in illustrating the principles and effects of the present invention and do not limit the invention. Those familiar with the art can modify or change the embodiments described above without departing from the spirit and scope of the invention. Therefore, any equivalent modifications or changes made by those with ordinary skill in the art without departing from the spirit and technical concept disclosed herein should be included within the claims of the present invention. [Explanation of Symbols]

[0064] 1 Staircase unit 10. Gentle slope section 11 Steep section 110 Planting hole 111 Root hole 20 Basal layer 21 Surface layer 30 Injection-type anchor rods 31 Geogrids 32 Linked reinforcing bars 34 bundles of straw 4. Downward-growing climbing plants 5 Upward-growing climbing plants 6 Shrubs 7 Drill Rod 8 Drill Bits 80 Main Unit 81 Roller Cutter 82 nozzles 9 Axis adjustment device 91 Radial contraction structure 911 Guide groove 912 Stretchable body 913 Telescopic power source

Claims

1. The steep slope of the open-pit mine includes multiple layers of stair units (1), and each stair unit (1) includes a gently sloping section (10) and a steeply sloping section (11) that are sequentially connected vertically. The aforementioned gently sloping section (10) includes direct re-greening, spraying a base layer (20) onto the bottom layer, spraying a surface base layer (21) onto the upper layer, and sowing mixed seeds within the surface base layer (21). The steep slope section (11) is reinforced and re-greened, the stability of the gentle slope section (10) and the steep slope section 11 is evaluated, and based on the evaluation results, protection is applied to the steep slope section (11), and then the steep slope section (11) is re-greened. To restore greenery to the steep slope (11), a drilling machine is used to drill multiple planting holes (110) on the slope at a downward angle of 30 to 60 degrees and to a depth of 50 to 100 cm, the diameter of which each planting hole (110) includes at least one enlarged section, which is used to form a root system position restriction structure. Multiple rooting holes (111) are drilled into each of the aforementioned planting holes (110), and the inside of the rooting holes (111) is in communication with the planting holes (110) and penetrates radially into the slope. After filling the planting hole (110) with ecological substrate, dwarf shrubs 6 are transplanted and allowed to re-green. The drilling machine used to drill the rooting hole (111) includes a drill rod (7), a drill bit (8), and an axis adjustment device (9), The drill bit (8) is connected to the end of the drill rod (7), and the axis adjustment device (9) is rotatably sleeve-mounted on the drill rod (7). A method for ecological restoration and protection of steep slopes in open-pit mining sites, characterized in that the diameter of the drill bit (8) is larger than the diameter of the drill rod (7), the initial outer diameter of the axis adjustment device (9) is smaller than the diameter of the drill bit (8), the axis adjustment device (9) has an inner ring surface that is rotatably fitted with the drill rod (7), and the outer ring surface is provided with three radially expandable structures (91), and when the radially expandable structures (91) are extended, the area corresponding to the axis adjustment device (9) exceeds the diameter range of the drill bit (8), the three radially expandable structures (91) extend and abut against the hole wall of the plant hole (110), and by controlling the amount of extension and contraction of each radially expandable structure (91), the amount of offset of the central axis of the drill rod (7) relative to the central axis of the plant hole (110) is adjusted, thereby causing the drill bit (8) to drill an enlarged diameter portion within the plant hole (110).

2. Protection against steep slopes (11) includes structural protection and surface protection. Structural protection involves forming multiple anchor points on the slope of the steep section (11) using injection anchor rods (30), laying a steel-plastic geogrid (31) on the slope of the steep section (11), and installing frame-shaped connecting reinforcing bars (32) between each anchor point. The method for ecological restoration and protection of a steep slope of an open-pit mine according to claim 1, characterized in that surface protection involves laying a protective net on the slope of the steep section (11) and spraying a base layer (20).

3. To restore greenery in the steep slope section (11), The surface base layer (21) is sprayed onto the base layer (20) of the steep slope (11), and mixed seeds are sown within the surface base layer (21). Downward-growing climbing plants (4) are planted at the top of the steep slope (11). The method for ecological restoration and protection of a steep slope of an open-pit mine according to claim 1, characterized by including planting upward-growing climbing plants (5) at the lower part of the slope of the steep section (11).

4. The method for ecological restoration and protection of steep slopes of open-pit mining sites according to claim 3, characterized in that the seeds include seeds of herbaceous plants, dwarf shrubs, and climbing plants, have a germination rate of 90% or more, seeds that are difficult to germinate are treated with a germination-inducing treatment before use, and the seeds further include plant seeds collected from the surrounding environment of the slope.

5. The method for ecological restoration and protection of steep slopes of open-pit mining sites according to claim 2, characterized in that horizontal straw bundles (34) are installed on the slope at regular height intervals before laying the protective net, the horizontal straw bundles (34) are fixed with anchor rods, and after laying the protective net, the straw bundles (34) and the protective net are tied and fixed again, and the protective net is made of covered plastic net.

6. The method for ecological restoration and protection of a steep slope of an open-pit mine according to claim 1, characterized in that the rooting holes (111) are located in the cave entrance area of ​​the slope and are covered with bundles of straw (34), the bundles of straw (34) are fixed to the slope, and the sprayed base layer (20) and surface base layer (21) are covered with bundles of straw (34).

7. The method for ecological restoration and protection of steep slopes of open-pit mining sites according to claim 2, characterized in that the spraying thickness of the base layer (20) is 7 to 10 cm, and the base layer (20) contains P32.5 cement at a mass ratio of 5%.

8. The base layer (20) sprayed over an area of ​​one square meter is: Planting soil 0.06-0.08 m ３ , 2-3 kg of fiber, 80g of adhesive, PAM 30-40g, 60-80g of water-retaining agent, The method for ecological restoration and protection of steep slopes of open-pit mining sites according to claim 1, characterized by containing 50 g of compound fertilizer.

9. The surface base layer (21) sprayed over an area of ​​one square meter is: Planting soil 0.06-0.04 m ３ , 1.6-1.8 kg of rice husks, 1.6-1.8 kg of chopped rice straw, Wood fiber 0.8-1kg, 15g of adhesive, PAM 8-10g, 8-10g of water-retaining agent, 6-8 kg of organic fertilizer, 30g of compound fertilizer, The method for ecological restoration and protection of steep slopes of open-pit mining sites according to claim 1, characterized by containing 55 g of seeds.

10. The radially expanding structure (91) includes a guide groove (911), an expandable body (912), and an expansion / contraction power source (913). The method for ecological restoration and protection of a steep slope of an open-pit mining site according to claim 1, characterized in that the guide groove (911) includes two structural plates fixedly connected to the outer ring surface, the telescopic body (912) is slidably installed between the two structural plates and the sliding direction is along the radial direction of the drill rod (7), and the telescopic power source (913) is installed between the outer ring surface and the telescopic body (912) and provides sliding power.

11. The drill bit (8) includes a body (80), a roller cutter (81), and a nozzle (82). The tail end of the main body (80) is connected to the drill rod (7), the head end of the main body (80) is a disc-shaped end face, the three roller cutters (81) are mounted on the disc-shaped end face in a circular arrangement at equal intervals, the axes of the roller cutters (81) are parallel to the axis of the drill bit (8) main body (80), and roller teeth are installed on the circumferential surface of the roller cutters (81). In adjacent regions of any two cutters 81, the roller teeth of the two cutters (81) are fitted together. The method for ecological restoration and protection of steep slopes in an open-pit mine according to claim 10, characterized in that the nozzle (82) is positioned outside the intermediate region between two adjacent cutters (81), and the nozzle (82) is directed towards the roller tooth engagement region inside the two adjacent cutters (81).

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