Slope ecological protection base material proportioning optimization construction method based on high and steep rock slope

Abstract

According to the slope ecological protection base material proportioning optimization construction method based on the high and steep rock slope, AB bacteria and graded muck scraps are added into an original improved base material, and a layered spray-seeding method of a base layer and a surface layer is adopted, so that the compressive strength, the anti-scouring capacity, the vegetation coverage rate and the root system depth are greatly improved, and the slope ecological protection base material proportioning optimization construction method based on the high and steep rock slope is achieved. The cost and the maintenance period are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of ecological slope protection engineering, in particular to a slope ecological protection base material ratio optimization construction method based on high and steep rock slopes. Background Art

[0002] Traditional slope protection technologies (such as soil seeding and reinforced grids) suffer from low substrate strength, poor erosion resistance, and low plant survival rates. These issues are particularly prevalent in areas with heavy rainfall and complex geological conditions, which can easily lead to substrate spalling and vegetation degradation. While existing slope ecological protection technologies offer both protection and ecological benefits, the substrate ratio is not optimized for specific environments, resulting in insufficient durability and adaptability. This invention determines the substrate ratio through multi-factor testing, combines anchoring and hanging mesh with intelligent monitoring, and achieves ecological restoration of steep rock slopes. The substrate's erosion resistance is increased to withstand rainfall of 120 mm / h, vegetation coverage reaches ≥95% within three months, and overall costs are reduced by 20-30%. This technology is suitable for slope projects in hydropower, transportation, municipal administration, and mining.

[0003] The existing "High Steep Slope Vegetation Concrete Slope Protection and Greening Technology" with publication number CN106927758A uses AB bacteria as an optimization point to improve the stability and adhesion of the vegetation concrete substrate and increase anti-slip resistance. However, the following problems still exist: 1. Compressive strength, anti-scouring rate, water holding rate, vegetation coverage rate and root depth need to be improved; 2. The protection cost is high and requires a lot of added substances; 3. The utilization rate of local debris is low, which makes it difficult to utilize the debris generated by slope projects, etc., resulting in the need for subsequent other treatments, which has high treatment costs, is not environmentally friendly, and has poor applicability. Summary of the Invention

[0004] The present invention provides a slope ecological protection base material ratio optimization construction method based on high and steep rock slopes, which solves the above-mentioned problems and further optimizes the properties of the base material.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: A slope ecological protection base material ratio optimization construction method based on a high and steep rock slope comprises the following steps: S1. Optimization of base material ratio: The base layer and the surface layer materials are configured according to the mass ratio, wherein the base layer materials include planting soil, graded debris, ordinary Portland cement, organic matter, AB bacteria bio-fertilizer, long-term slow-release fertilizer, water-retaining agent and a small amount of plant seeds; the surface layer materials include planting soil, graded debris, ordinary Portland cement, organic matter, AB bacteria bio-fertilizer, long-term slow-release fertilizer, water-retaining agent and a large amount of plant seeds; S2. Slope surface pretreatment: clean the loose soil and dangerous rocks on the slope surface, fill the local concave surface with mortar, and carve a U-shaped rough surface; S3. Anchoring and hanging mesh: Insert threaded steel anchors on the slope, lay galvanized wire mesh and tie it to the anchors; S4. Layered spraying: Use drones to spray the base material first, and then spray the surface material after initial setting to form a layered structure with the surface layer on top; S5. Maintenance and management: Install a sprinkler system and monitor substrate strength, vegetation coverage and pH value until the vegetation coverage is stable.

[0006] Preferably, the base material mass ratio in S1 includes: 450-550 kg of planting soil, 900-1100 kg of graded debris with a particle size of ≤8 mm, 60-80 kg of ordinary Portland cement, 25-30 kg of organic matter, 50-60 kg of AB bacteria biofertilizer, 18-22 kg of long-acting slow-release fertilizer, 0.8-1.2 kg of water-retaining agent, and 0.3-0.8 kg of plant seeds; Preferably, the mass ratio of the surface layer materials in S1 includes: 450~550kg of planting soil, 900~1100kg of graded slag debris with particle size ≤8mm, 50~70kg of ordinary Portland cement, 20~30kg of organic matter, 45~55kg of AB bacteria bio-fertilizer, 10~20kg of long-acting slow-release fertilizer, 0.1~0.3kg of water-retaining agent, and 1.0~2.0kg of plant seeds.

[0007] Furthermore, when the on-site debris debris in S1 is insufficient, the graded debris debris can be prepared by mixing planting soil with the on-site debris debris, with the mass ratio of planting soil to on-site debris debris being 1:2.

[0008] Furthermore, the particle size classification of the classified soil debris in S1 includes: particle sizes of 2-8 mm are coarse particles accounting for 40%, particle sizes ≤ 2 mm are fine particles accounting for 60%, and the porosity is controlled at 30-45%.

[0009] Furthermore, the plant seeds in S1 are a mixture of tall fescue, bermudagrass and amorpha fruticosa, with a mass ratio of 6:3:1.

[0010] Preferably, said S2 further includes the following steps: cleaning loose soil and dangerous rocks on the surface of the slope, filling local concave surfaces with mortar, and carving U-shaped rough surfaces with a depth of 3 cm and a spacing of 20 cm.

[0011] Preferably, the diameter of the threaded steel anchor in S3 is Φ16mm, the depth into the rock is ≥50cm, the spacing on the slope surface is 1m×1m, and the spacing on the top of the slope is increased to 0.5m; the galvanized wire mesh is 14# mesh, the mesh is 5cm×5cm, the mesh is 7cm away from the slope surface, and the overlap width is ≥5cm.

[0012] Preferably, S4 also includes the following steps: using a large-load drone to spray the base layer to a thickness of 8~10cm, and spraying the surface layer containing seeds to a thickness of 10~12cm within 4 hours after initial setting; the spraying pressure of the base material is ≥0.1MPa; after spraying the surface layer material, cover it with non-woven fabric to retain moisture.

[0013] Preferably, the step S5 further includes the following steps: the sprinkler system sprinkles water twice a day to maintain the substrate humidity at 60-70%; monitoring indicators include 28-day compressive strength ≥ 0.45 MPa, vegetation coverage ≥ 90%, and pH fluctuation ≤ 0.5; The embedded displacement monitor in S5 is used to monitor the displacement rate of the substrate in real time. When the displacement rate is ≥2mm / d, an early warning is triggered and reinforcement measures are taken.

[0014] Beneficial effects of the present invention: 1. Optimization of substrate performance By grading the soil particle size and controlling its porosity (30-45%), the substrate's anti-scouring ability (it can withstand rainfall of 120 mm / h, compared to only 80 mm / h with traditional technology) and water retention rate (≥35%) are improved, allowing it to adapt to alternating dry and wet environments. This improves the substrate's properties while utilizing local soil debris, which is environmentally friendly, increases the utilization rate of soil debris, and reduces soil debris disposal costs. AB bacteria (Activation Bacterium) biofertilizer combined with slow-release fertilizer forms a "bacteria-fertilizer-root" synergistic system, activating nutrients and extending the slow-release period to ≥6 months, promoting a 30% increase in root anchorage depth; AB bacteria (Activation Bacterium) biofertilizer is an innovative product based on the unique product of AB bacteria activation agent. The AB bacteria referred to in this invention refers to a biofertilizer. It is made of peanut shell powder and chicken as the main raw materials, and is added with three functional microbial inoculants: nitrogen-fixing bacteria, phosphate-dissolving bacteria, and silicate bacteria. In addition, a certain proportion of inorganic fertilizers are added. After a certain period of fermentation, it is made into compost. It is a known product used to adjust the pH of the substrate to 7.5-8.0, inhibit the damage of cement alkali to plant roots, and help solve the problem of plant root damage in vegetation concrete. Using it further improves the properties of this substrate 2.Construction technology innovation: The layered seeding design (10cm base layer + 2cm surface layer) takes into account both mechanical stability and ecological function. The base layer focuses on compressive strength, while the surface layer reduces cement usage and increases seed density to avoid seedling burn. Increased anchor density (0.5m spacing at the top of the slope) and flexible galvanized mesh support allow for slight deformation of the substrate (≤5mm), reducing the risk of cracking. 3. Innovation of spraying technology: Using drones equipped with lightweight spraying devices to replace traditional dry sprayers can achieve precise spraying in complex terrain. It can be used on extremely steep and steep slopes with slopes greater than 70° or inaccessible areas, thus reducing material waste, improving construction efficiency, and lowering the risk of high-altitude operations. 4. Intelligent monitoring and dynamic adjustment: Pre-buried soil moisture sensors and displacement monitors transmit data to the control platform in real time. The warning threshold is set at a displacement rate ≥ 2mm / d or humidity ≤ 40%, enabling early risk assessment and control. To meet the needs of highly alkaline rock masses and fast-growing landscapes, the dosage of AB bacteria (Activation Bacterium) biofertilizer can be dynamically adjusted or fiber materials can be added to expand application scenarios. 5. Ecological and economic synergy: The on-site utilization rate of waste soil is ≥80%, reducing transportation costs and ecological disturbance; The vegetation coverage rate is ≥95% within 2 months, shortening the ecological restoration cycle and reducing the overall cost by 20-30%. DETAILED DESCRIPTION

[0015] The examples are further described below.

[0016] As a preferred embodiment 1, a slope ecological protection base material ratio optimization construction method based on a steep rock slope includes the following steps: S1. Optimization of base material ratio: The base layer and the surface layer materials are configured according to the mass ratio, wherein the base layer materials include planting soil, graded debris, ordinary Portland cement, organic matter, AB bacteria bio-fertilizer, long-term slow-release fertilizer, water-retaining agent and a small amount of plant seeds; the surface layer materials include planting soil, graded debris, ordinary Portland cement, organic matter, AB bacteria bio-fertilizer, long-term slow-release fertilizer, water-retaining agent and a large amount of plant seeds; S2. Slope surface pretreatment: clean the loose soil and dangerous rocks on the slope surface, fill the local concave surface with mortar, and carve a U-shaped rough surface; S3. Anchoring and hanging mesh: Insert threaded steel anchors on the slope, lay galvanized wire mesh and tie it to the anchors; S4. Layered spraying: Use drones to spray the base material first, and then spray the surface material after initial setting to form a layered structure with the surface layer on top; S5. Maintenance and management: Install a sprinkler system and monitor substrate strength, vegetation coverage and pH value until the vegetation coverage is stable.

[0017] The base material mass ratio in S1 includes: planting soil 450-550 kg, debris (particle size ≤ 8 mm) 900-1100 kg, ordinary Portland cement (P42.5) 60-80 kg, organic matter (rice husk fermentation) 25-30 kg, AB bacteria (Activation Bacterium) biofertilizer 50-60 kg, long-term slow-release fertilizer (NPK=15-15-15) 18-22 kg, water-retaining agent (polyacrylamide) 0.8-1.2 kg, plant seeds (mixed grass and shrubs) 0.3-0.8 kg; The mass ratio of the surface layer materials in S1 includes: 450-550 kg of planting soil, 900-1100 kg of slag debris (particle size ≤ 8 mm), 50-70 kg of ordinary Portland cement, 20-30 kg of organic matter, 45-55 kg of AB bacteria (Activation Bacterium) biofertilizer, 10-20 kg of long-acting slow-release fertilizer, 0.1-0.3 kg of water-retaining agent, and 1.0-2.0 kg of plant seeds (mixed with grass and shrubs).

[0018] When the on-site debris in S1 is insufficient, the graded debris can be prepared by mixing planting soil with on-site debris, with the mass ratio of planting soil to on-site debris being 1:2.

[0019] The particle size classification of the classified debris in S1 includes: particle sizes of 2-8 mm are coarse particles accounting for 40%, particle sizes ≤ 2 mm are fine particles accounting for 60%, and the porosity is controlled at 30-45%.

[0020] The plant seeds in S1 are a mixture of tall fescue, bermudagrass and amorpha fruticosa, with a mass ratio of 6:3:1.

[0021] The AB bacteria (Activation Bacterium) biofertilizer is an innovative product based on the unique AB bacteria activation agent. The AB bacteria referred to in this invention refers to a biofertilizer made from peanut shell powder and chicken as primary ingredients, with the addition of three functional microbial inoculants: nitrogen-fixing bacteria, phosphate-dissolving bacteria, and silicate bacteria, along with a specific ratio of inorganic fertilizers. The compost is fermented for a certain period of time and is a known product. It is used to adjust the pH of the substrate to 7.5-8.0 and inhibit damage to plant roots caused by cement alkali reversion.

[0022] Said S2 also includes the following steps: cleaning the loose soil and dangerous rocks on the slope surface, filling the local concave surface with mortar, and carving a U-shaped rough surface with a depth of 3 cm and a spacing of 20 cm.

[0023] The diameter of the threaded steel anchor in S3 is Φ16mm, the depth of penetration into the rock is ≥50cm, the spacing on the slope surface is 1m×1m, and the spacing on the top of the slope is increased to 0.5m; the galvanized wire mesh is 14# mesh, with a mesh size of 5cm×5cm, the mesh is 7cm away from the slope surface, and the overlap width is ≥5cm.

[0024] The S4 also includes the following steps: using a large-load drone to spray the base layer to a thickness of 8-10 cm, spraying the surface layer containing seeds to a thickness of 10-12 cm within 4 hours after initial setting; the base material spraying pressure is ≥0.1 MPa; after spraying the surface layer material, covering it with non-woven fabric to retain moisture.

[0025] Said S5 also includes the following steps: the sprinkler system sprinkles water twice a day to maintain the substrate humidity at 60-70%; monitoring indicators include 28-day compressive strength ≥ 0.45MPa, vegetation coverage ≥ 90%, and pH fluctuation ≤ 0.5; The embedded displacement monitor in S5 is used to monitor the displacement rate of the substrate in real time. When the displacement rate is ≥2mm / d, an early warning is triggered and reinforcement measures are taken.

[0026] As a preferred embodiment 2, a slope ecological protection base material ratio optimization construction method based on a steep rock slope includes the following steps: Step 1: Slope pretreatment (1) Clearing of loose soil and dangerous rocks Use a jackhammer or electric hammer to remove loose rocks, loose soil and plant roots on the slope; use M10 cement mortar to fill local sunken areas (depth ≥ 10cm), and the filling surface must be 2cm lower than the slope surface to reserve space for substrate spraying; manually carve a U-shaped rough surface: use a rock drill to carve U-shaped grooves with a depth of 3cm and a width of 5cm along the slope at a horizontal spacing of 20cm and a vertical spacing of 15cm to form a rough interface to enhance the adhesion of the substrate.

[0027] (2) Slope improvement For barren or highly alkaline slopes (pH ≥ 9.0), spray oxalic acid solution (concentration 5%) to adjust the pH to 7.5-8.5; if the slope is made of loose soil, lay geogrids (tensile strength ≥ 50kN / m) and fix them with anchors to prevent the substrate from slipping after spraying.

[0028] Step 2: Anchoring and hanging the net (1) Anchor placement Anchor specifications: Φ16mm threaded steel bar, length determined according to the lithology of the slope (rock slope ≥80cm, soil slope ≥120cm); Layout parameters: The spacing in the middle of the slope is 1m×1m, and the spacing at the top and foot of the slope is increased to 0.5m×0.5m, arranged in a plum blossom shape; Construction points: Drill a hole with a diameter of Φ20mm, inject epoxy resin glue into the hole for anchoring, and leave 10cm of the exposed end of the anchor for tying wire mesh.

[0029] (2) Hanging mesh construction Mesh material selection: 14# galvanized wire mesh (mesh size 5cm×5cm, wire diameter 2.2mm), or biaxially oriented plastic geonet (tensile strength ≥8kN / m); Fixing method: The mesh should be laid close to the slope surface, 7cm away from the slope surface (supported by pads), with a mesh overlap width of ≥10cm. Use 18# galvanized iron wire and anchor nails to tie, wrapping each node ≥3 times; Slope top treatment: The wire mesh extends upward to 50cm inside the intercepting ditch and downward to the drainage ditch at the foot of the slope to prevent the edge from curling up.

[0030] Step 3: Substrate preparation and spraying (1) Material pretreatment Soil debris: sieve and classify, mix coarse particles (2-8mm) and fine particles (≤2mm) in a ratio of 4:6, and control the moisture content at 8-12%; Organic matter: Rice husk fermentation material needs to be crushed to a particle size of ≤5mm, mixed with humic acid (3%) and pre-fermented for 48 hours; Seed treatment: Soak grass and shrub seeds (such as tall fescue and Amorpha fruticosa) in 40℃ warm water for 12 hours, and mix with water retaining agent (0.1%) and rooting powder (0.05%) for later use.

[0031] (2) Base material mixing Base mix: Pour the slag, cement, organic matter, and AB bacteria (Activation Bacterium) biofertilizer into a forced mixer (such as JS500) according to the proportions and dry-mix for 3 minutes. Then add slow-release fertilizer, water-retaining agent, and water (water-cement ratio 0.28-0.32) and wet-mix for 5 minutes to mix evenly. Surface mixture: Reduce the amount of cement based on the base material, add pretreated seeds, and stir for ≤2min to avoid damaging seed activity.

[0032] (3) Layered spraying Base layer spraying: Use a large-load drone (such as models A660 and A670) to fly in a "Z" shape along the planned path, with a spraying pressure of 0.08-0.12MPa and a single coverage thickness of 3-5cm. The laser rangefinder provides real-time feedback on thickness data, and AI dynamically adjusts the flight speed and spraying volume to ensure a total base layer thickness of 8-10cm.

[0033] Surface layer spraying: After the base layer has initially solidified (within 4 hours), switch the spraying material to the surface layer, reduce the spraying pressure to 0.05-0.08MPa, add the water retaining agent and seed mixture, spray the thickness accurately to 2cm, and the seed density to 0.5kg / m² (error ≤5%); Step 4: Maintenance and Monitoring (1) Watering maintenance Watering plan: Start watering within 48 hours after spraying, once in the morning and once in the evening (10 minutes each time), and maintain the substrate humidity at 60-70%; Special climate: spray mist water once during hot days, and cover with rainproof film in rainy season to avoid saturation of substrate.

[0034] (2) Dynamic monitoring Physical indicators: Compressive strength: 7 days ≥ 0.3MPa, 28 days ≥ 0.45MPa (tested by portable pressure gauge); Displacement monitoring: Pre-buried inclinometer, displacement rate warning threshold ≥ 2mm / d.

[0035] Ecological indicators: Vegetation coverage: 30 days ≥ 70%, 60 days ≥ 90%; pH value: tested weekly, fluctuation range ≤0.5.

[0036] (3) Replanting and maintenance For areas with insufficient coverage (<80%), replant with spot sowing and apply additional organic liquid fertilizer (dilution concentration 1:200); When local peeling of the substrate is found, clean it and re-spray and increase the density of anchor nails.

[0037] As a preferred embodiment 3, the base material ratio is dynamically adjusted according to the alkalinity of the slope rock mass. When the rock mass pH is ≥9.0, the amount of base layer AB bacteria (Activation Bacterium) biofertilizer is increased to 15-20 kg / base layer.

[0038] As a preferred embodiment 4, natural plant fibers (such as bamboo fibers or coconut shell fibers) with a mass proportion of ≤5% can be added to the surface material to enhance crack resistance; or fast-growing grass species ryegrass (mass proportion ≥50%) can be added to achieve rapid coverage.

[0039] As a preferred embodiment 5, a more preferred embodiment based on embodiment 1: Components and ratio: The base material is divided into base layer and surface layer, and is configured according to the mass ratio: Base layer (8-10cm thick): 500kg planting soil, 1000kg soil debris (particle size ≤8mm), 70kg ordinary Portland cement (P42.5), 28kg organic matter (rice husk fermentation), 55kg AB bacteria (Activation Bacterium) biofertilizer, 20kg long-term slow-release fertilizer (NPK=15-15-15), 1kg water-retaining agent (polyacrylamide), 0.5kg plant seeds (mixed with grass and shrubs); Surface layer (thickness 2cm): 500kg of planting soil, 1000kg of debris (particle size ≤8mm), 60kg of ordinary Portland cement, 25kg of organic matter, 50kg of AB bacteria (Activation Bacterium) biofertilizer, 15kg of long-acting slow-release fertilizer, 0.2kg of water-retaining agent, and 1.5kg of plant seeds (mixed with grass and shrubs).

[0040] Slag classification: Slag debris coarse particles (2-8mm) account for 40%, fine particles (≤2mm) account for 60%, porosity 30-45%; Microbial regulation: AB bacteria (Activation Bacterium) biofertilizer adjusts the substrate pH to 7.5-8.0, inhibiting cement alkali reversion; Functional stratification: The base layer focuses on compressive strength (≥0.45MPa after 28 days), and the surface layer reduces cement usage (1.6%) and increases seed density (0.5kg / m²).

[0041] The base layer and surface layer ratios are determined according to the Technical Specification for Construction of Cement Soil Habitats for Vegetation on Slopes of Hydropower Projects NB / T 10490-2021 and related experiments. As shown in Table 1:

[0042] Optimization instructions: Muck debris: Local muck is used, with a particle size classification of 40% coarse particles (2-8mm) and 60% fine particles (≤2mm). This increases the base material's porosity (30-45%) and erosion resistance (able to withstand 120mm / h rainfall). (When the construction site does not have the required "usable soil", planting soil and muck debris are mixed at a mass ratio of 1:2 to create "usable soil"). AB bacteria (Activation Bacterium) biofertilizer: This is an innovative product based on the unique AB bacteria activation agent. The AB bacteria referred to in this invention refers to a biofertilizer. It is made from peanut shell powder and chicken as the main raw materials, with the addition of three functional microbial inoculants: nitrogen-fixing bacteria, phosphate-solubilizing bacteria, and silicate bacteria, and a certain proportion of inorganic fertilizer. The compost is fermented for a certain period of time. This is a known product that can promote microbial proliferation and nutrient activation, and inhibit cement alkali reversion.

[0043] Water-retaining agents and slow-release fertilizers: Improve the water holding rate of the substrate (≥35%) and the nutrient slow-release period (≥6 months) to adapt to the alternating environment of dry and rainy seasons.

[0044] As a preferred embodiment 6, a comparative test was conducted to prove the effect of the optimized ratio: 1. Experimental Materials and Equipment 1. Substrate components: The particle size of the slag debris is classified into coarse particles (2-8mm, accounting for 40%) and fine particles (≤2mm, accounting for 60%), with a porosity of 35%-45%; the AB bacterial biofertilizer is mainly composed of nitrogen-fixing bacteria, phosphate-solubilizing bacteria, and silicate bacteria, and has the ability to adjust the pH to 7.5-8.0; other materials are ordinary Portland cement (P42.5), rice husk fermented organic matter, long-term slow-release fertilizer (NPK=15-15-15), water-retaining agent (polyacrylamide), and mixed grass and shrub seeds (tall fescue: bermudagrass: amorpha fruticosa = 6:3:1).

[0045] 2. Control group and experimental group Control group: traditional substrate (planting soil: cement = 3:1, without soil debris and AB bacteria).

[0046] Experimental group: Group 1: Patented ratio substrate (graded soil debris + AB bacteria); Group 2: soil debris (unclassified) + AB bacteria; Group 3: soil debris (graded) + no AB bacteria.

[0047] 3. Equipment Compressive strength tester (range 0-5MPa); Artificial rainfall simulation device (spraying intensity 120mm / h); Water holding capacity meter, pH meter, plant root scanner; Constant temperature and humidity incubator (simulated day and night temperature difference of 10-35℃).

[0048] 2. Experimental Procedure 1. Substrate preparation and spraying (1) Material mixing: Taking Group 1 as an example, dry mix for 3 minutes and wet mix for 5 minutes according to the patented ratio (base layer: 1000 kg of graded debris, 70 kg of cement, 55 kg of AB bacteria, 1 kg of water-retaining agent, etc.), and control the water-cement ratio to 0.3.

[0049] (2) Spraying molding: Spray the base material into a mold (30cm×30cm×10cm), which is divided into a base layer (8cm) and a surface layer (2cm). The surface layer contains 1.5kg / m² of seeds and is covered with non-woven fabric to retain moisture.

[0050] Group 2 did not add classified debris, but directly added unclassified debris, and the rest were the same; Group 3 did not add AB bacteria, and the rest were the same.

[0051] 2. Performance Testing Compressive strength: Samples were taken at 7 days and 28 days of age to test the compressive strength (target ≥ 0.45 MPa).

[0052] Anti-scouring property: artificial rainfall is simulated at 120 mm / h for 1 hour, and the substrate loss rate is measured (loss rate ≤ 5% is qualified).

[0053] Water holding capacity and pH value: The water holding capacity was determined by the drying method (target ≥35%), and the pH fluctuation was monitored weekly (target ±0.5).

[0054] 3. Vegetation growth observation Germination rate and coverage rate: record seed germination time (target within 7 days), 30-day and 60-day coverage rates (target ≥95%).

[0055] Root development: Samples were taken after 60 days and root length and density were scanned (target anchoring depth ≥ 25 cm).

[0056] 3. Data Recording and Analysis

[0057] The experimental data are shown in Table 2. According to Table 2, the substrate anti-scouring loss rate of the patented ratio is the lowest, only 4%, while the 28-day compressive strength, water holding rate, vegetation coverage and root depth are all the highest and greatly improved. Both the graded soil debris and AB bacteria have a great influence on the properties. The addition of AB bacteria and the addition of graded soil debris in the ratio optimization are creative.

[0058] As a preferred embodiment 7: Case 1: Soil-rock mixed slope of Kunchu Expressway in Yunnan Background: The fill slope is 45m high, with a slope of 60°, and is mixed with soil and rocks, making it prone to shallow landslides.

[0059] Technology Application: Base layer (8-10cm thick): 500kg planting soil, 1000kg soil debris (particle size ≤8mm), 70kg ordinary Portland cement (P42.5), 28kg organic matter (rice husk fermentation), 55kg AB bacteria (Activation Bacterium) biofertilizer, 20kg long-term slow-release fertilizer (NPK=15-15-15), 1kg water-retaining agent (polyacrylamide), 0.5kg plant seeds (mixed with grass and shrubs); Surface layer (thickness 2cm): 500kg of planting soil, 1000kg of debris (particle size ≤8mm), 60kg of ordinary Portland cement, 25kg of organic matter, 50kg of AB bacteria (Activation Bacterium) biofertilizer, 15kg of long-acting slow-release fertilizer, 0.2kg of water-retaining agent, and 1.5kg of plant seeds (mixed with grass and shrubs).

[0060] Effect: The compressive strength of the substrate reached 0.48 MPa after 28 days, and the root anchorage depth reached 25 cm after 90 days; There was no landslide two years after the restoration, and the maintenance cost was only 65% of that of traditional methods.

[0061] Case 2: Abandoned slope of Dexing Copper Mine in Jiangxi Province Background: Acidic slag slope (pH=3.5), heavy metal pollution, and vegetation cannot recover naturally.

[0062] Technology Application: Base layer (8-10cm thick): 1500kg planting soil, 60kg ordinary Portland cement (P42.5), 25kg organic matter (rice husk fermentation), 60kg AB bacteria (Activation Bacterium) biofertilizer, 15kg long-acting slow-release fertilizer (NPK=15-15-15), 1kg water-retaining agent (polyacrylamide), 0.5kg plant seeds (mixed grass and shrubs); Surface layer (thickness 2cm): 1500kg planting soil, 50kg ordinary Portland cement, 25kg organic matter, 55kg AB bacteria (Activation Bacterium) biofertilizer, 15kg long-acting slow-release fertilizer, 0.2kg water-retaining agent, 1.5kg plant seeds (mixed grass and shrubs).

[0063] Substrate improvement: quicklime (5%) was added to neutralize the acidity, and AB bacteria were replaced with heavy metal resistant bacteria (≥1×10 7 CFU / g); Effect: After 6 months, the soil pH returned to 6.8, and the lead and cadmium levels decreased by 80%; Selected as an ecological restoration demonstration project by the Ministry of Natural Resources.

[0064] The above improvements and their effects are shown in Table 3:

[0065] Therefore, the ratio optimization and method optimization in this method are highly creative and valuable. The anti-scouring ability, vegetation coverage, and root anchoring depth are greatly improved, and the comprehensive cost, maintenance cycle, and maintenance fee are greatly reduced. It can also control heavy metal pollution.

Claims

1. A slope ecological protection base material ratio optimization construction method based on high and steep rock slopes, characterized in that: The following steps are involved: S1. Optimization of base material ratio: The base layer and the surface layer materials are configured according to the mass ratio, wherein the base layer materials include planting soil, graded debris, ordinary Portland cement, organic matter, AB bacteria bio-fertilizer, long-term slow-release fertilizer, water-retaining agent and a small amount of plant seeds; the surface layer materials include planting soil, graded debris, ordinary Portland cement, organic matter, AB bacteria bio-fertilizer, long-term slow-release fertilizer, water-retaining agent and a large amount of plant seeds; S2. Slope surface pretreatment: clean the loose soil and dangerous rocks on the slope surface, fill the local concave surface with mortar, and carve a U-shaped rough surface; S3. Anchoring and hanging mesh: Insert threaded steel anchors on the slope, lay galvanized wire mesh and tie it to the anchors; S4. Layered spraying: Use drones to spray the base material first, and then spray the surface material after initial setting to form a layered structure with the surface layer on top; S5. Maintenance and management: Install a sprinkler system and monitor substrate strength, vegetation coverage and pH value until the vegetation coverage is stable.

2. The slope ecological protection base material ratio optimization construction method based on high and steep rock slopes according to claim 1 is characterized in that: The mass ratio of the base materials in S1 includes: 450~550kg of planting soil, 900~1100kg of graded debris with a particle size of ≤8mm, 60~80kg of ordinary Portland cement, 25~30kg of organic matter, 50~60kg of AB bacteria biofertilizer, 18~22kg of long-acting slow-release fertilizer, 0.8~1.2kg of water-retaining agent, and 0.3~0.8kg of plant seeds.

3. The slope ecological protection base material ratio optimization construction method based on high and steep rock slopes according to claim 1 is characterized in that: The mass ratio of the surface layer materials in S1 includes: 450~550kg of planting soil, 900~1100kg of graded slag debris with a particle size of ≤8mm, 50~70kg of ordinary Portland cement, 20~30kg of organic matter, 45~55kg of AB bacteria biofertilizer, 10~20kg of long-acting slow-release fertilizer, 0.1~0.3kg of water-retaining agent, and 1.0~2.0kg of plant seeds.

4. A slope ecological protection base material ratio optimization construction method based on a high and steep rock slope according to any one of claims 1 to 3, characterized in that: When the on-site debris debris in S1 is insufficient, the graded debris debris can be prepared by mixing planting soil with on-site debris debris, with the mass ratio of planting soil to on-site debris debris being 1:

2.

5. A slope ecological protection base material ratio optimization construction method based on a high and steep rock slope according to any one of claims 1 to 3, characterized in that: The particle size classification of the classified debris in S1 includes: particle sizes of 2-8 mm are coarse particles accounting for 40%, particle sizes ≤ 2 mm are fine particles accounting for 60%, and the porosity is controlled at 30-45%.

6. A slope ecological protection base material ratio optimization construction method based on a high and steep rock slope according to any one of claims 1 to 3, characterized in that: The plant seeds in S1 are a mixture of tall fescue, bermudagrass and amorpha fruticosa, with a mass ratio of 6:3:

1.

7. The method for optimizing the ratio of base material for slope ecological protection based on high and steep rock slopes according to claim 1, characterized in that: Said S2 also includes the following steps: cleaning the loose soil and dangerous rocks on the slope surface, filling the local concave surface with mortar, and carving a U-shaped rough surface with a depth of 3 cm and a spacing of 20 cm.

8. The slope ecological protection base material ratio optimization construction method based on high and steep rock slopes according to claim 1 is characterized in that: The diameter of the threaded steel anchor in S3 is Φ16mm, the depth of penetration into the rock is ≥50cm, the spacing on the slope surface is 1m×1m, and the spacing on the top of the slope is increased to 0.5m; the galvanized wire mesh is 14# mesh, with a mesh size of 5cm×5cm, the mesh is 7cm away from the slope surface, and the overlap width is ≥5cm.

9. The method for optimizing the ratio of base material for slope ecological protection based on high and steep rock slopes according to claim 1, characterized in that: The S4 also includes the following steps: using a large-load drone to spray the base layer to a thickness of 8-10 cm, spraying the surface layer containing seeds to a thickness of 10-12 cm within 4 hours after initial setting; the base material spraying pressure is ≥0.1 MPa; after spraying the surface layer material, covering it with non-woven fabric to retain moisture.

10. The slope ecological protection base material ratio optimization construction method based on high and steep rock slopes according to claim 1 is characterized in that: Said S5 also includes the following steps: the sprinkler system sprinkles water twice a day to maintain the substrate humidity at 60-70%; monitoring indicators include 28-day compressive strength ≥ 0.45MPa, vegetation coverage ≥ 90%, and pH fluctuation ≤ 0.5; The embedded displacement monitor in S5 is used to monitor the displacement rate of the substrate in real time. When the displacement rate is ≥2mm / d, an early warning is triggered and reinforcement measures are taken.

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