Ecological restoration method for low / high and steep slope sponge soil

Abstract

The invention relates to a slope greening ecological restoration method. The invention discloses an ecological restoration method for low / high and steep slope sponge soil. Preparing a sponge soil forming agent; preparing a spray-seeding substrate and spray-seeding the spray-seeding substrate to the slope surface to be repaired; the invention relates to a process for forming ecological sponge soil with a porous structure through mixed spray-seeding and spray-seeding a sublayer after the sponge soil is formed. The soil forming agent comprises the following components in parts by weight: 20-50 parts of a component a; the component a is a basic reaction material which is an organic polymer material; component b: 20-40 parts of a foaming agent; 10 to 30 parts of a cross-linking agent; 10 to 50 parts of a toughening agent; a component c: 10-30 parts of a pH regulator; and 0.5 to 2 parts of a surfactant. According to the method, two mixed spray-seeding processes are adopted for a low slope and a high and steep slope respectively, and a proper reaction process can be reasonably selected according to the specific conditions and construction requirements of the slopes, so that efficient and high-quality sponge soil forming construction is realized, and the spray-seeding matrix has the characteristics of water absorption, water retention, high adsorption and scour prevention and has a lasting effect.

Description

Technical Field

[0001] The present invention relates to a slope revegetation ecological restoration method, aiming to create conditions for vegetation growth by artificially spraying soil and achieve efficient and economical slope restoration. Background Art

[0003] Traditional slope ecological revegetation restoration methods have insufficient resistance to rain erosion and are difficult to maintain long-term effects. Especially for high and steep mountain slopes, it is difficult to manually intervene in the traditional methods for restoration, the success rate of rock surface restoration is low, and the costs of net spraying or other restorations are too high. The engineering measures include processes such as lattice, anchor rod, cable anchor reinforcement, and net spraying. Limited by construction conditions, they have high technical requirements, great construction difficulty, and high cost investment. Moreover, they are greatly affected by natural factors and the effects are difficult to guarantee: Although comprehensive measures can improve the stability and disaster resistance of the mountain to a certain extent, it is still difficult to completely avoid the influence of natural factors. Extreme natural disasters such as heavy rain, strong wind, and earthquake may damage the restored mountain, resulting in damage to engineering structures, death of plants, etc. In order to reduce construction costs and enhance restoration effects, it is necessary to fundamentally solve the problem.

[0004] At present, the concept of "near-natural ecological restoration" has provided new ideas for the ecological restoration of high and steep mountain slopes. However, no matter which method is used for restoration, it is necessary to solve the problems of durability and firmness from a technical level, and solve the problems of water absorption, water retention, suitability for plant growth, and anti-erosion of the spraying matrix on the premise of retaining the sprayed slurry. Summary of the Invention

[0005] The present invention aims at the deficiencies of the prior art and proposes a slope revegetation ecological restoration method based on sponge soil.

[0006] A sponge soil ecological restoration method for low and gentle slopes includes the following steps: 1) Perform pre-treatment on low and gentle slopes to be restored with a slope of less than 60°; 2) Prepare a sponge soil forming agent; The soil forming agent, by weight, includes: Component a: 20 - 50 parts; Component a is a basic reaction material and uses an organic polymer material; Component b: Component b is composed of the following: Foaming agent: 20 - 40 parts; Cross-linking agent: 10 - 30 parts; Toughening agent: 10 - 50 parts; Component c: Component c is composed of the following: pH regulator: 10 - 30 parts; Surfactant: 0.5 - 2 parts; 3) Prepare the spraying matrix and spray it onto the slope to be repaired to form a porous ecological sponge soil: 3.1) Preparation of spraying matrix material A: According to the weight ratio, a foaming agent, a cross-linking agent, a toughening agent and a polymer material are added to the mixing tank of the spraying machine. At the same time, 200-500 parts by weight of soil or soil matrix material and an equal amount of water are added to the mixing tank of the spraying machine and stirred sufficiently to form a uniform spraying matrix material A. 3.2) Preparation of water solution C: According to the weight ratio, pH regulator and surfactant are added to the mixing equipment, water is added, stirred, and fully mixed to prepare the spraying aqueous solution C; 3.3) Mixed spraying: Spray the spraying matrix material A prepared in step 3.1) onto the slope to be repaired, so that it fully reacts to form a matrix layer; Then, the spraying aqueous solution C prepared in step 3.2) is evenly sprayed on the matrix layer formed on the slope surface, and the organic polymer material reacts with the foaming agent, cross-linking agent, toughening agent, pH regulator and surfactant to form an ecological sponge soil with a "sponge-like" three-dimensional network porous structure; the thickness of a single spraying is 2-3 cm; According to the engineering design requirements, the above steps can be followed by multiple spraying to make the total thickness of the ecological sponge soil reach 5-15 cm; 4) After the ecological sponge soil is formed, spray the seed layer: Repeat the process of step 3). In the process of preparing the spraying matrix material A in step 3.1), select grass, shrub, tree plant seeds and lower fungi and algae species suitable for local and surrounding environment growth, add water greater than the amount of soil or soil matrix material (the proportion of water is appropriately increased to make the mixed slurry appropriately thinner), and add 1-20 parts by weight of plant fiber. After fully stirring and mixing, spray on the surface of the ecological sponge soil to form a 1-2 cm thick plant seed layer; 5) After forming, cover with non-woven fabric or sunshade net to provide shade and moisture conservation; 6) Post-maintenance.

[0007] A method for ecological restoration of sponge soil on a steep slope, comprising the following steps: 1) Carry out preliminary treatment on the slope to be repaired with a slope exceeding 60°; 2) Equipped with sponge soil forming agent; The soil forming agent comprises, by weight: Component a: 20-50 parts; the component a is a basic reaction material, using organic polymer materials; b component: The b component is composed as follows: Foaming agent: 20 - 40 parts; Crosslinking agent: 10 - 30 parts; Toughening agent: 10 - 50 parts; Component C: The composition of component C is as follows: pH regulator: 10 - 30 parts; Surfactant: 0.5 - 2 parts; 3) Prepare the hydroseeding substrate and hydroseed it onto the slope to be repaired to form a porous ecological sponge soil: 3.1) Prepare the hydroseeding substrate material A: According to the weight ratio, take the foaming agent, crosslinking agent, and toughening agent and add them to the mixing tank of the hydroseeder. At the same time, take 200 - 500 parts by weight of soil or soil substrate material and the same weight of water and add them to the mixing tank of the hydroseeder, and stir well to form a uniform hydroseeding substrate material A; 3.2) Prepare the aqueous dispersion B: Take 20 - 50 parts by weight of the organic polymer material, add water and stir well to obtain the aqueous dispersion B; 3.3) Prepare the hydroseeding aqueous solution C: According to the weight ratio, take the pH regulator and surfactant material and add them to the mixing equipment, add water and mix to obtain the hydroseeding aqueous solution C; 3.4) Mixing and hydroseeding: Pump the hydroseeding substrate material A prepared in step 3.1) and the aqueous dispersion B prepared in step 3.2) to the nozzle through a hydroseeding pump and a high-pressure gear pump or screw pump (with adjustable flow rate) respectively. The two liquids are fully mixed at the nozzle, adhere to the slope after hydroseeding. After the hydroseeding substrate material A and the aqueous dispersion B fully react, spray the hydroseeding aqueous solution C prepared in step 3.3) on the substrate layer formed on the slope. After full reaction, the surfactant dissolves into the hydroseeding substrate layer, generating a sponge-like hydrophobic, crosslinked, and foaming reaction to form an ecological sponge soil structure; the single-pass hydroseeding thickness is 3 - 5 cm; According to the engineering design requirements, the total thickness can reach 10 - 15 cm through multiple passes of hydroseeding by the above steps; 4) After the ecological sponge soil is formed, hydroseed the seed layer: Repeat the process of step 3). During the process of preparing the hydroseeding substrate material A in step 3.1), select grass, shrub, and tree plant seeds and low-grade algal and fungal strains suitable for local and surrounding environment growth, and add water in an amount greater than that of the soil or soil substrate material (appropriately increase the proportion of water to make the mixed slurry slightly thinner). At the same time, add 1 - 20 parts by weight of plant fiber, stir well and mix, and then hydroseed it on the surface of the ecological sponge soil to form a 1 - 2 cm thick plant seed layer; 5) After forming, cover with non-woven fabric or sunshade net to shade and conserve moisture; 6) Post-maintenance.

[0008] In the sponge soil ecological restoration method for gentle / low-steep slopes of the present invention, the basic reaction materials used are sodium polyacrylate, sodium alginate or anionic polyacrylamide. The foaming agent used is calcium carbonate, sodium carbonate or sodium bicarbonate; the cross-linking agent used is calcium chloride, magnesium chloride or ferric chloride; the toughening agent used is aqueous chloroprene latex. The pH regulator used is dilute hydrochloric acid solution, dilute acetic acid solution or dilute phosphoric acid solution, and the addition amount of the pH regulator is adjusted according to the setting time required for the sponge soil; the surfactant used is the small molecule surfactant sodium dodecyl sulfate or the macromolecule surfactant polyethylene glycol.

[0009] In the sponge soil ecological restoration method for gentle / low-steep slopes, in step 3.1), when preparing the spray seeding aqueous dispersion A, 1-40 parts by weight of plant fibers are added to increase the soil viscosity.

[0010] In the sponge soil ecological restoration method for gentle / low-steep slopes, in step 3.1), the soil matrix material used for preparing the spray seeding matrix material A includes the following components by volume percentage: 14-16% of wood fibers, 14-16% of decomposed corn cobs, 9-11% of decomposed sheep manure, and the balance is the imported soil.

[0011] In the sponge soil ecological restoration method for gentle / low-steep slopes, a water retaining agent and a binder are added to the soil matrix material: the dosage of the water retaining agent is 140-160 g / m 3 ; the dosage of the binder is 140-160 g / m 3 .

[0012] In the sponge soil ecological restoration method for gentle / low-steep slopes, the fiber length of the wood fibers used is 2-3 cm; the decomposed corn cobs are prepared by composting and fermenting corn cobs with a particle size of 2-5 mm: the humidity of the compost is 40-65%, the inoculation ratio of microorganisms is 0.08-0.12% by mass percentage, and the composting time is 21-42 days.

[0013] The imported soil contains 65-70% of silt, 27.5-32.5% of sand and <2.5% of clay.

[0014] The two reaction processes of the present invention each have their own characteristics. In actual construction, the appropriate reaction process can be reasonably selected according to the specific conditions of the slope (such as slope, height, etc.) and construction requirements to achieve efficient and high-quality construction of sponge soil forming.

[0015] Among them, the mixing operation: Add the sponge soil forming agent, soil, and water into the mixing equipment according to the determined ratio, and carry out sufficient mixing to make the materials evenly mixed. The purpose is to form an ecological sponge soil with good water retention and air permeability. The spraying parameters include adjusting the spraying pressure and spraying speed of the spraying machine according to factors such as the slope and area of the slope surface, and can be adjusted by those skilled in the art according to the actual situation and restoration requirements.

[0016] Advantages of the invention: 1. The low and gentle slope sponge soil ecological restoration method of the present invention is applicable to the construction of forming sponge soil on low and gentle slopes. Such slopes have relatively low requirements for the conveying height and distance of the spraying machine, and can better exert the advantages of fast construction speed and low cost of this process. Mix all materials in the tank at one time, the operation is relatively simple and direct, and the construction process is relatively compact. For some construction scenarios of low and gentle slopes, the construction speed may be relatively fast, and the construction cost is relatively low. Because on low and gentle slopes, the conveying difficulty of the spraying machine is relatively small, and long-distance conveying is not required.

[0017] 2. The high and steep slope sponge soil ecological restoration method of the present invention is applicable to the construction of forming sponge soil on high and steep slopes, and can meet the demand for long-distance conveying of materials on such slopes, effectively solving the problem of material conveying in the construction of high and steep slopes. The thin slurry in the tank is convenient for long-distance conveying and can adapt to construction scenarios such as high and steep slopes that require long-distance conveying of materials. By instantaneously mixing and reacting at the gun head, it can ensure that the material has an appropriate viscosity when sprayed on the slope surface, ensuring the formation of a sponge soil layer with a certain thickness.

[0018] 3. The low and gentle / high and steep slope sponge soil ecological restoration method of the present invention utilizes the sponge soil forming technology to widely and evenly spray the mixed slurry onto the treated low and gentle or high and steep wound surfaces, and can form a sponge soil that can both absorb and retain water and is hydrophobic and erosion-resistant, solving the characteristics of water retention and erosion prevention of the spraying matrix, and being suitable for plant growth.

[0019] 4. The low and gentle / high and steep slope sponge soil ecological restoration method of the present invention uses a sponge soil forming agent to prepare sponge soil, forming a porous sponge soil matrix with good water absorption, water retention, and strong adhesion. Add grass seeds to the spraying material, and the grass seeds can grow by relying on the conditions provided by the sponge matrix, which can effectively achieve slope revegetation restoration. The sponge soil and the slope surface are firmly combined, and the effect is lasting; and in certain cases, it can reduce the pre-treatment measures of traditional restoration methods, reducing the construction difficulty and construction requirements.

[0020] 5. The sponge soil ecological restoration method for low - gentle / high - steep slopes of the present invention. The sponge soil preparation reaction processes in the two restoration methods have their own characteristics. In actual construction, the appropriate reaction process can be reasonably selected according to the specific conditions of the slope (such as slope, height, etc.) and construction requirements to achieve efficient and high - quality sponge soil forming construction. Detailed implementation manners

[0021] To make the technical concept and advantages of the present invention for achieving its invention purpose clearer, the technical solutions of the present invention will be further described in detail below. It should be understood that the following embodiments are only used to explain and illustrate the preferred implementation manners of the present invention and should not be regarded as and do not constitute a limitation to the scope of patent protection required by the present invention.

[0022] Embodiment 1 This embodiment is a sponge soil ecological restoration method for low - gentle slopes, including the following steps: 1) Conduct pre - treatment on the low - gentle slope to be restored with a slope of less than 60°. 2) Prepare the sponge soil forming agent. The soil forming agent, by weight, includes: Component a: 20 - 50 parts; Component a is the basic reaction material and uses organic polymer materials. Component b: The composition of component b is as follows: Foaming agent: 20 - 40 parts; Cross - linker: 10 - 30 parts; Toughening agent: 10 - 50 parts; Component c: The composition of component c is as follows: pH regulator: 10 - 30 parts; Surfactant: 0.5 - 2 parts; 3) Prepare the spray - seeding substrate and spray - seed it onto the slope to be restored to form a porous - structure ecological sponge soil: 3.1) Prepare the spray - seeding substrate material A: According to the weight ratio, take the foaming agent, cross - linker, toughening agent and polymer material and add them into the mixing tank of the spray - seeder. At the same time, take 200 - 500 parts by weight of soil or soil substrate material and the same weight of water and add them into the mixing tank of the spray - seeder, and stir well to form a uniform spray - seeding substrate material A. 3.2) Prepare the spray - seeding aqueous solution C: According to the weight ratio, take the pH regulator and surfactant and add them to the mixing equipment, add water and stir to mix well to prepare the spray - seeding aqueous solution C. 3.3) Mixing and spray - seeding: Spray - seed the spray - seeding substrate material A prepared in step 3.1) onto the slope to be restored to make it fully react to form a substrate layer. Then, the spraying aqueous solution C prepared in step 3.2) is evenly sprayed on the substrate layer formed on the slope surface. The organic polymer material reacts with the foaming agent, cross-linking agent, toughening agent, pH regulator and surfactant to form an ecological sponge soil with a "sponge-like" three-dimensional network porous structure. The single spraying thickness is 2-3 cm. According to the engineering design requirements, the total thickness of the ecological sponge soil can reach 5-15 cm through multiple spraying in the above steps subsequently. 4) After the ecological sponge soil is formed, spray the seed layer: Repeat the process of step 3). During the preparation of the spraying substrate material A in step 3.1), select the grass, shrub, arbor plant seeds and lower fungi and algae strains suitable for growing in the local and surrounding environments, and add water in an amount greater than that of the soil or soil substrate material (appropriately increase the proportion of water to make the mixed slurry a little thinner). At the same time, add 1-20 parts by weight of plant fiber, fully stir and mix, and then spray it on the surface of the ecological sponge soil to form a plant seed layer with a thickness of 1-2 cm. 5) After forming, cover with non-woven fabric or sunshade net to shade and conserve moisture. 6) Post-maintenance.

[0023] The organic polymer material is used as the basic reaction material, such as sodium polyacrylate, sodium alginate or anionic polyacrylamide, etc. The foaming agent can be calcium carbonate, sodium carbonate or sodium bicarbonate, etc. The cross-linking agent is used as calcium chloride, magnesium chloride or ferric chloride, etc. The toughening agent is used as aqueous chloroprene latex. The pH regulator is a dilute hydrochloric acid solution, dilute acetic acid solution or dilute phosphoric acid solution, and its addition amount is adjusted according to the setting time required for the sponge soil.

[0024] In step 1), the pre-treatment of the low and gentle slope restoration slope mainly includes the following aspects: Slope cleaning: Before construction, the slope surface needs to be trimmed, debris on the slope surface such as withered branches and leaves, construction waste, etc. should be removed, floating stones and loose rock blocks on the slope surface should be excluded to ensure that the slope surface is basically smooth to eliminate the hidden danger of falling stones. For relatively smooth slopes, transverse grooves can be opened on the slope surface to appropriately increase the roughness; for local reverse slopes, geotextile bags or soil bags can be used for backfilling to make it smooth.

[0025] Slope stability assessment: Through on-site investigation and mapping, find out the distribution, scale, susceptibility to geological disasters, main inducing factors, stability and development trend, hazard characteristics, etc. of the slope. According to the assessment results, adopt corresponding engineering treatment measures to reinforce the slope, such as removing loose and dangerous rock masses and potentially unstable blocks on the slope surface, cutting slopes of steep slopes, systematic anchoring, etc.

[0026] Set up water interception and drainage facilities: Surface water or groundwater will flow into the rock mass through cracks, which may cause the internal structure of the rock mass to be softened and eroded, and eventually lead to geological disasters such as landslides and soil erosion. Therefore, it is necessary to scientifically arrange water interception and drainage facilities based on the actual situation of the slope to discharge surface water and groundwater in a timely manner.

[0027] Soil condition survey: survey the soil type, fertility, water content, pH value, etc. of the slope to determine the appropriate vegetation planting method and soil improvement measures. If the soil is poor, consider adding organic fertilizers, water retaining agents, soil conditioners, etc. to improve the soil's fertility and ability to retain water and fertilizer.

[0028] The invention discloses an ecological restoration method for sponge soil on a gentle slope, and the preliminary treatment of a wound or slope surface includes: cleaning the slope surface to be repaired, removing debris and loose stones on the slope surface; for a relatively stable but bumpy slope surface, a climbing machine can be used to create suitable pits on the slope surface as needed to facilitate the retention of sponge soil.

[0029] During the specific construction process, the reasonable mixing ratio of sponge soil forming agent, soil and water is determined according to the specific conditions of the slope and the repair requirements. The sponge soil forming agent, soil and water are added to the mixing equipment according to the determined ratio, and fully mixed to make the materials evenly mixed, and then sprayed to form an ecological sponge soil with good water retention and air permeability.

[0030] Compared with the conventional slope repair construction method in the prior art, the method for ecological restoration of sponge soil on low and gentle slopes of the present invention mixes all matrix materials in a tank at one time (the pH adjuster and active additives are then sprayed on the spraying matrix material A and sprayed on the slope to be repaired, and the matrix layer is formed after sufficient reaction). The operation is relatively simple and direct, and the construction process is relatively compact. For some construction scenes of low and gentle slopes, the construction speed may be faster and the construction cost is relatively low. Because on low and gentle slopes, the transportation difficulty of the spraying machine is relatively small, and long-distance transportation is not required. It is especially suitable for sponge soil forming construction of low and gentle slopes. Such slopes have lower requirements on the transportation height and distance of the spraying machine, and can better play the advantages of fast construction speed and low cost of this process.

[0031] Example 2 This embodiment is a method for ecological restoration of sponge soil on steep slopes, which includes the following steps: 1) Carry out preliminary treatment on the slope to be repaired with a slope exceeding 60°; 2) Equipped with sponge soil forming agent; The soil forming agent comprises, by weight: Component a: 20-50 parts; the component a is a basic reaction material, using organic polymer materials; Component b: The component b is composed as follows: Foaming agent: 20-40 parts; Cross-linking agent: 10-30 parts; Toughening agent: 10-50 parts; C component: The C component is composed as follows: pH regulator: 10-30 parts; Surfactant: 0.5-2 parts; 3) Prepare the spraying matrix and spray it onto the slope to be repaired to form a porous ecological sponge soil: 3.1) Preparation of spraying matrix material A: According to the weight ratio, a foaming agent, a cross-linking agent, and a toughening agent are added to the mixing tank of the spraying machine. At the same time, 200-500 parts by weight of soil or soil matrix material and water of the same weight are added to the mixing tank of the spraying machine, and stirred sufficiently to form a uniform spraying matrix material A; 3.2) Preparation of aqueous dispersion B: Take 20-50 parts by weight of organic polymer material, add water and stir thoroughly to prepare aqueous dispersion B; 3.3) Preparation of water solution C: According to the weight ratio, pH regulator and surfactant material are added to the mixing equipment, and water is added to mix to prepare the spraying aqueous solution C; 3.4) Mixed spraying: The spraying matrix material A prepared in step 3.1) and the aqueous dispersion B prepared in step 3.2) are pumped to the nozzle through a spraying pump and a high-pressure gear pump or a screw pump (with adjustable flow rate) respectively. The two liquids are fully fused at the nozzle and adhere to the slope surface after spraying. After the spraying matrix material A and the aqueous dispersion B are fully reacted, the spraying aqueous solution C prepared in step 3.3) is sprayed on the matrix layer formed on the slope surface. After the full reaction, the surfactant is dissolved in the spraying matrix layer, generating a sponge-like hydrophobic, cross-linking, and foaming reaction to form an ecological sponge soil structure; the thickness of a single spraying is 3-5 cm; According to the engineering design requirements, the above steps can be followed by multiple spraying to achieve a total thickness of 10-15 cm; 4) After the ecological sponge soil is formed, spray the seed layer: Repeat the process of step 3). In the process of preparing the spraying matrix material A in step 3.1), select grass, shrub, and tree seeds and lower bacteria and algae species suitable for local and surrounding environment growth, and add water greater than the amount of soil or soil matrix material (the proportion of water is appropriately increased to make the mixed slurry appropriately thinner), and add 1-20 parts by weight of plant fiber. After fully stirring and mixing, spray on the surface of the ecological sponge soil to form a plant seed layer with a thickness of 1-2 cm; 5) After forming, cover with non-woven fabric or sunshade net to shade and conserve moisture; 6) Post-construction maintenance.

[0032] In step 1), the pre-treatment of the high-steep slope surface or slope mainly includes the following aspects: I. Treatment of dangerous rock masses and loose rock blocks 1. Removal of dangerous rock masses Manual removal: For dangerous rock masses with low height and small scale, manual chiseling or small mechanical crushing is used for removal; Blasting removal: For dangerous rock masses with large volume and steep position, controlled blasting techniques (such as millisecond blasting, static crack agent) are used to reduce the disturbance to the surrounding rock masses and the environment. After removal, the slope surface needs to be cleaned to ensure no overhanging rocks and loose rocks.

[0033] 2. Anchoring and retaining Reinforcement with anchor rods (cables): For locally unstable rock masses, anchor rods (cables) are used for fixation. Through the bonding force or frictional force between the anchor bars and the rock masses, the dangerous rock masses are connected to the stable rock masses. The length of the anchor rods needs to pass through the sliding surface, and the length of the anchorage section is not less than the design requirement.

[0034] Concrete lattice / masonry retaining: Concrete lattice beams or masonry retaining walls are set on the slope surface to form a skeleton structure, enhance the integrity of the slope surface, and at the same time provide a hanging net foundation for subsequent vegetation restoration.

[0035] II. Slope shaping and construction of drainage system 1. Slope shaping For slopes that are too steep (such as slopes > 60°), mechanical slope cutting is used to reduce the slope angle (usually controlled at 45° - 60°), reduce the self-weight load of the slope, and reduce the sliding force. Concrete or masonry is used to fill the depressions, cracks and cavities on the slope surface to ensure the smoothness of the slope surface and avoid the accumulation of rainwater to aggravate erosion.

[0036] 2. Drainage system design Surface drainage, intercepting ditch: An intercepting ditch is set 5 - 10 meters outside the outer edge of the top of the slope to intercept surface runoff and prevent rainwater from scouring the top of the slope. Chute and drainage ditch: Drainage ditches are set on the platform and at the foot of the slope, and rainwater is led into the natural water system or sump through the chute.

[0037] Subsurface drainage: For slopes with rich groundwater, inclined drainage holes (hole diameter 75 - 100mm, spacing 2 - 4 meters), blind ditches or drainage galleries are used to lower the groundwater level and reduce the softening effect of water on the rock masses.

[0038] III. Pretreatment of ecological restoration conditions 1. Hanging net and fixing with anchor nails Metal mesh (galvanized wire mesh / reinforcement mesh): For rocky slopes, the metal mesh is fixed to the slope surface by anchor bolts (spacing 1 - 2 m), the mesh hole size is 50 - 100 mm, and the distance between the mesh surface and the slope surface is 3 - 5 cm, providing an attachment basis for the hydroseeding substrate.

[0039] Ecological fiber mesh / polymer material mesh: Used for soil or weathered rock slopes, with both slope fixation and water retention functions, promoting the growth of vegetation roots.

[0040] 2. Preparation of the topsoil and substrate Backfilling of topsoil: For rocky slope surfaces lacking topsoil, the topsoil (mixed by loess, humus soil, organic fertilizer, etc.) is manually backfilled or hydroseeded, and the thickness is determined according to the growth requirements of plants (generally 30 - 50 cm).

[0041] Optimization of substrate ratio: When using the shotcrete planting technology, the substrate needs to contain aggregates (such as weathered sand, gravel), cement, water retainer, microbial inoculant, plant seeds, etc. The optimal ratio is determined through experiments to ensure the balance between the early strength of the substrate and the growth requirements of plants in the later stage.

[0042] The sponge soil ecological restoration method for high and steep slopes of the present invention is applicable to the construction of sponge soil formation for high and steep slopes, can meet the requirements of such slopes for long - distance transportation of materials, and effectively solves the problem of material transportation in the construction of high and steep slopes. The advantages of this technological process are as follows: The thin slurry in the tank is convenient for long - distance transportation and can adapt to construction scenarios such as high and steep slopes that require long - distance material transportation. Through instantaneous mixing and reaction at the gun head, it can ensure that the material has an appropriate viscosity when sprayed on the slope surface, ensuring the formation of a sponge soil layer with a certain thickness. Due to the high adsorption and adhesion properties of the sponge soil, all or part of the engineering measures such as lattice, anchor bolt, cable anchor reinforcement, and shotcrete with wire mesh can be reduced according to the actual construction environment without affecting the restoration effect. This greatly reduces the construction technical requirements and construction difficulty, reduces the construction cost and construction conditions, is economical and efficient, and has a long - lasting effect.

[0043] Similar to Example 1, the organic polymer material uses sodium polyacrylate, sodium alginate, or anionic polyacrylamide, etc.; the foaming agent can use calcium carbonate, sodium carbonate, or sodium bicarbonate, etc.; the cross - linker uses calcium chloride, magnesium chloride, or ferric chloride; the toughening agent uses aqueous chloroprene latex. Among them, the pH regulator uses dilute hydrochloric acid solution, dilute acetic acid solution, or dilute phosphoric acid solution; its addition amount is adjusted according to the setting time required for the sponge soil.

[0044] The above two processes of the present invention each have their own characteristics. In actual construction, according to the specific conditions of the slope (such as slope gradient, height, etc.) and construction requirements, a suitable reaction process can be reasonably selected to achieve efficient and high - quality sponge soil formation construction.

[0045] During the preparation of sponge soil, the sponge soil forming agent, soil, and water are added to the mixing equipment in a determined proportion and thoroughly mixed to make the materials evenly mixed, with the aim of forming an ecological sponge soil with good water retention and air permeability. The spraying parameters of the hydroseeder (including adjusting the spraying pressure and spraying speed of the hydroseeder according to factors such as the slope and area of the slope surface) can be adjusted by those skilled in the art according to the actual situation and restoration requirements.

[0046] In step 3.1) of the low - gentle / high - steep slope sponge soil ecological restoration method described in the present invention, when preparing the spraying aqueous dispersion a, 1 - 40 parts by weight of plant fibers can be added to increase the soil viscosity.

[0047] In step 3.1), soil matrix materials are used to prepare the spraying matrix materials to improve the soil. The soil matrix materials are composed of the following components by volume percentage: 14 - 16% of wood fibers, 14 - 16% of decomposed corn cobs, 9 - 11% of decomposed sheep manure, and the balance is the imported soil. A water - retaining agent and a binder are added to the soil matrix materials: the dosage of the water - retaining agent is 140 - 160 g / m 3 ; the dosage of the binder is 140 - 160 g / m 3 . The fiber length of the wood fibers used is 2 - 3 cm; the decomposed corn cobs are obtained by compost fermentation of corn cobs with a particle size of 2 - 5 mm: the humidity of the compost is 40 - 65%, the inoculation ratio of microorganisms is 0.08 - 0.12% by mass percentage, and the composting time is 21 - 42 days.

[0048] The imported soil contains 65 - 70% of silt particles, 27.5 - 32.5% of sand particles, and < 2.5% of clay particles.

[0049] The soil matrix materials can also be prepared by mixing planting soil and decomposed manure, which is prepared to meet the growth and development of seedlings. It contains various mineral nutrients, is loose and breathable, has strong water and fertilizer retention ability, and has no plant diseases and insect pests.

[0050] The fermented nutrient materials and the dried cow dung after crushing and screening are mixed in a ratio of 3:1; the pH value of the cultured nutrient medium should be measured before the spraying operation, and combined with the acidity and alkalinity of the local spraying planting soil, the pH value of the nutrient medium is adjusted specifically to make the spraying base material more conducive to the growth of the plant community.

[0051] Specific scheme for the stacking fermentation of the nutrient material layer: ①Material ratio. Add 1 kg of organic fertilizer fermentation agent to 1.5 tons of dry cow dung (about 2.5 tons of fresh dung), and mix 40% of crushed peanut shells, 48% of corn cobs, 4% to 5% of cottonseed cake powder, 1% of superphosphate, 1% to 2% of plant ash, 0.3% to 0.5% of urea, and 2% to 3% of lime (or substitutes such as sawdust and rice husks) in a ratio of 1:3 between cow dung and mixed materials; ②Build a pile of materials. When making a pile, it should not be too small or too short, as it will affect fermentation. The height should be 1.5 to 2 meters, the width should be 2 meters, and the length should be more than 2 to 4 meters. ③ Temperature requirements. The starting temperature should be above 15°C; ④ Moisture requirements. The moisture content of the fermentation material should be controlled at around 65%; ⑤ Turn the pile for ventilation. During the fermentation process, pay attention to proper oxygen supply and turning the pile (turn it over several times when the temperature rises to 75℃ or above), and control the temperature at around 65℃. Too high a temperature will affect nutrients. ⑥ Fermentation is completed. Generally, fermentation can be completed within 15 days. The material is dark brown and the temperature begins to drop to room temperature, indicating that fermentation is complete. If there are too many auxiliary materials such as sawdust, wood chips, and rice husks, the fermentation time should be extended. After the material is fully decomposed and fermented, it should be dried for later use.

[0052] In summary, the sponge soil ecological restoration method for low-lying / high-steep slopes of the present invention adopts sponge soil forming technology to form sponge soil that can absorb and retain water and is hydrophobic and erosion-resistant. The mixed slurry is widely and evenly sprayed onto the treated high-steep wound surface. After the slurry solidifies, a microenvironment suitable for plant growth is formed.

[0053] Normal maintenance and management are carried out in the later stage. The later maintenance includes: water management: after spraying, watering is carried out in time according to weather conditions and soil moisture on the slope to keep the soil moist and provide suitable water conditions for the germination of grass seeds and other vegetation seeds; vegetation monitoring: regular observation of vegetation growth, reseeding or taking other remedial measures for areas with poor growth or lack of vegetation; slope protection: in the early stage of vegetation growth, necessary protective measures can be taken to prevent the slope from being damaged by rain erosion and other damage.

[0054] The applicant also filed a patent application for a pan-jet stagnation natural ecological restoration technology. The differences between the sponge soil ecological restoration technology of the present invention and the pan-jet stagnation natural ecological restoration technology are as follows: Application scenarios: Sponge soil remediation technology is suitable for all types of slopes, such as low slopes and steep slopes, and requires the assistance of hanging nets for comprehensive coverage and repair; the near-natural ecological restoration technology of pan-jet mass is aimed at steep and sparsely populated areas, emphasizing the concept of near-natural restoration, and improving smooth slope conditions through pre-treatment such as climbing and hole making by climbing machines and slope improvement, creating a foundation for subsequent restoration.

[0055] Construction process: The sponge soil restoration technology uses direct spraying to cover the slope surface as a whole; the materials ejected by the fluid spraying technology are fluid and need to flow naturally to parts such as pits and rock crevices to achieve local precise restoration.

[0056] Solidification characteristics: The materials of the sponge soil restoration technology react immediately after spraying and can quickly form adhesions on smooth or raised slopes to construct the sponge soil structure; the materials of the fluid spraying technology have a relatively long solidification time and need to go through the process of flowing and positioning before solidification is completed.

[0057] Cost and effect: The fluid spraying technology has a relatively low construction cost. It does not pursue a high percentage coverage of slope greening, but pays more attention to presenting a natural effect, allowing rocks to be exposed and making the slope present a natural scattered state; while the sponge soil restoration technology pursues comprehensive coverage and restoration, and the corresponding construction cost is relatively high.

[0058] The present invention is an upgraded solution to traditional restoration technologies. It uses a porous sponge soil technology rich in nutrient matrix with high adsorption, high water absorption, and water retention properties to achieve the restoration of low - gentle or high - steep slopes. Therefore, the present invention mainly highlights the sponge soil technology. The applicant has previously filed many patent applications related to relevant technologies, and the application technologies involved are also applicable to the present invention, which will not be described in detail here.

Claims

1. A method for ecological restoration of sponge soil on low and gentle slopes, characterized in that: The steps include: 1) Carry out preliminary treatment on the low and gentle slopes to be repaired with a slope below 60°; 2) Equipped with sponge soil forming agent; The soil forming agent comprises, by weight: Component a: 20-50 parts; the component a is a basic reaction material, using organic polymer materials; Component b: The component b is composed as follows: Foaming agent: 20-40 parts; Cross-linking agent: 10-30 parts; Toughening agent: 10-50 parts; C component: The C component is composed as follows: pH regulator: 10-30 parts; Surfactant: 0.5-2 parts; 3) Prepare the spraying matrix and spray it onto the slope to be repaired to form a porous ecological sponge soil: 3.1) Preparation of spraying matrix material A: According to the weight ratio, a foaming agent, a cross-linking agent, a toughening agent and a polymer material are added to the mixing tank of the spraying machine. At the same time, 200-500 parts by weight of soil or soil matrix material and an equal amount of water are added to the mixing tank of the spraying machine and stirred sufficiently to form a uniform spraying matrix material A. 3.2) Preparation of water solution C: According to the weight ratio, pH regulator and surfactant are added to the mixing equipment, water is added, stirred, and fully mixed to prepare the spraying aqueous solution C; 3.3) Mixed spraying: Spray the spraying matrix material A prepared in step 3.1) onto the slope to be repaired, so that it fully reacts on the slope to form a matrix layer; Then, the spraying aqueous solution C prepared in step 3.2) is evenly sprayed on the matrix layer formed on the slope surface, and the organic polymer material reacts with the foaming agent, cross-linking agent, toughening agent, pH regulator and surfactant to form an ecological sponge soil with a "sponge-like" three-dimensional network porous structure; the thickness of a single spraying is 2-3 cm; According to the engineering design requirements, the above steps can be followed by multiple spraying to make the total thickness of the ecological sponge soil reach 5-15 cm; 4) After the ecological sponge soil is formed, spray the seed layer: Repeat the process of step 3). In the process of preparing the spraying matrix material A in step 3.1), select grass, shrub, tree plant seeds and lower fungi and algae species suitable for local and surrounding environment growth, add water greater than the amount of soil or soil matrix material, and add 1-20 parts by weight of plant fiber. After fully stirring and mixing, spray on the surface of the ecological sponge soil to form a 1-2 cm thick plant seed layer; 5) After forming, cover with non-woven fabric or sunshade net to provide shade and moisture conservation; 6) Post-maintenance.

2. A method for ecological restoration of sponge soil on steep slopes, characterized in that: The steps include: 1) Carry out preliminary treatment on the slope to be repaired with a slope exceeding 60°; 2) Equipped with sponge soil forming agent; The soil forming agent comprises, by weight: Component a: 20-50 parts; the component a is a basic reaction material, using organic polymer materials; Component b: The component b is composed as follows: Foaming agent: 20-40 parts; Cross-linking agent: 10-30 parts; Toughening agent: 10-50 parts; C component: The C component is composed as follows: pH regulator: 10-30 parts; Surfactant: 0.5-2 parts; 3) Prepare the spraying matrix and spray it onto the slope to be repaired to form a porous ecological sponge soil: 3.1) Preparation of spraying matrix material A: According to the weight ratio, a foaming agent, a cross-linking agent, and a toughening agent are added to the mixing tank of the spraying machine. At the same time, 200-500 parts by weight of soil or soil matrix material and water of the same weight are added to the mixing tank of the spraying machine, and stirred sufficiently to form a uniform spraying matrix material A; 3.2) Preparation of aqueous dispersion B: Take 20-50 parts by weight of organic polymer material, add water and stir thoroughly to prepare aqueous dispersion B; 3.3) Preparation of water solution C: According to the weight ratio, pH regulator and surfactant material are added to the mixing equipment, and water is added to mix to prepare the spraying aqueous solution C; 3.4) Mixed spraying: The spraying matrix material A prepared in step 3.1) and the aqueous dispersion B prepared in step 3.2) are pumped to the nozzle through a spraying pump and a high-pressure gear pump or a screw pump respectively. The two liquids are fully fused at the nozzle and adhere to the slope surface after spraying. After the spraying matrix material A and the aqueous dispersion B are fully reacted, the spraying aqueous solution C prepared in step 3.3) is sprayed on the matrix layer formed on the slope surface. After the full reaction, the surfactant is dissolved in the spraying matrix layer, generating a sponge-like hydrophobic, cross-linking, and foaming reaction to form an ecological sponge soil structure; the thickness of a single spraying is 3-5 cm; According to the engineering design requirements, the above steps can be followed by multiple spraying to achieve a total thickness of 10-15 cm; 4) After the ecological sponge soil is formed, spray the seed layer: Repeat the process of step 3). In the process of preparing the spraying matrix material A in step 3.1), select grass, shrub, tree seeds and lower fungi and algae species suitable for local and surrounding environment growth, add water greater than the amount of soil or soil matrix material, and add 1-20 parts by weight of plant fiber. After fully stirring and mixing, spray on the surface of the ecological sponge soil to form a plant seed layer with a thickness of 1-2 cm; 5) After forming, cover with non-woven fabric or sunshade net to provide shade and moisture conservation; 6) Post-maintenance.

3. The method for ecological restoration of sponge soil on low and gentle / high and steep slopes according to claim 1 or 2, characterized in that: The basic reaction material uses sodium polyacrylate, sodium alginate or anionic polyacrylamide.

4. The method for ecological restoration of sponge soil on low and gentle / high and steep slopes according to claim 3 is characterized by: The foaming agent uses calcium carbonate, sodium carbonate or sodium bicarbonate; the cross-linking agent uses calcium chloride, magnesium chloride or ferric chloride; and the toughening agent uses water-based chloroprene latex.

5. The method for ecological restoration of sponge soil on low and gentle / high and steep slopes according to claim 3, characterized in that: The pH regulator uses dilute hydrochloric acid solution, dilute acetic acid solution or dilute phosphoric acid solution, and the amount of the pH regulator added is adjusted according to the time required for the sponge soil to solidify; the surfactant uses a small molecule surfactant sodium dodecyl sulfate or a large molecule surfactant polyethylene glycol.

6. The method for ecological restoration of sponge soil on low and gentle / high and steep slopes according to claim 1, 2, 4 or 5, characterized in that: In step 3.1), when preparing the water dispersion A for spraying, 1-40 parts by weight of plant fiber is added to increase soil viscosity.

7. The method for ecological restoration of sponge soil on low and gentle / high and steep slopes according to claim 1, 2, 4 or 5, characterized in that: In step 3.1), the soil matrix material used for preparing the spraying matrix material A includes the following components in volume percentage: 14-16% of wood fiber, 14-16% of decomposed corn cobs, 9-11% of decomposed sheep manure, and the remainder is foreign soil.

8. The method for ecological restoration of sponge soil on low and gentle / high and steep slopes according to claim 7, characterized in that: Add water retaining agent and binder to the soil matrix material: the amount of water retaining agent is 140-160g / m 3 The amount of the binder is 140-160g / m 3 .

9. The method for ecological restoration of sponge soil on low and gentle / high and steep slopes according to claim 7, characterized in that: The fiber length of the wood fiber used is 2-3 cm; the decomposed corn cobs are made by composting and fermenting corn cobs with a particle size of 2-5 mm; the humidity of the compost is 40-65%, the inoculation ratio of microorganisms is 0.08-0.12% by mass, and the composting time is 21-42 days.

10. The method for ecological restoration of sponge soil on low and gentle / high and steep slopes according to claim 7, characterized in that: The imported soil contains 65-70% of silt particles, 27.5-32.5% of sand particles and less than 2.5% of clay particles.