Coastal area graded double-layer ecological water-retaining slope-fixing green-recovering base material and spray-seeding method
By using a graded double-layer ecological water-retaining and slope-stabilizing substrate on coastal slopes, and utilizing a coarse and fine fiber network and a water-retaining gel structure, the problems of uneven substrate, insufficient improvement of saline soil, and poor structural stability on coastal slopes have been solved. This has achieved high efficiency in water retention and stability, promoting rapid revegetation and long-term ecological restoration.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA THREE GORGES UNIV
- Filing Date
- 2026-01-30
- Publication Date
- 2026-05-12
AI Technical Summary
Existing hydroseeding technology has problems in coastal environments, such as uneven substrate, insufficient improvement of saline soil, poor water retention, poor structural stability, easy loss, and reduced pore connectivity. This leads to short-term revegetation, long-term degradation, and secondary soil and water loss after coastal slope revegetation.
The substrate adopts a graded double-layer ecological water-retaining, slope-stabilizing, and greening material. The bottom layer is composed of coarse fibers forming a network of interconnected macropores, while the surface layer is composed of fine fibers forming a network of microcapillary pores. Combined with water-retaining agents and soil conditioners, it forms an interlocking structure that provides deep shear resistance and wind erosion resistance. It also stores water through a gel-like structure, reducing evaporation loss.
It significantly improves the structural stability and water retention of coastal slopes, increases vegetation survival rate and coverage speed, maintains a stable water supply in high salt spray and high wind environments, prevents substrate detachment, and achieves rapid revegetation and long-term ecological restoration.
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Figure CN122004097A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of slope restoration engineering technology, and in particular to a graded double-layer ecological water-retaining and slope-stabilizing restoration substrate and a spraying method for coastal areas. Background Technology
[0002] With the accelerated development of infrastructure in coastal areas, exposed slopes created by port, highway, and dike projects face severe ecological problems. The unique coastal environment, characterized by high salt spray, strong typhoons, seasonal torrential rains, and the upwelling of groundwater from saline soils, exacerbates soil salinization, nutrient loss, and structural loosening. Traditional hydroseeding substrates exhibit significant drawbacks in such environments: firstly, high salinity inhibits seed germination and impairs the water-absorbing properties of water-retaining agents; secondly, heavy rainfall and typhoons easily erode the substrate, leading to fiber layer stripping and vegetation cover failure; and thirdly, sodium ion accumulation in saline soil causes soil compaction, further hindering root development. These problems often result in "short-term revegetation followed by long-term degradation" after coastal slope revegetation, and can even trigger secondary soil erosion.
[0003] While existing hydroseeding technology has been applied in general slope restoration, its adaptability to coastal environments is insufficient. During the hydroseeding process, uneven mixing of the substrate may occur, resulting in high cement content in some areas of the slope after hydroseeding, severely impacting plant growth. In some areas, excessive sunshine hours and high water evaporation rates lead to severe water shortages for plants, all of which can contribute to bare patches on the slope.
[0004] Patent CN103664325A discloses a method for preparing and spraying a flexible molecular film-based greening substrate. The invention incorporates polyvinyl alcohol, which, after brief dehydration, forms a multi-layered, uniformly dispersed molecular film within the substrate, effectively locking in moisture, enhancing its resistance to rain erosion, increasing its strength, and preventing detachment. However, this substrate spraying method involves both dry and wet spraying. The polyvinyl alcohol requires separate delivery at the nozzle, making the spraying process cumbersome. Furthermore, the water-retaining agent's water absorption rate decreases by over 50% when the salt content exceeds 0.3%, failing to address the problem of saline soil improvement. Patent CN102986418B discloses a hydroseeding substrate for southern slopes and its preparation method. This hydroseeding substrate boasts advantages such as wide applicability, erosion and soil erosion resistance, rapid vegetation recovery, fast construction speed, high efficiency, and low construction cost. However, this substrate cannot fundamentally reduce moisture evaporation and loss. Some substrates have insufficient water retention, failing to maintain the water required for plant growth under drought conditions; others have poor structural stability, easily eroded by rain or wind, affecting the anchorage of plant roots. Patent CN120794423A discloses a composite substrate for ecological slope protection, its preparation method, and slope protection method. This hydroseeding substrate introduces water-absorbing polymers into the soil system to improve water retention. After absorbing water, these materials typically form a continuous phase on the surface of soil particles, thus providing a certain degree of cementation or solidification to the soil. However, under conditions of heavy rainfall or salt spray, the aforementioned cemented structure dominated by soil particles is prone to overall rigidity and reduced pore connectivity in the hydroseeding layer, thereby affecting the slow release and regulation of water and the normal growth of plant roots. Furthermore, under the conditions of strong winds and torrential rains in coastal areas, the hydroseeding layer still faces the risk of localized peeling or overall instability.
[0005] In view of the shortcomings of existing technologies, there is an urgent need for a graded double-layer ecological water-retaining, slope-stabilizing, and greening substrate and a spraying method for coastal areas. Summary of the Invention
[0006] This invention provides a graded double-layer ecological water-retaining, slope-stabilizing, and greening substrate and a hydroseeding method for coastal areas. It solves the problems of existing substrates and hydroseeding methods, such as cumbersome spraying methods, failure to address the problem of saline soil improvement, insufficient water retention, poor structural stability that makes the substrate easily washed away by rain or wind, overall rigidity of the hydroseeding layer, and reduced pore connectivity.
[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A graded double-layer ecological water-retaining, slope-stabilizing, and greening substrate for coastal areas, comprising a bottom layer and a top layer of hydroseeding substrate; The underlying substrate includes a supportive interlocking network formed by coarse and medium fibers. The coarse fibers serve as the skeleton material and are entangled and interlocked with the medium fibers. After spraying and curing, a network of interconnected macropores with an equivalent pore size of 0.5 mm to 2.0 mm is formed to provide deep shear resistance and a channel for plant roots to penetrate. The surface substrate includes a dense network of fine fibers, which fill the gaps in the skeleton to form a microcapillary network with an equivalent pore size of 0.01 mm to 0.1 mm. This forms a hierarchical interlocking double-layer structure of fibers, creating a pore size gradient from the bottom layer to the surface layer, which is used to increase the water content at capillary fracture and reduce evaporation loss. Both the bottom substrate and the top substrate contain water-retaining agents. After absorbing water and swelling, the water-retaining agents form a gel structure. The gel structure is distributed in the pores of the fiber hierarchical interlocking network and at the fiber crossing points, and works in conjunction with the fiber network to store water, release moisture slowly, and reduce the erosion and peeling of the sprayed layer.
[0008] Preferably, the underlying substrate comprises the following components by weight: 20-30 parts coconut shell fiber, 10-20 parts flax fiber, 40-50 parts natural soil, 2-4 parts gypsum, 0.5-1 part water-retaining agent, 2-3 parts humic acid, 1-2 parts binder, 10-15 parts fertilizer, 5-7 parts polyacrylamide, 3-5 parts zeolite, 3-5 parts bentonite, 8-12 parts seeds, and 25-35 parts water.
[0009] Preferably, the underlying fiber network is constructed with coconut shell fibers with a diameter of not less than 200 μm and a length of not less than 10 cm to form the main load-bearing skeleton, and is further wound with flax fibers with a diameter of not less than 100 μm, forming a connected macroporous network with an equivalent pore size of 0.5 mm to 2.0 mm after spraying and curing.
[0010] Preferably, the surface substrate comprises, by weight, the following components: 30-40 parts wood fiber, 20-30 parts bamboo fiber, 5-10 parts seaweed fiber, 40-50 parts natural soil, 1-2 parts gypsum, 0.5-1 part water-retaining agent, 2-3 parts humic acid, 1-2 parts adhesive, 10-12 parts fertilizer, 8-12 parts seeds, and 20-25 parts water.
[0011] Preferably, the surface fiber network is composed of wood fibers with a diameter of no more than 50 μm, bamboo fibers with a diameter of no more than 100 μm, and seaweed fibers with a diameter of 20~50 μm. After the seaweed fibers absorb water and swell, they fill the micropores formed by the overlap of wood fibers and bamboo fibers, forming a microcapillary network with an equivalent pore size of 0.01 mm~0.1 mm.
[0012] Preferably, the water-retaining agent is a polyacrylate polymer that expands in volume and forms a continuous gel structure after absorbing water. It is composed of a mixture of acrylic acid, nanocellulose crystals-g-polyacrylamide, and a crosslinking agent in a mass ratio of 1:0.02:0.00025, wherein the crosslinking agent is polyethyleneimine, which is used to improve the water-holding capacity of the substrate and reduce moisture evaporation.
[0013] Preferably, in the substrate: The gypsum is used to neutralize sodium ions in saline-alkali soil and enhance the substrate's resistance to salting. The fulvic acid is a highly mineralized humic acid derivative that can reduce the opening of plant stomata and inhibit water transpiration. Its dosage ratio to water is 1:25, and the solid product requires a fulvic acid content of ≥95%. The binder is polyvinyl alcohol, used to improve the adhesion of the mixture and its stability on the slope; The fertilizer is a compound fertilizer, and the ratio of nitrogen, phosphorus and potassium is 1:0.4:1.3.
[0014] Preferably, in the substrate: the seeds are plant species with good soil and water conservation capabilities, including one or more of Bermuda grass, Bahia grass, and Imperata cylindrica.
[0015] Preferably, in the substrate: The bentonite contains >90% montmorillonite.
[0016] A method for spraying a substrate, using the aforementioned graded double-layer ecological water-retaining, slope-stabilizing, and revegetating substrate for coastal areas, to perform secondary spraying repair on bald patches on coastal slopes formed after typhoons, rainstorms, or human disturbance, includes the following steps: Pre-treatment of bald patches on slopes: including clearing debris, leveling the slope surface, and reinforcing unstable areas; Spraying substrate preparation: Separately prepared bottom substrate and top substrate. The bottom substrate includes a supportive interlocking network formed by coarse and medium fibers, and the top substrate includes a dense covering network formed by fine fibers. Water-retaining agent is added to both the bottom substrate and the top substrate. Hydroseeding of the base substrate: Use hydroseeding equipment to evenly spray the base substrate onto the bald spots on the pretreated slope, ensuring that the substrate is in full contact with the slope surface and forms initial fixation. The spray thickness is 3cm. Hydroseeding of the top substrate: After the bottom substrate has initially cured, the top substrate is evenly sprayed onto the cured bottom substrate using hydroseeding equipment to form the final vegetation growth medium. The thickness of the spray is 2cm. Covering and protection: After spraying, cover the sprayed area with non-woven fabric to reduce moisture evaporation and prevent the seeds from being blown away by the wind.
[0017] The beneficial effects of this invention are: 1. Structural Stability: This invention introduces natural fiber materials such as coconut shell fiber, flax fiber, wood fiber, bamboo fiber, and seaweed fiber into the bottom and top layers, respectively, forming a hierarchical interlocking network structure composed of coarse and fine fibers. In the bottom layer, coconut shell fiber has a large diameter and high strength, while flax fiber has good flexibility and strong water absorption. The two interlock to form a loose skeletal support network with an equivalent pore size controlled between 0.5 and 2.0 mm. This large-pore structure significantly improves the adhesion between the substrate and the slope surface and the overall shear strength, while ensuring unobstructed penetration of plant roots and breathable drainage within the substrate. In the top layer, wood fiber, bamboo fiber, and seaweed fiber have a high specific surface area and good adsorption capacity, forming a dense protective covering network that significantly reduces the equivalent pore size to 0.01 to 0.1 mm. This effectively resists rainwater erosion and strong wind erosion, reduces the risk of substrate detachment, and significantly improves the structural stability of the slope.
[0018] 2. Water Retention: The water-retaining agent in this invention forms a gel structure after absorbing water and swelling. This gel structure is mainly distributed in the pores formed by the hierarchical interlocking fiber network and at fiber intersections, acting as a functional phase to participate in the water storage and slow release process, rather than as the main structure of the cemented soil particles. This avoids the overall rigidity of the sprayed layer due to material cementation, thus maintaining the flexibility and porous characteristics of the sprayed layer. Furthermore, this invention employs a double-layer hierarchical pore structure. The bottom layer provides ample water storage space with larger pores, while the surface layer slows down water evaporation with smaller pores. During the migration of water from coarse to fine capillaries, multi-level capillary fractures occur, increasing the water content at capillary fracture points and effectively reducing ineffective evaporation losses. This further enhances the water-holding capacity of the substrate, enabling the substrate of this invention to maintain a high effective moisture content even under high temperature and strong wind conditions in coastal areas.
[0019] 3. Effects on Saline-Alkali Soil Improvement: This invention utilizes gypsum, zeolite, bentonite, and humic acid to synergistically improve the saline-alkali soil environment. Calcium ions in gypsum can replace sodium ions in saline soil, alleviating soil compaction; zeolite has strong ion exchange capacity, adsorbing and fixing salts; bentonite has good expansion and water retention properties, improving soil structure; humic acid can regulate stomatal opening, reduce transpiration water loss, and enhance root absorption of water and nutrients, thus significantly improving the plant's salt tolerance and stress resistance. This allows the hydroseeding layer to maintain stable water retention under typical coastal environmental conditions such as salt spray, high humidity, and high evaporation, improving the survival rate of vegetation on coastal slopes.
[0020] 4. Revegetation Capacity: This invention selects plant species with good wind resistance, salt spray tolerance, and soil and water conservation capabilities, such as Bermuda grass, Bahia grass, and Imperata cylindrica, enabling the hydroseeded vegetation to quickly adapt to the harsh coastal environment and form a stable vegetation cover. Combined with the good water retention environment and stable structural support provided by the double-layer substrate, the plants emerge uniformly, cover evenly, and revegetate quickly and sustainably. The results of the examples show that the moisture content of the substrate and the vegetation coverage of this invention are significantly higher than those of the comparative example, demonstrating the superior performance of this invention in the ecological restoration of coastal slopes.
[0021] In summary, this invention achieves a comprehensive improvement in water retention, structural stability, and revegetation capacity through the synergistic effect of natural fiber graded structure, functional water-retaining materials, and soil conditioners, providing an efficient, reliable, and widely applicable technical solution for the ecological restoration of coastal slopes. Attached Figure Description
[0022] Figure 1 This is a schematic diagram of the spraying method of the present invention; Figure 2 This is a schematic diagram of the structure of the substrate of the present invention; Figure 3The bar chart shows the results of a 72-hour cumulative evaporation test for embodiments and comparative examples of the present invention. Figure 4 The bar chart shows the results of a 14-day seed germination rate test for embodiments and comparative examples of the present invention. Detailed Implementation
[0023] The embodiments will be further described below with reference to the accompanying drawings.
[0024] like Figure 1 and Figure 2 As shown in Example 1, a graded double-layer ecological water-retaining, slope-stabilizing, and revegetation substrate is composed of the following components by weight: The bottom layer contains 20 parts coconut shell fiber, 10 parts flax fiber, 40 parts natural soil, 2 parts gypsum, 0.5 parts water-retaining agent, 2 parts humic acid, 1 part binder, 10 parts fertilizer, 5 parts polyacrylamide, 3 parts zeolite, 3 parts bentonite, 8 parts seeds, and 35 parts water. The top layer contains 30 parts wood fiber, 20 parts bamboo fiber, 5 parts seaweed fiber, 40 parts natural soil, 1 part gypsum, 0.5 parts water-retaining agent, 2 parts humic acid, 2 parts binder, 10 parts fertilizer, 12 parts seeds, and 25 parts water.
[0025] In this embodiment, the process for preparing the double-layer ecological water-retaining, slope-stabilizing, and revegetation substrate is as follows: Coconut shell fiber, flax fiber, wood fiber, bamboo fiber, and seaweed fiber are washed and dried separately to ensure that the fibers do not contain impurities.
[0026] The natural soil is sieved to remove clods larger than 5mm to ensure uniform soil particle size.
[0027] Mix coconut fiber, flax fiber, natural soil, gypsum, water-retaining agent, humic acid, binder, fertilizer, polyacrylamide, zeolite, bentonite and water in a mixer according to the specified proportions, and mix for 20 minutes to form the base substrate.
[0028] Wood fiber, bamboo fiber, seaweed fiber, natural soil, water-retaining agent, humic acid, binder, fertilizer and water are mixed in a mixer and stirred for 20 minutes to form a surface substrate.
[0029] The mixed base material is evenly sprayed onto the pretreated slope using a hydroseeding device to form a 3cm thick base layer.
[0030] After the base substrate has initially cured, the top substrate is sprayed onto the base substrate to form a 2cm thick top layer.
[0031] After spraying, cover the sprayed area with non-woven fabric to reduce moisture evaporation and improve seed germination rate.
[0032] As a specific embodiment 2, a graded double-layer ecological water-retaining, slope-stabilizing, and revegetation substrate is composed of the following components by weight: The bottom layer contains 25 parts coconut shell fiber, 15 parts flax fiber, 30 parts natural soil, 3 parts gypsum, 0.5 parts water-retaining agent, 2 parts humic acid, 1 part binder, 10 parts fertilizer, 7 parts polyacrylamide, 3 parts zeolite, 3 parts bentonite, 8 parts seeds, and 35 parts water. The top layer contains 35 parts wood fiber, 25 parts bamboo fiber, 8 parts seaweed fiber, 30 parts natural soil, 1 part gypsum, 0.5 parts water-retaining agent, 2 parts humic acid, 2 parts binder, 10 parts fertilizer, 12 parts seeds, and 25 parts water.
[0033] In this embodiment, the process for preparing the double-layer ecological water-retaining, slope-stabilizing, and revegetation substrate is as follows: Coconut shell fiber, flax fiber, wood fiber, bamboo fiber, and seaweed fiber are washed and dried separately to ensure that the fibers do not contain impurities.
[0034] The natural soil is sieved to remove clods larger than 5mm to ensure uniform soil particle size.
[0035] Mix coconut fiber, flax fiber, natural soil, gypsum, water-retaining agent, humic acid, binder, fertilizer, polyacrylamide, zeolite, bentonite and water in a mixer according to the specified proportions, and mix for 20 minutes to form the base substrate.
[0036] Wood fiber, bamboo fiber, seaweed fiber, natural soil, water-retaining agent, humic acid, binder, fertilizer and water are mixed in a mixer and stirred for 20 minutes to form a surface substrate.
[0037] The mixed base material is evenly sprayed onto the pretreated slope using a hydroseeding device to form a 3cm thick base layer.
[0038] After the base substrate has initially cured, the top substrate is sprayed onto the base substrate to form a 2cm thick top layer.
[0039] After spraying, cover the sprayed area with non-woven fabric to reduce moisture evaporation and improve seed germination rate.
[0040] As a specific embodiment 3, a graded double-layer ecological water-retaining, slope-stabilizing, and revegetation substrate is composed of the following components by weight: The bottom layer contains 30 parts coconut shell fiber, 30 parts flax fiber, 20 parts natural soil, 4 parts gypsum, 0.5 parts water-retaining agent, 2 parts humic acid, 1 part binder, 10 parts fertilizer, 5 parts polyacrylamide, 4 parts zeolite, 3 parts bentonite, 8 parts seeds, and 35 parts water. The top layer contains 40 parts wood fiber, 30 parts bamboo fiber, 10 parts seaweed fiber, 20 parts natural soil, 2 parts gypsum, 0.5 parts water-retaining agent, 2 parts humic acid, 2 parts binder, 10 parts fertilizer, 12 parts seeds, and 25 parts water.
[0041] In this embodiment, the process for preparing the double-layer ecological water-retaining, slope-stabilizing, and revegetation substrate is as follows: Coconut shell fiber, flax fiber, wood fiber, bamboo fiber, and seaweed fiber are washed and dried separately to ensure that the fibers do not contain impurities.
[0042] The natural soil is sieved to remove clods larger than 5mm to ensure uniform soil particle size.
[0043] Mix coconut fiber, flax fiber, natural soil, gypsum, water-retaining agent, humic acid, binder, fertilizer, polyacrylamide, zeolite, bentonite and water in a mixer according to the specified proportions, and mix for 20 minutes to form the base substrate.
[0044] Wood fiber, bamboo fiber, seaweed fiber, natural soil, water-retaining agent, humic acid, binder, fertilizer and water are mixed in a mixer and stirred for 20 minutes to form a surface substrate.
[0045] The mixed base material is evenly sprayed onto the pretreated slope using a hydroseeding device to form a 3cm thick base layer.
[0046] After the base substrate has initially cured, the top substrate is sprayed onto the base substrate to form a 2cm thick top layer.
[0047] After spraying, cover the sprayed area with non-woven fabric to reduce moisture evaporation and improve seed germination rate.
[0048] As a specific embodiment of Comparative Example 1, Example 4 describes a graded, double-layered ecological water-retaining, slope-stabilizing, and revegetation substrate, composed of the following components by weight: The bottom layer contains 80 parts natural soil, 4 parts gypsum, 0.5 parts water-retaining agent, 1 part binder, 10 parts fertilizer, 5 parts polyacrylamide, 2 parts zeolite, 3 parts bentonite, 8 parts seeds, and 35 parts water. The top layer contains 80 parts natural soil, 0.5 parts water-retaining agent, 1-2 parts binder, 10 parts fertilizer, 12 parts seeds, and 25 parts water.
[0049] In this embodiment, the process for preparing the re-greening substrate is as follows: The natural soil is sieved to remove clods larger than 5mm to ensure uniform soil particle size.
[0050] Mix natural soil, gypsum, water-retaining agent, binder, fertilizer, polyacrylamide, zeolite, bentonite and water in a mixer and stir for 20 minutes to form a substrate.
[0051] Natural soil, gypsum, water-retaining agent, binder, fertilizer and water are mixed in a mixer and stirred for 20 minutes to form a substrate.
[0052] After spraying, cover the sprayed area with non-woven fabric to reduce moisture evaporation and improve seed germination rate.
[0053] Comparing the results of Example 3 and Comparative Example 1 through soil dispersibility tests, the substrate of Example 3 exhibited excellent particle stability in water. Even after stirring, most particles did not disperse significantly, and the amount of suspended particles in the water was minimal. The substrate of Comparative Example 1 dispersed rapidly in water, with a large number of fine particles suspended in the water. Therefore, the hydroseeding substrate of the present invention possesses stronger stability and long-lasting properties, making it suitable for harsh coastal and slope ecological restoration environments.
[0054] By comparing the results of simulated rainfall erosion tests with those of Example 3 and Comparative Example 1, the mass loss rate of the sprayed layer formed on the substrate of Example 3 under simulated rainfall erosion was 7%, significantly lower than that of Comparative Example 1, which did not employ a fiber hierarchical interlocking structure and had a mass loss rate of 15%. Therefore, this invention, through the synergistic effect of the fiber hierarchical interlocking structure and the water-retaining gel structure distributed within the fiber network, can effectively reduce the peeling and loss of the sprayed layer under rainfall erosion conditions and improve the overall stability of the sprayed layer.
[0055] Cumulative evaporation test: A 72-hour cumulative evaporation test was conducted on each example and comparative example. The results are attached. Figure 3 As shown, the evaporation rate of each embodiment is significantly lower than that of the comparative example, indicating that the hydroseeding substrate of the present invention effectively blocks the evaporation path of water through its double-layer structure and fiber network, exhibiting excellent water retention and drought resistance performance. Moisture content tests were conducted, and the results are shown in Table 1. Table 1
[0056] Note: All "moisture content" in Table 1 refers to volumetric moisture content.
[0057] Moisture content test: As shown in Table 1, the moisture content, capillary fracture moisture content, and vegetation coverage of the hydroseeding substrates (Examples 1-3) prepared using the present invention are all greater than those of Comparative Example 1. The moisture content in the examples is higher than that in the comparative example because fibers were added in the examples, allowing the wood fibers to mix with the soil and form an interlocking mesh structure. This effectively bonds with the hydroseeding surface, counteracting the erosive force of rainwater while providing moisture and fertilizer, ensuring that the resulting bottom layer is conducive to plant growth.
[0058] Seed germination rate test: Seed germination rate tests were conducted on each example and comparative example after 14 days. Results are attached. Figure 4 As shown, the seed germination rates of each embodiment are significantly higher than those of the comparative example, indicating that the double-layer hydroseeding substrate structure of the present invention can provide a more stable moisture environment in the early stage of hydroseeding, ensuring successful seed germination and thus improving the overall effectiveness of slope greening.
[0059] In summary, the double-layer hydroseeding substrate composite structure prepared by this invention blocks some of the water evaporation, effectively increases the capillary fracture water content, and enhances the water retention effect. This demonstrates that adjusting the fiber-to-soil mixing ratio in this invention is beneficial to the water retention effect of the hydroseeding substrate.
Claims
1. A graded, double-layered ecological water-retaining, slope-stabilizing, and revegetation substrate for coastal areas, characterized in that... Includes a double-layer sprayed substrate, consisting of a base layer and a surface layer; The underlying substrate includes a supportive interlocking network formed by coarse and medium fibers. The coarse fibers serve as the skeleton material and are entangled and interlocked with the medium fibers. After spraying and curing, a network of interconnected macropores with an equivalent pore size of 0.5 mm to 2.0 mm is formed to provide deep shear resistance and a channel for plant roots to penetrate. The surface substrate includes a dense network of fine fibers, which fill the gaps in the skeleton to form a microcapillary network with an equivalent pore size of 0.01 mm to 0.1 mm. This forms a hierarchical interlocking double-layer structure of fibers, creating a pore size gradient from the bottom layer to the surface layer, which is used to increase the water content at capillary fracture and reduce evaporation loss. Both the bottom substrate and the top substrate contain water-retaining agents. After absorbing water and swelling, the water-retaining agents form a gel structure. The gel structure is distributed in the pores of the fiber hierarchical interlocking network and at the fiber crossing points, and works in conjunction with the fiber network to store water, release moisture slowly, and reduce the erosion and peeling of the sprayed layer.
2. The graded double-layer ecological water-retaining, slope-stabilizing, and revegetation substrate for coastal areas according to claim 1, characterized in that, The underlying substrate comprises the following components by weight: 20-30 parts coconut shell fiber, 10-20 parts flax fiber, 40-50 parts natural soil, 2-4 parts gypsum, 0.5-1 part water-retaining agent, 2-3 parts humic acid, 1-2 parts binder, 10-15 parts fertilizer, 5-7 parts polyacrylamide, 3-5 parts zeolite, 3-5 parts bentonite, 8-12 parts seeds, and 25-35 parts water.
3. The graded double-layer ecological water-retaining, slope-stabilizing, and revegetation substrate for coastal areas according to claim 2, characterized in that, The underlying fiber network consists of a main load-bearing skeleton constructed from coconut shell fibers with a diameter of not less than 200 μm and a length of not less than 10 cm, and secondary winding of flax fibers with a diameter of not less than 100 μm. After spraying and curing, it forms a network of interconnected macropores with an equivalent pore size of 0.5 mm to 2.0 mm.
4. The graded double-layer ecological water-retaining, slope-stabilizing, and revegetation substrate for coastal areas according to claim 1, characterized in that, The surface substrate comprises, by weight, the following components: 30-40 parts wood fiber, 20-30 parts bamboo fiber, 5-10 parts seaweed fiber, 40-50 parts natural soil, 1-2 parts gypsum, 0.5-1 part water-retaining agent, 2-3 parts humic acid, 1-2 parts adhesive, 10-12 parts fertilizer, 8-12 parts seeds, and 20-25 parts water.
5. A graded double-layer ecological water-retaining, slope-stabilizing, and revegetation substrate for coastal areas according to claim 4, characterized in that, The surface fiber network is composed of wood fibers with a diameter of no more than 50 μm, bamboo fibers with a diameter of no more than 100 μm, and seaweed fibers with a diameter of 20~50 μm. After the seaweed fibers absorb water and swell, they fill the micropores formed by the overlap of wood fibers and bamboo fibers, forming a microcapillary network with an equivalent pore size of 0.01 mm~0.1 mm.
6. A graded double-layer ecological water-retaining, slope-stabilizing, and revegetation substrate for coastal areas according to any one of claims 1 to 5, characterized in that, The water-retaining agent is a polyacrylate polymer that expands in volume and forms a continuous gel structure after absorbing water. It is composed of a mixture of acrylic acid, nanocellulose crystals-g-polyacrylamide, and a crosslinking agent in a mass ratio of 1:0.02:0.00025. The crosslinking agent is polyethyleneimine, which is used to improve the water-holding capacity of the substrate and reduce moisture evaporation.
7. A graded double-layer ecological water-retaining, slope-stabilizing, and revegetation substrate for coastal areas according to any one of claims 2 to 5, characterized in that, In the substrate: The gypsum is used to neutralize sodium ions in saline-alkali soil and enhance the substrate's resistance to salting. The fulvic acid is a highly mineralized humic acid derivative that can reduce the opening of plant stomata and inhibit water transpiration. The ratio of fulvic acid to water is 1:25, and the solid product requires a fulvic acid content of ≥95%. The binder is polyvinyl alcohol, used to improve the adhesion of the mixture and its stability on the slope; The fertilizer is a compound fertilizer, and the ratio of nitrogen, phosphorus and potassium is 1:0.4:1.
3.
8. A graded double-layer ecological water-retaining, slope-stabilizing, and revegetation substrate for coastal areas according to any one of claims 2 to 5, characterized in that, In the substrate: the seeds include one or more of Bermuda grass, Bahia grass, and Imperata cylindrica.
9. A graded double-layer ecological water-retaining, slope-stabilizing, and revegetation substrate for coastal areas according to any one of claims 2 to 3, characterized in that, In the substrate: The bentonite contains >90% montmorillonite.
10. A method for spraying a substrate, characterized in that, Using the graded double-layer ecological water-retaining, slope-stabilizing, and revegetating substrate for coastal areas as described in any one of claims 1 to 9, secondary spraying repair is performed on bald patches on coastal slopes formed after typhoons, rainstorms, or human disturbances, including the following steps: Pre-treatment of bald patches on slopes: including clearing debris, leveling the slope surface, and reinforcing unstable areas; Spraying substrate preparation: Separately prepared bottom substrate and top substrate. The bottom substrate includes a supportive interlocking network formed by coarse and medium fibers, and the top substrate includes a dense covering network formed by fine fibers. Water-retaining agent is added to both the bottom substrate and the top substrate. Hydroseeding of the base substrate: Use hydroseeding equipment to evenly spray the base substrate onto the bald spots on the pretreated slope, ensuring that the substrate is in full contact with the slope surface and forms initial fixation. The spray thickness is 3cm. Hydroseeding of the top substrate: After the bottom substrate has initially cured, the top substrate is evenly sprayed onto the cured bottom substrate using hydroseeding equipment to form the final vegetation growth medium. The thickness of the spray is 2cm. Covering and protection: After spraying, cover the sprayed area with non-woven fabric to reduce moisture evaporation and prevent the seeds from being blown away by the wind.