Protective material applied to side slope as well as preparation method and application of protective material

Abstract

The invention relates to the technical field of protective materials, in particular to a protective material applied to a side slope and a preparation method and application thereof.The protective material comprises a reinforcing layer, a polymer layer, a waterproof layer and a functional layer which are sequentially connected from top to bottom, the reinforcing layer is made of a polypropylene material, the polymer layer is made of a polyester material, and the waterproof layer is made of a polypropylene material. The waterproof layer is made of a polyethylene material, and the functional layer comprises a polyester grid and a connecting layer connected between the waterproof layer and the polyester grid. The reinforcing layer can provide stable foundation support for the whole protective material, the overall bearing capacity of the protective material is effectively enhanced, the polyester grids can provide a reinforcement effect and form a good interlocking effect with a soil body, the overall stability of the slope is improved, local instability or slippage is prevented, and the service life of the slope is prolonged. The waterproof layer can prevent external water from permeating into the slope, and the adopted macromolecule layer and the connecting layer can block soil and rapidly drain water at the same time.

Description

Technical Field

[0001] The present invention relates to the technical field of protective materials, in particular to a protective material applied to a slope, and a preparation method and application thereof. Background Art

[0002] Increasing demands for environmental quality have driven profound changes in the construction industry. Against this backdrop, the construction industry, particularly slope support technology, urgently needs to develop towards more environmentally friendly and efficient approaches. Currently, traditional support structures such as soil nail walls, cast-in-place piles, underground diaphragm walls, and concrete supports are commonly used in slope engineering projects. For example, shotcrete support has a complex construction process, requiring the use of a specialized drill to drive anchor bolts, followed by the installation of a reinforced mesh surface layer in the foundation pit, followed by 5-10 cm of concrete spraying, and finally, anchor grouting.

[0003] However, traditional support methods have numerous drawbacks. They require large quantities of energy-intensive and highly polluting products such as steel and cement, significantly polluting the air, soil, and water, while also endangering the health of workers. Furthermore, they present significant challenges such as complex processes, high labor and machinery inputs, and long construction periods. With the increasing demands placed on support structure stability, deformation control, and environmental protection in high-grade slope projects, traditional support methods are no longer able to meet the requirements of ecological and green construction, hindering the development of resource-saving and environmentally friendly slope projects.

[0004] A new type of green prefabricated recyclable slope protection technology has emerged. This technology effectively protects the slope by directly covering the slope surface with a slope protection layer, supplemented by components such as T-bars, wire ropes, and recyclable concrete blocks. As an extended application of geosynthetics, this technology has significant advantages such as resource conservation, pollution reduction, and environmental protection. However, existing green prefabricated technologies also face challenges in application. Due to the relatively simple structural form of the slope protection surface layer, its structural strength, durability, and waterproof performance are not yet sufficient to fully meet actual engineering needs, which limits the widespread application of this technology in new foundation pit slope support.

[0005] Therefore, developing a slope protection material that has excellent structural strength, long-term durability and reliable waterproof performance has become an urgent need to promote the development of new green prefabricated foundation pit slope support technology. Summary of the Invention

[0006] In view of the technical problem mentioned above that in the application of the existing green new assembly technology, the slope protection surface structure is relatively simple, and its structural strength, durability and waterproof performance cannot meet the use requirements, the technical solution adopted by the present invention to solve the technical problem is: A protective material for slopes, comprising a reinforcement layer, a polymer layer, a waterproof layer, and a functional layer connected in sequence from top to bottom, wherein the reinforcement layer is made of polypropylene, the polymer layer is made of polyester, the waterproof layer is made of polyethylene, and the functional layer comprises a polyester grid and a connecting layer connected between the waterproof layer and the polyester grid.

[0007] The reinforcement layer of the present invention can provide a solid foundation support for the entire protective material, effectively enhancing the overall bearing capacity of the protective material. The polyester grid can provide reinforcement, forming a good interlocking effect with the soil, improving the overall stability of the slope, and preventing local instability or slippage. The waterproof layer can block external moisture from penetrating into the interior of the slope. The polymer layer and the connecting layer can block the soil while quickly draining water. The polypropylene, polyester, and polyethylene used in the present invention all have good recyclable and reusable characteristics, which can reduce construction waste and resource consumption.

[0008] Optionally, in some embodiments, the protective material is a flexible roll material, which can be easily stored, transported and spread, thereby improving construction efficiency and reducing storage costs.

[0009] Specifically, polypropylene is not easily corroded by chemical substances such as acids and alkalis, and can maintain stable performance for a long time in different soil environments and external environments; polyester materials can withstand the influence of natural factors such as wind, sun, temperature changes, and are not prone to aging or brittleness; polyethylene has long-lasting waterproof properties and is durable itself, and can resist erosion during long-term use, thereby extending the service life of protective materials and reducing the frequency of replacement, thereby improving the long-term effectiveness of slope support; polyester grid itself has high tensile strength, and the reinforcement provided by the grid structure forms a good interlocking effect with the soil, which can improve the overall stability of the slope and prevent local instability or slippage.

[0010] Specifically, the reinforcement layer is made of polypropylene, a material with a low density that facilitates transportation. Polypropylene also has high strength and rigidity, providing a solid foundation for the entire protective material, effectively enhancing its overall load-bearing capacity. This prevents deformation and breakage from the pressure of the slope soil and external impacts, ensuring the structural stability of the protective material within the slope support and better maintaining the stability of the slope. Polypropylene also has a hydrophobic effect, which can reduce the accumulation of moisture on the material's surface.

[0011] Specifically, the polyester grid in the functional layer further enhances structural strength. Compared to the polypropylene reinforcement layer, the polyester grid has superior mechanical properties, higher load-bearing capacity, and greater resistance to deformation. Its grid-like structure effectively disperses stress, evenly distributing the forces acting on the protective material from the slope, thus preventing damage to the protective material caused by excessive localized stress. The polyester grid, in conjunction with the reinforcement layer, significantly improves the overall tensile and compressive strength of the protective material.

[0012] Specifically, the waterproof layer is made of polyethylene, which has extremely low water permeability and can effectively block external moisture from penetrating into the slope, preventing problems such as increased moisture content and reduced shear strength in the slope soil due to water infiltration, thereby maintaining the stability of the mechanical properties of the slope soil.

[0013] Specifically, the polymer layer, located above the waterproof layer, is made of polyester with excellent weather and aging resistance, offering long-term resistance to UV rays, wind and rain erosion, and extending the slope protection's service life. Positioned between the reinforcement layer and the waterproof layer, the polymer layer serves as a bonding transition, buffering stresses, and enhancing interlayer bonding. It also allows water to pass through while blocking soil, reducing the loss of soil particles with water.

[0014] Specifically, the connecting layer is located between the polyester grid and the waterproof layer, and can play the role of bonding transition, stress buffering, and enhancing the bonding force between layers. In addition, the connecting layer can reduce the risk of sharp sand and gravel piercing the waterproof layer, and can also block the soil, thereby avoiding the wear of the waterproof layer surface when the soil particles slide, thereby extending the service life of the waterproof layer.

[0015] Optionally, in some embodiments, polypropylene, polyester, and polyethylene are all thermoplastics with excellent recyclability. Compared to traditional reinforced concrete support, the protective material of the present invention can significantly reduce the use of high-energy-consuming and highly polluting raw materials such as cement, sand, gravel, and steel, thereby reducing construction waste and resource consumption. Compared to existing protective materials, the present invention uses polyester grids to enhance the interlocking effect between the protective material and the soil layer, while also improving the overall stability of the slope through its supporting effect. The connecting layer reduces the wear of the sand, gravel, and soil on the waterproof layer, thereby extending the service life of the protective material.

[0016] Furthermore, the polymer layer is made of polyester fiber geotextile, and the polyester fiber geotextile is connected to the reinforcement layer and the waterproof layer respectively by hot pressing.

[0017] Specifically, polyester fiber geotextile serves as a polymer layer, and its porous network structure formed by interwoven fibers has a high friction coefficient and excellent planar drainage capacity, which can quickly guide water out and avoid excessive water accumulation on the slope. The hot pressing process forms a continuous sealing belt at the connection interface, completely sealing the infiltration channel between the reinforcement layer and the polyester fiber geotextile, eliminating the hidden danger of water leakage between layers. After hot pressing connection, the rigid base of the polypropylene reinforcement layer and the flexible fiber network of the polyester fiber geotextile form an interlocking structure, and the surface of the waterproof layer can be covered with a protective layer that blocks the soil. Polyester fiber geotextile has excellent chemical corrosion resistance, wear resistance and weather resistance, and can maintain good performance under long-term exposure to the external environment. There is no adhesive aging problem at the hot pressing interface, avoiding the interlayer debonding caused by ultraviolet radiation or hydrolysis in traditional bonding.

[0018] Specifically, the fibers of polyester geotextiles can be embedded in the surface of softened or heat-melted polypropylene layers, significantly increasing the shear strength between layers. The fiber ductility of polyester geotextiles can effectively disperse the tensile stress generated by slope deformation, making the composite material less susceptible to brittle failure when impacted. The vertical permeability of polyester geotextiles can quickly drain pore water that has penetrated the surface layer, preventing the accumulation of water pressure that can damage the waterproof layer. Polyester geotextiles form a stress buffer for the waterproof layer, preventing rupture of the waterproof layer due to local stress concentration. In addition, the anti-filtration function of polyester geotextiles prevents the loss of fine soil particles and maintains the stability of the slope.

[0019] Additionally, in some embodiments, polypropylene, polyester, and polyethylene are all polyolefin / polyester materials with a melting temperature range of 120-260° C., which can achieve integrated hot-melt recycling and regeneration with a recycling purity of >95%.

[0020] Furthermore, the connecting layer includes a needle-punched non-woven geotextile connected between the waterproof layer and the polyester grid, and the connecting layer is connected to the polyester grid and the waterproof layer respectively by hot pressing.

[0021] Specifically, needle-punched non-woven geotextiles simultaneously form a filter layer while guiding water, preventing the waterproof layer from being punctured by sharp aggregate, thus resolving the problem of single waterproof layers failing under the impact of backfill soil. Polyester grids provide high-strength planar tensile strength, mechanically interlocking with the soil through the grid holes, converting localized loads into uniformly distributed stress. The polyester grid creates a gap between the connecting layer and the soil, reducing the area of ​​direct contact between sharp aggregate and the connecting layer.

[0022] Optionally, in some embodiments, the needle-punched non-woven geotextile has a certain pore structure, which can block some large particles on the surface of the slope, prevent them from clogging or damaging the waterproof layer, and play a preliminary isolation and protection effect. At the same time, its pores allow fluids such as water to pass through to a certain extent, filter the water flow, and prevent soil particles from migrating with the water flow, thereby maintaining the relative stability of the soil structure of the slope and ensuring the stability of the slope. The needle-punching process causes the fibers to entangle with each other to form a high-density structure. When hot-pressed with the waterproof layer, the rough surface of the needle-punched non-woven fabric can increase the contact area with the waterproof layer. Through thermal compounding, the polyethylene molecular chains are embedded in the fiber gaps, which can provide a stronger interface bond and prevent stratification or slippage. In addition, the needle-punched cloth can also buffer the settlement differences of the backfill soil and eliminate the wrinkle stress of the waterproof layer.

[0023] Optionally, in some embodiments, the polyester grid interacts with the slope soil, and the grid of the grid can be embedded in the soil, acting as a reinforcement, increasing the shear strength of the soil, and improving the overall stability of the soil. It can constrain the lateral displacement of soil particles, making the slope soil less prone to landslides, collapses, etc. when subjected to external forces. The fiber network of the needle-punched non-woven geotextile can prevent damage caused by stress concentration at the grid nodes. The needle-punching process enables the polyester fibers and the polyester grid ribs to form structural welds, reducing the possibility of grid slippage.

[0024] Furthermore, the reinforcing layer includes homopolymer polypropylene, UV inhibitor, antioxidant, ethylene-octene copolymer POE, chopped glass fiber, colorant, β-crystal nucleating agent, calcium stearate, silicone masterbatch, PMMA microspheres, the reinforcing layer is a bidirectional grid, the UV inhibitor includes carbon black and hindered amine light stabilizer HALS 944, and the antioxidant includes antioxidant 1010 and antioxidant 168.

[0025] Specifically, homopolymer polypropylene possesses a certain strength and rigidity, providing the fundamental structural support for bidirectional grids. Its excellent crystallization properties enable the resulting grid to maintain a stable shape at room temperature, withstanding certain tension, compression, and external shear forces. In slope protection applications, it effectively constrains the displacement of soil or other reinforced materials, enhancing overall structural stability.

[0026] Specifically, chopped glass fiber boasts exceptionally high strength and modulus. Adding it to the reinforcement layer, forming a composite structure with homopolymer polypropylene, enhances the grid's tensile strength and rigidity. The glass fiber acts as a load-bearing agent within the matrix, enabling the bidirectional grid to withstand greater forces in the tensile direction. For example, when used in slope protection, it can better resist the tensile forces generated by soil sliding and water movement, thereby enhancing the slope's reinforcement.

[0027] Specifically, the addition of ethylene-octene copolymer (POE) improves the low-temperature toughness of the reinforcement layer, enhancing the material's toughness and impact resistance. When the grid is subjected to external impact, POE absorbs and disperses energy through its elastic deformation, preventing stress concentration that can cause cracks or damage in materials such as fiberglass, thereby improving the impact resistance of the bidirectional grid. Furthermore, POE blocks chloride ion penetration, reducing the risk of erosion in the reinforcement layer.

[0028] Specifically, carbon black absorbs ultraviolet light and converts it into heat, reducing its damaging effects on the material's molecular chains. The hindered amine light stabilizer HALS 944 inhibits photooxidation through various mechanisms, such as capturing free radicals and decomposing peroxides, thereby slowing the material's aging process. The synergistic effect of carbon black and hindered amine light stabilizer HALS 944 enhances the weather resistance of bidirectional grilles during long-term outdoor use, allowing them to maintain excellent physical and mechanical properties even under harsh weather conditions such as prolonged exposure to sunlight and rain, thereby extending the service life of the reinforcement layer and reducing maintenance costs.

[0029] Specifically, the combination of antioxidant 1010 and antioxidant 168 can effectively capture free radicals generated during the processing and use of the material, inhibit the occurrence of oxidation chain reactions, and prevent homopolymer polypropylene and other organic components from experiencing molecular chain breakage, material brittleness, and strength reduction due to oxidation, thereby ensuring its reliability and durability in engineering applications.

[0030] Specifically, the β-crystal nucleating agent can effectively improve the nucleation efficiency of homopolymer polypropylene, promote the formation of β-crystal form, and increase the content of β-crystals, which not only helps to improve the toughness and impact resistance of the material, but also improves the crystallization behavior of the material during the processing process, making the crystallization more uniform and fine, thereby improving the overall quality of the bidirectional grid, making it easier to operate in processing links such as stretching and forming, and obtaining products with higher dimensional accuracy and more stable performance. Moreover, the β-crystal nucleating agent can maintain toughness at low temperatures, solving the problem of brittleness of slope protection grids in cold areas in winter.

[0031] Specifically, calcium stearate can reduce friction between materials and processing equipment during processing. It neutralizes acids, allowing materials to flow more smoothly through extruders, molds, and other equipment, facilitating the formation of bidirectional grids. It also improves the surface quality of finished products, making the grid surface smoother, reducing surface defects caused by friction, and enhancing the product's appearance.

[0032] Specifically, silicone masterbatch facilitates the removal of bidirectional grille from the mold after extrusion, improving production efficiency. It also improves the material's processing fluidity, helping to better fill the mold cavity and ensure the shape and dimensional accuracy of the grille. Furthermore, it can improve the material's friction resistance to a certain extent, making the grille less susceptible to scratches during use and maintaining a good appearance.

[0033] Specifically, PMMA microspheres can enhance pore formation and wear resistance, adjusting the material's specific gravity and improving its processing properties without significantly increasing its density. During the bidirectional grid processing, they help ensure a more even mixing of the components, uniform thickness of the grid ribs, and avoid localized stress. They can also improve the grid's appearance and texture, making its surface more refined.

[0034] Specifically, the addition of colorants can impart a specific color to bidirectional grilles, thereby masking some of the color of the raw material. This not only meets the personalized color requirements of different engineering scenarios, but also allows for the differentiation of grille products of different specifications and uses by color, improving their recognition. For example, on a construction site, this allows workers to quickly and accurately identify the reinforcement layer, improving construction efficiency, while also facilitating subsequent inspection and maintenance of installed grilles.

[0035] Specifically, calculated by mass, the reinforcement layer includes 80-90 parts of homopolypropylene, 5-10 parts of ethylene-octene copolymer POE, 5-10 parts of chopped glass fiber, colorant, 0.3-0.5 parts of β-crystal nucleating agent, 0.2-0.5 parts of calcium stearate, 0.5-1 parts of silicone masterbatch, 0.5-1 parts of PMMA microspheres, 1-2 parts of carbon black, 0.5-1 parts of hindered amine light stabilizer HALS 944, 0.1-0.5 parts of antioxidant 1010, and 0.1-0.5 parts of antioxidant 168.

[0036] During the hot pressing process, at 160-180°C, the reinforcement layer is in the transition zone between the high elastic state and the viscous flow state. The β-crystal nucleating agent can increase the crystallization rate of polypropylene, and quickly rebuild the crystal network when the melt cools, further inhibiting flow deformation. Short-cut glass fiber serves as a physical support skeleton and penetrates the polypropylene matrix to form an interlocking network structure, which can maintain the macroscopic shape of the grid. Silicone masterbatch can maintain the viscoelasticity of the melt and avoid grid fracture due to cohesive fracture. PMMA microspheres are dispersed in the melt as rigid particles to form micro support points, reduce melt shrinkage, and maintain local dimensional stability. Carbon black can improve the thermal conductivity of the material, promote temperature uniformity, prevent melt collapse caused by local overheating, and protect the detailed structure of the grid. Ethylene-octene copolymer POE is an elastomer with a low melting point that can promote the diffusion and penetration of the melt at the interface, thereby filling the interface micro-gaps and improving impact toughness.

[0037] Furthermore, the polyester grid includes polyethylene terephthalate, chopped glass fiber, polyester TPU, NBR particles, antioxidant, carbodiimide stabilizer, epoxy resin, carbon black, benzotriazole, and ethylene bisstearamide. The polyester grid is a bidirectional grid, and the antioxidant includes antioxidant 1010 and antioxidant 168.

[0038] Specifically, polyethylene terephthalate has high strength and modulus, and can provide good structural support for the grid, so that it maintains a stable shape when subjected to external forces, has a certain load-bearing capacity, and maintains the stability of the overall structure.

[0039] Specifically, chopped glass fibers possess exceptional strength and rigidity. When added to polyester grids, they form a composite structure with the polyethylene terephthalate (PET) matrix, significantly improving the grid's tensile strength and overall rigidity. As a rigid filler, the glass fibers form an interfacial bond with the PET matrix. When subjected to stress, the chopped glass fibers bear the load, limiting the slippage of the PET molecular chains and sharing the stress. This allows the bidirectional grid to withstand greater forces in the tensile direction, thereby enhancing the grid's load-bearing capacity.

[0040] Specifically, polyester TPU, or thermoplastic polyurethane elastomer, possesses excellent elasticity and toughness. When the grille is subjected to external forces, it absorbs and disperses energy through its own elastic deformation, preventing stress concentration that could lead to cracks or breakage in the material and improving the grille's impact resistance and flexibility. NBR particles, or nitrile rubber particles, increase the material's toughness and elasticity. When combined with thermoplastic polyurethane elastomer, they further optimize the grille's elastic recovery and fatigue resistance, allowing it to maintain excellent mechanical properties even under long-term, repeated stress, extending its service life. Nitrile rubber particles also help the grille maintain its toughness at low temperatures, reducing the material's brittleness.

[0041] Specifically, antioxidant 1010 and antioxidant 168, when used together, effectively capture free radicals generated during material processing and use, inhibiting oxidation chain reactions and preventing molecular chain breakage, embrittlement, and strength loss in polyethylene terephthalate and other organic components due to oxidation. Antioxidant 1010 provides active hydrogen atoms to capture alkyl radicals generated by polyethylene terephthalate oxidation, interrupting the oxidation chain reaction. Antioxidant 168 preferentially reacts with (ROOH) generated by polyethylene terephthalate oxidation, breaking it down into inactive substances and reducing the source of free radicals.

[0042] Specifically, carbodiimide processing aids can be used to improve the compatibility between components. Polyethylene terephthalate contains ester bonds and is easily hydrolyzed under high temperature and high humidity conditions. Carbodiimides react with the carboxylic acids produced by hydrolysis to form stable ureide derivatives, which block the hydrolysis chain reaction.

[0043] Specifically, epoxy resin can react with the terminal hydroxyl or terminal carboxyl groups of polyethylene terephthalate to form a chemical bond; at the same time, it combines with the silane coupling agent on the surface of the glass fiber to improve the fiber-matrix interface bonding strength, and enhance the bonding force between the components during the processing. For reinforcing agents such as chopped glass fibers, it can make the bonding between them and the polyethylene terephthalate matrix stronger, ensuring that there will be no fiber pullout during the stress process, maintaining the overall structural strength of the grid. At the same time, epoxy resin can also improve the melt strength, which is beneficial to improving the molding quality of the material, so that the manufactured bidirectional grid has a regular shape and stable size.

[0044] Specifically, in addition to playing a certain role in anti-ultraviolet radiation during processing, carbon black can also improve the processing performance of the material and eliminate surface charge accumulation during high-speed extrusion.

[0045] Specifically, benzotriazole additives can enhance UV resistance and reduce molecular chain breakage and yellowing of polyethylene terephthalate under long-term light exposure.

[0046] Specifically, during the processing of polyester grilles, ethylene bisstearamide can prevent filler agglomeration and reduce the friction between the material and the processing equipment, allowing the material to flow more smoothly in extruders, molds and other equipment, facilitating the molding of bidirectional grilles. At the same time, it can also improve the surface quality of the product, making the grille surface smoother, reducing surface defects caused by friction, and improving the appearance quality of the product.

[0047] Specifically, calculated by mass, the polyester grid includes 80-90 parts of polyethylene terephthalate, 10-15 parts of chopped glass fiber, 5-10 parts of polyester TPU, 3-5 parts of NBR particles, 0.5-1 part of carbodiimide stabilizer, 1-2 parts of epoxy resin, 1-2 parts of carbon black, 0.3-0.5 parts of benzotriazole, 0.5-1 parts of ethylene bisstearamide, 0.1-0.5 parts of antioxidant 1010, and 0.1-0.5 parts of antioxidant 168.

[0048] In some embodiments, at 160-180°C, the polyester of the polyester grid can react with the maleic anhydride grafted polypropylene of the connecting layer after softening, and the polyester TPU and epoxy resin flow to form an adhesive phase that can penetrate into the connecting layer. The polypropylene fiber of the connecting layer can be connected to the hollow polyester fiber and the polyester of the polyester grid respectively through the maleic anhydride grafted polypropylene.

[0049] Furthermore, the polymer layer includes polyester, butene copolymer linear low-density polyethylene, maleic anhydride grafted polypropylene, UV inhibitor, antioxidant, carbodiimide stabilizer, epoxy resin, and nano-silica. The UV inhibitor includes hindered amine light stabilizer HALS 944, and the antioxidant includes antioxidant 1010 and antioxidant 168.

[0050] Specifically, polyester processed into hollow polyester fibers has a hollow structure that allows for rapid drainage. While maintaining a certain level of strength, the fibers can effectively reduce the overall density of the material, making the polymer layer relatively lightweight and facilitating construction, operation, and transportation. Furthermore, the fibers possess a certain degree of tensile strength and modulus, which reinforce the polymer layer and work together with other components to absorb external forces, improving the polymer layer's tensile and tear resistance. This allows the polymer layer to maintain structural integrity even when subjected to external forces such as tension and pressure generated by slope soil deformation, thereby better fulfilling its function in the protection system.

[0051] Specifically, linear low-density polyethylene (LLDPE) boasts higher strength than low-density polyethylene (LDPE) while maintaining good flexibility and tear resistance. Combined with hollow polyester fibers, it enhances the toughness of the polymer layer while enabling it to better adapt to stress changes caused by minor slope deformations. This prevents cracking and breakage caused by excessively hard and inflexible materials, improving the polymer layer's stability under complex stresses.

[0052] Additionally, in some embodiments, linear low density polyethylene can be clad to form a microporous waterproof layer.

[0053] Specifically, the anhydride groups in the maleic anhydride-grafted polypropylene have high reactivity. They can react chemically with functional groups on the surface of the hollow polyester fibers to form chemical bonds, thereby enhancing the compatibility between the polyester fibers and the polyethylene and polypropylene in the reinforcement layer, allowing them to better integrate and improve the overall performance and stability of the polymer layer. Furthermore, the methyl groups in the maleic anhydride-grafted polypropylene can entangle the linear low-density polyethylene, achieving a connection between the hollow polyester fibers, the linear low-density polyethylene, and the polypropylene in the reinforcement layer. Furthermore, they also act as a bonding agent to a certain extent, tightly bonding the various components and increasing the cohesion of the polymer layer. This ensures that component separation and structural loosening do not occur during stress, maintaining excellent mechanical properties.

[0054] Specifically, the hindered amine light stabilizer HALS 944 can delay the aging process of hollow polyester fibers, avoiding phenomena such as molecular chain breakage, yellowing, and brittleness of the material caused by ultraviolet rays.

[0055] Specifically, antioxidant 1010 and antioxidant 168 are used together to efficiently capture free radicals generated during the processing and use of materials, inhibit the occurrence of oxidation chain reactions, and prevent hollow polyester fibers, butene copolymer linear low-density polyethylene, maleic anhydride grafted polypropylene and other organic components from experiencing molecular chain breakage, material brittleness, and strength reduction due to oxidation.

[0056] Specifically, the carbodiimide stabilizer can react with the carboxyl groups produced by the hydrolysis of the hollow polyester fiber, inhibiting the further progress of the hydrolysis reaction and protecting the molecular chain structure of the hollow polyester fiber, so that the entire polymer layer can maintain good mechanical properties and stability in a water environment, thereby extending its service life.

[0057] Specifically, epoxy resin strengthens the bonding between components during processing, particularly between hollow polyester fibers and other polymer components, ensuring a stronger bond and preventing loose fibers or fiber shedding under stress. This maintains the structural strength of the polymer layer. At high temperatures, epoxy resin forms a partially cross-linked structure with the anhydride groups in maleic anhydride-grafted polypropylene, enhancing creep resistance. The addition of nanosilica increases the rigidity of the second masterbatch coating and inhibits shrinkage.

[0058] Specifically, calculated by mass, the polymer layer includes 75-85 parts of hollow polyester fiber, 15-20 parts of butene copolymer linear low-density polyethylene, 5-10 parts of maleic anhydride grafted polypropylene, 0.5-1 parts of hindered amine light stabilizer HALS 944, 0.1-0.5 parts of antioxidant 1010, 0.1-0.5 parts of antioxidant 168, 0.5-1 parts of carbodiimide stabilizer, 1-2 parts of epoxy resin, and 0.5-1 parts of nano-silica.

[0059] In some embodiments, butene copolymer linear low-density polyethylene and maleic anhydride grafted polypropylene are coated on the surface of the hollow polyester fiber. At 160-180°C, the butene copolymer linear low-density polyethylene and maleic anhydride grafted polypropylene melt and penetrate into the interior of the hollow polyester fiber to form a mechanical interlock. Part of the maleic anhydride grafted polypropylene can connect the butene copolymer linear low-density polyethylene, the hollow polyester fiber and the homopolymer polypropylene of the reinforcement layer, thereby improving the bonding strength between the reinforcement layer and the polymer layer.

[0060] Specifically, the needle-punched non-woven geotextile includes polyester, polypropylene, maleic anhydride grafted polypropylene, an anti-ultraviolet agent, an antioxidant, a carbodiimide stabilizer, an epoxy resin, and nano-silica. The anti-ultraviolet agent includes a hindered amine light stabilizer HALS 944, and the antioxidant includes antioxidant 1010 and antioxidant 168.

[0061] Specifically, hollow polyester fibers made from polyester have a hollow structure that allows for rapid drainage. They also have high strength and good chemical stability, providing good mechanical support for geotextiles, making them less susceptible to tearing and damage when subjected to external forces such as tension, thereby maintaining structural integrity. Polypropylene fibers made from polypropylene have the characteristics of light weight, relatively low cost, and good water resistance. Furthermore, the contact angle of polypropylene fibers is greater than 130°, which can act as a hydrophobic and water-conducting agent. The combined use of the two allows geotextiles to meet certain strength requirements while also optimizing their economy and water resistance. Even in environments exposed to moisture for long periods, they can still maintain their stable structure and performance.

[0062] Specifically, the anhydride group in maleic anhydride grafted polypropylene has a high reactivity. It can react chemically with functional groups such as hydroxyl groups on the polyester surface to form chemical bonds, thereby enhancing the compatibility between polyester and polypropylene, allowing the two materials with poor compatibility to be better integrated together, forming a bridge structure to reduce slippage between fibers, improve the cohesive strength of the fiber mesh during the needle punching process, and avoid delamination during use. In addition, the methyl chain in maleic anhydride grafted polypropylene can entangle the polypropylene fibers, reducing the problem of delamination at the interface between polyester and polypropylene, thereby improving the overall performance and stability of the needle-punched non-woven geotextile. At the same time, it can also improve the bonding ability between the needle-punched non-woven geotextile and the polyester grid and waterproof layer to a certain extent, making the connection between the layers more compact, working synergistically, and enhancing the integrity of the entire protective structure.

[0063] Specifically, the hindered amine light stabilizer HALS 944 can delay the aging process of hollow polyester fibers, avoiding phenomena such as molecular chain breakage, yellowing, and brittleness of the material caused by ultraviolet rays.

[0064] Specifically, antioxidant 1010 and antioxidant 168 are used together to efficiently capture free radicals generated during the processing and use of materials, inhibit the occurrence of oxidation chain reactions, and prevent hollow polyester fibers, maleic anhydride grafted polypropylene and other organic components from experiencing molecular chain breakage, material brittleness, and strength reduction due to oxidation.

[0065] Specifically, the carbodiimide stabilizer can react with the carboxyl groups produced by the hydrolysis of the hollow polyester fiber, inhibiting the further progress of the hydrolysis reaction and protecting the molecular chain structure of the hollow polyester fiber, so that the entire polymer layer can maintain good mechanical properties and stability in a water environment, thereby extending its service life.

[0066] Specifically, epoxy resin enhances the bonding strength between components during processing, especially the bonding between hollow polyester fibers and other polymer components, making the bonding stronger and ensuring that the fibers do not become loose or fall off during stress, thereby maintaining the structural strength of the polymer layer. Epoxy resin can form a partially cross-linked structure with the anhydride groups in maleic anhydride-grafted polypropylene at high temperatures, thereby improving creep resistance. Nano-silica is used to prevent hot-pressing migration of hollow polyester fibers.

[0067] Specifically, calculated by mass, the needle-punched non-woven geotextile includes 50-60 parts of hollow polyester fiber, 30-40 parts of polypropylene fiber, 3-8 parts of maleic anhydride grafted polypropylene, 0.5-1 part of carbodiimide stabilizer, 1-2 parts of epoxy resin, 1-2 parts of nano-silica, 0.5-1 part of hindered amine light stabilizer HALS 944, 0.1-0.5 part of antioxidant 1010, and 0.1-0.5 part of antioxidant 168.

[0068] In some embodiments, at 155-165°C, the polypropylene fiber is connected to the activated maleic anhydride grafted polypropylene and together with the reinforced softened hollow polyester fiber, during the hot pressing process, part of the maleic anhydride grafted polypropylene can connect the polypropylene fiber, the hollow polyester fiber and the polyester ester group of the polyester grid, thereby improving the bonding strength between the connecting layer and the polyester grid.

[0069] Furthermore, the waterproof layer includes high-density polyethylene, butene copolymer linear low-density polyethylene, ethylene-octene copolymer POE, silicone masterbatch, maleic anhydride grafted polyethylene, erucamide, and zinc stearate.

[0070] Specifically, high-density polyethylene itself has the characteristics of high crystallinity and high density, which makes its molecular chains arranged tightly, forming an effective barrier structure, and has excellent water blocking ability. It has high strength and good rigidity, can withstand a certain amount of pressure and tension, and is not easily torn or damaged, thereby ensuring that the waterproof layer can continue to maintain a good waterproof barrier function during long-term use and effectively prevent water penetration.

[0071] Specifically, butene copolymer linear low-density polyethylene (LLDPE) has a moderate degree of crystallinity, and its linear molecular chain structure imparts excellent flexibility and tear resistance, while also offering higher strength than low-density polyethylene. When used in conjunction with high-density polyethylene (HDPE), while ensuring sufficient strength in the waterproof layer, it further optimizes its flexibility, enabling it to better adapt to minor deformations in the base layer. For example, even on curved slopes or surfaces subject to slight deformation due to foundation settlement, it maintains a close fit with the base layer, preventing leakage caused by deformation-induced rupture of the waterproof layer and strengthening the overall waterproofing effect.

[0072] Ethylene-octene copolymer (POE) exhibits excellent elasticity and flexibility. When incorporated into a waterproof layer, it absorbs and disperses energy through its elastic deformation when subjected to external forces, preventing stress concentration that could cause cracks or damage in the waterproof layer, thereby enhancing the waterproof layer's impact resistance and toughness. Furthermore, POE improves the overall flexibility of the material and lowers the low-temperature catalytic temperature of high-density polyethylene (HDPE). This allows it to more easily adhere to various substrate surfaces during laying. Furthermore, even with dynamic changes in the substrate over long-term use, the waterproof layer can adapt accordingly, maintaining its integrity and waterproofing performance.

[0073] Specifically, the anhydride group in maleic anhydride grafted polyethylene has high reactivity. It can react chemically with high-density polyethylene, butene copolymer linear low-density polyethylene, etc. to form chemical bonds, which enhances the compatibility between the polyethylene components and helps promote the interfacial bonding strength of other polymers, forming a more uniform and stable material system, thereby avoiding delamination and cracking due to poor internal compatibility of the material when under stress, ensuring that the waterproof layer maintains structural stability when subjected to external forces such as tension and pressure, and continues to play a waterproof role.

[0074] Specifically, silicone masterbatch imparts excellent surface slip, scratch resistance, and mold release properties to the waterproof layer. During the processing of the waterproof layer material, such as when extruding it into a film, it facilitates the material's release from the mold, improving production efficiency. It also improves the material's processing fluidity, helping it to better fill the mold cavity and ensure the shape and dimensional accuracy of the waterproof layer product.

[0075] Specifically, during the processing of the waterproof layer, erucamide can reduce the friction between the material and the processing equipment, making the material flow more smoothly in the extruder, mold and other equipment, facilitating the molding operation, and helping to obtain a waterproof layer product with a smooth surface and uniform quality.

[0076] Specifically, zinc stearate can improve the processing properties of materials, enhancing their fluidity and reducing processing energy consumption. It also refines grain size and increases density, helping to enhance the appearance of waterproofing products, creating a smoother surface and reducing surface defects. During construction, it can also reduce the friction coefficient between the waterproofing layer and the base layer, as well as between adjacent materials, facilitating the installation of the waterproofing layer and subsequent connection operations, ensuring a smooth construction process.

[0077] Specifically, calculated by mass, the waterproof layer includes 60-70 parts of high-density polyethylene, 25-30 parts of butene copolymer linear low-density polyethylene, 10-15 parts of ethylene-octene copolymer POE, 1-1.5 parts of silicone masterbatch, 3-4 parts of maleic anhydride grafted polyethylene, 0.5-1 part of erucamide, and 0.3-0.5 part of zinc stearate.

[0078] Specifically, in some embodiments, when the connecting layer is connected to the waterproof layer, at 120°C, the maleic anhydride grafted polyethylene is in a viscoelastic state, and the maleic anhydride grafted polypropylene is in a highly elastic state. At 130°C, the maleic anhydride grafted polyethylene is in a molten state, and the maleic anhydride grafted polypropylene is in a highly elastic state. The anhydride groups on its surface have high reactivity, and the maleic anhydride grafted polyethylene can react with the functional groups on the polyester surface to fill the interface gap through the ethylene-octene copolymer POE.

[0079] Optionally, in some embodiments, some of the unreacted maleic anhydride grafted polypropylene can react with the maleic anhydride grafted polyethylene after activation to form a cross-linked network between polyolefins.

[0080] Specifically, in some embodiments, when the polymer layer is connected to the waterproof layer, part of the butene copolymer linear low-density polyethylene is melted and connected to the maleic anhydride grafted polyethylene, and the maleic anhydride grafted polyethylene can react with the functional groups on the polyester surface, thereby improving the connectivity between the polymer layer and the waterproof layer.

[0081] Optionally, in some embodiments, a portion of the unreacted maleic anhydride grafted polypropylene can react with a portion of the unreacted maleic anhydride grafted polyethylene after activation to form a cross-linked network between polyolefins.

[0082] Another object of the present invention is to provide a method for preparing a protective material for slopes, comprising the protective material as described above, comprising the following steps: S1. Prepare the reinforcement layer, polymer layer, waterproof layer, connecting layer and polyester grid respectively; Specifically, the strengthening layer preparation method is: M1. Weigh the materials and mix them evenly: Add homopolymer polypropylene, ethylene-octene copolymer POE, UV inhibitor, antioxidant, and colorant to the mixer in proportion and stir at 300 rpm for 1 minute for preliminary mixing. Gradually add β-crystal nucleating agent, calcium stearate, silicone masterbatch, and PMMA microspheres and stir at 1000 rpm for 5 minutes. Finally, add 3-6 mm long chopped glass fibers and stir at 500 rpm for 2 minutes to prevent the chopped glass fibers from breaking. Soak the PMMA microspheres and chopped glass fibers in 1% silane coupling agent KH550 at 40°C for 2 hours to improve the interfacial bonding ability. M2, melt blending and extrusion to obtain masterbatch: the premixed raw materials are melt blended through a twin-screw extruder to produce polypropylene particles containing functional additives. The temperature of the feed section in section 1 is controlled at 160-170°C to avoid premature melting and ensure feed stability; the temperature of the compression section in section 2 is controlled at 190-200°C, at which time the mixture begins to melt, which can promote dispersion; the temperature of the melting section in section 3 is 190-200°C; the temperature of the homogenization section in section 4 is controlled at 205-210°C, and the mixture is fully melted and mixed to reach a uniform state; the temperature of the die is controlled at 205-215°C to ensure that the melt pressure is stable to avoid overheating and degradation. After the molten material is extruded through the die, it is water-cooled and pelletized; M3, Masterbatch Melt-Stretch Molding: The dried granules from step M2 are melted through an extruder, extruded through a die into a grid prototype, and then stretched and oriented to form a bidirectional structure. The extrusion temperature is 190-210°C, the longitudinal stretching temperature is 120-130°C, the stretching ratio is 4-5 times, and the speed is 5-10 m / min. The transverse stretching temperature is 130-135°C, the stretching ratio is 4-6 times, and the speed is synchronized. The heat setting temperature is 120-130°C for 3-5 minutes to eliminate internal stress. The cooling method is to cool naturally to room temperature to avoid shrinkage and deformation caused by sudden cooling. The grid size is then cut as required.

[0083] Wherein, the waterproof layer preparation method is: N1. Use a high-speed mixer to dry-mix all the raw materials, melt blend them, and extrude them through a twin-screw extruder. The temperature is set from the feed port to the die head: the temperature of the feed section of section 1 is 155°C; the temperature of the compression section of section 2 is 165°C; the temperature of the melting section of section 3 is 175°C; the temperature of the homogenization section of section 4 is 170°C; the die head temperature is controlled at 170-180°C; and a pelletizer is used to form granules; due to the low melting point of the overall waterproof layer material, the temperature setting of step N1 can reduce the decomposition of erucamide and reduce the decrease in the molecular weight of the ethylene-octene copolymer POE.

[0084] N2. The prepared waterproof layer pellets are melted and plasticized through a single-screw extruder, and the melt is extruded into sheets through a T-die. The melt temperature is 170-180°C, and the die temperature is 170-180°C. The die temperature is set in this range to avoid the deactivation of the anhydride group. The film is quickly cooled and shaped on a cooling roller. The cooling roller temperature is 20-40°C.

[0085] Wherein, the polyester grid preparation method is: P1. Premix the raw materials and use a mixer to evenly disperse the components. Add polyethylene terephthalate, carbon black, benzotriazole, and antioxidant to the mixer in proportion and stir at 300 rpm for 1 minute for preliminary mixing. Gradually add thermoplastic polyurethane elastomer, nitrile rubber particles, carbodiimide stabilizer, epoxy resin, and ethylene bisstearamide and stir at 1000 rpm for 5 minutes. Finally, add 3-6 mm long chopped glass fibers and stir at 300 rpm for 2 minutes to prevent the chopped glass fibers from breaking. Soak the chopped glass fibers in 1% silane coupling agent KH550 at 40°C for 2 hours to improve interfacial bonding. P2, melt blending extrusion, twin-screw extruder, wherein the temperature of the feed section in section 1 is 240-250°C; the temperature of the compression section in section 2 is 260-270°C; the temperature of the melting section in section 3 is 265-270°C; the temperature of the homogenizing section in section 4 is 270-275°C; the die head temperature is 270-275°C; a pelletizer is used to form granules; the die head temperature is controlled to avoid excessively high temperature to prevent degradation of polyethylene terephthalate.

[0086] P3: The dried granules from step P2 are melted through an extruder and extruded through a die into a grid prototype. The product is then stretched and oriented to form a bidirectional structure. The extrusion temperature is 265-275°C, the longitudinal stretching temperature is 95-110°C, the stretch ratio is 3-4 times, and the speed is 8-12 m / min. The transverse stretching temperature is 100-115°C, the stretch ratio is 3.5-4.5 times, and the speed is synchronized to prevent premature crystallization. Heat setting is performed at a temperature of 130-135°C for 120-180 seconds to eliminate internal stress, complete crystallization relaxation, and stabilize the dimensions. The product is cooled naturally to room temperature to avoid shrinkage and deformation caused by sudden cooling. The product is then cut to the desired grid size.

[0087] Wherein, the preparation method of the polymer layer is: Calculated by weight, the polymer layer includes 75-85 parts of polyester, 10-15 parts of butene copolymerized linear low-density polyethylene, 3-8 parts of maleic anhydride grafted polypropylene, 0.5-1 parts of hindered amine light stabilizer HALS 944, 0.1-0.5 parts of antioxidant 1010, 0.1-0.5 parts of antioxidant 168, 0.5-1 parts of carbodiimide stabilizer, 0.5-1 parts of epoxy resin, and 0.5-1 parts of nano-silicon dioxide; Q1. Polyester is mixed with carbodiimides and some anti-UV agents at high speed (1000 rpm, 5 minutes), melt-blended, and extruded in a twin-screw extruder at a temperature of 240-260°C and a screw speed of 150-200 rpm to produce the first masterbatch; butene copolymerized linear low-density polyethylene, maleic anhydride grafted polypropylene, antioxidant, some anti-UV agents, epoxy resin, and nano-silica are melt-blended and extruded in a twin-screw extruder at a temperature of 190-210°C and a screw speed of 150-200 rpm to produce the second masterbatch for later use; Q2, polyester melt spinning, processed into hollow polyester fiber non-woven fabric base fabric; the surface of the base fabric is coated with 0.5% polyurethane coupling agent, the spray amount is 2-5g / m², and dried at 80℃ for 2min to improve the interface adhesion; Q3. Preheat the base fabric at 80-95°C to improve bonding strength and prevent deformation of the hollow fiber. Add the second masterbatch to the single-screw extruder for melting and plasticization at a temperature of 190-200°C for extrusion into a film to activate the interfacial chemical reaction. Apply the coating synchronously through the twin extruders at a lamination roller temperature of 90-110°C. The molten film is adhered to the surface of the moving polyester base fabric under pressure with a coating amount of 20-50g / m². Use step cooling, first air-cooling to 100°C for initial solidification, then slowly cooling to room temperature in a 50°C drying oven to eliminate stress and obtain a polymer layer.

[0088] Wherein, the preparation method of the connecting layer is: T1, polyester, carbodiimide, part of the anti-ultraviolet agent, and nano-silica are mixed at high speed (1000 rpm, 5 minutes) and melt-blended in a twin-screw extruder at a temperature of 240-260°C and a screw speed of 150-200 rpm to produce a first masterbatch; polypropylene, maleic anhydride grafted polypropylene, antioxidant, part of the anti-ultraviolet agent, and epoxy resin are melt-blended in a twin-screw extruder at a temperature of 180-200°C and a screw speed of 150-200 rpm to produce a third masterbatch for standby use; T2. The first masterbatch was spun to produce hollow polyester fibers; the third masterbatch was spun to produce polypropylene fibers; the first masterbatch was spun at a temperature of 270-275°C, and the third masterbatch was spun at a temperature of 200-210°C. The hollow polyester fibers were preheated to 95°C, with a hot air relaxation time of 1-2 minutes and a humidity of 30% RH. To improve web formation and eliminate curl stress, a 0.5% maleic anhydride-grafted polypropylene ethanol solution was sprayed on the polypropylene fiber surface to increase the interfacial connection strength between the hollow polyester fiber and the polypropylene fiber; T3: Hollow polyester fibers and polypropylene fibers are mixed into a web, needle-punched for reinforcement, and then hot-air bonded and heat-set to create the connecting layer. The needle-punching density is 180-220 punches / cm², the needle depth is 2-7mm, and the hot-air bonding temperature is 165-170°C at a wind speed of 15m / s for 30 seconds to prevent excessive softening of the hollow polyester fibers. The heat setting temperature is 125°C, and the hot-air treatment lasts for two minutes to eliminate internal stress and stabilize the dimensions.

[0089] S2, the reinforcement layer and the polymer layer are connected by hot pressing to form a first composite layer, and the hot pressing temperature is between 160-180°C; S3. The connecting layer and the polyester grid are connected by hot pressing to form a second composite layer, and the hot pressing temperature is between 155-165°C; S4, hot pressing the second composite layer and the waterproof layer to form a third composite layer, the hot pressing temperature is between 120-130 ° C; S5. The first composite layer and the third composite layer are connected by hot pressing to form a protective material. The hot pressing temperature is between 120-130° C.

[0090] Specifically, by hot pressing and laminating, the reinforcing layer, polymer layer, waterproof layer, connecting layer and polyester grid are connected together, so that a tight bond is formed between the layers, avoiding delamination and displacement of the layers during use. Under appropriate hot pressing temperatures, the molecular structure of the material can be adjusted to a certain extent, for example, making the crystallization of some polymer materials more uniform, improving the material's strength, hardness and other performance indicators, and also helping to eliminate some minor defects that may exist within the material, improving the overall quality of the material. The reinforcing layer can enhance the overall mechanical properties, the polymer layer assists in connection and can have a buffering effect, the waterproof layer can prevent water penetration, the connecting layer ensures a good connection between the layers, and the polyester grid interacts with the slope soil to enhance friction and interlocking force, thereby improving stability. Together, they enhance the protective effect of the protective material on the slope, enabling it to more effectively respond to stress changes in the slope soil, external loads and environmental factors, and maintain the stability of the slope.

[0091] Specifically, the hot pressing temperature of 160-180°C in step S2 is suitable for the fusion of the reinforcing layer and the polymer layer, which can enable the molecular chains of the two to move appropriately and penetrate each other at this temperature to form a strong connection, which not only ensures the smooth progress of the hot pressing process, but also does not damage the material performance due to excessive temperature; similarly, the temperature of 120-130°C in steps S4 and S5 is used for hot pressing and compounding the polymer layer, the waterproof layer and the connecting layer, so that the waterproof layer can fit well with the adjacent layers and keep its waterproof function unaffected, and step S3 uses a temperature of 155-165°C for hot pressing for 30-60 seconds. On the one hand, it will not cause the polypropylene fiber to melt and deform, and on the other hand, it can activate the interface of the maleic anhydride grafted polypropylene, so that the connecting layer is tightly connected to the polyester grid, ensuring that the entire protective material has a stable structure from the inside to the outside, and the synergistic effect of each layer achieves the best effect.

[0092] Specifically, this step-by-step preparation method involves fabricating each layer separately before hot-pressing and laminating them. This allows the majority of the manufacturing process to be completed in a relatively controlled environment, ensuring the quality and stability of the protective material while minimizing the negative impacts of complex construction site conditions (such as weather and dust) on material production. Furthermore, once the prefabricated protective material is transported to the construction site, only relatively simple operations such as laying and installation are required. This significantly improves construction efficiency and shortens construction schedules, making it particularly convenient for large-scale slope protection projects.

[0093] Another object of the present invention is to provide an application of a protective material, including the protective material as described above, which is applied to foundation pit support engineering of a slope.

[0094] Specifically, the protective material used in this invention utilizes an assembled installation method that eliminates extensive on-site wet work, such as concrete spraying and grouting, reducing dust, noise, and water pollution. This multi-layer composite material can be pre-produced into standardized rolls in the factory, making on-site installation convenient and efficient, significantly shortening construction timelines, reducing labor and heavy machinery investment, and mitigating construction safety risks.

[0095] Specifically, the polypropylene grid and polyester grid in the protective material have a grid-like structure, which can play a reinforcing role in the slope soil. They interlock and rub with the soil, effectively dispersing the stress on the soil, improving the shear strength of the soil, and restraining the lateral displacement of the soil, thereby enhancing the overall stability of the slope, effectively preventing the slope from sliding and collapsing due to factors such as the weight of the soil and external loads, and ensuring the safety of the surrounding area of ​​the foundation pit and the entire project. The layers of protective materials are closely coordinated, and the polyester fiber geotextile and needle-punched non-woven geotextile can make the connection between the layers more stable, synergizing the reinforcement effect of the grid and the waterproof function of the waterproof layer to form an organic whole, further enhancing the reinforcement effect of the slope soil, so that the slope can still maintain a stable structure under complex stress conditions. The waterproof layer can effectively block the infiltration of external moisture and prevent rainwater, groundwater and other water bodies from penetrating into the slope soil. Polyester fiber geotextiles, needle-punched non-woven geotextiles, etc. have certain water permeability and anti-filtration functions. While allowing water to be discharged, they can prevent soil particles from being lost with water, play a role in drainage and pressure reduction, reduce the risk of slope instability caused by water accumulation, keep the moisture in the slope soil in a reasonable state, and ensure the stability of the slope during long-term use.

[0096] Specifically, antioxidants and UV inhibitors added to the protective material impart excellent weather resistance and antioxidant capabilities, enabling it to withstand the harsh effects of long-term outdoor exposure to sunlight, rain, and temperature fluctuations, preventing premature aging and performance degradation. The synergistic effect of these components ensures that the protective material maintains its desired mechanical and waterproof properties for an extended period of time, thereby extending the service life of the foundation pit support project and reducing the cost and workload of frequent repairs and replacements.

[0097] Recyclable polypropylene and polyester can be recycled after use in the project, thereby reducing solid waste pollution to the environment and achieving resource recycling. The geotextiles and grids of protective materials have certain flexibility and operability. They are relatively easy to unfold, position and fix when laid on the slope. They can complete construction quickly according to design requirements, improve construction efficiency, and reduce construction period. Especially for large-scale slope support projects, their construction convenience advantage can be better reflected. This protective material can be appropriately adjusted and applied according to different slope gradients, soil conditions, etc., and has good adaptability. Whether it is a relatively gentle slope or a steep slope, or a slope with different soil types such as sand, clay, etc., it can play a corresponding protective role through reasonable laying methods and fixing methods, reducing the difficulty of construction and dependence on special construction technology.

[0098] The construction methods of foundation pit support engineering are: V1. Prefabricate the top and bottom of the slope, excavate the earth, trim the slope, and insert reinforcement; V2, protective material paving, joint connection, snap kit and wire rope connection; V3. Construction of flanging at the top and bottom of the slope, installation of standardized safety guardrails, construction of drainage holes, and support recycling.

[0099] Specifically, the protective material is made of flexible coiled material. For step V2, the coil size of the protective material is first determined. The protective material is manually rolled. The slope surface should be flat, and an appropriate deformation margin should be left. The upper surface layer of the protective material is the reinforcement layer. The overlap of the surface layer is connected using stainless steel self-locking flat clips. The overlap width of the surface layer is 0.3m, and the spacing between the stainless steel self-locking flat clips is 500mm. It is fixed by soil nails. The ends of the soil nails are connected using longitudinal and transverse steel wire ropes. The ends of the soil nails are tied together using butterfly-shaped clips, thus forming a flexible prefabricated surface foundation pit support system with high tensile strength, waterproofness, and coordinated deformation capabilities. The protective material has water discharge and filtration functions. Drain holes are set on the slope surface, forming a drainage system with the drainage ditches at the top and bottom of the slope of the support structure to enhance the stability of the slope. The width of the slope top should be consistent. After the protective material, soil nails, and steel wire ropes are applied, precast concrete blocks are used to press the flanges of the protective material surface layer.

[0100] The top edge of the slope should be ≥ 800mm, and the toe edge should be ≥ 300mm. Protective material should be rolled from the top of the slope. During staged excavation, cut the material according to the drawings and actual on-site excavation conditions to minimize horizontal overlap and reduce material loss. Adjacent sections of the protective material surface layer should be overlapped using stainless steel flat clips, with a width of ≥ 300mm.

[0101] The beneficial effects of the present invention are as follows: 1) The reinforcement layer of the present invention can provide a solid foundation support for the entire protective material, effectively enhancing the overall bearing capacity of the protective material. The polyester grid can provide reinforcement, forming a good interlocking effect with the soil, improving the overall stability of the slope, and preventing local instability or slippage. The waterproof layer can block external moisture from penetrating into the interior of the slope. The polymer layer and connecting layer used can block soil while quickly draining water. The polypropylene, polyester, and polyethylene used in the present invention are all recyclable and reusable, which can reduce construction waste and resource consumption.

[0102] 2) The controllable and stable preparation method of this invention ensures the consistent quality of the protective material. The compact structure formed by hot-pressing and the good synergy between the layers ensure that the protective material maintains its integrity and the functionality of each layer even under long-term exposure to complex outdoor environments. The layers of material will not easily separate or damage, the waterproof layer maintains its waterproofing properties, and the reinforcement layer and polyester grid provide continuous mechanical support, thereby extending the service life of the protective material.

[0103] 3) The protective material used in the present invention is applied to foundation pit support projects on slopes. Its prefabricated installation method itself avoids on-site wet operations, which can reduce dust, noise and water pollution. The multi-layer composite material can be pre-produced into standardized rolls in the factory, and on-site laying and installation are convenient and efficient, significantly shortening the construction period, reducing the investment in manpower and large machinery, and lowering construction safety risks. DETAILED DESCRIPTION

[0104] In order to make those skilled in the art more clearly understand the technical solutions of the present invention, the following examples are given for illustration. Unless otherwise specified, the raw materials, reagents or devices used in the following embodiments can be obtained from conventional commercial channels or can be obtained by existing known methods.

[0105] A method for preparing a protective material for slopes, comprising the protective material as described above, comprising the following steps: S1. Prepare the reinforcement layer, polymer layer, waterproof layer, connecting layer and polyester grid respectively; S2, the reinforcement layer and the polymer layer are connected by hot pressing to form a first composite layer, and the hot pressing temperature is between 160-180°C; S3. The connecting layer and the polyester grid are connected by hot pressing to form a second composite layer, and the hot pressing temperature is between 155-165°C; S4, hot pressing the second composite layer and the waterproof layer to form a third composite layer, the hot pressing temperature is between 120-130 ° C; S5. The first composite layer and the third composite layer are connected by hot pressing to form a protective material. The hot pressing temperature is between 120-130° C.

[0106] Specifically, the ethylene-octene copolymer POE uses Dow POE 8137 from the United States, and the β-crystal nucleating agent uses nucleating agent TMB-5; the ethylene-octene copolymer POE uses Dow POE 8137 from the United States, the high-density polyethylene uses Dow polyethylene particles 3364 from the United States, and the butene copolymer linear low-density polyethylene uses Borealis butene copolymer monomer linear low-density polyethylene FG5190; the polyester TPU uses Wanhua Chemical WHT-1190, the NBR particles use Mingyuan Plastics' carboxyl NBR particles, and the benzotriazole uses ultraviolet absorber UVP; the polypropylene uses S1005 homopolymer polypropylene.

[0107] The strengthening layer preparation method is as follows: Calculated by mass, the reinforcement layer includes 85 parts of homopolypropylene, 5 parts of ethylene-octene copolymer POE, 5 parts of chopped glass fiber, 0.2 parts of colorant, 0.3 parts of β-crystal nucleating agent, 0.2 parts of calcium stearate, 0.5 parts of silicone masterbatch, 0.5 parts of PMMA microspheres, 1 part of carbon black, 0.5 parts of hindered amine light stabilizer HALS 944, 0.2 parts of antioxidant 1010, and 0.3 parts of antioxidant 168.

[0108] M1. Weigh the materials and stir evenly. Add homopolypropylene, ethylene-octene copolymer (POE), UV inhibitor, antioxidant, and colorant to the mixer in proportion. Stir at 300 rpm for 1 minute to initially mix. Gradually add β-crystal nucleating agent, calcium stearate, silicone masterbatch, and PMMA microspheres, stirring at 1000 rpm for 5 minutes. Finally, add 5mm chopped glass fiber, stirring at 500 rpm for 2 minutes. Soak the PMMA microspheres and chopped glass fiber in 1% silane coupling agent KH550 at 40°C for 2 hours. M2. Melt blending and extrusion to obtain masterbatch: The premixed raw materials are melt blended through a twin-screw extruder to produce PP particles containing functional additives. The temperature of the feed section in section 1 is controlled at 165°C; the temperature of the compression section in section 2 is controlled at 190°C; the temperature of the melting section in section 3 is controlled at 195°C; the temperature of the homogenization section in section 4 is controlled at 205°C; and the temperature of the die is controlled at 210°C. After the molten material is extruded through the die, it is water-cooled and pelletized into strands; M3, Masterbatch Melt-Stretch Molding: The dried granules from step M2 are melted in an extruder, extruded through a die into a grid prototype, and then stretched and oriented to form a bidirectional structure. The extrusion temperature is 205°C, the longitudinal stretching temperature is 120°C, the stretch ratio is 4x, and the speed is 5 m / min; the transverse stretching temperature is 130°C, the stretch ratio is 5x, and the speed is matched simultaneously. Heat setting is performed at 130°C for 3 minutes. Cooling is performed naturally to room temperature, and the grid is then cut to the desired size.

[0109] Wherein, the waterproof layer preparation method is: Calculated by mass, the waterproof layer includes 65 parts of high-density polyethylene, 25 parts of butene copolymer linear low-density polyethylene, 10 parts of ethylene-octene copolymer POE, 1 part of silicone masterbatch, 4 parts of maleic anhydride grafted polyethylene, 0.5 parts of erucamide, and 0.3 parts of zinc stearate.

[0110] N1. Use a high-speed mixer to dry-blend all the raw materials, melt-blend them, and extrude them through a twin-screw extruder. Set the temperature from the feed port to the die head: Section 1, feed section temperature 155°C; Section 2, compression section temperature 165°C; Section 3, melting section temperature 175°C; Section 4, homogenization section temperature 170°C; the die head temperature is controlled at 170°C; and pelletizer is used to form pellets. N2. The prepared waterproof layer pellets are melted and plasticized by a single-screw extruder, and the melt is extruded into sheets through a T-die with a melt temperature of 170°C and a die temperature of 175°C. The sheets are quickly cooled and shaped into films on a cooling roller with a cooling roller temperature of 25°C.

[0111] Wherein, the polyester grid preparation method is: Calculated by mass, the polyester grid includes 85 parts of polyethylene terephthalate, 10 parts of chopped glass fiber, 5 parts of polyester TPU, 3 parts of NBR particles, 0.5 parts of carbodiimide, 1 part of epoxy resin, 2 parts of carbon black, 0.3 parts of benzotriazole, 0.5 parts of ethylene bisstearamide, 0.2 parts of antioxidant 1010, and 0.3 parts of antioxidant 168; P1. Premix the raw materials. Add polyester grid including polyethylene terephthalate, polyester TPU, NBR particles, carbodiimide stabilizer, epoxy resin, carbon black, benzotriazole, ethylene bisstearamide, antioxidant 1010, and antioxidant 168 into the mixer to evenly disperse the components. Then add chopped glass fiber at a low speed and stir. The chopped glass fiber is first soaked in 1% silane coupling agent KH550 at 40°C for 2 hours to improve the interfacial bonding ability. P2, melt blending extrusion, twin-screw extruder, wherein the temperature of section 1, feed section, is 240°C; the temperature of section 2, compression section, is 260°C; the temperature of section 3, melting section, is 265°C; the temperature of section 4, homogenization section, is 270°C; the temperature of die head is 275°C; pelletizer is used to produce pellets; P3. The dried granules in step P2 are melted through an extruder, extruded through a die into a grid prototype, and then stretched and oriented to form a bidirectional structure; the extrusion temperature is 275°C, the longitudinal stretching temperature is 105°C, the stretching ratio is 3 times, and the speed is 10 m / min; the transverse stretching temperature is 110°C, the stretching ratio is 3.5 times, the speed is synchronously matched, the heat setting temperature is 135°C, and the time is 120 seconds; the cooling method is natural cooling to room temperature, and the grid size is cut as required.

[0112] Wherein, the preparation method of the polymer layer is: Calculated by mass, the polymer layer includes 75 parts of polyethylene terephthalate, 15 parts of butene copolymer linear low-density polyethylene, 10 parts of maleic anhydride grafted polypropylene, 0.5 parts of hindered amine light stabilizer HALS 944, 0.2 parts of antioxidant 1010, 0.3 parts of antioxidant 168, 0.5 parts of carbodiimide, 1 part of epoxy resin, and 0.5 parts of nano-silicon dioxide; Q1, polyester and carbodiimide, 0.2 parts of anti-UV agent were mixed at high speed (1000 rpm, 5 minutes), melt blended, and extruded in a twin-screw extruder at a temperature of 240°C and a screw speed of 150 rpm to produce the first masterbatch; butene copolymerized linear low-density polyethylene, maleic anhydride grafted polypropylene, antioxidant, remaining anti-UV agent, epoxy resin, and nano-silica were melt blended in a twin-screw extruder at a temperature of 200°C and a screw speed of 170 rpm to produce the second masterbatch for standby use; Q2, polyester melt spinning, processed into hollow polyester fiber non-woven fabric base fabric; the surface of the base fabric is coated with 0.5% polyurethane coupling agent, the spray amount is 3g / m², and dried at 80℃ for 2min to improve the interface adhesion; Q3. Preheat the base fabric to 95°C. Add the second masterbatch into a single-screw extruder for melting and plasticization at 190°C. Extrusion into a film is performed by a twin extruder for simultaneous coating. The lamination roller temperature is 105°C. The molten film is adhered to the surface of the moving polyester base fabric under pressure. The coating amount is 30g / m². Step cooling is adopted. First, air cool to 100°C to form an initial solidification. Then, it is slowly cooled to room temperature in a 50°C drying room to eliminate stress to obtain a polymer layer.

[0113] Wherein, the preparation method of the connecting layer is: Calculated by mass, the connecting layer includes 60 parts of polyethylene terephthalate, 40 parts of polypropylene, 8 parts of maleic anhydride grafted polypropylene, 0.5 parts of carbodiimide, 1 part of epoxy resin, 1 part of nano-silica, 0.5 parts of hindered amine light stabilizer HALS 944, 0.2 parts of antioxidant 1010, and 0.3 parts of antioxidant 168.

[0114] T1, polyester, carbodiimide, 0.2 parts of anti-UV agent, and nano-silica were mixed at high speed (1000 rpm, 5 minutes) and melt-blended in a twin-screw extruder at a temperature of 240°C and a screw speed of 150 rpm to prepare a first masterbatch; polypropylene, maleic anhydride grafted polypropylene, antioxidant, remaining anti-UV agent, and epoxy resin were melt-blended in a twin-screw extruder at a temperature of 190°C and a screw speed of 150 rpm to prepare a third masterbatch for standby use; T2. The first masterbatch was spun to produce hollow polyester fibers; the third masterbatch was spun to produce polypropylene fibers; the first masterbatch was spun at 270°C, the third masterbatch was spun at 200°C, the hollow polyester fibers were preheated to 95°C, the hot air relaxation time was 1-2 minutes, the humidity was 30% RH, and a 0.5% maleic anhydride-grafted polypropylene ethanol solution was sprayed on the surface of the polypropylene fibers; T3, hollow polyester fiber to polypropylene fiber mix ratio of 6:4, airflow velocity: 15-20 m / s (hollow polyester fiber) / 8-12 m / s (polypropylene fiber), fiber drop height: 1.2-1.5 m, ionization rod voltage: ±6 kV, ambient humidity: 45-50% RH, air-laid to produce a three-dimensional interlaced fiber, needle-punched reinforcement, hot air bonding, and heat setting to produce the connecting layer. Pre-needling density: 80 punches / cm², 4 mm depth; main needle punch density: 180 punches / cm², 7 mm depth; fine needle punch density: 80 punches / cm², 2 mm depth; hot air bonding temperature: 165°C, air velocity: 15 m / s, time: 30 seconds; heat setting temperature: 125°C, and hot air treatment for two minutes.

[0115] Based on the above content, the following are specific embodiments of the present invention: Example 1 The method for preparing the protective material comprises the following steps: S1. Prepare the reinforcement layer, polymer layer, waterproof layer, connecting layer and polyester grid respectively; S2. The reinforcement layer and the polymer layer are connected by hot pressing to form a first composite layer at a hot pressing temperature of 160°C; S3, the connecting layer and the polyester grid are connected by hot pressing to form a second composite layer, and the hot pressing temperature is 155°C; S4, hot pressing the second composite layer and the waterproof layer to form a third composite layer, the hot pressing temperature is 120 ° C; S5. The first composite layer and the third composite layer are connected by hot pressing to form a protective material, and the hot pressing temperature is 120°C.

[0116] According to GB / T 17689-2022 and GB / T 13763-2010, in Example 1, the thickness of the reinforcement layer is 2 mm, the longitudinal tensile strength of the reinforcement layer is 80 kN / m, the transverse tensile strength is 65 kN / m, the elongation at break (longitudinal / transverse) is ≤8% / ≤8%, and the tear strength is 1000 N.

[0117] According to GB / T 17689-2022 and GB / T 13763-2010, in Example 1, the polyester grid has a thickness of 2.5 mm, a longitudinal tensile strength of 100 kN / m, a transverse tensile strength of 70 kN / m, an elongation at break (longitudinal / transverse) ≤8% / ≤8%, and a tear strength of 1050N.

[0118] According to GB / T 13761-2021 and GB / T 15788-2017, in Example 1, the polymer layer has a thickness of 1.5 mm, a longitudinal tensile strength of 8 kN / m, a transverse tensile strength of 6 kN / m, an elongation at break (longitudinal / transverse) ≤25% / ≤25%, and a tear strength of 350 N. According to GB / T 19979.1-2005, the permeability coefficient is 1×10 -2 cm / s, according to GB / T 17631-2023, UV aging resistance 500h, strength retention rate after UV irradiation 85%, according to GB / T 17632-2018, hydrolysis resistance (humid heat aging), strength retention rate 80%.

[0119] According to GB / T 13761-2021 and GB / T 15788-2017, in Example 1, the thickness of the connecting layer is 2 mm, the longitudinal tensile strength of the connecting layer is 7 kN / m, the transverse tensile strength is 5.5 kN / m, the elongation at break (longitudinal / transverse) is ≤30% / ≤28%, the tear strength is 320 N, and according to GB / T 19979.1-2005, the permeability coefficient is 1×10 -2 cm / s, according to GB / T 17631-2023, UV aging resistance 500h, strength retention rate after UV irradiation 83%, according to GB / T 17632-2018, hydrolysis resistance (humid heat aging), strength retention rate 82%.

[0120] According to GB / T 1040.2 and GB / T 16578.1-2008, in Example 1, the tensile strength of the waterproof layer is 25 MPa, the elongation at break is 350%, the tear strength is 70 N, and the thickness of the waterproof layer is 0.2 mm. According to GB / T 1037-2021, the permeability coefficient is 1.8×10 -11 g·cm / (cm 2 ·s·Pa), according to GB / T 16422.3-2022, UV aging resistance 500h, strength retention rate after UV irradiation 86%, according to GB / T 12000-2017, hydrolysis resistance (humid heat aging), strength retention rate 92%. According to ASTM E96, water vapor transmission rate 0.8g / m²×10 -12 d, according to GB / T 19979.1, hydrostatic pressure resistance 420 kPa. According to GB / T 19979.1-2005, liquid permeability coefficient is 1.0×10 -12 cm / s.

[0121] Example 2 The difference between the second embodiment and the first embodiment is that: The preparation method of the protective material comprises the following steps, with different hot pressing temperatures.

[0122] S1. Prepare the reinforcement layer, polymer layer, waterproof layer, connecting layer and polyester grid respectively; S2, the reinforcement layer and the polymer layer are connected by hot pressing to form a first composite layer, and the hot pressing temperature is 180°C; S3, the connecting layer and the polyester grid are connected by hot pressing to form a second composite layer, and the hot pressing temperature is 165°C; S4, hot pressing the second composite layer and the waterproof layer to form a third composite layer, the hot pressing temperature is 130 ° C; S5. The first composite layer and the third composite layer are connected by hot pressing to form a protective material, and the hot pressing temperature is 130° C.

[0123] Example 3 The difference between the third embodiment and the first embodiment is that the hot pressing temperature is different.

[0124] S1. Prepare the reinforcement layer, polymer layer, waterproof layer, connecting layer and polyester grid respectively; S2, the reinforcement layer and the polymer layer are connected by hot pressing to form a first composite layer, and the hot pressing temperature is 175°C; S3, the connecting layer and the polyester grid are connected by hot pressing to form a second composite layer, and the hot pressing temperature is 160°C; S4, hot pressing the second composite layer and the waterproof layer to form a third composite layer, the hot pressing temperature is 125 ° C; S5. The first composite layer and the third composite layer are connected by hot pressing to form a protective material, and the hot pressing temperature is 125° C.

[0125] Example 4 The difference between Example 4 and Example 1 is that the preparation order in steps S3 to S5 is different.

[0126] A method for preparing a protective material, comprising the protective material as described above, comprises the following steps: S1. Prepare the reinforcement layer, polymer layer, waterproof layer, connecting layer and polyester grid respectively; S2. The reinforcement layer and the polymer layer are connected by hot pressing to form a first composite layer at a hot pressing temperature of 160°C; S3, hot pressing the first composite layer and the waterproof layer to form a second composite layer, the hot pressing temperature is 120°C; S4. The second composite layer and the connecting layer are hot-pressed and connected to form a third composite layer. The hot-pressing temperature is 120° C. S5. The third composite layer and the polyester grid are hot-pressed and connected to form a protective material, and the hot-pressing temperature is 155° C.

[0127] Example 5 The difference between Example 5 and Example 1 is that the preparation order in step S4-step S5 is different.

[0128] The method for preparing the protective material comprises the following steps: S1. Prepare the reinforcement layer, polymer layer, waterproof layer, connecting layer and polyester grid respectively; S2. The reinforcement layer and the polymer layer are connected by hot pressing to form a first composite layer at a hot pressing temperature of 160°C; S3, the connecting layer and the polyester grid are connected by hot pressing to form a second composite layer, and the hot pressing temperature is 155°C; S4, hot pressing the first composite layer and the waterproof layer to form a third composite layer, the hot pressing temperature is 120 ° C; S5. The second composite layer and the third composite layer are connected by hot pressing to form a protective material, and the hot pressing temperature is 120°C.

[0129] Example 6 Example 6 differs from Example 1 in that, in the polymer layer, a polyester blend and a butene copolymerized linear low-density polyethylene blend are melt-spun. The hollow polyester fibers and butene copolymerized linear low-density polyethylene fibers are mixed in a mass ratio of 7:3 to form a web, needle-punched, and reinforced. The connecting layer is then hot-air bonded and heat-set. The needle-punching density is 180-220 punches / cm², the needle depth is 2-7mm, and the hot-air bonding temperature is 165-170°C at a wind speed of 15m / s for 30 seconds to prevent softening of the hollow polyester fibers. The heat-setting temperature is 125°C, and the hot-air bonding lasts for two minutes.

[0130] Table 1 Overall waterproof performance test results of Examples 1 to 6

[0131] The protective materials of Examples 1, 2, and 3 have better effects such as water vapor permeability, hydrostatic pressure resistance, and permeability coefficient than those of Example 4. Compared with Example 1, the hot pressing temperature of 155°C used in the S5 stage of Example 4 is too high, and the waterproof layer is sandwiched in the middle at this time; at this high temperature, the waterproof layer with a melting point of approximately 130 to 140°C will soften or even melt, resulting in structural damage or delamination, or the connection between the waterproof layer and the polymer layer or the connecting layer is not strong enough; after aging, its waterproof performance is prone to failure and deterioration.

[0132] In Example 1, because the tie layer contains polypropylene and the polymer layer contains butene copolymerized linear low-density polyethylene, the compatibility between the tie layer and the waterproof layer is worse than that between the polymer layer and the waterproof layer. The waterproof layer is first heat-pressed with the tie layer, and then the waterproof layer and the tie layer are first connected. When the waterproof layer and the polymer layer are connected, the waterproof layer is heated a second time to connect to the polymer layer. The heated waterproof layer can reconnect to the tie layer, thereby improving the connection between the waterproof layer and the tie layer and ensuring the connection between the waterproof layer and the polymer layer. Compared to Example 1, in Example 5, the waterproof layer is first connected to the polymer layer and then to the tie layer. The polymer layer contains butene copolymerized linear low-density polyethylene and maleic anhydride-grafted polypropylene, which can react first with the maleic anhydride-grafted polyethylene in the waterproof layer. However, because the maleic anhydride-grafted polyethylene reacts first, some of the hollow polyester and maleic anhydride-grafted polypropylene in the tie layer react with the remaining maleic anhydride-grafted polyethylene, resulting in the tie layer, which has a poorer compatibility, not being able to connect well with the polymer layer, resulting in a deterioration in its anti-leakage effect during subsequent aging.

[0133] In Example 1, the butene copolymer linear low-density polyethylene mixture is coated on the surface of the hollow polyester fiber. Since the melting point of the butene copolymer linear low-density polyethylene and the maleic anhydride grafted polypropylene is higher than that of the butene copolymer linear low-density polyethylene and the maleic anhydride grafted polypropylene during hot pressing, the butene copolymer linear low-density polyethylene and the maleic anhydride grafted polypropylene can fill part of the interior of the hollow polyester fiber, thereby forming a partial waterproof layer, and can be mechanically interlocked with the hollow polyester fiber. Compared with Example 1, the butene copolymer linear low-density polyethylene mixture spinning fiber in Example 6 melts, causing the hollow polyester fiber structure to collapse and deform. Due to the curling and deformation of the polymer layer, the connection stability between the polymer layer and the waterproof layer is affected, resulting in the deterioration of its waterproof effect during subsequent aging.

[0134] The reinforcement layer of the present invention can provide a solid foundation support for the entire protective material, effectively enhancing the overall bearing capacity of the protective material. The polyester grid can provide reinforcement, forming a good interlocking effect with the soil, improving the overall stability of the slope, and preventing local instability or slippage. The waterproof layer can block external moisture from penetrating into the interior of the slope. The polymer layer and connecting layer used can block the soil while quickly draining water. The polypropylene, polyester, and polyethylene used in the present invention all have good recyclable characteristics, which can reduce construction waste and resource consumption.

[0135] The controllable and stable preparation method of the present invention ensures the consistent quality of the protective material. The compact structure formed by hot-pressing and the good synergy between the layers ensure that the protective material maintains its integrity and the functions of each layer even under long-term exposure to complex outdoor environments. The layers of material will not easily separate or damage, the waterproof layer maintains its waterproofness, and the reinforcement layer provides continuous mechanical support, thereby extending the service life of the protective material.

[0136] The protective material used in the present invention is applied to foundation pit support projects on slopes. Its assembled installation method itself avoids on-site wet operations, can reduce dust, noise and water pollution, and the multi-layer composite material can be pre-produced into rolls or plates in the factory in a standardized manner. On-site laying and installation are convenient and efficient, significantly shortening the construction period, reducing manpower and large-scale machinery investment, and reducing construction safety risks.

[0137] The above examples are merely provided to further illustrate the technical content of the present invention for easier understanding by the reader, but do not limit the embodiments of the present invention to these examples. Any extension or re-creation of the technology based on the present invention is protected by the present invention. The scope of protection of the present invention shall be determined by the claims.

Claims

1. A protective material for slopes, characterized by: It includes a reinforcement layer, a polymer layer, a waterproof layer, and a functional layer connected in sequence from top to bottom. The reinforcement layer is made of polypropylene, the polymer layer is made of polyester, the waterproof layer is made of polyethylene, and the functional layer includes a polyester grid and a connecting layer connected between the waterproof layer and the polyester grid.

2. The protective material for slope application according to claim 1, characterized in that: The polymer layer is made of polyester fiber geotextile, and the polyester fiber geotextile is connected to the reinforcement layer and the waterproof layer respectively by hot pressing.

3. The protective material for slope application according to claim 1, characterized in that: The connecting layer comprises a needle-punched non-woven geotextile connected between the waterproof layer and the polyester grid, and the connecting layer is respectively connected to the polyester grid and the waterproof layer by hot pressing.

4. The protective material for slope application according to claim 1, characterized in that: The reinforcing layer includes homopolypropylene, an anti-ultraviolet agent, an antioxidant, ethylene-octene copolymer POE, chopped glass fiber, a colorant, a β-crystal nucleating agent, calcium stearate, a silicone masterbatch, and PMMA microspheres. The reinforcing layer is a bidirectional grid. The anti-ultraviolet agent includes carbon black and hindered amine HALS 944. The antioxidant includes antioxidant 1010 and antioxidant 168.

5. The protective material for slope application according to claim 1, characterized in that: The polyester grid includes polyethylene terephthalate, chopped glass fiber, thermoplastic polyurethane elastomer, nitrile rubber particles, antioxidant, carbodiimide stabilizer, epoxy resin, carbon black, benzotriazole, and ethylene bisstearamide. The polyester grid is a bidirectional grid, and the antioxidant includes antioxidant 1010 and antioxidant 168.

6. The protective material for slope application according to claim 1, characterized in that: The polymer layer includes polyester, butene copolymer linear low-density polyethylene, maleic anhydride grafted polypropylene, anti-ultraviolet agent, antioxidant, carbodiimide stabilizer, epoxy resin, and nano-silica. The anti-ultraviolet agent includes hindered amine HALS 944, and the antioxidant includes antioxidant 1010 and antioxidant 168.

7. The protective material for slope application according to claim 1, characterized in that: The connecting layer includes polyester, polypropylene, maleic anhydride grafted polypropylene, an anti-ultraviolet agent, an antioxidant, a carbodiimide stabilizer, an epoxy resin, and nano-silica. The anti-ultraviolet agent includes carbon black and hindered amine HALS 944. The antioxidant includes antioxidant 1010 and antioxidant 168.

8. The protective material for slope application according to claim 1, characterized in that: The waterproof layer comprises high-density polyethylene, butene copolymer linear low-density polyethylene, ethylene-octene copolymer POE, silicone masterbatch, maleic anhydride grafted polyethylene, erucamide, and zinc stearate.

9. A method for preparing a protective material for slope application, comprising the protective material according to any one of claims 1 to 8, characterized in that: The following steps are included: S1. Prepare the reinforcement layer, polymer layer, waterproof layer, connecting layer and polyester grid respectively; S2, the reinforcement layer and the polymer layer are connected by hot pressing to form a first composite layer, and the hot pressing temperature is between 160-180°C; S3. The connecting layer and the polyester grid are connected by hot pressing to form a second composite layer, and the hot pressing temperature is between 155-165°C; S4, hot pressing the second composite layer and the waterproof layer to form a third composite layer, the hot pressing temperature is between 120-130 ° C; S5. The first composite layer and the third composite layer are connected by hot pressing to form a protective material. The hot pressing temperature is between 120-130° C.

10. A use of a protective material, comprising the protective material according to any one of claims 1 to 8, characterized in that: This protective material is used in foundation pit support projects on slopes.

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