A method for repairing gravel curtain layers in photovoltaic areas based on modified plant fiber consolidation.

Abstract

This invention discloses a method for repairing a gravel curtain layer in photovoltaic areas based on modified plant fiber consolidation, belonging to the field of gravel curtain layer repair technology. It achieves on-site resource utilization of aggregates by screening in-situ gravel mixtures in the photovoltaic field, constructing a self-interlocking structure of gravel-coarse sand-fine sand in a 4:3:1 mass ratio; combining transverse anti-slip grooves and anchoring pits to enhance the interface's anti-slip ability; employing layered spreading of fine-grained material followed by coarse-grained material and light vibration compaction to form a dense "gravel-sand" skeleton; then, through a two-stage spraying process of initial penetration anchoring and subsequent cross-linking enhancement, a 3-5mm thick continuous, high-strength, crack-resistant composite solidification layer is generated; finally, multispectral imaging non-destructive testing and targeted spraying are used to achieve controllable quality and long-term stability throughout the entire process, significantly improving the ecological, durable, and construction reliability of the gravel curtain layer repair in photovoltaic areas.

Description

Technical Field

[0001] This invention relates to the field of gravel curtain layer repair technology, specifically to a method for repairing photovoltaic area gravel curtain layers based on modified plant fiber consolidation. Background Technology

[0002] Photovoltaic power plants are typically built in windy and sandy areas such as the Gobi Desert. The original gravel layer on the surface is a natural anti-erosion structure formed by long-term wind erosion, playing a vital role in resisting wind erosion, suppressing dust, and maintaining surface stability. However, during the excavation of photovoltaic array foundations, construction of cable trenches, and compaction by maintenance vehicles, the original gravel layer is often extensively damaged, leading to exposed ground. This, in turn, intensifies wind erosion, causes dust storms, and accumulates dust on the photovoltaic panels, seriously affecting the power plant's power generation efficiency and ecological safety. Therefore, the scientific restoration of the damaged gravel layer in photovoltaic areas has become a crucial step in the ecological restoration of Gobi desert photovoltaic power plants.

[0003] Currently, existing gravel curtain layer repair methods mostly adopt two approaches: simple artificial gravel covering or cement (or chemical binder) consolidation. The artificial gravel covering method usually only relies on single-size or simply mixed gravel for paving, resulting in a loose covering layer with high porosity. Under wind erosion and rainwater erosion, gravel peeling and overall structural collapse can easily occur, making it difficult to form a stable anti-corrosion layer. While cement or chemical binders can bond gravel and sand into a cohesive whole, cement-based materials are highly alkaline and brittle, easily shrinking and cracking after curing. They also have poor compatibility with the soil environment in photovoltaic areas, leading to damage and detachment of the hard shell layer with long-term use. Furthermore, traditional chemical binders are mostly petroleum-based polymers that are not biodegradable, releasing volatile organic compounds (VOCs) during construction, polluting the environment and the surface of photovoltaic modules, which does not meet the requirements of green and low-carbon ecological restoration. At the same time, conventional one-time spraying of consolidation grout is difficult to achieve both deep penetration and anchoring and surface film sealing, often resulting in a phenomenon of "surface crusting and internal looseness." The bonding force between the consolidated layer and the original foundation is weak, and the interface is prone to slippage or delamination.

[0004] Therefore, there is an urgent need to develop a method for repairing the gravel curtain layer in photovoltaic areas that can achieve integrated deep anchoring and surface consolidation, and is easy to inspect and maintain, in order to solve the technical problems existing in the above-mentioned prior art. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a method for repairing photovoltaic zone gravel curtain layers based on modified plant fiber consolidation.

[0006] This invention discloses a method for repairing a photovoltaic zone gravel curtain layer based on modified plant fiber consolidation, comprising the following steps: S1, Material Allocation The in-situ gravel mixture in the photovoltaic field is screened in multiple stages using a screening device to obtain gravel, coarse sand and fine sand of various particle size gradients. Then, the gravel, coarse sand and fine sand are grouped and prepared in a mass ratio of 4:3:1 for later use. S2, Surface treatment The ground surface was cleaned and leveled according to the direction of the photovoltaic array, and transverse anti-slip grooves and anchoring pits with micro-topographic features were constructed on the leveled ground surface. S3, Material Spreading First, mix the coarse sand and fine sand in S1, then spread and level it using a layered spreading process, then cover it with gravel, and compact it using a light vibrating device, so that the coarse sand and fine sand fully fill the gaps between the gravel, thereby constructing a "gravel-sand" interlocking skeleton layer. S4, modified plant fiber dual-stage spraying Initial spraying stage: Spray modified plant fiber slurry to penetrate deep into the bottom of the gravel-sand interlocking framework layer and form anchor bolts. The spraying rate of modified plant fiber slurry is 0.75-1.1 kg / m³. 2 ; Re-spraying stage: After the initial sprayed modified plant fiber slurry has cured for 4-6 hours, a film-like solidified layer forms on the surface and within the pores of the "gravel-sand" interlocking skeleton layer. Then, a reinforced modified plant fiber slurry containing 3-5% crosslinking agent is sprayed to fill the film-like solidified layer. Subsequently, a curing treatment is performed for 24-72 hours to generate a composite cured layer with a thickness of 3-5 mm. The spraying rate of the reinforced modified plant fiber slurry is 0.88-1.05 kg / m³. 2 ; S5. Quality Inspection and Maintenance Multispectral image recognition was used to test the integrity and strength of the composite curing layer, and substandard areas were repaired by spraying.

[0007] Furthermore, the gravel has a particle size gradient of 10-12mm and 12-15mm, the coarse sand has a particle size gradient of 1-2mm and 2-3mm, and the fine sand has a particle size of 0.08-0.5mm. When the gravel, coarse sand, and fine sand are mixed as aggregates, the mass ratio of gravel with a particle size of 10-12mm, gravel with a particle size of 12-15mm, coarse sand with a particle size of 1-2mm, coarse sand with a particle size of 2-3mm, and fine sand is 2:2:1.5:1.5:1.

[0008] Explanation: 10-12mm and 12-15mm gravel serve as the core of the framework, forming a stable interlocking structure to support the overall load-bearing capacity of the gravel curtain layer; 1-2mm and 2-3mm coarse sand fill the medium pores between the gravel, reducing the space for loosening of the framework; 0.08-0.5mm fine sand fills the remaining fine pores. The multi-level particle size interlocking structure reduces porosity, ensuring the integrity after subsequent paving and compaction, and providing a reasonable channel for the infiltration of modified plant fiber slurry. It takes into account both the air permeability and consolidation strength of the gravel curtain layer, and is suitable for the surface load requirements and rainwater infiltration and drainage requirements of the photovoltaic area.

[0009] Furthermore, in S2, several of the transverse anti-slip grooves are distributed in a mesh pattern, and several of the anchoring pits are located in the grid areas enclosed by the mesh pattern. The cross-section of the transverse anti-slip groove is an inverted trapezoid. The groove depth is 5-7cm, the top width is 8-12cm, and the bottom width is 4-6cm. The bottom of the groove is compacted to form a rough surface. The depth and diameter of the anchoring pit are both 10-12cm.

[0010] Explanation: On the already leveled Gobi Desert surface, transverse anti-slip grooves and anchoring pits are artificially created to alter the surface's smoothness, forming a rough interface and mechanical interlocking structure. After the subsequent modified plant fiber slurry and gravel mixture are laid and cured, these transverse anti-slip grooves and anchoring pits will embed themselves into the bottom of the repair layer like barbs or tenons, thereby significantly increasing the anti-slip capacity and shear strength between the repair layer and the original soil layer. The dimensional parameters of the grooves and anchoring pits are designed in conjunction with the surface load, soil properties, and slurry penetration depth of the photovoltaic area, ensuring both anti-slip and anchoring effects while avoiding excessive excavation that could damage the original surface structure, and also adapting to the thickness requirements of subsequent layered paving.

[0011] Further, in S2, after cleaning the surface according to the photovoltaic array orientation, the salt content of the original soil layer is tested using the conductivity method. When the salt content of the original soil layer is >1%, shallow loosening is performed using a disc rake or spiked rake to a depth of 3-5cm. Then, a modified starch adhesive with a mass fraction of 1-3% is sprayed onto the loosened surface to allow it to penetrate into the surface of the loosened soil layer and form a bonding transition layer. Subsequently, leveling is carried out and the transverse anti-slip grooves and anchoring pits are constructed. The spraying amount of modified starch adhesive is 1.2-1.8L / m². 2 .

[0012] Note: When the salt content is >1%, salt tends to crystallize and compact on the soil surface, which will seriously affect the solidification effect of the subsequent modified plant fiber slurry and reduce the bonding strength between the gravel curtain layer and the ground surface. Therefore, the conductivity method is first used to quickly and accurately detect the salt content of the original soil layer, and targeted treatment measures can be taken. The depth of shallow loosening is controlled at 3-5cm, which can break up the compacted layer and release the salt in the soil without excessively disturbing the deep soil structure and avoiding surface subsidence. Spraying modified starch adhesive can utilize its good adhesion and permeability to form a uniform bonding transition layer on the surface of the loose soil layer. On the one hand, it can fix the loose surface soil and prevent sanding during subsequent leveling and spreading; on the other hand, it can prevent the salt in the soil layer from penetrating into the "gravel-sand" skeleton layer, avoid the interference of salt on the solidification reaction of the modified plant fiber slurry, and at the same time improve the bonding force between the base surface and subsequent materials, laying a stable foundation for the repair of the gravel curtain layer.

[0013] Furthermore, after spraying modified starch adhesive onto the surface of the shallowly loosened soil, static compaction is performed using a lightweight rubber roller, and the surface is covered with non-woven geotextile to retain moisture for 2-4 hours.

[0014] Instructions: After spraying the modified starch adhesive, light static pressure is applied to ensure full contact and penetration of the adhesive with the loose soil layer. This prevents the adhesive from forming a skin on the surface without proper penetration. Simultaneously, it compacts the surface soil, enhancing the density and stability of the bonding transition layer. This ensures effective connection between the transition layer and the original soil layer, as well as the subsequent gravel-sand layer. Covering with non-woven geotextile for 2-4 hours to maintain moisture provides a suitable humidity environment for the initial curing of the modified starch adhesive. This prevents cracking and peeling caused by rapid evaporation, ensuring the adhesive fully cures and forms a continuous and complete bonding transition layer. This avoids problems such as loosening and delamination of the subsequent gravel curtain layer due to poor transition layer quality.

[0015] Furthermore, in S4, the dynamic viscosity of the modified plant fiber slurry in the initial spraying stage is 50-150 mPa·s at 25°C, and the dynamic viscosity of the reinforced modified plant fiber slurry in the supplementary spraying stage is 200-800 mPa·s at 25°C.

[0016] Explanation: The core purpose of the initial spraying stage is to allow the grout to penetrate to the bottom of the "gravel-sand" interlocking skeleton layer to form anchor bolts. Therefore, the grout viscosity needs to be controlled between 50-150 mPa·s (25℃). This viscosity range ensures that the grout has good fluidity and permeability, allowing it to smoothly penetrate the gaps in gravel and coarse sand, reaching the bottom of the skeleton layer and the anchoring pits on the ground surface. The core of the supplementary spraying stage is to form a film-like consolidation layer on the surface and within the pores of the skeleton layer, and to fill the pores to form a composite curing layer. Therefore, the grout viscosity needs to be increased to 200-800 mPa·s (25℃). Higher viscosity makes the grout less prone to flow, allowing it to adhere stably to the surface of the skeleton layer, filling small pores and forming a continuous and dense film structure. At the same time, it complements the anchor bolts formed by the initial spraying, improving the integrity and strength of the composite curing layer, and meeting the erosion and crush resistance requirements of the gravel curtain layer in photovoltaic areas.

[0017] Furthermore, in S4, the crosslinking agent is an aqueous solution of glutaraldehyde or epichlorohydrin.

[0018] Note: Glutaraldehyde or epichlorohydrin is selected as the crosslinking agent. The core is to utilize their excellent crosslinking reaction performance to react with the active groups in the modified plant fiber slurry to form a three-dimensional network structure, thereby significantly improving the curing strength, water resistance and anti-aging properties of the slurry.

[0019] Furthermore, in S4, the curing process adopts a staged curing method, specifically including the following steps: S4-1. Allow the reinforced modified plant fiber slurry to stand and cure for 12-24 hours at 20-25℃ and 60%-70% relative humidity to initially bond and fuse with the membrane-like consolidation layer, forming a stable preliminary consolidation structure. S4-2. Continue curing at 28-30℃ and relative humidity of 50%-60% for 24-40 hours. During this period, spray the moisturizing mixture with a mist every 8 hours to replenish the moisture evaporated during the curing process. The moisturizing mixture is composed of water, propylene glycol and polyvinyl alcohol in a mass ratio of 100:1-3:0.3-0.8. S4-3. Reduce the ambient temperature to 22-24℃ and restore the relative humidity to 60%-70% for constant temperature slow condensation.

[0020] Note: A phased curing method is adopted instead of one-time curing. The core is to avoid defects such as cracking, shrinkage, and hollowing of the composite cured layer due to excessive curing speed and large fluctuations in temperature and humidity, so as to ensure its integrity and strength stability. S4-1 is the initial curing stage, which controls the temperature at 20-25℃ and the relative humidity at 60%-70%. This allows the reinforced modified plant fiber slurry to slowly and fully bond and fuse with the film-like solidified layer, gradually forming a preliminary stable structure. S4-2 is the strength enhancement stage, which appropriately increases the temperature to 28-30℃ and decreases the humidity to 50%-60%. This can accelerate the cross-linking reaction and improve the strength and density of the cured layer. At the same time, a specific ratio of moisturizing mixture is sprayed every 8 hours to replenish the moisture evaporated during the curing process and prevent the cured layer from cracking due to lack of water.

[0021] Furthermore, in S4-1, S4-2, and S4-3, by adjusting the tilt angle of the photovoltaic panels in the corresponding gravel curtain layer repair area of ​​the photovoltaic array, the reflected light from the photovoltaic panel surface accurately covers the surface and surrounding area of ​​the "gravel-sand" interlocking skeleton layer to be cured, thereby utilizing the thermal radiation effect of the reflected light to maintain the temperature of the repair area.

[0022] Explanation: The surface of the photovoltaic panel has a certain ability to reflect light. By adjusting the tilt angle of the photovoltaic panel, the reflected light can be precisely directed to the gravel curtain layer area to be cured. Utilizing the thermal radiation effect of the reflected light, the temperature conditions required for curing can be stably maintained, avoiding the impact of outdoor temperature fluctuations (such as low temperature or large temperature difference between day and night) on the curing effect. Especially in low outdoor environments, this method can effectively increase the local temperature of the repair area, ensuring that the cross-linking reaction proceeds normally. At the same time, the uniform coverage of reflected light can avoid uneven curing caused by excessively high or low local temperatures, ensuring that the overall performance of the composite curing layer is consistent and adaptable to the overall repair requirements of the photovoltaic gravel curtain layer, realizing the green repair concept of "light-assisted curing".

[0023] Furthermore, in S4-1, the tilt angle of the photovoltaic panel is controlled at 15°-30°, and the shading effect of the photovoltaic panel is used to maintain the curing environment temperature under the panel at 20-25°. In S4-2, the tilt angle of the photovoltaic panel is controlled at 45°-60°, and the heat radiation from the back of the photovoltaic panel is used to raise the curing environment temperature under the panel to 28-30°. In S4-3, the tilt angle of the photovoltaic panel is controlled at 80°-90°, so that the environment under the panel is exposed to natural conditions, and the curing environment temperature drops to 22-24°.

[0024] Instructions: S4-1 requires maintaining a mild temperature of 20-25℃, with the photovoltaic panel tilt angle controlled at 15°-30°. This ensures the photovoltaic panel fully covers the area to be cured, providing shading and preventing excessively high local temperatures caused by direct sunlight. Simultaneously, the photovoltaic panel's own heat dissipation helps maintain a stable temperature under the panel within a suitable range, meeting the initial curing temperature requirements. S4-2 requires increasing the temperature to 28-30℃ to accelerate strength enhancement, adjusting the tilt angle to 45°-60°. This allows the back of the photovoltaic panel to face the area to be cured, enabling the back heat radiation generated by the photovoltaic panel to directly act on the gravel curtain layer. The combined effect of reflected light's heat radiation achieves precise temperature increase without the need for additional heating equipment. S4-3 requires lowering the temperature to 22-24℃ for constant-temperature slow curing, adjusting the tilt angle to 80°-90° so the photovoltaic panel is essentially perpendicular to the ground, with the area under the panel fully exposed to the natural environment. This avoids the photovoltaic panel's heat radiation and shading affecting the temperature while utilizing the mild conditions of the natural environment for slow curing, releasing internal stress and ensuring the stability and toughness of the cured layer.

[0025] Compared with the prior art, the beneficial effects of the present invention are reflected in the following aspects: (1) The photovoltaic area gravel curtain layer repair method of the present invention addresses the pain points of existing gravel curtain layer repair technologies, such as the lack of self-interlocking structure due to the single aggregate gradation, weak interlayer bonding and easy slippage, the environmental unfriendliness and easy cracking of traditional cement / chemical binders, difficulty in quality inspection after construction, and high maintenance costs. It constructs an integrated ecological restoration process of material compounding self-interlocking skeleton layer - surface micro-topography anchoring - layered spreading and compaction - modified plant fiber two-stage spraying film formation. This process realizes the on-site resource utilization of aggregates by screening the in-situ gravel mixture in the photovoltaic field area, according to a ratio of 4:3: The mass ratio constructs a self-interlocking structure of gravel-coarse sand-fine sand; combined with transverse anti-slip grooves and anchoring pits, it enhances the interface anti-slip ability; adopts layered paving from fine to coarse and light vibration compaction to form a dense "gravel-sand" skeleton; then, through a two-stage spraying process of initial spraying penetration anchoring and supplementary spraying cross-linking enhancement, a 3-5mm thick continuous, high-strength, crack-resistant composite solidification layer is generated; finally, multispectral imaging non-destructive testing and point-by-point supplementary spraying are used to achieve full-process quality control and long-term stability, significantly improving the ecological, durable and construction reliability of the gravel curtain layer repair in photovoltaic areas; (2) The present invention adopts a two-stage modified plant fiber spraying mode of initial spraying and anchoring + supplementary spraying to form a layer. It is different from the defects of traditional single-spray slurry that is prone to surface crusting, insufficient internal penetration and uneven consolidation depth. The initial spraying stage uses low viscosity modified plant fiber slurry, which relies on good fluidity to quickly penetrate through the gravel-sand skeleton gaps and reach the bottom of the layer and the interior of the anchoring pit to form a deep anchoring bolt structure, thereby achieving deep bonding between the consolidation layer and the substrate. The supplementary spraying stage uses high viscosity reinforced fiber slurry with added specific crosslinking agent, which is not easy to flow and stick to the wall. It can be evenly spread on the surface of the skeleton and between the fine pores to form a continuous and dense film-like consolidation layer, which is connected with the initial spraying and anchoring structure to form an overall composite curing layer. Simultaneously, through dual-stage viscosity differentiation control, reasonable spraying ratio, and time-segmented curing control, the modified plant fibers and crosslinking agents are fully crosslinked to form a three-dimensional network consolidation system. The cured layer has uniform thickness, high strength, and excellent water resistance and anti-aging properties. It not only ensures the deep anchoring effect of the slurry but also achieves surface sealing and soil stabilization and sand prevention, precisely meeting the requirements of windbreak and sand fixation, water permeability and soil retention, and durable service of the gravel curtain layer in photovoltaic areas. Attached Figure Description

[0026] Figure 1 This is a schematic diagram showing the distribution of the transverse anti-slip grooves and anchoring pits of the present invention; 1-Horizontal anti-slip groove, 2-Anchoring pit. Detailed Implementation

[0027] Example 1: A method for repairing a photovoltaic zone gravel curtain layer based on modified plant fiber consolidation, comprising the following steps: S1, Material Allocation The in-situ gravel mixture in the photovoltaic field area was screened in multiple stages using a screening device to obtain gravel, coarse sand, and fine sand of various particle size gradients. Then, the gravel, coarse sand, and fine sand were grouped and prepared in a mass ratio of 4:3:1 for later use. The gravel had a particle size gradient of 10mm and 12mm, the coarse sand had a particle size gradient of 1mm and 2mm, and the fine sand had a particle size of 0.08mm. When the gravel, coarse sand, and fine sand were compounded as aggregates, the mass ratio of gravel with a particle size of 10mm, gravel with a particle size of 12mm, coarse sand with a particle size of 1mm, coarse sand with a particle size of 2mm, and fine sand was 2:2:1.5:1.5:1. S2, Surface treatment The ground surface was cleaned and leveled according to the direction of the photovoltaic array, and a transverse anti-slip groove 1 and an anchoring pit 2 with micro-topographic features were constructed on the leveled ground surface. S3, Material Spreading First, mix the coarse sand and fine sand in S1, then spread and level it using a layered spreading process, then cover it with gravel, and compact it using a light vibrating device, so that the coarse sand and fine sand fully fill the gaps between the gravel, thereby constructing a "gravel-sand" interlocking skeleton layer. S4, modified plant fiber dual-stage spraying Initial spraying stage: Modified plant fiber slurry is sprayed using a high-pressure sprayer to penetrate deep into the bottom of the gravel-sand interlocking skeleton layer to form anchor bolts. The spraying rate of modified plant fiber slurry is 0.75 kg / m³. 2 The modified plant fiber slurry has a dynamic viscosity of 50 mPa·s at 25℃. Re-spraying stage: After the initial sprayed modified plant fiber slurry has cured for 4 hours, a film-like solidified layer is formed on the surface and within the pores of the "gravel-sand" interlocking skeleton layer. Then, a reinforced modified plant fiber slurry containing a 3% (w / w) glutaraldehyde aqueous solution is sprayed to fill the film-like solidified layer. Subsequently, a curing treatment is performed for 24 hours to generate a composite cured layer with a thickness of 3 mm. The spraying rate of the reinforced modified plant fiber slurry is 0.88 kg / m³. 2 The dynamic viscosity of the reinforced modified plant fiber slurry at 25℃ is 200 mPa·s. S5. Quality Inspection and Maintenance Multispectral image recognition was used to test the integrity and strength of the composite curing layer, and substandard areas were repaired by spraying.

[0028] Example 2: This example differs from Example 1 in that it uses a method for repairing a photovoltaic zone gravel curtain layer based on modified plant fiber consolidation, including the following steps: S1, Material Allocation The in-situ gravel mixture in the photovoltaic field area was screened in multiple stages using a screening device to obtain gravel, coarse sand, and fine sand of various particle size gradients. Then, the gravel, coarse sand, and fine sand were grouped and prepared in a mass ratio of 4:3:1 for later use. The gravel had a particle size gradient of 11mm and 13mm, the coarse sand had a particle size gradient of 2mm and 3mm, and the fine sand had a particle size of 0.3mm. When the gravel, coarse sand, and fine sand were compounded as aggregates, the mass ratio of gravel with a particle size of 11mm, gravel with a particle size of 13mm, coarse sand with a particle size of 2mm, coarse sand with a particle size of 3mm, and fine sand was 2:2:1.5:1.5:1. S2, Surface treatment The ground surface was cleaned and leveled according to the direction of the photovoltaic array, and a transverse anti-slip groove 1 and an anchoring pit 2 with micro-topographic features were constructed on the leveled ground surface. S3, Material Spreading First, mix the coarse sand and fine sand in S1, then spread and level it using a layered spreading process, then cover it with gravel, and compact it using a light vibrating device, so that the coarse sand and fine sand fully fill the gaps between the gravel, thereby constructing a "gravel-sand" interlocking skeleton layer. S4, modified plant fiber dual-stage spraying Initial spraying stage: Modified plant fiber slurry is sprayed using a high-pressure sprayer, utilizing its penetrating ability to reach the bottom of the gravel-sand interlocking skeleton layer to form anchor bolts, and the spraying rate of modified plant fiber slurry is 0.9 kg / m³. 2 The modified plant fiber slurry has a dynamic viscosity of 100 mPa·s at 25℃. Re-spraying stage: After the initial sprayed modified plant fiber slurry has cured for 5 hours, a film-like solidified layer is formed on the surface and within the pores of the "gravel-sand" interlocking skeleton layer. Then, a reinforced modified plant fiber slurry containing a 4% (w / w) glutaraldehyde aqueous solution is sprayed to fill the film-like solidified layer. Subsequently, a curing treatment is performed for 62 hours to generate a composite cured layer with a thickness of 4 mm. The spraying rate of the reinforced modified plant fiber slurry is 0.95 kg / m³. 2 The dynamic viscosity of the reinforced modified plant fiber slurry at 25℃ is 500 mPa·s. S5. Quality Inspection and Maintenance Multispectral image recognition was used to test the integrity and strength of the composite curing layer, and substandard areas were repaired by spraying.

[0029] Example 3: This example differs from Example 1 in that it is a method for repairing a photovoltaic zone gravel curtain layer based on modified plant fiber consolidation, comprising the following steps: S1, Material Allocation The in-situ gravel mixture in the photovoltaic field area was screened in multiple stages using a screening device to obtain gravel, coarse sand, and fine sand of various particle size gradients. Then, the gravel, coarse sand, and fine sand were grouped and prepared in a mass ratio of 4:3:1 for later use. The gravel had a particle size gradient of 12mm and 15mm, the coarse sand had a particle size gradient of 2mm and 3mm, and the fine sand had a particle size of 0.5mm. When the gravel, coarse sand, and fine sand were compounded as aggregates, the mass ratio of gravel with a particle size of 12mm, gravel with a particle size of 15mm, coarse sand with a particle size of 2mm, coarse sand with a particle size of 3mm, and fine sand was 2:2:1.5:1.5:1. S2, Surface treatment The ground surface was cleaned and leveled according to the direction of the photovoltaic array, and a transverse anti-slip groove 1 and an anchoring pit 2 with micro-topographic features were constructed on the leveled ground surface. S3, Material Spreading First, mix the coarse sand and fine sand in S1, then spread and level it using a layered spreading process, then cover it with gravel, and compact it using a light vibrating device, so that the coarse sand and fine sand fully fill the gaps between the gravel, thereby constructing a "gravel-sand" interlocking skeleton layer. S4, modified plant fiber dual-stage spraying Initial spraying stage: Modified plant fiber slurry is sprayed using a high-pressure sprayer to penetrate deep into the bottom of the gravel-sand interlocking skeleton layer to form anchor bolts. The spraying rate of modified plant fiber slurry is 1.1 kg / m³. 2 The modified plant fiber slurry has a dynamic viscosity of 150 mPa·s at 25℃. Re-spraying stage: After the initial sprayed modified plant fiber slurry has cured for 6 hours, a film-like solidified layer is formed on the surface and within the pores of the "gravel-sand" interlocking skeleton layer. Then, an enhanced modified plant fiber slurry containing 5% epichlorohydrin is sprayed to fill the film-like solidified layer. Subsequently, a curing treatment is performed for 72 hours to generate a composite cured layer with a thickness of 5 mm. The spraying rate of the enhanced modified plant fiber slurry is 1.05 kg / m³. 2 The enhanced modified plant fiber slurry has a dynamic viscosity of 800 mPa·s at 25°C. The modified plant fiber used in this embodiment is a commercially available conventional modified plant fiber, which can also be prepared using existing physical, chemical, or biological modification processes known in the art. This invention does not improve the modification and preparation process of plant fibers; the specific processes and formulations for fiber modification are prior art and not within the scope of this patent protection. S5. Quality Inspection and Maintenance Multispectral image recognition was used to test the integrity and strength of the composite curing layer, and substandard areas were repaired by spraying.

[0030] Example 4: This example differs from Example 2 in that: Figure 1 As shown in S2, several transverse anti-slip grooves 1 are distributed in a mesh pattern, and several anchoring pits 2 are located in the grid areas enclosed by the mesh pattern. The cross-section of the transverse anti-slip groove 1 is an inverted trapezoid. The depth of the transverse anti-slip groove 1 is 5cm, the top width is 8cm, and the bottom width is 4cm. The bottom of the groove is compacted to form a rough surface. The depth and diameter of the anchoring pit 2 are both 10cm.

[0031] Example 5: The difference between this example and Example 2 is that in S2, several transverse anti-slip grooves 1 are distributed in a mesh pattern, and several anchoring pits 2 are located in each grid area enclosed by the mesh pattern. The cross-section of the transverse anti-slip groove 1 is an inverted trapezoid. The depth of the transverse anti-slip groove 1 is 7cm, the top width is 12cm, and the bottom width is 6cm. The bottom of the groove is compacted to form a rough surface. The depth and diameter of the anchoring pit 2 are both 12cm.

[0032] Example 6: This example differs from Example 4 in that: In S2, after cleaning the surface according to the photovoltaic array orientation, the salt content of the original soil layer is detected using the conductivity method. When the salt content of the original soil layer is >1%, a disc rake or spiked rake is used for shallow loosening, with a loosening depth of 3cm. Then, a modified starch adhesive with a mass fraction of 1% is sprayed onto the loosened surface to allow it to penetrate into the surface of the loosened soil layer and form a bonding transition layer. Subsequently, leveling is carried out and the transverse anti-slip groove 1 and anchoring pit 2 are constructed. The spraying amount of modified starch adhesive is 1.2L / m². 2 ; After spraying modified starch adhesive onto the surface of the shallowly loosened soil, static compaction is performed using a lightweight rubber roller, and the surface is covered with non-woven geotextile to retain moisture for 2 hours.

[0033] Example 7: This example differs from Example 4 in that: In S2, after cleaning the surface according to the photovoltaic array orientation, the salt content of the original soil layer is detected using the conductivity method. When the salt content of the original soil layer is >1%, a disc rake or spiked rake is used for shallow loosening, with a loosening depth of 5cm. Then, a modified starch adhesive with a mass fraction of 3% is sprayed onto the loosened surface to allow it to penetrate into the surface of the loosened soil layer and form a bonding transition layer. Subsequently, leveling is carried out and the transverse anti-slip groove 1 and anchoring pit 2 are constructed. The spraying amount of modified starch adhesive is 1.8L / m². 2 ; After spraying modified starch adhesive onto the surface of the shallowly loosened soil, static compaction is performed using a lightweight rubber roller, and the surface is covered with non-woven geotextile to retain moisture for 4 hours.

[0034] Example 8: This example differs from Example 6 in that: in S4, the curing process adopts a staged curing method, specifically including the following steps: S4-1. Allow the reinforced modified plant fiber slurry to stand and cure for 24 hours at 20℃ and 70% relative humidity to initially bond and fuse with the membrane-like consolidation layer, forming a stable preliminary consolidation structure. S4-2. Continue curing at 28℃ and 60% relative humidity for 24 hours, with 8-hour intervals between applications of a moisturizing mixture sprayed via mist to replenish moisture evaporated during curing. The moisturizing mixture is composed of water, propylene glycol, and polyvinyl alcohol in a mass ratio of 100:1:0.3, and the single spray volume is 0.3 L / m². 2 ; S4-3. Reduce the ambient temperature to 22℃ and restore the relative humidity to 70% for constant temperature slow condensation; In S4-1, S4-2 and S4-3, by adjusting the tilt angle of the photovoltaic panel in the corresponding gravel curtain layer repair area in the photovoltaic array, the reflected light from the photovoltaic panel surface accurately covers the surface and surrounding area of ​​the "gravel-sand" interlocking skeleton layer to be cured, thereby using the thermal radiation effect of the reflected light to maintain the temperature of the repair area. In S4-1, the tilt angle of the photovoltaic panel is controlled at 15°, and the shading effect of the photovoltaic panel is used to maintain the curing environment temperature under the panel at 20°. In S4-2, the tilt angle of the photovoltaic panel is controlled at 45°, and the heat radiation from the back of the photovoltaic panel is used to raise the curing environment temperature under the panel to 28°. In S4-3, the tilt angle of the photovoltaic panel is controlled at 80°, so that the environment under the panel is exposed to natural conditions, and the curing environment temperature drops to 22°.

[0035] Example 9: This example differs from Example 6 in that: in S4, the curing process adopts a staged curing method, specifically including the following steps: S4-1. Allow the reinforced modified plant fiber slurry to stand and cure for 18 hours at 23℃ and 65% relative humidity to initially bond and fuse with the membrane-like consolidation layer, forming a stable preliminary consolidation structure. S4-2. Continue curing at 29℃ and 55% relative humidity for 35 hours, with 8-hour intervals between applications of a moisturizing mixture sprayed as a mist to replenish moisture evaporated during curing. The moisturizing mixture is composed of water, propylene glycol, and polyvinyl alcohol in a mass ratio of 100:2:0.5, with a single spray volume of 0.45 L / m³. 2 ; S4-3. Reduce the ambient temperature to 23℃ and restore the relative humidity to 65% for constant temperature slow condensation; In S4-1, S4-2 and S4-3, by adjusting the tilt angle of the photovoltaic panel in the corresponding gravel curtain layer repair area in the photovoltaic array, the reflected light from the photovoltaic panel surface accurately covers the surface and surrounding area of ​​the "gravel-sand" interlocking skeleton layer to be cured, thereby using the thermal radiation effect of the reflected light to maintain the temperature of the repair area. In S4-1, the tilt angle of the photovoltaic panel is controlled at 20°, and the shading effect of the photovoltaic panel is used to maintain the curing environment temperature under the panel at 23°. In S4-2, the tilt angle of the photovoltaic panel is controlled at 50°, and the heat radiation from the back of the photovoltaic panel is used to raise the curing environment temperature under the panel to 29°. In S4-3, the tilt angle of the photovoltaic panel is controlled at 85°, so that the environment under the panel is exposed to natural conditions, and the curing environment temperature drops to 23°.

[0036] Example 10: This example differs from Example 6 in that: in S4, the curing process adopts a staged curing method, specifically including the following steps: S4-1. Allow the reinforced modified plant fiber slurry to stand and cure for 12 hours at 25℃ and 60% relative humidity to initially bond and fuse with the membrane-like consolidation layer, forming a stable preliminary consolidation structure. S4-2. Continue curing at 30℃ and 50% relative humidity for 40 hours, with 8-hour intervals between applications of a moisturizing mixture sprayed as a mist to replenish moisture evaporated during curing. The moisturizing mixture is composed of water, propylene glycol, and polyvinyl alcohol in a mass ratio of 100:3:0.8, with a single spray volume of 0.6 L / m³. 2 ; S4-3. Reduce the ambient temperature to 24℃ and restore the relative humidity to 60% for constant temperature slow condensation; In S4-1, S4-2 and S4-3, by adjusting the tilt angle of the photovoltaic panel in the corresponding gravel curtain layer repair area in the photovoltaic array, the reflected light from the photovoltaic panel surface accurately covers the surface and surrounding area of ​​the "gravel-sand" interlocking skeleton layer to be cured, thereby using the thermal radiation effect of the reflected light to maintain the temperature of the repair area. In S4-1, the tilt angle of the photovoltaic panel is controlled at 30°, and the shading effect of the photovoltaic panel is used to maintain the curing environment temperature under the panel at 25°. In S4-2, the tilt angle of the photovoltaic panel is controlled at 60°, and the heat radiation from the back of the photovoltaic panel is used to raise the curing environment temperature under the panel to 30°. In S4-3, the tilt angle of the photovoltaic panel is controlled at 90°, so that the environment under the panel is exposed to natural conditions, and the curing environment temperature drops to 24°.

[0037] Experimental Example 1: Experimental objective: To verify the advantages of the multi-level particle size gradient aggregate compounding scheme defined in this invention in forming a "gravel-sand" interlocking skeleton, improving compaction and slurry permeability compared to conventional aggregate proportions, and to adapt to the surface load and rainwater infiltration requirements of the Hami photovoltaic park in the Gobi Desert.

[0038] Experimental Groups: Example group: Gravel, coarse sand and fine sand of various particle size gradients used in Examples 1-3; Control group 1: Conventional single-size gravel aggregate (10-15mm), without graded sand blending; Control group 2: Simplified gradation, consisting of only 12-15mm gravel + 0.08-0.5mm fine sand, without the gradient ratio of two grades of gravel and two grades of coarse sand; Test method: 1. Each group shall carry out the complete repair process S1-S5 of this invention, including surface cleaning and leveling, construction of transverse anti-slip grooves and anchoring pits, layered paving and compaction, two-stage spraying of modified plant fibers, staged curing and quality inspection. 2. During construction, except for aggregate gradation, all other process parameters (anti-slip groove / anchor pit size, slurry viscosity, crosslinking agent dosage of 3%, curing regime, etc.) strictly follow the standards defined in this invention; 3. After 72 hours of curing, four indicators were tested for each group: compaction degree of the skeleton, uniformity of interlayer porosity, uniformity of grout penetration, and structural stability. Three parallel samples were set up for each group, and the average value was taken as the final result. The test results are shown in Table 1. Table 1: Comparative Test Results of Performance of Different Aggregate Gradation

[0039] Conclusion: As shown in Table 1, the multi-grade particle size gradient composite aggregates of Examples 1-3 can form a stable self-interlocking skeleton, significantly improve compaction and slurry penetration uniformity, and have better structural stability than conventional and simplified gradation schemes, thus meeting the working conditions of Hami Photovoltaic Park.

[0040] Experimental Example 2: Experimental objective: To verify the effectiveness of the pretreatment process (shallow loose soil + modified starch adhesive transition layer) of the present invention for some high-salt surfaces (salt content > 1%) in Hami photovoltaic park in solving salt crystal caking, improving interlayer bonding strength, and avoiding salt interference with curing.

[0041] Experimental Groups: Example group: The pretreatment process of Examples 6-7 was adopted, and the subsequent repair process followed the standards of this invention; Control group: Selected plots of land in the same area with the same salinity. Only surface cleaning and leveling were carried out. No soil loosening or modified starch adhesive pretreatment was performed. The rest of the remediation process was the same as that of the example group. Blank group: Selected plots of land in the park with a salt content of ≤1%, which were leveled in a conventional manner without any special treatment for salt damage. The rest of the remediation process was the same as that of the example group.

[0042] Test method: 1. All groups were constructed according to the S2-S5 process of this invention. The example group additionally performed a high-salinity surface pretreatment step, while the control group and blank group omitted the pretreatment. 2. Before construction, the salt content of each group of plots was tested using the conductivity method. During construction, all process parameters except for pretreatment were strictly controlled to be uniform. 3. After 72 hours of curing, the interlayer bond strength, cured layer cracking rate, and salt penetration interference were tested for each group. After 30 days of curing, the interlayer delamination and sandblasting were observed. Three parallel samples were set up for each group. The test results are shown in Table 2. Table 2: Comparative Experiment Results of Pretreatment Effects on High-Salinity Surfaces

[0043] Conclusion: As shown in Table 2, the high-salinity surface pretreatment process of Examples 6-7 can effectively break up salt crystal caking, prevent salt infiltration, significantly improve interlayer bonding strength, and avoid delamination and sanding. It is suitable for the repair of gravel curtain layer on high-salinity surface in Hami photovoltaic park.

[0044] Experimental Example 3: Experimental objective: To verify the advantages of the modified plant fiber two-stage spraying process of this invention in improving the integrity, strength and erosion resistance of the cured layer, and to adapt it to the outdoor working conditions of Hami with large day-night temperature differences. Experimental Groups: Example group: The two-stage spraying process of Examples 8-10 is adopted, with staged curing + photovoltaic panel tilt angle temperature adjustment and spraying with moisturizing mixture; Control group 1: The spraying process was reversed (initial spraying at high viscosity 500 mPa·s, follow-up spraying at low viscosity 100 mPa·s), and the rest of the process was the same as the example group; Control group 2: Single-stage one-time spraying (viscosity 300 mPa·s), natural open-air curing, no adjustment of photovoltaic panel tilt angle, and the rest of the process is the same as the example group; Test method: 1. All groups were constructed according to the S1-S5 process of this invention, with only differences in the spraying and curing processes. 2. During construction, environmental conditions should be kept consistent with the outdoor conditions of the Hami Photovoltaic Industrial Park, and temperature changes during the curing process should be recorded; 3. After 72 hours of curing, the bottom anchoring effect, surface curing layer thickness, 24-hour rainwater erosion rate, and curing layer shrinkage and cracking rate of each group were tested. Three parallel samples were set up for each group. The test results are shown in Table 3. Table 3: Comparative Test Results of Two-Stage Spraying and Stage-by-Stage Curing Processes

[0045] Conclusion: As shown in Table 2, the two-stage spraying process in Examples 8-10 can achieve the dual effects of bottom anchoring and surface film formation. The staged curing + photovoltaic panel temperature regulation process can avoid cracking caused by outdoor temperature changes, significantly improve the integrity and erosion resistance of the cured layer, and is suitable for outdoor working conditions in Hami.

Claims

1. A method for repairing a photovoltaic zone gravel curtain layer based on modified plant fiber consolidation, characterized in that, Includes the following steps: S1, Material Allocation The in-situ gravel mixture in the photovoltaic field is screened in multiple stages using a screening device to obtain gravel, coarse sand and fine sand of various particle size gradients. Then, the gravel, coarse sand and fine sand are grouped and prepared in a mass ratio of 4:3:1 for later use. S2, Surface treatment The surface was cleaned and leveled according to the direction of the photovoltaic array, and a transverse anti-slip groove (1) and an anchoring pit (2) with micro-topographic features were constructed on the leveled surface. S3, Material Spreading First, mix the coarse sand and fine sand in S1, then spread and level it using a layered spreading process, then cover it with gravel, and compact it using a light vibrating device, so that the coarse sand and fine sand fully fill the gaps between the gravel, thereby constructing a "gravel-sand" interlocking skeleton layer. S4, modified plant fiber dual-stage spraying Initial spraying stage: Spray modified plant fiber slurry to penetrate deep into the bottom of the gravel-sand interlocking skeleton layer and form anchor bolts. The spraying rate of modified plant fiber slurry is 0.75-1.1 kg / m³. 2 ; Re-spraying stage: After the initial sprayed modified plant fiber slurry has cured for 4-6 hours, a film-like solidified layer forms on the surface and within the pores of the "gravel-sand" interlocking skeleton layer. Then, a reinforced modified plant fiber slurry containing 3-5% crosslinking agent is sprayed to fill the film-like solidified layer. Subsequently, a curing treatment is performed for 24-72 hours to generate a composite cured layer with a thickness of 3-5 mm. The spraying rate of the reinforced modified plant fiber slurry is 0.88-1.05 kg / m³. 2 ; S5. Quality Inspection and Maintenance Multispectral image recognition was used to test the integrity and strength of the composite curing layer, and substandard areas were repaired by spraying.

2. The method according to claim 1, characterized in that, In S1, the gravel has a particle size gradient of 10-12mm and 12-15mm, the coarse sand has a particle size gradient of 1-2mm and 2-3mm, and the fine sand has a particle size of 0.08-0.5mm. When the gravel, coarse sand and fine sand are mixed as aggregates, the mass ratio of gravel with a particle size of 10-12mm, gravel with a particle size of 12-15mm, coarse sand with a particle size of 1-2mm, coarse sand with a particle size of 2-3mm and fine sand is 2:2:1.5:1.5:

1.

3. The method according to claim 1, characterized in that, In S2, several transverse anti-slip grooves (1) are distributed in a mesh pattern, and several anchoring pits (2) are located in each grid area enclosed by the mesh pattern. The cross-section of the transverse anti-slip groove (1) is an inverted trapezoid. The depth of the transverse anti-slip groove (1) is 5-7cm, the top width is 8-12cm, and the bottom width is 4-6cm. The bottom of the groove is compacted to form a rough surface. The depth and diameter of the anchoring pit (2) are both 10-12cm.

4. The method according to claim 1, characterized in that, In S2, after cleaning the surface according to the photovoltaic array orientation, the salt content of the original soil layer is detected by the conductivity method. When the salt content of the original soil layer is >1%, shallow loosening is carried out using a disc rake or spiked rake, with a loosening depth of 3-5cm. Then, a modified starch adhesive with a mass fraction of 1-3% is sprayed onto the surface after shallow loosening, allowing it to penetrate into the surface of the loosened soil layer to form a bonding transition layer. Subsequently, leveling is carried out and the transverse anti-slip groove (1) and anchoring pit (2) are constructed. The spraying amount of modified starch adhesive per square meter is 1.2-1.8L / m. 2 .

5. The method according to claim 4, characterized in that, After spraying modified starch adhesive onto the surface of the shallowly loosened soil, use a light rubber roller for static compaction and cover with non-woven geotextile to retain moisture for 2-4 hours.

6. The method according to claim 1, characterized in that, In S4, the dynamic viscosity of the modified plant fiber slurry in the initial spraying stage is 50-150 mPa·s at 25℃, and the dynamic viscosity of the reinforced modified plant fiber slurry in the supplementary spraying stage is 200-800 mPa·s at 25℃.

7. The method according to claim 1, characterized in that, In S4, the crosslinking agent is an aqueous solution of glutaraldehyde or epichlorohydrin.

8. The method according to claim 1, characterized in that, In S4, the curing process adopts a staged curing method, specifically including the following steps: S4-1. Allow the reinforced modified plant fiber slurry to stand and cure for 12-24 hours at 20-25℃ and 60%-70% relative humidity to initially bond and fuse with the membrane-like consolidation layer, forming a stable preliminary consolidation structure. S4-2. Continue curing at 28-30℃ and relative humidity of 50%-60% for 24-40 hours. During this period, apply a mist-spray of a moisturizing mixture every 8 hours to replenish the moisture evaporated during curing. The moisturizing mixture is composed of water, propylene glycol, and polyvinyl alcohol in a mass ratio of 100:1-3:0.3-0.

8. The single spraying volume of the moisturizing mixture is 0.3-0.6 L / m³. 2 ; S4-3. Reduce the ambient temperature to 22-24℃ and restore the relative humidity to 60%-70% for constant temperature slow condensation.

9. The method according to claim 8, characterized in that, In S4-1, S4-2 and S4-3, by adjusting the tilt angle of the photovoltaic panels in the corresponding gravel curtain layer repair area in the photovoltaic array, the reflected light from the photovoltaic panel surface accurately covers the surface and surrounding area of ​​the "gravel-sand" interlocking skeleton layer to be cured, thereby utilizing the thermal radiation effect of the reflected light to maintain the temperature of the repair area.

10. The method according to claim 9, characterized in that, In S4-1, the tilt angle of the photovoltaic panel is controlled at 15°-30°, and the shading effect of the photovoltaic panel is used to maintain the curing environment temperature under the panel at 20-25℃. In S4-2, the tilt angle of the photovoltaic panel is controlled at 45°-60°, and the heat radiation from the back of the photovoltaic panel is used to raise the curing environment temperature under the panel to 28-30℃. In S4-3, the tilt angle of the photovoltaic panel is controlled at 80°-90°, so that the environment under the panel is exposed to natural conditions, and the curing environment temperature drops to 22-24℃.

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