Flexible ecological comprehensive supporting system for expansive soil side slope

Abstract

The invention belongs to the technical field of rock-soil side slope protection, and particularly relates to an expansive soil side slope flexible ecological comprehensive supporting system which comprises an intercepting ditch, a vegetation protection layer, a composite waterproof layer, flexible anchor rods, water seepage and drainage pipes, cultivation and planting soil, a drainage ditch, a backfill soil layer, a step-shaped slope surface, a slope surface and slope protection vegetation. The slope surface is excavated into a step-shaped slope surface, a composite waterproof layer, expansive soil backfill soil, a vegetation protection layer and cultivation and planting soil are sequentially arranged on the step-shaped slope surface from bottom to top, and slope protection vegetation is planted and formed on the cultivation and planting soil; the composite waterproof layer is fixed to the step-shaped slope face through the flexible anchor rods. The vegetation protection layer and the slope protection vegetation together reinforce the shallow soil body, and the composite waterproof layer and the flexible anchor rod play a role in absorbing and relieving the received expansive force. The method has an ecological greening effect, has the functions of common supporting of the shallow surface layer and the deep layer of the expansive soil slope, flexible reinforcement and expansion reduction and allowable generation of a small amount of deformation, is simple in construction and high in efficiency, and can realize long-term stability of the shallow surface layer and the deep layer of the expansive soil slope.

Description

Technical Field

[0001] The invention belongs to the technical field of rock and soil slope protection, and in particular relates to a flexible ecological comprehensive support system for expansive soil slopes. Background Art

[0002] Expansive soil is widely distributed in my country and covers a large area. It is distributed in plains, basins, hills and other places formed by various river basins from the Yunnan-Guizhou Plateau in the southwest to the North China Plain, covering many provinces, cities and autonomous regions. Expansive soil is a geological body with significant expansion and contraction and developed fissures formed in the natural geological process. The main components of expansive soil contain more clay minerals such as montmorillonite and illite, so it has strong hydrophilicity. It expands and softens when absorbing water, and shrinks and contracts when losing water.

[0003] Expansive soil landslides mainly include deep landslides controlled by structural surfaces and shallow instability. The former is due to the presence of relatively obvious structural surfaces in the expansive soil layer, which play an important role in the formation of landslides. Shallow instability will inevitably lead to loosening and damage of a certain area in the deep layer as the depth extends.

[0004] Previous studies have mostly focused on shallow treatment of expansive soil slopes, and most of them use rigid structures with poor reinforcement and swelling reduction effects. They ignore the irreversible damage caused by repeated expansion and contraction deformation and swelling force of expansive soil in both shallow and deep layers, which greatly reduces the durability of the structure and weakens its support capacity, thus causing certain destructive effects. Therefore, it is necessary to develop a flexible ecological comprehensive support structure for deep and shallow layers. To this end, we provide a flexible ecological comprehensive support structure and construction method for deep and shallow layers. Summary of the invention

[0005] In view of the technical problems existing in the prior art, the purpose of the present invention is to propose a flexible ecological integrated support system for expansive soil slopes, which can reduce soil erosion and protect the ecology while effectively maintaining the stability of the expansive soil slopes.

[0006] To achieve the above-mentioned purpose, the present invention provides a flexible ecological integrated support system for expansive soil slopes, including intercepting ditches, vegetation protection layers, composite waterproof layers, flexible anchor rods, seepage drainage pipes, cultivated soil, drainage ditches, backfill soil layers, stepped slope surfaces, slope surfaces and slope protection vegetation.

[0007] like Figure 1 As shown in the figure, the slope is excavated into a stepped slope, which is formed by alternating stepped slopes and stepped bottoms from bottom to top. A water interception ditch is excavated on the top of the slope, and a drainage ditch is excavated on the bottom of the slope. A composite waterproof layer, expansive soil backfill, vegetation protection layer, and cultivated soil are arranged on the stepped slope in a direction perpendicular to the stepped slope from bottom to top, and plants are planted on the cultivated soil to form slope protection vegetation. Flexible anchor rods fix the composite waterproof layer on the stepped slope.

[0008] like Figure 2 As shown, the composite waterproof layer adopts a three-layer composite structure, the upper layer is a permeable geotextile, the lower layer is a waterproof geotextile, and the middle layer is an elastic sponge permeable board, which is attached to the stepped slope layer by layer from bottom to top.

[0009] like Figure 3 As shown, the seepage drainage pipe is a pipe network structure composed of a horizontal seepage drainage pipe, a longitudinal seepage drainage pipe and a connecting pipe. The length of the horizontal seepage drainage pipe is 10-20m, and its two ends are connected to the longitudinal seepage drainage pipe through a connecting pipe. The longitudinal seepage drainage pipe is parallel to the step slope, and the length of the longitudinal seepage drainage pipe is equal to the length of the step slope along the slope direction. The two ends of the longitudinal seepage drainage pipe are connected to the horizontal seepage drainage pipe through a connecting pipe. The longitudinal seepage drainage pipe above the lowest step slope diverts water to the drainage ditch at the bottom of the slope below the slope through a PVC drainage pipe.

[0010] like Figure 4 As shown, the flexible anchor rod and the composite waterproof layer form a coordinated body, and the flexible anchor rod includes an anchor rod nut, a small pad, a large pad and an anchor rod, the large pad is between the composite waterproof layer and the stepped slope, and the composite waterproof layer is between the large pad and the small pad. When laying the composite waterproof layer, a hole matching the diameter of the anchor rod is reserved at the preset anchor rod point, the anchor rod passes through the hole, and is fixed by the anchor rod nut.

[0011] like Figure 5 As shown, the seepage drainage pipe is arranged between the elastic sponge seepage board and the waterproof geotextile, and the elastic sponge seepage board and the waterproof geotextile are tightly bonded by polyurethane glue A, wherein the transverse seepage drainage pipe is arranged between the elastic sponge seepage board and the waterproof geotextile attached to the bottom of each step slope, and the rainwater collected by the elastic sponge seepage board enters the transverse seepage drainage pipe, and the seepage drainage pipe is tightly bonded to the waterproof geotextile by using foam glue B.

[0012] The construction method of the above-mentioned flexible ecological integrated support system for expansive soil slope comprises the following steps:

[0013] (1) Slope trimming: According to the design requirements, the slope is trimmed into a stepped slope according to the slope height. The inclination angle of each step slope is 5-15° greater than the inclination angle of the slope, and the bottom of each step slope is leveled and parallel to the horizontal plane.

[0014] (2) The intercepting ditch and drainage ditch are excavated at the top and bottom of the slope according to the design requirements. When the intercepting ditch and drainage ditch are excavated, a depth of at least 10 cm is reserved at the bottom for the composite waterproof layer and the vegetation protection layer.

[0015] (3) Measurement and laying out, drilling, hole cleaning, anchor rod installation, and anchor section grouting. The flexible anchor rods are arranged in a plum blossom pattern, with an anchor hole inclination of 15-45°, an anchor rod depth of 4-10m greater than the sliding surface depth of the expansive soil slope, and an anchor section grouting length of 4-8m. After the slurry solidifies and reaches the strength requirement, a large pad is installed. After the composite waterproof layer and the seepage drainage pipe are laid, a small pad is installed and fixed with an anchor rod nut. Among them, the specific process of laying the composite waterproof layer and the seepage drainage pipe is as follows: laying the composite waterproof layer is divided into two steps: first, laying a waterproof geotextile and arranging a seepage drainage pipe on the waterproof geotextile; then, laying an elastic sponge seepage board and a seepage geotextile in sequence. Before laying the composite waterproof layer, holes that match the diameter of the anchor rod and its setting position are reserved on the seepage geotextile, the waterproof geotextile, and the elastic sponge seepage board. Arrange transverse seepage drainage pipes and longitudinal seepage drainage pipes according to actual requirements, use connecting pipes to connect the two, and use PVC drainage pipes to divert water to the drainage ditch at the bottom of the slope.

[0016] (4) The expansive soil obtained by excavating the stepped slope is backfilled onto the composite waterproof layer as backfill soil to form a backfill soil layer, and a vegetation protection layer is laid after leveling and fixed with U-shaped nails, and then cultivated soil is laid on the vegetation protection layer. The vegetation protection layer is formed by a three-dimensional vegetation net.

[0017] (5) Select the seeds of slope protection plants with strong root growth ability and strong stress resistance that can be artificially planted in batches on the slopes of expansive soil, and spray them evenly in the cultivated soil. After spraying, cover the surface of the cultivated soil with a transparent plastic film. After the plants grow to a certain height, remove the film, water and fertilize regularly to form slope protection vegetation.

[0018] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0019] 1. The vegetation protection layer is laid flat from the foot of the slope to the outside of the potential sliding surface of the slope, which restricts the development of cracks at the top of the slope and is conducive to the overall stability of the slope. The composite whole composed of the vegetation protection layer and the vegetation can effectively adjust the migration of water, limit the cracking of the surface soil, limit the development of cracks to the deep, and prevent the atmospheric impact depth from developing deep into the soil. The vegetation protection layer combined with the stems and leaves of the slope protection vegetation can weaken the impact of rainwater and reduce the runoff, thereby effectively preventing rainwater from eroding the surface soil.

[0020] 2. The vegetation protection layer, the roots of the slope protection vegetation and the shallow expansive soil are tightly intertwined, which can effectively prevent the shallow surface soil from sliding and collapsing, and make up for the shortcomings of traditional slope protection methods in preventing the surface soil from sliding and collapsing.

[0021] 3. The vegetation protection layer is made of fiber reinforced composite material (FRP), which has the characteristics of strong tensile strength, corrosion resistance and low elastic modulus. While it plays a role in fixing the soil, it also allows the expansive soil to produce a certain deformation to release the expansion force, thereby reducing the harm caused by the expansion and contraction deformation of the expansive soil.

[0022] 4. The composite waterproof layer adopts a three-layer composite structure, with permeable geotextile on the upper side, waterproof geotextile on the lower side, and elastic sponge permeable board in the middle. This composite structure can form an effective water collection and drainage function, and prevent the overall collapse and slippage caused by the expansion of expansive soil when it encounters water.

[0023] 5. The composite waterproof layer is fixed by the double pads of the anchor rod. The composite waterproof layer is arranged in a large pad and then fixed with nuts and small pads to form a flexible waterproof overall support. The elastic water-permeable material in the middle of the composite waterproof layer can absorb and alleviate the expansion force of the anchor rod as a whole.

[0024] 6. The seepage drainage pipe mainly adopts flexible PVC steel fiber composite pipe, and is perforated to collect water from the composite waterproof layer and connected with the longitudinal seepage drainage pipe. The longitudinal drainage pipe is connected to the drainage ditch at the bottom of the slope through the PVC drainage pipe and finally incorporated into the drainage system, which greatly enhances the water collection function and can play a more effective drainage role in rainy and snowy weather.

[0025] 7. Flexible anchor rods use fiber reinforced polymer (FRP) anchor rods. Compared with traditional steel anchor rods, steel materials are prone to corrosion and have poor durability in expansive soil environments. They cannot reach the designed service life, have many safety hazards, and require a lot of replacement and maintenance work. Fiber reinforced polymer (FRP) anchor rods have the advantages of high tensile strength, corrosion resistance, good fatigue resistance, light weight, and low elastic modulus. It is precisely because of its high tensile strength, good fatigue resistance, and low elastic modulus that it can better coordinate with the small deformation of expansive soil, such as volume expansion and softening due to water absorption, and volume reduction and shrinkage due to water loss, and can also protect its stability.

[0026] 8. Flexible anchor rods are used to connect the composite waterproof layer, vegetation protection layer, slope protection vegetation, and slope soil into a whole, taking into account the advantages of rigid support and flexible support. The overall deformation coordination ability of the structure is excellent, and at the same time, shallow protection, deep anti-slip and ecological management of the expansive soil slope are achieved, ensuring the overall long-term stability of the slope. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of the flexible ecological integrated support system for expansive soil slopes of the present invention.

[0028] Figure 2 It is a schematic diagram of the structure of the composite waterproof layer in the present invention.

[0029] Figure 3It is a schematic diagram of the structure of the seepage and drainage network in the present invention.

[0030] Figure 4 It is a schematic diagram of the structure of the flexible anchor rod in the present invention.

[0031] Figure 5 It is a schematic diagram of the arrangement structure of the seepage and drainage pipes of the present invention in the composite waterproof layer.

[0032] In the attached drawings: intercepting ditch 1, vegetation protection layer 2, composite waterproof layer 3, flexible anchor rod 4, seepage drainage pipe 5, cultivated soil 6, drainage ditch 7, backfill soil layer 8, stepped slope 9, slope 10, slope protection vegetation 11, permeable geotextile 301, elastic sponge permeable board 302, waterproof geotextile 303, anchor nut 401, small pad 402, large pad 403, transverse seepage drainage pipe 501, longitudinal seepage drainage pipe 502, connecting pipe 503, PVC drainage pipe 504, step slope 901, step slope bottom 902, polyurethane glue A, foam glue B. DETAILED DESCRIPTION

[0033] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0034] Example 1

[0035] like Figures 1 to 5 As shown, a flexible ecological integrated support system for expansive soil slope includes a ditches 1, a vegetation protection layer 2, a composite waterproof layer 3, a flexible anchor rod 4, a seepage drainage pipe 5, cultivated soil 6, a drainage ditch 7, a backfill soil layer 8, a stepped slope 9, a slope 10 and slope protection vegetation 11.

[0036] like Figure 1 As shown, the slope 10 is excavated into a stepped slope 9, which is formed by alternating stepped slopes 901 and stepped slope bottoms 902 from bottom to top. A water interception ditch 1 is excavated on the top of the slope 10, and a drainage ditch 7 is excavated on the bottom of the slope. A composite waterproof layer 3, expansive soil backfill 8, a vegetation protection layer 2, and cultivated soil 6 are sequentially arranged on the stepped slope 9 from bottom to top in a direction perpendicular to the stepped slope, and plants are planted on the cultivated soil 6 to form slope protection vegetation 11. Flexible anchor rods 4 fix the composite waterproof layer 3 on the stepped slope 9.

[0037] like Figure 2 As shown, the composite waterproof layer 3 adopts a three-layer composite structure, the upper layer is a permeable geotextile 301, the lower layer is a waterproof geotextile 303, and the middle layer is an elastic sponge permeable board 302, which is attached to the stepped slope 9 layer by layer from bottom to top.

[0038] like Figure 3As shown, the seepage drainage pipe 5 is a pipe network structure consisting of a horizontal seepage drainage pipe 501, a longitudinal seepage drainage pipe 502 and a connecting pipe 503. The length of the horizontal seepage drainage pipe 501 is 15m, and its two ends are connected to the longitudinal seepage drainage pipe 502 through the connecting pipe 503. The longitudinal seepage drainage pipe 502 is parallel to the step slope 901, and the two are equal in length. The two ends of the longitudinal seepage drainage pipe 502 are connected to the horizontal seepage drainage pipe 501 through the connecting pipe 503. The longitudinal seepage drainage pipe 502 above the lowest step slope 901 guides water to the drainage ditch 7 at the bottom of the slope below the slope 10 through the PVC drainage pipe 504.

[0039] like Figure 4 As shown, the flexible anchor rod 4 forms a coordinated body with the composite waterproof layer 3, and the flexible anchor rod 4 includes an anchor rod nut 401, a small pad 402, a large pad 403 and an anchor rod, the large pad 403 is between the composite waterproof layer 3 and the stepped slope 9, and the composite waterproof layer 3 is between the large pad 403 and the small pad 402. When laying the composite waterproof layer 3, a hole matching the diameter of the anchor rod is reserved at the preset anchor rod point, the anchor rod passes through the hole, and is fixed by the anchor rod nut 401.

[0040] like Figure 5 As shown, the seepage drainage pipe 5 is arranged between the elastic sponge seepage board 302 and the waterproof geotextile 303, and the elastic sponge seepage board 302 and the waterproof geotextile 303 are tightly bonded by polyurethane glue A, wherein the transverse seepage drainage pipe 501 is arranged between the elastic sponge seepage board 302 and the waterproof geotextile 303 attached to the bottom of each step slope 902, and the rainwater collected by the elastic sponge seepage board 302 enters the transverse seepage drainage pipe 501, and the seepage drainage pipe 5 is tightly bonded to the waterproof geotextile 303 by using foam glue B.

[0041] The flexible anchor rod 4 is a fiber reinforced polymer (FRP) anchor rod, the transverse seepage drainage pipe 501 and the longitudinal seepage drainage pipe 502 are flexible PVC steel fiber composite pipes, and the vegetation protection layer is formed by a three-dimensional vegetation net made of fiber reinforced composite material (FRP).

[0042] Example 2

[0043] The construction method of the flexible ecological integrated support system for expansive soil slope of Example 1 comprises the following steps:

[0044] (1) trimming the slope surface. According to the design requirements and the height of the slope surface 10, the slope surface 10 is trimmed into a stepped slope surface 9. The inclination angle of each step slope surface 901 is greater than the inclination angle of the slope surface 10 by 10°, and each step slope bottom 902 is flattened to be parallel to the horizontal plane.

[0045] (2) The intercepting ditch 1 and the drainage ditch 7 are excavated at the top and bottom of the slope according to the design requirements. When the intercepting ditch 1 and the drainage ditch 7 are excavated, a depth of 20 cm is reserved at the bottom for the composite waterproof layer 3 and the vegetation protection layer 2.

[0046] (3) Measurement and laying out, drilling, hole cleaning, anchor rod installation, and anchor section grouting. The flexible anchor rods 4 are arranged in a plum blossom pattern, with an anchor hole inclination of 30°, an anchor rod depth of 8m greater than the sliding surface depth of the expansive soil slope, and an anchor section grouting length of 7m. After the slurry solidifies and reaches the strength requirement, the large pad 403 is installed. After the composite waterproof layer 3 and the seepage drainage pipe 5 therein are laid, the small pad 402 is installed and fixed with the anchor rod nut 401. Among them, the specific process of laying the composite waterproof layer 3 and the seepage drainage pipe 5 therein is that the laying of the composite waterproof layer 3 is divided into two steps: first, laying the waterproof geotextile 303, and arranging the seepage drainage pipe 5 on the waterproof geotextile 303; then, laying the elastic sponge seepage board 302 and the seepage geotextile 301 in turn. Before laying the composite waterproof layer 3, holes matching the diameter of the anchor rod and its setting position are reserved on the water-permeable geotextile 301, the waterproof geotextile 303, and the elastic sponge water-permeable board 302. According to actual requirements, the horizontal seepage drainage pipe 501 and the longitudinal seepage drainage pipe 502 are arranged, and the two are connected by a connecting pipe 503, and the water is diverted to the drainage ditch 7 at the bottom of the slope through the PVC drainage pipe.

[0047] (4) The expansive soil obtained from the excavation of the stepped slope 9 is backfilled onto the composite waterproof layer 3 as backfill soil to form a backfill soil layer 8. After leveling, a vegetation protection layer 2 is laid and fixed with U-shaped nails. Next, a 5 cm thick cultivated soil 6 is laid on the vegetation protection layer 2.

[0048] (5) Select the seeds of slope protection plants with strong root growth ability and strong stress resistance and can be artificially planted in batches on the expansive soil slope, and spray them evenly in the cultivated soil 6. After the spraying is completed, cover the surface of the cultivated soil 6 with a transparent plastic film. When it grows to 2 cm high, remove the film, water and fertilize regularly to form slope protection vegetation 11.

[0049] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A flexible ecological integrated support system for expansive soil slope, comprising a water intercepting ditch, a vegetation protection layer, a composite waterproof layer, a flexible anchor rod, a seepage drainage pipe, cultivated soil, a drainage ditch, a backfill soil layer, a stepped slope surface, a slope surface and slope protection vegetation; The slope is excavated into a stepped slope, which is formed by alternating stepped slopes and stepped bottoms from bottom to top; a water interception ditch is excavated on the top of the slope, and a drainage ditch is excavated on the bottom of the slope; a composite waterproof layer, expansive soil backfill, vegetation protection layer, and cultivated soil are sequentially arranged on the stepped slope from bottom to top in a direction perpendicular to the stepped slope, and plants are planted on the cultivated soil to form slope protection vegetation; flexible anchor rods fix the composite waterproof layer on the stepped slope; The composite waterproof layer adopts a three-layer composite structure, the upper layer is a permeable geotextile, the lower layer is a waterproof geotextile, and the middle layer is an elastic sponge permeable board, which is attached to the stepped slope layer by layer from bottom to top; The seepage drainage pipe is a pipe network structure composed of a horizontal seepage drainage pipe, a longitudinal seepage drainage pipe and a connecting pipe. The length of the horizontal seepage drainage pipe is 10-20m, and its two ends are connected to the longitudinal seepage drainage pipe through a connecting pipe. The longitudinal seepage drainage pipe is parallel to the step slope, and the length of the longitudinal seepage drainage pipe is equal to the length of the step slope along the slope direction. The two ends of the longitudinal seepage drainage pipe are connected to the horizontal seepage drainage pipe through a connecting pipe; the longitudinal seepage drainage pipe above the lowest step slope is guided to the drainage ditch at the bottom of the slope below the slope through a PVC drainage pipe; The flexible anchor rod and the composite waterproof layer form a coordinated body, and the flexible anchor rod comprises an anchor rod nut, a small pad, a large pad and an anchor rod, wherein the large pad is located between the composite waterproof layer and the stepped slope, and the composite waterproof layer is located between the large pad and the small pad; when laying the composite waterproof layer, a hole matching the diameter of the anchor rod is reserved at a preset anchor rod point, the anchor rod passes through the hole, and is fixed by the anchor rod nut; The seepage drainage pipe is arranged between the elastic sponge seepage board and the waterproof geotextile, and the elastic sponge seepage board and the waterproof geotextile are tightly bonded by polyurethane glue A. The transverse seepage drainage pipe is arranged between the elastic sponge seepage board and the waterproof geotextile attached to the bottom of each step. The rainwater collected by the elastic sponge seepage board enters the transverse seepage drainage pipe, and the seepage drainage pipe is tightly bonded to the waterproof geotextile using foam glue B.

2. The construction method of the flexible ecological integrated support system for expansive soil slope according to claim 1 comprises the following steps: (1) Trim the slope surface. According to the design requirements, the slope surface is trimmed into a stepped slope surface according to the slope height. The inclination angle of each step slope surface is 5-15° greater than the inclination angle of the slope. The bottom of each step slope is leveled and parallel to the horizontal plane. (2) Excavating the intercepting ditch and drainage ditch at the top and bottom of the slope according to the design requirements; when excavating the intercepting ditch and drainage ditch, a depth of at least 10 cm is reserved at the bottom for the composite waterproof layer and the vegetation protection layer; (3) measuring and laying out, drilling, hole cleaning, anchor bolt installation, and anchor section grouting; the flexible anchor bolts are arranged in a plum blossom pattern, the anchor hole inclination angle is 15-45°, the anchor bolt depth is 4-10m greater than the sliding surface depth of the expansive soil slope, and the anchor section grouting length is 4-8m; after the slurry solidifies to reach the strength requirement, the large pad is installed, and after the composite waterproof layer and the seepage drainage pipe are laid, the small pad is installed and fixed with the anchor bolt nut; wherein, The specific process of laying the composite waterproof layer and the seepage drainage pipe therein is as follows: laying the composite waterproof layer is divided into two steps: first, laying the waterproof geotextile and arranging the seepage drainage pipe on the waterproof geotextile; then, laying the elastic sponge seepage board and the seepage geotextile in sequence; before laying the composite waterproof layer, holes matching the diameter of the anchor rod and its setting position are reserved on the seepage geotextile, the waterproof geotextile and the elastic sponge seepage board; arranging the horizontal seepage drainage pipe and the longitudinal seepage drainage pipe according to actual requirements, connecting the two with a connecting pipe, and diverting the water to the drainage ditch at the bottom of the slope through the PVC drainage pipe; (4) The expansive soil obtained from the excavation of the stepped slope is backfilled onto the composite waterproof layer as backfill soil to form a backfill soil layer, and a vegetation protection layer is laid after leveling and fixed with U-shaped nails, and then cultivated soil is laid on the vegetation protection layer; (5) Select the seeds of slope protection plants with strong root growth ability and strong stress resistance and which are artificially planted in batches on the slopes of expansive soil, and spray them evenly in the cultivated soil. After spraying, cover the surface of the cultivated soil with a transparent plastic film. After the plants grow to a certain height, remove the film, water and fertilize them regularly to form slope protection vegetation.

3. The construction method according to claim 2, characterized in that: The vegetation protection layer is formed by a three-dimensional vegetation net.

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