Soil nail and soilbag combined slope protection system and construction method thereof

Abstract

The invention discloses a soil nailing and soilbag combined side slope protection system and a construction method thereof, relates to the technical field of side slope protection engineering, and aims to solve the technical problems that when a traditional soil nailing wall protection system is arranged, the surface of a side slope needs to be covered with a large amount of cement paste, and pollution is likely to be caused to the environment. The bag body is made of high-strength polyester fiber materials, the appearance of the bag body is a cuboid, and when the bag body is filled with soil, the total length of the bottom face is 1.5 m, the width is 0.4 m or 0.2 m, and the height is 0.2 m; the filler is slope in-situ soil, and the in-situ soil obtained through excavation is tamped and compacted; the soilbag unit is composed of a plurality of soilbags, each layer is composed of four standard soilbags 1 filled with aggregate and two standard soilbags 2 filled with aggregate, and each soilbag unit is provided with two layers of soilbags which are overlapped. According to the method, the slope can be supported without adding any concrete, and the method has the advantage of being good in environment-friendly performance.

Description

Technical Field

[0001] The invention relates to the technical field of slope protection engineering, and more specifically to a slope protection system combining soil nails and geobags and a construction method thereof. Background Art

[0002] Soil nailing is a geotechnical reinforcement technology used for slope stabilization and foundation pit support. Soil nails are mostly slender rods made of steel bars or steel pipes. The principle is to insert them into the soil to form a composite soil body to improve the overall stability and bearing capacity. Soil nailing is simple to construct and low in cost. It is suitable for various geological and engineering scales, can control soil deformation, enhance self-stabilization ability, and has little impact on the environment.

[0003] As buildings develop in a higher direction, the foundations of high-rise buildings will inevitably become deeper and deeper, which will lead to increasing requirements for the overall stability of the slope. Soil nailing is a new retaining technology developed in recent years for soil excavation and slope stabilization. When the horizontal thrust of the soil in the active area of ​​the slope is balanced by the friction between the nails and the soil in the stable area, the internal stability of the entire soil nailing support structure can be guaranteed. However, the current traditional soil nailing wall protection system is mainly arranged by laying concrete walls on the surface of the slope, connecting the soil nails to the concrete walls, and the soil nails pass through the soil in the active area and are inserted into the soil in the stable area. Cement slurry is injected into the soil nails so that the soil nails are in close contact with the soil to form a stable slope protection structure. It requires a large amount of cement slurry to cover the surface of the slope, which is easy to cause pollution to the environment. In view of this, we propose a slope protection system combining soil nails and geobags and a construction method thereof. Summary of the invention

[0004] The purpose of the present invention is to provide a slope protection system combining soil nails and geobags and a construction method thereof, so as to solve the technical problem that the traditional soil nail wall protection system needs to cover a large amount of cement slurry on the slope surface during layout, which easily causes environmental pollution.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: a slope protection system combining soil nails and geobags, comprising

[0006] Bag body: Made of high-strength polyester fiber material, the shape is a cuboid. When filled with soil, the total length of the bottom is 1.5m, the width is 0.4m or 0.2m, and the height is 0.2m;

[0007] Filling material: the in-situ soil of the slope, which is compacted by tamping the in-situ soil obtained by excavation;

[0008] Geobag unit: It is composed of several geobags. Each layer is composed of four standard geobags 1 filled with aggregates and two standard geobags 2 filled with aggregates. A geobag unit has two layers of geobags stacked on top of each other. The first layer of geobags consists of standard geobag 1, standard geobag 2 and standard geobag 1 filled with compacted in-situ soil from left to right; the second layer of geobags consists of two standard geobags 1 and standard geobag 2 filled with compacted in-situ soil from left to right. The second layer of geobags is laid horizontally 0.5m to the left of the first layer of geobags.

[0009] Geobag unit connection structure: The main body is composed of geobag units stacked in an interlaced manner. The soil samples are divided in a stepped manner, and every two layers of geobags constitute a capillary barrier unit; from right to left, they are organic soil, fine aggregate, coarse aggregate, backfill soil and original foundation; soil samples are separated by geogrids, and each capillary barrier unit is horizontally shifted to the right by 0.5m compared to the previous capillary barrier unit. The units are separated by geogrids. In the uppermost layer of each capillary barrier unit, geogrids are used to fix standard geobags. Among them, the standard geobag 1 filled with fine aggregate on the far right is not provided with geogrids to facilitate the construction of soil nails; and in the lowermost layer of each geobag unit, all geobags are covered by geogrids;

[0010] Soil nails: Use steel bars with an angle of 5° to the horizontal plane. The ends are welded with screw end rods. The screw end rods are partially exposed outside the geobags. After the geobags are installed, they are rammed in 5 cm above the center of the outermost geobag in the geobag wall.

[0011] The reinforcement is Tresca material subject to the Tresca yield condition;

[0012] Based on the Tresca yield condition, the critical soil slope height for soil nailing slope to maintain equilibrium is derived. The power exerted by the external force is equal to the vector product of the soil weight W and the velocity v:

[0013]

[0014] The dissipation rate of internal energy is:

[0015]

[0016] Yield conditions by Tresca:

[0017]

[0018] Right now:

[0019]

[0020] Where k refers to the yield strength coefficient of Tresca material. Substituting the above formula into the internal energy consumption formula, we can get:

[0021]

[0022] According to the virtual work equation, the work done by the external force is equal to the internal energy dissipation rate, so:

[0023]

[0024] when When , the upper limit solution of the critical height of soil nailing slope under the final friction reinforcement theory can be obtained:

[0025]

[0026] Where K is the yield strength coefficient of Tresca material,

[0027] T max is the maximum tensile force when the soil nail yields;

[0028] τ max is the maximum shear stress when the soil nail yields;

[0029] S H , S v are the horizontal and vertical spacing of soil nails respectively;

[0030] γ is the weight of the soil mass on the slope;

[0031] φ is the internal friction angle of soil;

[0032] θ is the slope of the toe of the earth slope;

[0033] Surface green plant slope protection structure: Due to the existence of the slope gradient, the organic soil part separated by the geogrid in the geobag can be exposed in a stepped manner to facilitate the planting of green plants.

[0034] Preferably, in the geobag unit connection structure, the geogrid is used to connect multiple geobags to form a continuous slope protection structure, and the geogrid combined with soil nails can stabilize each geobag unit to ensure a firm connection and prevent the geobag from falling off or breaking.

[0035] Preferably, the filler of the geobag is compacted by a tamping agent so that the density of the original soil is increased, the integrity is enhanced, and it is in an unsaturated state, with a certain water-proof property to prevent rainwater from seeping in and damaging the internal structure of the slope. The unique arrangement of the geobag units can give full play to the capillary barrier effect of the unsaturated soil and play a certain role in water stopping and anti-seepage.

[0036] Preferably, in the surface green plant slope protection structure, after the green plant root system is fully developed, it can play a role in strengthening the support effect, thereby maximizing the overall reinforcement effect of the geobag, and the well-developed root system of the plant can stabilize the organic soil and prevent soil erosion.

[0037] Preferably, the soil nails are made of HRB400 steel bars with an angle of 5° to the horizontal plane. Screw end rods are welded at the ends, and the screw end rods are partially exposed outside the geobag. This structural design can provide sufficient tensile strength, enhance the stability of the system, and ensure the slope protection effect.

[0038] Preferably, the material properties and size specifications of the bag body are specific. It is made of high-strength polyester fiber material and has a rectangular shape. When filled with soil, the total length of the bottom is 1.5m, the width is 0.4m or 0.2m, and the height is 0.2m. This design is beneficial to the overall performance of the system and the capillary barrier effect, and is also convenient for construction operations and system maintenance.

[0039] Preferably, the arrangement and connection structure of the geobag units work together to not only give full play to the capillary barrier effect of unsaturated soil to stop water and prevent seepage, but also ensure the integrity and stability of the system, prevent the geobags from falling off or breaking, and improve the slope protection effect.

[0040] Preferably, the processing method and characteristics of the filler have an important impact on the system performance. By tamping and compacting the in-situ soil as filler, its density is increased, the integrity is enhanced, and it is in an unsaturated state and has a certain water-proof property. This property helps to protect the internal structure of the slope and prevent damage caused by rainwater infiltration. It is also beneficial to the stability and durability of the system.

[0041] A construction method for a slope protection system combining soil nails and geobags comprises the following steps:

[0042] For the construction operation of standard geobag 1 and standard geobag 2, the overall shape of standard geobag 1 is a rectangular parallelepiped, and the total length of its bottom surface is 1.5m;

[0043] Excavate the slope, compact the in-situ soil of the slope, and fill it into standard geobag 1 and standard geobag 2 to shape them, thereby constructing the geobag unit;

[0044] Arrange the geobags filled with aggregates. Every six standard geobags form a geobag unit. Each capillary barrier unit is composed of two layers of overlapping geobags. The first layer of geobags is composed of standard geobag 1, standard geobag 2, and standard geobag 1 filled with compacted in-situ soil from left to right. The second layer of geobags is composed of two standard geobags 1 and one standard geobag 2 filled with compacted soil from left to right. The second layer of geobags is laid horizontally 0.3m to the left of the first layer of geobags and stacked in this way.

[0045] The geobags are sealed and arranged along the slope, with standard geobags 1 and standard geobags 2 arranged alternately, four standard geobags 1 arranged at the bottom layer, and three standard geobags 1 and two standard geobags 2 arranged on the upper layer, with two standard geobags 2 arranged on both sides and three standard geobags 1 arranged in the middle, thereby forming a capillary barrier unit, and each unit is arranged in a progressive and hierarchical manner;

[0046] The top layer of each geobag unit is fixed with geogrids, among which the standard geobag 1 on the far right is not provided with geogrids; the bottom layer of each geobag unit is fixed with geogrids to connect all geobags to ensure the overall stability of the geobag unit;

[0047] The soil nails are rammed into the soil 5 cm above the center of the outermost geobag of the geobag wall. The soil nails are made of HRB400 steel bars, which form an angle of 5° with the horizontal plane and are welded with screw end rods at the ends; part of the screw end rods is exposed outside the geobag.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] 1. The present invention uses geogrids to partition the internal structure of geobag units, and also serves as a connecting structure to connect multiple geobags to form a continuous protective wall; when the geogrid stabilizes the geobag units, the use of soil nails further strengthens the integrity and stability of the geobag system. The soil nails provide sufficient tensile and friction resistance, so that the entire slope protection system has sufficient strength to cope with various severe weather conditions and even some extreme situations; after the production is completed, the geobags can be transported to the slopes that need to be reinforced for arrangement and installation, which is convenient and quick to construct and can effectively improve the project efficiency.

[0050] 2. The organic soil in the upper geotextile bag of the present invention is used to plant green vegetation, which can not only stabilize the upper structure, but also has the characteristics of green and beautiful appearance. The design of the slope protection system allows plants to grow on it, which not only reduces the impact on the ecological environment, but can also be used in combination with plant protection methods to achieve drainage and anti-seepage. In addition, the transpiration of plants is also important for the recovery of the system's function after heavy rainfall. Therefore, this slope protection system can not only achieve slope protection, but also take into account the ecological protection of the slope, and better meet the needs of environmental protection.

[0051] 3. The capillary barrier effect of the unsaturated in-situ rammed earth of the present invention enables the geobag unit to form a water-stop barrier, preventing rainwater from eroding the slope, and also preventing rainwater from rusting the soil nails, further extending the life of the soil nails and enhancing the stability of the slope protection. This structural setting makes it difficult for the coarse-grained layer to crack under the effects of dry-wet cycles and thermal expansion and contraction, ensuring the stability and durability of the system.

[0052] 4. The compacted in-situ soil in the geobag of the present invention affects the rising speed and height of capillary water, which can effectively reduce the risk of cracking of the slope soil layer below due to evaporation, while playing a role in heat preservation and insulation, further reducing soil cracks caused by thermal expansion and contraction. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 It is a force diagram of the soil nail support structure of the present invention;

[0054] Figure 2 It is a schematic diagram of the principle of the yield mechanism of the present invention;

[0055] Figure 3 It is a front cross-sectional view of a geobag unit of the present invention;

[0056] Figure 4 is a side sectional view of the slope protection system of the present invention;

[0057] Figure 5 It is a front view of the geobag unit of the present invention;

[0058] Figure 6 is a side view of a geobag unit of the present invention;

[0059] Figure 7 It is a top view of the geobag unit of the present invention. DETAILED DESCRIPTION

[0060] In order to facilitate those skilled in the art to understand the technical solution of the present invention, the technical solution of the present invention is further described in conjunction with the accompanying drawings of the specification.

[0061] like Figure 1-Figure 7As shown, a slope protection system combining soil nails and geobags is characterized by comprising

[0062] Bag body: Made of high-strength polyester fiber material, the shape is a cuboid. When filled with soil, the total length of the bottom is 1.5m, the width is 0.4m or 0.2m, and the height is 0.2m;

[0063] Filling material: the in-situ soil of the slope, which is compacted by tamping the in-situ soil obtained by excavation;

[0064] Geobag unit: It is composed of several geobags. Each layer is composed of four standard geobags 1 filled with aggregates and two standard geobags 2 filled with aggregates. A geobag unit has two layers of geobags stacked on top of each other. The first layer of geobags consists of standard geobag 1, standard geobag 2 and standard geobag 1 filled with compacted in-situ soil from left to right; the second layer of geobags consists of two standard geobags 1 and standard geobag 2 filled with compacted in-situ soil from left to right. The second layer of geobags is laid horizontally 0.5m to the left of the first layer of geobags.

[0065] Geobag unit connection structure: The main body is composed of geobag units stacked in an interlaced manner. The soil samples are divided in a stepped manner, and every two layers of geobags constitute a capillary barrier unit; from right to left, they are organic soil, fine aggregate, coarse aggregate, backfill soil and original foundation; soil samples are separated by geogrids, and each capillary barrier unit is horizontally shifted to the right by 0.5m compared to the previous capillary barrier unit. The units are separated by geogrids. In the uppermost layer of each capillary barrier unit, geogrids are used to fix standard geobags. Among them, the standard geobag 1 filled with fine aggregate on the far right is not provided with geogrids to facilitate the construction of soil nails; and in the lowermost layer of each geobag unit, all geobags are covered by geogrids;

[0066] Soil nails: Use steel bars with an angle of 5° to the horizontal plane. The ends are welded with screw end rods. The screw end rods are partially exposed outside the geobags. After the geobags are installed, they are rammed in 5 cm above the center of the outermost geobag in the geobag wall.

[0067] The reinforcement is Tresca material subject to the Tresca yield condition;

[0068] Based on the Tresca yield condition, the critical soil slope height for soil nailing slope to maintain equilibrium is derived. The power exerted by the external force is equal to the vector product of the soil weight W and the velocity v:

[0069]

[0070] The dissipation rate of internal energy is:

[0071]

[0072] Yield conditions by Tresca:

[0073]

[0074] Right now:

[0075]

[0076] Where k refers to the yield strength coefficient of Tresca material. Substituting the above formula into the internal energy consumption formula, we can get:

[0077]

[0078] According to the virtual work equation, the work done by the external force is equal to the internal energy dissipation rate, so:

[0079]

[0080] when When , the upper limit solution of the critical height of soil nailing slope under the final friction reinforcement theory can be obtained:

[0081]

[0082] Where K is the yield strength coefficient of Tresca material,

[0083] T max is the maximum tensile force when the soil nail yields;

[0084] τ max is the maximum shear stress when the soil nail yields;

[0085] S H , S v are the horizontal and vertical spacing of soil nails respectively;

[0086] γ is the weight of the soil mass on the slope;

[0087] φ is the internal friction angle of soil;

[0088] θ is the slope of the toe of the earth slope;

[0089] Surface green plant slope protection structure: Due to the existence of the slope gradient, the organic soil part separated by the geogrid in the geobag can be exposed in a stepped manner to facilitate the planting of green plants.

[0090] In the geobag unit connection structure, geogrids are used to connect multiple geobags to form a continuous slope protection structure, and geogrids with soil nails can stabilize each geobag unit to ensure a firm connection and prevent the geobag from falling off or breaking. The filler of the geobag is compacted by a tamping agent to increase the density of the original soil and enhance its integrity. It is in an unsaturated state and has a certain water-proof property to prevent rainwater from seeping in and damaging the internal structure of the slope. The unique arrangement of geobag units can give full play to the capillary barrier effect of unsaturated soil and play a certain role in water stopping and anti-seepage. In the surface green plant slope protection structure, after the root system of green plants develops and improves, it can play a role in strengthening the support, thereby maximizing the overall reinforcement of the geobag, and the developed root system of the plants can stabilize the organic soil and prevent soil and water loss. The soil nails are made of HRB400 steel bars with an angle of 5° to the horizontal plane. Screw end rods are welded at the ends, and the screw end rods are partially exposed outside the geobag. This structural design can provide sufficient tensile strength , enhance the stability of the system and ensure the slope protection effect. The material properties and size specifications of the bag body are specific. It is made of high-strength polyester fiber material and has a rectangular shape. When filled with soil, the total length of the bottom is 1.5m, the width is 0.4m or 0.2m, and the height is 0.2m. This design is conducive to the overall performance of the system and the capillary barrier effect. It is also convenient for construction operations and system maintenance. The arrangement and connection structure of the geobag units work together to not only give full play to the capillary barrier effect of unsaturated soil and play a role in water stopping and anti-seepage, but also ensure the integrity and stability of the system, prevent the geobag from falling off or breaking, and improve the slope protection effect. The processing method and characteristics of the filler have an important influence on the performance of the system. By tamping and compacting the in-situ soil as a filler, its density is increased, the integrity is enhanced, and it is in an unsaturated state and has a certain water-proof property. This characteristic helps to protect the internal structure of the slope and prevent damage caused by rainwater infiltration. It is also beneficial to the stability and durability of the system.

[0091] A construction method for a slope protection system combining soil nails and geobags comprises the following steps:

[0092] For the construction operation of standard geobag 1 and standard geobag 2, the overall shape of standard geobag 1 is a rectangular parallelepiped, and the total length of its bottom surface is 1.5m;

[0093] Excavate the slope, compact the in-situ soil of the slope, and fill it into standard geobag 1 and standard geobag 2 to shape them, thereby constructing the geobag unit;

[0094] Arrange the geobags filled with aggregates. Every six standard geobags form a geobag unit. Each capillary barrier unit is composed of two layers of overlapping geobags. The first layer of geobags is composed of standard geobag 1, standard geobag 2, and standard geobag 1 filled with compacted in-situ soil from left to right. The second layer of geobags is composed of two standard geobags 1 and one standard geobag 2 filled with compacted soil from left to right. The second layer of geobags is laid horizontally 0.3m to the left of the first layer of geobags and stacked in this way.

[0095] The geobags are sealed and arranged along the slope, with standard geobags 1 and standard geobags 2 arranged alternately, four standard geobags 1 arranged at the bottom layer, and three standard geobags 1 and two standard geobags 2 arranged on the upper layer, with two standard geobags 2 arranged on both sides and three standard geobags 1 arranged in the middle, thereby forming a capillary barrier unit, and each unit is arranged in a progressive and hierarchical manner;

[0096] The top layer of each geobag unit is fixed with geogrids, among which the standard geobag 1 on the far right is not provided with geogrids; the bottom layer of each geobag unit is fixed with geogrids to connect all geobags to ensure the overall stability of the geobag unit;

[0097] The soil nails are rammed into the soil 5 cm above the center of the outermost geobag of the geobag wall. The soil nails are made of HRB400 steel bars, which form an angle of 5° with the horizontal plane and are welded with screw end rods at the ends; part of the screw end rods is exposed outside the geobag.

[0098] Embodiment 1:

[0099] The slope was excavated and compacted, and the excavated soil was placed in several standard geobags 1 with dimensions of 1.5 meters long, 0.6 meters wide, and 0.3 meters high, and standard geobags 2 with dimensions of 1.5 meters long, 0.3 meters wide, and 0.3 meters high, and the geobags were assembled. The geobag unit was constructed by using two layers of overlapping geobags. The geobags were connected and fixed by geogrids, and then soil nails were arranged from the outermost geobag to the inner layer. Among them, the lower geobag of the geobag unit was laid horizontally 0.3 meters to the right of the upper geobag, and stacked in this way. A total of 20 geobag unit groups were used to reinforce a slope with a height of 3 meters, a width of 6 meters, and a slope of 45 degrees. The 20 geobag units were divided into 4 columns, with a total of 5 in each column, and were staggered and stacked with a horizontal spacing of 0.3 meters. Finally, organic soil is evenly covered on the outermost side of the capillary barrier unit, and green plants are planted. The green plants stabilize the surface of the slope protection system with their well-developed root system and ensure the beautiful appearance of the protection system.

[0100] Embodiment 2:

[0101] In order to reinforce a slope with a length of 7.5 meters, a height of 4.8 meters and a slope of 45°, a reinforcement method of staggered stacking of standard geobags 1 and standard geobags 2 with soil nails and geogrids was adopted. Two standard geobags 1 and one standard geobag 2 were stacked horizontally from the inside to the outside and reinforced with geogrids. The soil used in the geobags was the in-situ compacted soil of the slope; at a depth of 0.3 meters above these geobags, the corresponding geobags were stacked in the order of one standard geobag 1, one standard geobag 2 and one standard geobag 1 from the inside to the outside. A total of 16 layers of geobags were stacked in this way. These 48 geobags were regarded as a group of capillary barrier units. Each group was equipped with a soil nail for reinforcement, and five such geobag groups were set in the length direction of the slope to reinforce the slope. Finally, organic soil was used to cover the surface of the geobags to construct a geobag slope protection system with a length of 7.5 meters, a height of 4.8 meters and a slope of 45°.

[0102] The embodiments of the present invention disclose preferred embodiments, but are not limited thereto. A person skilled in the art can easily understand the spirit of the present invention based on the above embodiments and make different extensions and changes. However, as long as they do not deviate from the spirit of the present invention, they are all within the protection scope of the present invention.

Claims

1. A slope protection system combining soil nails and geobags, characterized in that: include Bag body: Made of high-strength polyester fiber material, the shape is a cuboid. When filled with soil, the total length of the bottom is 1.5m, the width is 0.4m or 0.2m, and the height is 0.2m; Filling material: the in-situ soil of the slope is compacted by tamping the in-situ soil obtained by excavation; Geobag unit: It is composed of several geobags. Each layer is composed of four standard geobags 1 filled with aggregates and two standard geobags 2 filled with aggregates. A geobag unit has two layers of geobags stacked on top of each other. The first layer of geobags consists of standard geobag 1, standard geobag 2 and standard geobag 1 filled with compacted in-situ soil from left to right; the second layer of geobags consists of two standard geobags 1 and standard geobag 2 filled with compacted in-situ soil from left to right. The second layer of geobags is laid horizontally 0.5m to the left of the first layer of geobags. Geobag unit connection structure: The main body is composed of geobag units stacked in an interlaced manner. The soil samples are divided in a stepped manner, and every two layers of geobags constitute a capillary barrier unit; from right to left, they are organic soil, fine aggregate, coarse aggregate, backfill soil and original foundation; soil samples are separated by geogrids, and each capillary barrier unit is horizontally shifted to the right by 0.5m compared to the previous capillary barrier unit. The units are separated by geogrids. In the uppermost layer of each capillary barrier unit, geogrids are used to fix standard geobags. Among them, the standard geobag 1 filled with fine aggregate on the far right is not provided with geogrids to facilitate the construction of soil nails; and in the lowermost layer of each geobag unit, all geobags are covered by geogrids; Soil nails: Use steel bars with an angle of 5° to the horizontal plane. The ends are welded with screw end rods. The screw end rods are partially exposed outside the geobags. After the geobags are installed, they are rammed in 5 cm above the center of the outermost geobag in the geobag wall. The reinforcement is Tresca material subject to the Tresca yield condition; Based on the Tresca yield condition, the critical soil slope height for soil nailing slope to maintain equilibrium is derived. The power exerted by the external force is equal to the vector product of the soil weight W and the velocity v: The dissipation rate of internal energy is: Yield conditions by Tresca: Right now: Where k refers to the yield strength coefficient of Tresca material. Substituting the above formula into the internal energy consumption formula, we can get: According to the virtual work equation, the work done by the external force is equal to the internal energy dissipation rate, so: when When , the upper limit solution of the critical height of soil nailing slope under the final friction reinforcement theory can be obtained: Where K is the yield strength coefficient of Tresca material, T max is the maximum tensile force when the soil nail yields; τ max is the maximum shear stress when the soil nail yields; S H , S v are the horizontal and vertical spacing of soil nails respectively; γ is the weight of the soil mass on the slope; φ is the internal friction angle of soil; θ is the slope of the toe of the earth slope; Surface green plant slope protection structure: Due to the existence of the slope gradient, the organic soil part separated by the geogrid in the geobag can be exposed in a stepped manner to facilitate the planting of green plants.

2. A slope protection system combining soil nails and geobags according to claim 1, characterized in that: In the geobag unit connection structure, the geogrid is used to connect multiple geobags to form a continuous slope protection structure, and the geogrid combined with soil nails can stabilize each geobag unit, ensure a firm connection, and prevent the geobag from falling off or breaking.

3. A slope protection system combining soil nails and geobags according to claim 2, characterized in that: The filler of the geobag is compacted by a tamping agent to increase the density of the original soil and enhance its integrity. It is in an unsaturated state and has a certain water-proof property to prevent rainwater from seeping in and damaging the internal structure of the slope. The unique arrangement of the geobag units can give full play to the capillary barrier effect of the unsaturated soil and play a certain role in water stopping and preventing seepage.

4. A slope protection system combining soil nails and geobags according to claim 3, characterized in that: In the surface green plant slope protection structure, after the green plant root system is fully developed, it can play a role in strengthening the support effect, thereby maximizing the overall reinforcement effect of the geobag, and the well-developed root system of the plant can stabilize the organic soil and prevent soil erosion.

5. A slope protection system combining soil nails and geobags according to claim 4, characterized in that: The soil nails are made of HRB400 steel bars with an angle of 5° to the horizontal plane. Screw end rods are welded at the ends, and the screw end rods are partially exposed outside the geobag. This structural design can provide sufficient tensile strength, enhance the stability of the system, and ensure the slope protection effect.

6. A slope protection system combining soil nails and geobags according to claim 5, characterized in that: The material properties and size specifications of the bag body are specific. It is made of high-strength polyester fiber material and has a rectangular shape. When filled with soil, the total length of the bottom is 1.5m, the width is 0.4m or 0.2m, and the height is 0.2m. This design is beneficial to the overall performance of the system and the capillary barrier effect, and is also convenient for construction operations and system maintenance.

7. A slope protection system combining soil nails and geobags according to claim 6, characterized in that: The arrangement and connection structure of the geobag units work together to not only give full play to the capillary barrier effect of unsaturated soil to stop water and prevent seepage, but also ensure the integrity and stability of the system, prevent the geobags from falling off or breaking, and improve the slope protection effect.

8. The slope protection system combining soil nails and geobags according to claim 7 is characterized in that: The processing method and characteristics of the filler have an important impact on the system performance. By tamping and compacting the in-situ soil as filler, its density is increased, the integrity is enhanced, and it is in an unsaturated state and has a certain water-proof property. This property helps to protect the internal structure of the slope and prevent damage caused by rainwater infiltration. It is also beneficial to the stability and durability of the system.

9. A construction method for a slope protection system combining soil nails and geobags, characterized in that: The following steps are involved: For the construction operation of standard geobag 1 and standard geobag 2, the overall shape of standard geobag 1 is a rectangular parallelepiped, and the total length of its bottom surface is 1.5m; Excavate the slope, compact the in-situ soil of the slope, and fill it into standard geobag 1 and standard geobag 2 to shape them, thereby constructing the geobag unit; Arrange the geobags filled with aggregates. Every six standard geobags form a geobag unit. Each capillary barrier unit is composed of two layers of overlapping geobags. The first layer of geobags is composed of standard geobag 1, standard geobag 2, and standard geobag 1 filled with compacted in-situ soil from left to right. The second layer of geobags is composed of two standard geobags 1 and one standard geobag 2 filled with compacted soil from left to right. The second layer of geobags is laid horizontally 0.3m to the left of the first layer of geobags and stacked in this way. The geobags are sealed and arranged along the slope, with standard geobags 1 and standard geobags 2 arranged alternately, four standard geobags 1 arranged at the bottom layer, and three standard geobags 1 and two standard geobags 2 arranged on the upper layer, with two standard geobags 2 arranged on both sides and three standard geobags 1 arranged in the middle, thereby forming a capillary barrier unit, and each unit is arranged in a progressive and hierarchical manner; The top layer of each geobag unit is fixed with geogrids, among which the standard geobag 1 on the far right is not provided with geogrids; the bottom layer of each geobag unit is fixed with geogrids to connect all geobags to ensure the overall stability of the geobag unit; The soil nails are rammed into the soil 5 cm above the center of the outermost geobag of the geobag wall. The soil nails are made of HRB400 steel bars, which form an angle of 5° with the horizontal plane and are welded with screw end rods at the ends; part of the screw end rods is exposed outside the geobag.

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