Loess foundation unstable slope backfill retaining structure

Abstract

A backfill retaining structure for unstable slopes in collapsible loess foundations is disclosed. This structure mainly comprises weather-resistant vegetation bags filled with silty clay containing grass seeds, ordinary vegetation bags filled with silty clay, and lime-soil compaction piles. The lime-soil compaction piles are arranged within the collapsible loess foundation. Weather-resistant vegetation bags and ordinary vegetation bags are arranged sequentially from the outside to the inside of the upper part of the collapsible loess foundation, and backfilled layer by layer with compaction. A backfill soil layer is placed between the unstable slope and the tail of the ordinary vegetation bags. The ordinary vegetation bags are wrapped and counter-compressed with geogrid every 3-4 layers; the ends are fixed to the geogrid with staggered anchor bars. This invention satisfies the bearing capacity requirements of the collapsible loess foundation and also resists horizontal thrust on the backfill soil of the slope, allowing the structure to fully perform its functions, minimizing environmental disturbance, and the planted grass seeds beautify the surrounding environment.

Description

Technical Field

[0001] This utility model relates to the field of slope reinforcement engineering construction, specifically to a backfilling and retaining structure for unstable slopes on collapsible loess foundations. Background Technology

[0002] In the field of engineering, the design and construction technology of retaining structures for embankment slopes has become an important topic.

[0003] In practice, people have found that reinforced concrete retaining walls are mostly used for slope backfilling. The limitations of this traditional design are as follows: (1) The wall material is mainly reinforced concrete, which requires multiple construction steps such as formwork, reinforcement binding, and pouring. The construction cycle is long, especially in remote mountainous areas where the material transportation cost is high. (2) The wall color after demolding is mainly bluish-gray (concrete color), which is not in harmony with the surrounding environment of the mountainous area. If the retaining wall needs to be demolished in the future, it will be time-consuming and laborious, and the concrete and other construction waste after demolition will pollute the environment. (3) The retaining wall has high requirements for the longitudinal drainage blind ditch behind the wall. The water in the backfill soil behind the wall can only be discharged through limited drainage holes. (4) The construction of the retaining wall has special requirements. When the wall foundation is excavated, it may affect the stability of the slope. Full excavation is not allowed. Large trench construction must be carried out in sections. The excavation section must be followed by the construction section. The construction cycle is long and the overall stability requirements of the slope are high.

[0004] It is evident that traditional support structures have many technical shortcomings, which are problems that urgently need to be solved in this field. Utility Model Content

[0005] This utility model provides a backfill retaining structure for unstable slopes in collapsible loess foundations. It is easy to construct, reduces the high bearing capacity requirements of collapsible loess foundations, causes little environmental pollution after demolition, beautifies the surrounding environment, and is suitable for mountainous areas or areas where material transportation is inconvenient.

[0006] To solve the above problems, the technical solution adopted by this utility model is as follows:

[0007] A backfill retaining structure for unstable slopes in collapsible loess foundations is disclosed. The retaining structure mainly includes weathering-resistant vegetation bags filled with silty clay containing grass seeds, ordinary vegetation bags filled with silty clay, and lime-soil compaction piles. The lime-soil compaction piles are arranged in the collapsible loess foundation. Weathering-resistant vegetation bags and ordinary vegetation bags are arranged from the outside to the inside of the upper part of the collapsible loess foundation and backfilled layer by layer with compaction. A backfill soil layer is set between the unstable slope and the tail of the ordinary vegetation bags.

[0008] The ordinary planting bags are wrapped and pressed with geogrid every 3 to 4 layers; the ends are fixed with staggered anchor bars.

[0009] This utility model of retaining structure is mainly used in collapsible loess areas where the weight of the backfill structure places high demands on the bearing capacity of the foundation after treatment. The structure not only supports the backfill soil but also beautifies the surrounding environment, achieving a "dual-purpose" effect. Compared with existing technologies, this utility model has the following advantages:

[0010] 1. It reduces the bearing capacity requirements of traditional reinforced concrete retaining walls for collapsible loess foundation treatment.

[0011] 2. Reduce the use of building materials such as steel bars and concrete. The soil in the planting bags can be sourced locally, reducing material transportation and construction costs. Grass seeds are plants adapted to the local climate and have a high survival rate. Herbaceous plants on the retaining structure can blend in with the surrounding environment.

[0012] 3. It reduces the risk of environmental pollution. The color of traditional reinforced concrete retaining walls after demolding is mainly bluish-gray (the color of concrete), which is inconsistent with the surrounding environment in mountainous areas. If the retaining wall needs to be demolished in the future, it will be time-consuming and labor-intensive, and the concrete and other construction waste will pollute the environment.

[0013] 4. It avoids affecting the stability of the slope when the reinforced concrete wall foundation is excavated, and the construction of lime-soil compaction piles has less impact on slope vibration. Attached Figure Description

[0014] Figure 1 This is a schematic cross-sectional view of the structure of this utility model;

[0015] In the figure: 1—weather-resistant vegetation bag, 2—ordinary vegetation bag, 3—geogrid, 4—anchor reinforcement, 5—backfill soil, 6—lime-soil compaction pile, 7—collapseable loess, 8—unstable slope, 9—potential slip surface. Detailed Implementation

[0016] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings.

[0017] refer to Figure 1 A backfill retaining structure for unstable slopes in collapsible loess foundations is disclosed, primarily comprising weather-resistant vegetation bags 1 filled with silty clay containing grass seeds, ordinary vegetation bags 2 filled with silty clay, geogrid 3, anchor bars 4, and lime-soil compaction piles 6. The lime-soil compaction piles 6 are arranged within the collapsible loess foundation 7. Weather-resistant vegetation bags 1 and ordinary vegetation bags 2 are arranged sequentially from the outside to the inside of the collapsible loess foundation 7, and backfilled layer by layer with compaction. A backfill soil layer 5 is provided between the unstable slope 8 and the tail of the ordinary vegetation bags 2.

[0018] Firstly, the collapsible loess foundation 7 should be treated with lime-soil compaction piles 6 to ensure that the superstructure meets the requirements for bearing capacity and collapsibility. The foundation treatment process does not require foundation excavation, minimizes construction interference on the unstable slope 8, and reduces the likelihood of collapse during construction.

[0019] After the foundation treatment is completed, weather-resistant vegetation bags 1 and ordinary vegetation bags 2 are used to compact the unstable slope 8 layer by layer. The slope ratio of the compaction is controlled according to the site conditions and design requirements. Weather-resistant vegetation bags 1 are filled on the outside and ordinary vegetation bags 2 are filled on the inside. The bags are staggered and overlapped. Backfill soil layer 5 can be used for compaction near the unstable slope 8. The vegetation bags should be compacted to inhibit the penetration and development of potential slip surfaces 9, and to strengthen the unstable slope 8.

[0020] After the weather-resistant vegetation bags 1 on the outer side are compacted, water is sprayed on the surface, and the grass seeds can take root and sprout, which can beautify the surrounding environment.

[0021] During the filling process, ordinary vegetation bags 2 are wrapped and compressed with geogrid 3 every 3 to 4 layers. The ends are fixed with staggered anchor bars 4 to the geogrid 3 to ensure the overall stability of the compacted ordinary vegetation bags 2. This process should follow the principle of "from low to high, from outside to inside".

[0022] The technical solution provided by this utility model has been described in detail above. Specific examples have been used to illustrate the principle and implementation of this utility model. The descriptions of the embodiments above are only for the purpose of helping to understand the structure and core idea of ​​this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made to this utility model without departing from the principle of this utility model, and these improvements and modifications also fall within the protection scope of the claims of this utility model.

Claims

1. A backfill retaining structure for unstable slopes in collapsible loess foundations, characterized in that, The retaining structure mainly includes weathering-resistant planting bags (1) filled with silty clay containing grass seeds, ordinary planting bags (2) filled with silty clay, and lime-soil compaction piles (6); the lime-soil compaction piles (6) are arranged in the collapsible loess foundation (7), and weathering-resistant planting bags (1) and ordinary planting bags (2) are arranged from the outside to the inside on the upper part of the collapsible loess foundation (7) and backfilled layer by layer; a backfill soil layer (5) is set between the unstable slope (8) and the tail of the ordinary planting bag (2).

2. The backfill retaining structure for unstable slopes in collapsible loess foundations according to claim 1, characterized in that, The ordinary planting bag (2) is wrapped and pressed with geogrid (3) every 3 to 4 layers; the ends are fixed with staggered anchor bars (4) for the geogrid.

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