cological treatment of the channel in expansive soil section of the Water diversion project from the Yangtze to Huaihe River
- Article
- Figures
- Metrics
- Preview PDF
- Reference
- Related
- Cited by
- Materials
Abstract:
Total length of the Yangtze-to-Huaihe Water Transfer Project is 723 km, more than 100 km of the river section is distributed with weak and medium expansive soil, and the maximum excavation depth of the canal is 46 m. The stability of the expansive soil section is one of the key technical problems of the project. In the preliminary design stage, the treatment measures of over digging, replacing and filling cement-modified soil were proposed for the expanded land section, but some ecological and environmental problems were generated, such as the cement modified soil is easy to be alkali, and makes it difficult for plants to grow. Moreover, slope overcutting would produce a large amount of waste soil which is adverse to the ecological environment. Whether simplified treatment measures can be applied to some weak expansion channels with slope heights less than 10 m is a question that needs to be addressed.Under the principle of ecological priority and technological innovation, the researchers carried out systematic research work using field experiments, indoor unit tests, and numerical analysis. The ecological restoration scheme using surface cultivated soil and grass was put forward through field sampling tests and numerical analysis for the low river embankment in the weak expansive soil around Chaohu Lake. An ecological substrate was developed to solve the problems such as soil alkali plate and plant growth difficulty in the medium expansive cement-modified soil replacement layer. The field pilot test proved that the ecological substrate is a new kind of ecological slope planting material. An ecologically friendly expansive soil slope protection structure is proposed using unsaturated soil theory based on the characteristics of a large difference in permeability coefficient between sand and clay. This structure can better solve the dual protection requirements of expansive soil slopes to prevent rainfall infiltration and water evaporation. At the same time, it can also use the compression effect of the sand layer to restrain the expansion and deformation of soil layer.The field pilot test and application results show that the ecological substrate developed can adapt to the planting needs of cement-modified soil so that the slope can achieve a good greening effect. The double-layer slope protection structure can better solve the dual protection requirements of the expansive soil slope to prevent rainfall infiltration and water evaporation. The expansion and deformation of the soil layer can also be controlled by the compression effect of the sand layer. The research results provide technical support for the engineering design and late operation management of the project, effectively solving the technical problems related to the expansion land section of the project, and provide a basis for the design and optimization of related river slope. Together, breakthroughs have been made in the engineering application of unsaturated soil theory and the ecological treatment of expansive soil slopes.
Keywords:
Project Supported:
Clc Number:
Mobile website
® 2024 All Rights Reserved
冀公网安备13010502002656号
冀公网安备13010502002656号