Numerical Analysis Of The Long-term Stability Of The Expansive Soil Embankment

This thesis is based on the Nanyang someone highway and the object of thestudy being the typical expansive soil in Nanyang. On the basis of the theoreticalanalysis of the particular engineering properties of expansive soil, the thesis givessufficient consideration to the role of the temperature and humidity changes caused bythe environmental factors such as rainfall infiltration, evapotranspiration and changesin groundwater. What’s more, through the basic properties of expansive soil test andindoor environment simulation experiments, numerical analysis and calculation on theembankment slope stability, the thesis explores the impact mechanism of the soilmoisture migration patterns to the long-term stability of expansive soil embankmentunder the role of environmental factors. In addition, the thesis consults theembankment filling and construction program and proposes the correspondingconstruction technology methods.By analysis of the special engineering behavior of expansive soil,summed thatmoisture migration caused by climate forcing is the main factor of affecting expansivesoil engineering properties, which shows the special traits of environmental impact toexpansive soils.For the typical soil, consider changes in soil moisture content and dry cycles onthe long-term strength of expansive soil, carried out a series of physical andmechanical properties of test results and show: using improved expansive soil withlime is an effective way to restrain the contraction of expansive soils, and remarkably improve its permeability and water holding capacity, and enhance the long-termintensity of expansive soils.Consider rainfall infiltration, evapotranspiration, and changes in groundwater andother environmental factors, the use of finite element software GeoStudio VADOSE/Wmodules and SLOPE/W modules for different working conditions embankment workscarried out numerical simulation analysis, the results showed that:when the atmospheric environment continues to be dry, the body stability of both plainsoil embankment and improved expansive lime soil embankment can meet theregulatory requirements, and the safety of the improved expansive lime soilembankment body stability is higher than the plain soil embankment.Therefore, edgingexpansive soil embankment with improved expansive soil with lime can effectivelyresist harsh weather environment effects and ensure long-term stability of thesubgrade.