The Application Of Theory Of Unsaturated Soil In High Liquid Limit Clay Embankment

Generally speaking,embankment is above water level and the soil is unsaturated. The settlement of embankment is calculated with the traditional consolidation theory of saturated soil. There are many questions which can't accord with the reality. In this paper, the settlement of embankment will be calculated with unsaturated soil theory.For unsaturated soil, although solid and liquid is not compressed, gas is compressible. Unsaturated soil is three phase soil. Not only in compression, but also in seepage, it is much complexer than the saturated soil(two phase soil). By this time, there don't have any consolidation theory of unsaturated soil which adapt to all state. Based on two phase flow consolidation theory of unsaturated soil devised by Fredlund and Hasan, this paper supposes that air pressure is the atmospheric pressure in the process of consolidation.The characteristic of the high liquid limit clay is analysed by field test and room test and the GeoStudio FEM software is used to calculate some freeway of Fujian. Because the nature foundation is below water level and the deformation produced in the process of the filling is small, the linear elasticity model, combining with Biot consolidation theory can be used to coupled calculate. High liquid limit filling clay is unsaturated soil. The deformation is great in the process of the pressing. Therefore, unsaturated soil consolidation theory combining with Duncan-Chang model is used to coupled calculate.Application of unsaturated soil theory in project is at the exploration stage. This paper calculates the consolidation of embankment of high liquid limit clay with unsaturated soil theory, and analyses the rationality of the resule. The study is a beneficial attempt for the unsaturated soil consolidation theory application in embankment.