Two-dimensional plane strain consolidation for unsaturated soils with a strip-shaped distributed permeable boundary

摘要

The preloading consolidation method has been widely applied to ground treatment. In this case, the top surface of unsaturated soil stratum is fully covered with a geosynthetics blanket to aid water and air flowing from the soil, which may cause uneconomic and wasteful design. This paper presents semi-analytical solutions of twodimensional (2D) plane strain consolidation for unsaturated soils with a strip-shaped distributed permeable boundary. Based on the 2D consolidation theory proposed by Dakshanamurthy and Fredlund (1980), semianalytical solutions of excess pore pressures and settlement in Laplace domain are derived by jointly adopting Fourier sine series, Laplace transformation, and differential operator method. Then, the analytical solutions in the time domain are derived and the corresponding computing program is developed based on Crump's method. The validity of obtained solutions has been conducted by comparing the current solutions with those under the permeable top boundary in the literature. A series of calculating examples are performed to study the consolidation properties under a strip-shaped distributed permeable boundary. Parametric studies are carried out for the 2D distribution of excess pore pressures and settlement considering the coverage percentage of geosynthetics, anisotropy consolidation coefficient, the width and thickness of unsaturated soil stratum.