Numerical analysis for bearing capacity of undrained two-layer clays by FEM with strength reduction

Classical theory formulae of ultimate bearing capacity are considered only applicable to homogeneous ground.For nonhomogeneous ground of two-layer soils,there is a more reasonable and rigorous method based on finite element method with strength reduction.Plaxis8.2,a finite element software for geotechnical engineering,is able to calculate safety factor of foundations by finite element method with strength reduction.By comparing to Prandtl's solution,the precision of plaxis is considered well satisfying.Then plaxis was used to building the model of undrained two-layer soils clays and educed ultimate bearing capacity which is related to the thickness of upper layer and the strength of sublayer.Based on the results,the influence factor and characteristic of ultimate bearing capacity were analysed in detail.