Abstract：Soil lateral dilation is one of the important factors causing foundation settlement，but the results of one- dimensional layer-wise summation method(LSM) can not consider lateral deformation because it is based on the uniaxial compression test with lateral deformation being completely confined. In order to improve the settlement calculation accuracy of highway embankment on soft ground，the modified formulae which combine with height of embankment and void ratio of common clay and soft clay in roadbed are put forward according to nonlinear FEM analyses，which are applicable to uniform or nonuniform roadbeds. Examples prove that，with this method，one-dimensional methods can consider soil lateral deformation and their results are much close to the measurements；so these formulae are of significance in practical projects.
