Abstract: An integrated corrected formula for settlement related to compressibility of subbed soil layer and the height of earth bank is obtained by a large quantity of non-linear FEM calculation using the data from a certain freeway. After corrected by formula the calculation result from unidirectional compression index method is available to considering lateral deformation. The case study has shown that the settlement value corrected by this formula is much more approaching the observed value, error is tiny, and can be referred by other projects.