Numerical Analysis of Steps Excavation Plans at the New and Old Subgrade Interaction Part by FEM

Abstract

Highway widening is a very important component of highway construction in China. For subgrade widening, the steps to excavate the old side slope and construct the new embankment in layers is the method used commonly at the new and old subgrade interaction part in the subgrade widen project. Combining the reality of many highway widening projects, excavation steps at the new and old subgrade interaction part, define four plans of the steps excavation. According to the actual Hatong highway widening project, the geometric analyzing model was determined and the physical and mechanical parameters of soil were gained by the test of the site survey and different soils. The numerical simulation and the analysis was done by using the elastic-plasticity finite element software ABAQUS for the different excavation steps and new embankment construction. The appropriate step excavation plan was suggested and the main corresponding construction points were given. The results have the practical significance to enhance the effective union of the new and the old subgrade to reduce the unequal settlement of the new and old subgrade and to reduce to the old road's damage.