Influence of Widened Embankment on the Slope of Existing Pavement on Soft Soils

Adding a new embankment adjacent to the existing highway embankment is a cost effective choice compared with building another new one and can mitigate the heavy traffic pressure. However, it may also cause some engineering problems including the change of slope of existing pavement or even local or global instability of embankments especially those on soft soils. How to prevent excessive change of the slope of the existing pavement induced by widening the existing embankments is of great importance in engineering practice. A numerical analysis by using a commercial FEM program was performed to explore the influence of the thickness of soft foundation soils, the widening width and the embankment height as well as the starting time of widening construction on the slope of the existing pavement. The results indicate that the bigger the thickness of the foundation soils as well as the bigger the widening width will result in bigger values of the slope of the existing pavement, especially at the early period of reconsolidation. Adverse slope will be induced by widening of the existing embankment.