Stability analysis of embankment on soft ground (a case study)

Abstract

The effects of partial drainage and construction settlement on stability analysis of embankment on soft ground have been investigated by analyzing a built to failure embankment on Muar clay deposit, Malaysian. Although for design, ignoring the partial drainage and construction settlement effects in stability analysis is on safe side, to understand the failure mechanism and to back-analyze the mobilized strength of soft ground at failure, these effects need to be considered. For the embankment analyzed, undrained strength increase and settlement of the ground during construction can cause a increase of factor of safety by about 0.2, or each of the effect by 0.1. The contour of shear stress level (shear stress/shear strength) of the soft ground has been analyzed from finite element analysis results. It has been illustrated that the contour of shear stress level of soft ground can indicate the stability condition of the embankment. At the embankment failure, a large area beneath the embankment and around the embankment toe, the shear stress level is 1.0. However, finite element analysis yields a poor simulation of the foundation deformation ratio (horizontal/vertical).