Stability and Deformation Analysis of Embankment on Soft Clay

Abstract

Soft clay generally poses a problem for civil engineers due to its high compressibility and low shear strength. Structures built on soft soil are subjected to excessive settlement and the settlement is attributed to the consolidation process. A large percentage of the settlement is accredited to a consolidation process that could persist for a long period, depending on the ability of the soil to dispel excess pore water. Prediction of the settlement of embankment is important for the design of the highway, to prevent excessive post-construction settlement which can lead to failure. Construction on soft clays has become more important and common in urban areas In this study, the time-settlement behavior of an embankment on soft clay predicted using analytical methods is compared with those predicted by Geo studio SIGMA/W software. Thus the magnitudes of final settlement using Terzaghi theory differ from the magnitudes of final settlement computed from SIGMA/W software by approximately ±10% difference. The differences could be due to the assumption properties such as Young’s modulus (E) and Poisson’s ratio (ν) in the SIGMA/W Geo studio, and the coefficient of compressibility considered in the analytical method. Moreover, this study presented the results of the stability analysis of the embankment on soft clay, and the performances of the barrier were analyzed. The limit equilibrium method (LEM) using Geo studio SLOPE/W software and hand calculations were used to calculate the factor of safety. The results showed that the calculated factors of safety obtained from Fellenius, Bishop, Janbu, and Morgenstern-Price methods using both ways are very similar, with an approximate difference of only ±10%.