A practical procedure for determining soil parameters of peat for finite element analysis using the cam clay model

Abstract

This paper presents a practical procedure for determining soil parameters used when analysing the deformation of peat ground by finite element analysis (FE analysis) using the Cam clay model. In practice, FE analysis has not been used frequently to predict the deformation of peat ground, even though FE analysis can be a powerful tool for its prediction. The main reason is that a practical method for determining parameters has not been established. In this paper, firstly, the remarkable correlation between the soil parameters required for FE analysis using the Cam clay model and the natural water content (w n ) and ignition loss (L i ), respectively, of peat and organic clay is presented. Next, based on this correlation, a flowchart for determining the soil parameters of peat and organic clay is proposed. By using this chart, it is possible to directly determine the soil parameters from triaxial compression, oedometer and other detailed tests or to estimate the soil parameters from w n , L i and other physical indexes. We also conducted a trial embankment on peat ground in Hokkaido, Japan. FE analysis was performed on the trial embankment using the proposed procedure for determining soil parameters. The results of the FE analysis corresponded to the measured settlement behaviour in the trial embankment with an accuracy in the range of −4% to +8%. The FE analysis results also expressed the measured behaviour of pore water pressure and lateral and vertical displacement in the trial embankment very well.