Spatial Variability of Material Parameter and Bearing Capacity of Clay

Abstract

A stochastic analysis that incorporates spatial variability of material parameter of clay i.e. undrained shear strength, c within the finite element analysis was done. A smoother change of c between two neighbouring soil elements is expected than two elements at a distance apart, thus a spatial correlation length is used within the random field to describe the distance over which random values tend to be correlated. When the correlation lengths in horizontal and vertical directions are same, the soil elements can be described ‘isotropic’. Most of the previous studies investigated the effect of variation of c in terms of coefficient of variation, COV (standard deviation/mean) and the isotropic correlation length on bearing capacity. However, the correlation length of soil may not be isotropic as they may be deposited in layers i.e. correlation length in horizontal direction may be higher than that in vertical direction. Thus, this study investigated the effect of isotropic as well as anisotropic (in terms of correlation length) conditions and their lengths over a range of COV of c on the bearing capacity. The result of this study would help to understand the effect of soil anisotropy on bearing capacity.