ANALYSIS OF CONSOLIDATION BEHAVIOR OF SUBSOILS UNDER CYCLIC TRAPEZOIDAL LOADING

الملخص

This paper is aiming to develop a numerical procedure using the finite element method for the
analysis of soil consolidation by taking into consideration the loading and unloading cycles with
particular emphases on the pore pressure built up. The study is concerned with trapezoidal cyclic
loading. The shear stresses that are developed in the subsoil due to cyclic loading cause shear strains
and change in the mean normal stresses due to distortion of soil element. Biot’s consolidation theory
that adopted in this study may be able to take these changes into consideration. The results indicated
that the excess pore water pressure increases with load cycles and finally, a steady state conditions are
reached. This may be attributed to the undrained cyclic shearing stresses to the origin initial cyclic
shear stress ratio. Also it can be explained that when the load is applied very fast the collapse load
approaches that undrained conditions, whereas when the load is applied very slowly the collapse load
approaches that under drained conditions. When the elastoplastic model is considered the pore pressure
are considerably larger than those predicted by the elastic consolidation analysis. This can be attributed
to the plastic volume strain that have been taken into consideration in the elastoplastic model.