Abstract

Generally, the effects of suction in fine sands can be evidenced by a stiffening of the material, as the capillary front advances in the granular skeleton. In geotechnical retention structures this effect can be translated in an increasing of earth pressure, which is not normally considered in geotechnical designs. This study analyzes the capillary effects by implementing a physical modelling in centrifuge and a numerical simulation, using different constitutive models that involve suction within the analysis. The modelling is based on a structure of retention in sheetpiles built on a real scale. Some factors that affect both physical and numerical modelling were taken into account and should be considered in the analysis of the results obtained and, in the comparisons, carried out by both methodologies. As a point of interest, numerical modelling showed less dispersion in the results obtained than physical modelling, these and other aspects are analyzed in the document

Abstract

The Wave Based Method (WBM), which describes field variables of a boundary value problem with weighted wave functions, is used to model a layered halfspace under harmonic loading. This 2D soil structure is investigated for partially saturated layers. According to the Berryman-Thigpen-Chin model (BTC model) the capillary effects between the water and air phases enclosed by pores are negligibly small for elastic waves in the low frequency range. The mixture of water and air is treated as one fluid, for which the material parameters used in Biot's theory for fully saturated poroelastic structures have to be computed. Within this work, the BTC model is applied to describe soil layers within a halfspace, which are not perfectly dry or fully saturated. It is presented how the degree of saturation within a partially saturated soil layer affects the system's response.