Abstract
In this study, an attempt has been made to investigate the deformation and moisture transfer behaviour of Shirahama sandstone using small cylindrical samples. A series of comprehensive laboratory experiments were performed in one-dimensional moisture transfer condition under zero confining pressure. Saturated cylindrical samples were dried in a climatic chamber and thereafter rewetted by high air humidity while deformation and evaporative water loss were being monitored. The quasi-continuous strain measurements gave three-dimensional deformability of the samples with respect to water content variation. The results obtained from the experiments were further used to evaluate matric suction evolution following the linear poroelastic relation. Following this the observed strains and estimated matric suctions were examined in conjunction with their pore structures obtained from mercury intrusion porosimetry. Moreover, mercury intrusion porosimetry also helped to understand the nature of pore available in the samples and their relative abundance in the selection of the mathematical model to represent the estimated matric suction behaviour. This study revealed that Shirahama sandstone can withstand the volume reduction until saturation decreased to 60% and will not show significant hardening until saturation lower than 50%. Although, further testing and confirmation by numerical modeling is required to understand this behaviour more completely, the present experimental test results shed light on essential elements in the studies of ground movement, fluid flow and isolation properties around underground facilities and large structure foundation.
