Study on Mechanical Behaviors of Unsaturated Loess in terms of Moistening Level

Abstract

Water sensitivity is the special feature of unsaturated loess, which is the main cause of engineering problems in loessial regions. Previous studies have generally focused on potential changes on mechanical properties of loess when it is moistened to saturation, while the moistening process is often ignored. In order to investigate the mechanical behaviors of unsaturated loess during the moistening process, this paper takes unsaturated loess obtained from Ili, Xinjiang Autonomous Regions, China, as study object. A self-developed oedometer was used which was available for adding water into the soil sample during loading, measuring the coefficient of earth pressure at rest and matrix suction during moistening. Loess samples obtained from 3 buried depths were tested under 4 different vertical loads. The moistening level was defined to refer to the relative level of water content with regard to the initial and saturated water contents of a soil sample. Change tendencies of moistening deformation, the coefficient of earth pressure at rest as well as suction versus the moistening level were investigated.