Unconfined compression shear strength of an unsaturated silty soil subjected to high total suctions

There does not appear to be data available that shows the relationship between the soil-water characteristic curve and experimental shear strength beyond the residual stale. This paper describes the shear strength of a compacted unsaturated silty soil beyond residual conditions. This study involved performing unconfined compression tests on a compacted unsaturated silty soil subjected to high total suction. The soil-water characteristic curves also measured over a wide range of suctions. The highest total suction was maximum 93,600 kPa corresponding to a relative humidity of 50 %. The relationship between shear strength and total suction for the silty soil shows an essentially horizontal failure surface beyond residual conditions. Prior to the soil reaching residual conditions, the failure envelope is non-linear.