粘性土斜面の掘削に伴う応力 : ひずみ挙動と安定性評価について

Abstract

It has been known that stress release produced by excavation in the ground causes reduction in confining pressure and swelling of soils, which in turn result in a loss of shear strength to be required for slope stability. In the ground composed of a sedimentary soft rock such as mudstone, which is expansive and/or ready to show slaking, change in soil properties due to stress release can be another influential factor for slope instability. This paper concerns behavior of cut slopes composed of expansive mudstone. FEM analysis was carried out to investigate deformation of slope surface due to swelling and stress redistribution (stress release) developed in the ground by excavation, by introducing actual swelling properties of mudstone obtained in the laboratory. Stability evaluation was then conducted by use of FEM and the Bishop's approach in order to discuss accuracy and reliability of the estimated behavior of clay slopes.