The factors affecting the behaviour of soft soil under cyclic loading in railway
The design of rail tracks is often challenged by the high compressible behaviour of soft estuarine clays under cyclic loading. In the coastlines of NSW and QLD in particular have very soft clays character-ised by low bearing capacity and excessive settlement. Due to the ongoing pressure by the community to ac-quire high speed rail for greater commuter efficiency and faster heavy haul for improved mining and agricul-ture productivity, the need for detailed studies involving moving loads with high cyclic frequencies is paramount. In this study, apart from the general non-linear stress strain behaviour of soft subgrade soil, how the physical and mechanical properties are affecting the soft soil in terms of developing excess pore water pressure and axial strains under cyclic loading. The rates of degradation of the soil stiffness, the final resilient modulus and the damping ratio related to hysteresis have also been considered. Detailed experimental efforts and outcomes support the conclusion and the analysis should be carried out incorporating with the essential factors such as the cyclic stress ratio, frequency, number of cycles to failure, applied confining pressure, and principal stress rotation.