Shakedown behavior of saturated weathered red mudstone

Red mudstone is widely distributed in the southwest part of China, and it has been used as the fill material in the construction of railway embankment. Shakedown behavior of saturated red mudstone fill material(SRMF) was characterized via a series of drained cyclic triaxial tests. Three types of deformation response were recorded in this study. Strong correlation was observed between deformation response and stress state (confining pressure, cyclic amplitude and cyclic stress ratio). In order to determine the shakedown limit and the creep limit, responses of axial strain, axial strain rate and dissipated energy were used. Especially for the determination of the creep limit, correlation between dissipated energy and cyclic stress ratio was used to overcoming the difficulty encountered in conventional method. Tests results showed that the cyclic stress ratios corresponding to the shakedown and creep limits were lower than the monotonic compression strength. A clear power function was identified to correlate the limits with confining pressure.