Influence of the initial static stress state on the accumulation behaviour of a coarse-grained soil under long-term cyclic loading

A series of cyclic triaxial tests were carried out to explore the accumulation behaviour of coarse-grained soil (CGS) with different initial static stress states. The test results show that more accumulated axial strain can be detected for the specimen with a higher initial stress ratio or a lower confining stress under identical cyclic loading. The plastic shakedown limits are then identified, which indicates that a higher initial stress ratio or a lower confining pressure yields a lower plastic shakedown limit. Furthermore, the stress states at the plastic shakedown limit for the soils with various initial static stress states are presented in the plane of p -q, and all data trended towards converging on a straight line, which is approximately parallel to the strength envelope. A united plastic shakedown criterion is then proposed for soils under different initial stress states, which provides a simple approach to predicting the plastic shakedown limit.

Automated summary

A series of cyclic triaxial tests were conducted to investigate the accumulation behavior of coarse-grained soil (CGS) under different initial static stress states. The results show that specimens with higher initial stress ratios or lower confining stresses exhibit greater accumulated axial strain under identical cyclic loading. The plastic shakedown limits were identified, indicating that higher initial stress ratios or lower confining pressures result in lower plastic shakedown limits. Furthermore, the stress states at the plastic shakedown limit for soils with various initial stress states were plotted in the p-q plane and showed a convergence towards a straight line approximately parallel to the strength envelope. A unified plastic shakedown criterion is proposed for soils under different initial stress states, providing a simple method to predict the plastic shakedown limit.