Dynamic stress accumulation effects on soil strength under cyclic loading

Abstract

To further understand the influence of dynamic stress accumulation effects on soil strength under cyclic loading, a series of dynamic–static coupling tests and stepwise cyclic loading tests were carried out using typical granite residual soil. The mechanism of dynamic stress accumulation was analyzed from the macro and micro perspectives, and the effect thereof on soil strength was discussed from the perspectives of energy and mechanics. The test results showed that a dynamic stress accumulation effect would occur in the soil under cyclic loading, which was one of the main reasons for the failure of the soil structure and the change of the strength. When the accumulation degree was small, the effect facilitated the compaction of soil, and improved the static load strength of the soil. When the accumulation degree exceeded a certain threshold, the effect resulted in rapid the soil damage. The greater the dynamic stress accumulation in the soil, the more obvious the weakening degree of the progressive cyclic loading strength. At the same time, the more prone the soil to dynamic stress accumulation, the greater the internal accumulation of variable situation energy. Failure occurred when the dynamic stress accumulation in the soil exceeded the bearing capacity of the structure, providing further insight for solving the negative impact of dynamic stress accumulation on subgrade soil.