Dynamic Compaction Model Tests for the Characteristics of Red Clay Under equal Energy Level

Red clay has obvious nonlinear dynamic characteristics during dynamic compaction. In this paper, based on equal energy level, the dynamic compaction model tests on red clay under different testing programs were conducted. Dynamic stress, duration of dynamic compaction and crater depth were measured. During dynamic compaction, the distribution and the variation of dynamic stress and the reinforcement effect were analyzed. The best fitting equation of crater depth was established. Test results show that during dynamic compaction, the peak dynamic stress decreased with the depth. In addition, dynamic stress at each point had obvious time lag. By increasing drop numbers, the peak dynamic stress in soil also increased. Until the peak dynamic stress variation fluctuated within a certain range and also the depth, the optimum number of the drop was achieved. When single tamping energy was the same, the peak dynamic stress with heavier tamper was larger than that with lighter tamper at same point. Dimensional analysis was applied to obtain the fitting equation of crater depth. The parameters of fitting equation demonstrated that the influence of the weight of tamper on crater depth was greater than that of the drop height under the identical tamping energy. Consequently, the utilization efficiency and reinforcement effects of heavier tamper with lower drop height are greater than that of lighter tamper with higher drop height at an identical energy level.