Dynamic stress accumulation model of granite residual soil under cyclic loading based on small-size creep tests基于小尺寸蠕变试验的花岗岩残积土循环荷载下的动应力累积模型

The creep behaviors of granite residual soil with pre-stress of 100 kPa was investigated by a series of small size creep tests. Three different types of strain curves were obtained at different stress levels. Based on creep characteristics of the granite residual soil under different stress levels, a creep model of the granite residual soil was established by rheological theory, and related parameters of the model were determined according to the experimental data at the same time. Further on, based on the established creep model, a theoretical model of dynamic stress accumulation in the granite residual soil under cyclic loading was deduced. It is found that there is a threshold of dynamic stress accumulation in this theoretical model. The dynamic stress accumulation laws of the granite residual soil are different under different cyclic loading stress. Finally, with the dynamic stress accumulation laws in the small-size samples of granite residual soil under different cycle loading studied and the experimental results comparing with the theoretical results, it verifies the validity of the theoretical model.