Abstract
It is a well known fact that excess pore pressure builds up when the soil is subjected to cyclic loading. In the case of clays, the dissipation of pore pressure causes long term settlement. Dynamic simple shear test was carried out using different types of clays. Measurement was made of the residual excess pore pressure and volumetric change after cyclic shear. Then, drainage mechanism is discussed in details. The settlement or axial strain caused by the drainage of pore water can be expressed by a hyperbolic function of pore pressure ratio. This relation is not influenced by the amplitude and speed of cyclic shear stress. In addition, it was found that the drainage mechanism of normally consolidated clays after cyclic shear is closely related to the compressive coefficient Cc and swelling coefficient Cs which are obtained by a consolidation test. Finally, the settlement simulation was excuted in order to apply this research to the field, involving discussions on the effect of over consolidation ratio.
