Undrained cyclic behavior of underconsolidated marine clay in multidirectional simple shear tests

In the field of marine reclamation engineering, underconsolidated marine clay often presents challenges owing to its susceptibility to multidirectional cyclic stresses and potential for excessive deformation. This research examined the undrained cyclic behavior of underconsolidated marine clay through multidirectional cyclic simple shear tests. It explored shear strain evolution, the cyclic shear stress-strain relationship, and stiffness degradation by analyzing the impacts of clay consolidation levels and phase differences in the cyclic stress. The findings indicated that as the degree of consolidation increased, the rate of cyclic shear strain development in marine clay gradually diminished. Conversely, an enhanced phase difference led to a quicker evolution of shear strain. Additionally, as loading continued, the tested clay exhibited notable softening behavior, leading to stiffness degradation. A larger phase difference resulted in more pronounced stiffness degradation, although a higher degree of consolidation effectively delayed this degradation. These findings provide new insights on the cyclic behavior of underconsolidated marine clay under multidirectional loading, offering crucial information for marine reclamation engineering.