Experimental study of the effects of initial shear stress on liquefaction potential through an energy-based approach

In submarine inclined terrains, granular soils are subjected to considerable initial shear stress, which significantly affects their cyclic behavior and liquefaction potential. When the external cyclic load is applied in varying directions relative to the dip direction, the prediction of liquefaction resistance may be complicated using conventional stress-based methods. This paper presents the effects of initial static shear stress in submarine slopes through an energy-based approach. Oval-shaped and linear shear stress paths are employed to replicate the stress condition commonly encountered in offshore environments. The test results indicate that the correlation between cumulative energy and pore water pressure is independent of the orientation of initial shear stress. On the other hand, increasing the initial shear stress level within a certain range will increase the dissipated energy required for reaching a given pore water pressure. At the end of this paper, a relationship is given for estimating the liquefaction energy considering the effects of initial shear stress.