Abstract
This paper employs numerical modeling to investigate the potential effects of weak clayey interlayers on seismic behavior of a deepwater slope. Results from a dynamic finite-element analysis addressing the earthquake response of a deepwater slope with single and multiple weak clayey interlayers, subjected to a specific base excitation, are presented and discussed in terms of computed earthquake-induced permanent displacements and characteristics of the ground motion at the seafloor. The numerical outcomes indicate that the earthquake-induced permanent slope displacements at the seafloor may be exacerbated by the presence of weak interlayers characterized by an undrained shear strength falling below a specific threshold. A gradual attenuation in the computed peak earthquake acceleration at the seafloor was also observed in relation to decreasing undrained shear strength of the weak interlayers. On the other hand, the computed predominant period of the ground motion at the seafloor was not affected by the presence of weak interlayers on the slope.