Mechanism of wave-induced liquefaction around suction caissons

ABSTRACT: Excess pore pressure build-up around offshore foundations may threaten the safety of the foundations. Despite the extensive research effort on mechanism of wave-induced liquefaction around gravity-based foundations and monopile foundations in recent years, there is still a lack of knowledge on mechanism of wave-induced liquefaction around suction caissons. In this paper, CycliqCPSP constitutive soil model implemented in OpenSees is adopted to capture the response of sandy seabed around the suction caisson. Biot’s consolidation theory, linear wave theory and the advanced soil model are eventually combined to evaluate the soil response accounting for the hydrodynamic pressure of wave imposed on the seabed surface in the presence of a suction caisson foundation considering the wave-seabed-foundation interaction (WSFI). The results show that occurrence of liquefaction around suction caissons greatly depends on some factors including, initial static stresses, confinement impact of caisson’s skirt, drainage path, hydraulic gradient and contact pressure.