The aim of this study is to evaluate the influence of consolidation state on the undrained shear strength of marine structured soft clay (MSSC) under discontinuous loading conditions. A series of undrained triaxial tests is conducted on laboratory-prepared MSSC specimens under cyclic loading and subsequent reconsolidation. The results indicate that reconsolidation enhances the undrained shear strength of normally consolidated MSSC (OCR = 1) following cyclic loading, weakens that of heavily overconsolidated MSSC (OCR = 4), and has negligible influence in the moderately overconsolidated state (OCR = 2). These behaviors are governed by the pore pressure response and structural evolution during cyclic loading and reconsolidation. Positive excess pore pressure dissipation densifies normally consolidated MSSC, while negative pressure dissipation loosens overconsolidated MSSC. To interpret these mechanisms, a bounding surface constitutive model incorporating state-dependent dilatancy and structural degradation is developed. Model simulations show good agreement with experimental observations, confirming the capability of the proposed model to capture the evolution of MSSC's undrained shear strength under reconsolidation-induced discontinuous loading.
Chen et al. (Mon,) studied this question.