Uplift behaviors of perforated mudmats in soft saturated clay

Perforation can cause lower uplift resistance in soft clay, giving rise to less difficulty of the retrieval of “mudmat” shallow foundations. Six different perforated forms are designed to perform in the model tests on the uplift behaviors in soft saturated clay. The suction that develops at the mudmat-soil interface is conducted during the whole uplift procedure. The composition and development laws of uplift resistance are revealed. The characteristics of how the perforation ratio and effective width reduce uplift resistance and suction at the mudmat-soil interface are obtained. Numerical simulation is used to figure out the uplift behaviors of perforated mudmats in soft saturated clay on the basis of model tests, revealing different soil failure modes in soft saturated clay. The limit analysis method is used to calculate the uplift resistance though the velocity fields from numerical simulation results. The upper bound solution of uplift resistance is derived, and uplift bearing factor N_c is obtained considering the influences of perforation ratio and effective width. The study shows that compared with that of the Skempton formula, the uplift resistance solved in this study has a nonlinear reduction law with the increase of perforation ratio.