Effect of a surficial crust on mudmat capacity under fully three-dimensional loading

Submarine sediments in many deep-water regions exhibit a thin crust overlying geologically normally consolidated clay. Load-carrying capacity of mudmat foundations for supporting subsea infrastructure installed on seabeds with a surficial crust is of great interest to foundation designers. Finite-element analyses have been performed to investigate the undrained response of mudmats under combined six degree-of-freedom loading in terms of the effect of crust thickness, foundation embedment and relative shear strengths of the underlying soft clay and crust. Results are presented as failure envelopes and expressions are presented to enable calculation of the uniaxial and combined load capacities under fully three-dimensional loading.