Effect of Skirts on the Lateral Capacity of Mudmats in Soft Clay

This paper presents the development of a three-Dimensional Finite Element Analysis (3D FEA) model using Finite Element Code PLAXIS 3D to investigate the skirt’s effect on the lateral capacity of a mudmat in soft clay. It is found that, for a skirted mudmat, 1) the stiffness of skirts had an influence on the mobilization of its ultimate lateral capacity; 2) the required lateral displacement to mobilize the ultimate lateral capacity was about 1% of its width; 3) the lateral capacity is proportional to skirt depth under a soft clay condition with a linearly increasing strength; 4) the ultimate lateral capacity can also be increased by adding internal skirts, but the rate of increase becomes less prominent with the increase of internal skirt number; 5) an empirical formula in ISO19901-4 [5] was confirmed to conservatively estimate the lateral capacity of a skirted mudmat. Moreover, the influence of skirt on the involved soil mass was discussed.