ABSTRACT
The tests reported in this paper were carried out at 167 g in the beam centrifuge at the University of
1 INTRODUCTION
Skirted foundations are steel or concrete foundations with a thin circumferential skirt around the periphery that penetrates the seabed confining a soil plug. Figure 1 illustrates a selection of applications of skirted foundations offshore. Skirted foundations are attractive offshore as the skirts transmit foundation loads to deeper, more competent soil where surficial soils provide insufficient bearing capacity. Weak surface soils cannot be treated or removed prior to placement of a foundation offshore, as in onshore practice, but must be incorporated into the foundation. Internal mechanisms can develop within the soil plug if the skirts confine soft soil, resulting in a lower bearing capacity than if the soil plug deformed as a rigid block (Yun & Bransby 2007). Soft deposits contained within foundation skirts can be strengthened by preloading. Preloading is provided by the weight of the structure and foundation, but additional or accelerated preloading can be achieved through ballasting or suction.
