EFFECT OF GAPPING ON THE TRANSIENT AND SUSTAINED UPLIFT CAPACITY OF A SHALLOW SKIRTED FOUNDATION IN CLAY

Shallow skirted foundations are an attractive solution for supporting offshore platforms that are subject to uplift due to overturning or buoyancy loading. In practice, gapping may occur along the skirt-soil interface leading to a detrimental effect on uplift capacity. This paper presents results from beam centrifuge tests that investigated the effect of gapping on the transient and sustained uplift capacity of shallow skirted foundations. The results indicate that the transient uplift capacity following the formation of a gap was around 60% of that for intact soil contact along the skirt-soil interface. Under sustained uplift, the time to accumulate a displacement of 1% of the foundation diameter was reduced by an order of magnitude due to the presence of a gap.