Investigations into the Uplift of Skirted Foundations on Clay at Varying Rates

This paper presents finite-element simulations to reinterpret a series of full-model and particle image velocimetry (PIV) (half model) centrifuge tests to study the uplift of skirted foundations. The focus is on the influence of uplift rate on the uplift capacity and the mechanism of breakaway (i.e., the phenomenon of sudden loss of uplift resistance). A backbone curve, quantifying the uplift rate-capacity relationship, is established for uplift based on the numerical and experimental results. The dimensionless velocities V=6 and 130 are found to be the boundaries for drained, partially drained, and undrained conditions. The breakaway is found related to ambient water infiltration. In the numerical modeling, the remaining length of the skirt inside soil is used as an indicator for breakaway, i.e., breakaway happens when this length is smaller than a critical value. This hypothesis is demonstrated to be effective by comparing the numerical modeling with the experimental results.