Bucket foundation model testing under tensile axial loading

Abstract

The present study focusses on bucket foundation behaviour under long-term cyclic loading. The paper analyses testing results of a bucket foundation model exposed to cyclic tensile loading. The model, with dimensions of 1 m in diameter and 0.5 m in skirt length, was, installed in dense water-saturated sand. Slow monotonic loading tests and cyclic tensile loading tests were performed (up to 40 000 load cycles) including tests with mean cyclic loading in tension, which is a unique testing condition. High-quality data were documented for load, displacement, and pore pressure response. Conclusions have been drawn regarding static and cyclic loading stiffness and displacement development during long-term cyclic loading. Four cyclic loading tests induced partially drained soil conditions and showed that pore pressure can accumulate during the long-term loading. Post-cyclic monotonic tensile loading tests showed up to 25% reduction in load capacity of the foundation. The research results provide valuable information for the design of an upwind bucket foundation under a jacket structure.