FIELD-TESTS OF ANCHORS IN CLAY .1. DESCRIPTION

A description of and selected test results for four field model test, are presented. The model tests were designed to simulate the conditions of a suction anchor for a tension-leg platform in soft clay. The intention of these tests was not to produce results that would be extrapolated directly to prototype conditions, instead, they form a basis for a critical evaluation of design procedures for suction anchors (originally developed for offshore gravity base structures). One static and three cyclic tests were performed. The model was loaded in tension with a load inclination of about 10-degrees from the vertical. Different cyclic loading histories, geometries, and eccentricities were tested. Applied load, all components of displacement, pore pressure on and outside the model, pressure within the skirt compartments, earth pressure, and final failure patterns in the clay were measured. Selected results are presented. The tests provided results that could be compared to analytical predictions (as presented in a companion paper), which showed that suction anchors are a viable foundation for tension-leg platform in soft clay.