Undrained Cyclic Strength of Marine Soils

The results of an extensive cyclic loading test program using six deep ocean soils and one bay mud are presented. Emphasis is placed on presentation of undrained cyclic strength results for various combinations of static and cyclic loading. The results are expected to be useful in the analysis of a variety of seafloor loading problems. Cyclic loading with stress direction reversal is compared to cyclic loading without stress reversal. The extent to which cyclic loading with stress reversal is more effective in bringing about failure is quantified for the seven soils of this study. A general trend of increase in normalized cyclic resistance with increase in plasticity was observed and data were presented that help to quantify this trend.