Offshore Gravity Structures: Analysis

Experimental and analytical studies are described on the offshore gravity structure foundations with their soil foundations when subjected to wave forces. The experimental tests were performed in a centrifuge at 100g centrifugal acceleration with a 10-cm diam model structure bearing on a normally consolidated deposit of Santa Barbara silt, and therfore apply to a 10-m diam prototype structure. The analytical predicitions, for the particular prototype situation considered in this study, were obtained by using a finite element program which incorporates a three-dimensional nonlinear soil model capable of describing the behavior of the Santa Barbara silt under both monotonic and cyclic loading conditions. The results of both two-dimensional (plane strain) and three-dimensional calculations are reported, and the are compared with the experimental test results obtained in the centrifuge.