Strength Behavior of Cemented Marine Clay Subjected to Storm Type Loading

Abstract

Cyclic loading on offshore structures leads to an increase in long term deformations. These deformations will cause additional stresses in structural members. Overloading of offshore structures may have serious consequences and they must be designed to accommodate the increased deformations. During a storm, there is a surge in the mean sea level causing an increase in stress and they are believed to represent critical conditions for offshore foundations. This program encompasses an experimental investigation for establishing the behavior of soil subjected to storm type varied cyclic loading conditions on Indian East coast marine clay samples. In field situations where cyclic loading is imposed on the soil, it can be considered a stress controlled phenomenon. If the effects of cyclic loading on any soil have to evaluated, it is considered more appropriate if the cyclic load test results are compared with reference static strength results obtained from stress controlled tests. To meet these requirements, a series of triaxial shear tests are conducted by adopting different load durations at each load increment. In order to estimate the effect brought in by storm type cyclic loading, it becomes necessary to conduct reference standard tests under uniform cyclic loading at various cyclic stress ratios (CSR) on identical soil specimens and these stress levels are chosen in such a way that there is no failure taking place during testing. This paper presents the behavior of marine clay subjected to uniform and storm type of varied cyclic loading. The effects of this cyclic loading are brought through the comparisons of the results obtained from testing under both strain and stress controlled monotonic loading.