Analysis of Jack-Up Platform Subjected To Irregular Waves in Granular Soil

In order to model real behavior of Jack-up platforms subjected to wave loading, a nonlinear dynamic analysisconsidering soil-structure interaction (SSI) is investigated. For this purpose, a 3D Finite Element model of the platformunder consideration is generated and Nonlinear Winkler Foundation method is employed for soil media modeling. anirregular wave representing a seastate is used for applying wave loads on the platform. Using this model, spudcansperformance, soil nonlinear behavior near the structure, contact phenomena at the interface of soil and spudcan andgeometrical nonlinear behavior of the structure are studied. Results of this study show that inelastic behavior of the soil causes an increase in displacement at hull elevation and permanent unequal settlement in soil below the foundations which is increased by decreasing friction angle of soil. In fact spudcans and the underlying soil cause a relative fixity at support of the platform which changes dynamic response of structure compared to the case where the structure is assumed to have a fixed support. For simulating this behavior without considering SSI, moment-rotation curves at the end of platform legs which are dependent on foundation dimensions and soil characteristics are extracted. These curves can be used in a simplified model of the platform for considering relative fixity at soil-foundation interface

کلیدواژه ها:

Jackup Platforms ، Irregular Wave Loading ، Nonlinear Dynamic Analysis ، Soil-Structure Interaction ، Beam on Nonlinear Winkler Foundation (BNWF)