Hamed Rahman Shokrgozar - Assistant Professor, Civil Engineering Faculty, University of Mohaghegh Ardabili, Iran
Behrouz Asgarian - Associate Professor, Civil Engineering Faculty, K.N.Toosi University of Technology, Tehran, Iran

Dynamic response of Pile Supported Structures is highly depended on the Pile SoilStructure Interaction. In this paper, by comparison of experimental and numerical dynamicresponse of a prototype jacket type offshore platform for both hinge based and pile supportedboundary conditions, effect of soil-pile-structure interaction is studied. Jacket and deck of aprototype platform is installed on a hinge-based case first and then platform is installed oneight skirt piles embedded on continuum monolayer sand. Dynamic characteristics of bothcases of platform in term of natural frequencies, mode shapes and modal damping arecomputed and compared with the others.Numerical simulation of responses for the studied structure is also performed for both casesusing capability of ABAQUS software. The 3D model of ABAQUS is created using continuumelements for soil and piles, and beam elements for jacket and deck elements. Mohr-Coulombmodel and pile-soil contact theory are used for considering nonlinear inelastic soil properties.It is observed that dynamic characteristics of the system changes significantly due to soil-pilestructureinteraction. Meanwhile, finite element model can also predict this effect accuratelyfor the studied platform in small range of deformation.

Steel Jacket type Offshore Platform: Soil-Pile-Structure Interaction: Experimental Modal Analysis; Finite element