Abstract

Impact forces from berthing of ships have significantly influences which appear for dynamic responses of these offshore structures and must be treated critical dynamic loads during design for these structures. Given their substantial impact on platform safety during berthing, considerations of berthing are important in the design stage. Abaqus program is used to simulate the soil, pile and deck in addition to all secondary members effecting in the response of platform. Model of the pile –soil interaction (PSI) is considered during analysis of platform. The plastic model (which is depended on plasticity theory) is done to simulate the soil where the soil is treated as continues material under long term deformations. Cam clay model is according to theory of plasticity to show the volume changing for different cases of a loadings. The mathematical model for soil is used. 3D brick elements to simulate the soil is performed (C3D20RP), 21 nodes, linear pore pressures, and quadratic equation for displacements. For piles and in addition members for platform deck, (B32) element to achieve that simulation is used where in each of that elements consist of (3Nodes) to make results more accurate. This paper studies the structural response for deck and piles of platform under impact load from ship berthing where Al-Basrah Oil Port (ABOP) represents a case study. Two models in this case are investigated during the F.E.A, with linear behaviour model for the piles and also for the deck, the soil has been treated with nonlinear model. results indicate the natural frequencies of structure are decreasing with any increasing thickness of pile also the results show decreasing in displacement response for pile and deck.