Effects of soil-pile interaction on the response of bridge pier to barge collision using energy distribution method

In this paper, the effects of soil-structure interaction (SSI) on the response of a girder bridge pier is evaluated by assessing the energy distributions in the barge-pier collision system. The finite-element models of two example piers of St. George Island Causeway Bridge, which have different structural and geometrical characteristics, are developed in LS-DYNA software to simulate the barge-pier collision scenarios. By comparing the energy distribution results among the barge and pier components, it is obtained that barge bow component has greater value of the internal energy contribution than pier components in the barge collision with more stiff pier. While, in the barge collision with more flexible pier, the pier components including the pier structure, piles and SSI have more internal energy contributions than the barge component. In addition, From the comparison of energy absorbed by the pier structure between the cases with and without SSI, it is found that the effect of the substructure and its relevant SSI on the response of the more flexible pier affected by the produced large deformations and relative displacements of the pier substructure, is more than that of stiff pier which displaces with semi-rigid and global deflections.