Seismic Performance Evaluation of Integral Bridges Considering Soil-Structure Interaction

Integral abutment bridges (IAB) are structures, in which the substructure and superstructure can move together to accommodate the required translation and rotation. There are no expansion joints and bearings, also the deck is continuous across the length of the fully IABs. In recent years, IABs have become popular because of the economic, functional, and durability advantages of the structures. This paper presents the seismic performances of an integral abutment bridge built in South Korea. A railroad bridge designed and built in the region is selected for a case study. The finite element analysis program, SAP2000, is utilized to model the studied bridge. Fully integral abutment and soil-pile interaction are considered in the numerical model. Nonlinear static (pushover) analyses in both transverse and longitudinal directions are performed. Capacity curves (i.e., pushover curves) in terms of total base shear and lateral displacement at the top of piers and abutments are accordingly obtained. The plastic hinge formations in the structure are also achieved during pushover analyses. A set of damage states of bridge piers are then proposed based on the section analysis.