Effect of Abutment Modeling on the Seismic Behavior of Horizontally Curved RC Box-Girder Bridges

Seismic behavior of one straight and six horizontally curved four-span RC box-girder bridges with roller, pinned and simplified seat-type abutment is investigated using linear and nonlinear time history analyses in this paper. Roller and pinned models contain only single point constraints. The simplified abutment model is constrained in vertical direction with a longitudinal response that accounts for the gap and passive pressures of embankment fill and abutment back wall response and a transverse response representing the backfill, wing wall and pile system responses. Overall strength of the numericalmodel of abutments is validated by pushover analysis. Results show that taking bridgeabutment interaction into account leads to ۸۰% reduction in abutment displacements and ۳۵% reduction in column bent drift ratios. Using roller and simplified abutment modeling leads to axial force reduction in superstructure. Roller abutment modeling also neutralizes effects of curvature on the shear forces of the superstructure.

Keywords:

Curved bridge , Abutment modeling , Time history analysis , Pushover analysis