Seismic pushover analysis of steel integral abutment bridge

Abstract

Integral abutment bridges (IABs) have a continuous deck monolithically encased into abutment stem. A lack of information on their seismic design and performance may discouraged their usage in high seismic zones.

In this study, current research and implementation of IABs are comprehensively reviewed. The properties and typical construction details are presented. Three real-life IABs with steel-concrete girders provided by NYDOT are chosen as prototypes for intensive seismic study. Three-dimensional finite element models of IABs for nonlinear seismic analysis are elaborated to capture the behavior of components of steel-concrete superstructure, abutment stem, piles, backfill, etc.

Pushover analyses are carried out to obtain the capacity curve. To evaluate the seismic performance of the three IABs, capacity spectrum method from the ATC-40 specification is studied and executed by CSibridge@ software. By parametric studies, the effects of bearing and skew are outlined. Conclusions and some recommendations are made for seismic evaluation and design practice.