Seismic retrofit of a typical reinforced concrete bridge bent in Iran

This paper presents the results of an experimental study which was carriedout to identify the vulnerabilities of existing multicolumn bridge bents constructed in iranand to develop an appropriate retrot measure to alleviate such vulnerabilities. in thisstudy a three column reinforced concrete bridge bent, which was designed for gravity loadwith inadequate seismic detailing, is considered. two identical specimens scaled to 30%of prototype dimensions were tested under in-plane cyclic loading condition. one of thespecimens simulated the as-built condition while the other specimen was retrotted byexternal prestressing along the cap beam as well as transverse prestressing of an exteriorjoint. the test results on the as-built specimen indicate that joint shear distress and bondfailure of longitudinal column reinforcement within the joints are the predominant failuremodes. such failure modes adversely aected the behavior and energy absorbing capacityof the as-built specimen. seismic behavior and energy absorbing capacity of the retrottedspecimen improved signicantly. the improved behavior of the retrotted specimen wasmainly due to better performance of the joints.