Comparison of Seismic Performance of Socket and Pocket Connections for Reinforced Concrete Bridge Column Base Hinges

The goal of this study was to evaluate two connection types for reinforced concrete two-way rebar hinges and to assess their seismic performance if incorporated in accelerated bridge construction applications. Two large-scale models of bridge systems were tested on shake tables; the first utilized a pocket connection with the opening preformed in the column and the second implemented a socket connection with the opening preformed in the footing. Both bridges were subjected to multiple ground motions ranging from 30% to 225% of the design level earthquake. Rebar hinge behavior during the earthquakes including interface slippage, rotation, reinforcement strains, observed damage, and bent forces were used to evaluate the connections and their relative merit and to make recommendation for implementation in the field.