Cardinal Raul Silva Henriquez Bridge During the 2010 Chile Earthquake Failure Analysis and Retrofit Strategy

This paper presents a case study of the Cardinal Raul Silva Henriquez Bridge, which experienced significant damage during an earthquake that occurred in Chile on February 27, 2010. Supported by reinforced concrete and steel columns of varying heights, the superstructure of the bridge consisted of 22 steel-girder spans, with one intermediate expansion joint located at the middle of the bridge. At each end of the bridge, the bottom flanges of the girders were welded to their bearing steel plates, which were embedded and anchored into the bridge abutment. Two, three-dimensional, finite element models (global versus local) with beam and solid elements, respectively, were established for bridge response and damage process simulations. Field observations indicated, and finite element simulations verified, that the damage was caused mainly by the excessive seismic load of 11 continuous steel-girder spans under longitudinal earthquake loading and its eccentricity from the girder-to-abutment connection, which resulted in a significant bending effect. Parametric studies demonstrated that an effective retrofit strategy could be developed through a reduction in the number of continuous spans, modification of the girder-to-abutment connection detail, an increase in the capacity of girders with enlarged bearing seats, added stiffeners for girders, and thicker flanges and webs.