Structural Testing of New East Bay Skyway Piers

This paper discusses two proof-of-concept tests conducted at 114 scale on a typical hollow, rectangular reinforced concrete pier designed to support the new East Bay Skyway Structures of the San Francisco-Oakland Bay Bridge. Vie test units were loaded according to quasi-static, fully-reversed, cyclic loading histories to simulate the force-displacentent response of the-prototype pier under seismic forces. Both tests withstood inelastic deformations greater than those expected in response to the 1500-year governing design earthquake for the Bay Bridge. Based on results front both tests, structural details such as the architectural concrete and transverse reinforcement were improved to enhance constructibility and service-level performance. This paper discusses three different approaches to evaluating experimental plastic hinge lengths and demonstrates the ambiguity inherent in evaluating the force-displacement behavior of such piers according to strain-based seismic performance criteria.