Out-of-Plane Seismic Response of Reinforced Concrete Bridge Pier Walls

The objective of this research was to evaluate the out-of-plane seismic behavior of representative bridge pier walls that exist in the U.S. and to develop an analytical model to determine the seismic response of bridge pier walls. A comprehensive bridge pier wall survey was conducted based on seven one-half scale wall specimens designed and tested under slow cyclic loads that were perpendicular to the plane of the walls. The confinement steel in all the specimens was less than that required in current seismic design codes. The failure mode of the wall specimens was either compression failure of the concrete or fracture of the vertical reinforcing bars due to low-cycle fatigue. The data showed that even with confinement steel as low as one-half the seismic code requirements, a displacement ductility capacity of five or more could be expected. The analytical studies showed that good correlation between the calculated and measured data can be expected using the modeling assumptions and failure criteria incorporated in the model.