During the past 20 years, the satisfactory behavior of many reinforced concrete buildings during damaging earthquakes has been attributed to the presence of structural walls. Structural walls provide stiffness to the building systems, and control the drift and damage in the buildings. A critical concern for the design of structural walls in seismic regions has been the specification of reinforcement details to insure ductile response. The performance of buildings in Vina del Mar during the March 1985 Chilean earthquake appears to contradict professional opinion, because the buildings performed well and the reinforcement details were essentially nonexistent. This research project develops methods for determining the strength, effective stiffness, and deformation capacity of reinforced concrete walls. Walls are used as the primary lateral-load resisting system in many reinforced concrete structures, yet many fundamental concepts have not been verified experimentally. The experimental phase of the project involves lateral load tests of reinforced concrete walls. Major variables include the geometry of the cross section, amount of web reinforcement, type of loading, and amount of confinement reinforcement. Walls subjected to static load reversals and dynamic loading. The analytical phase of the project uses the observed response and the measured response of the experiments to develop a hysteresis model suitable for reproducing nonlinear response in shear and flexure. Methods are developed to determine the strength, likely mode of failure, and effective stiffness of structural walls during the design process.
