Effect of Displacement and Hysteretic Energy on Earthquake Damage in Reinforced Concrete Structures

Abstract

A seismic damage index is validated using data from shaking table tests on full-scale and scaled reinforced concrete (RC) specimens. The experimental specimens include wall and frame lateral building systems and ductile and nonductile detailing. The index accounts for the hysteretic energy dissipated by a single degree of freedom oscillator and the building roof displacement. The use of hysteretic energy allows the index to incorporate the number and amplitude of strong-motion cycles, which are important for large-magnitude, long-duration earthquakes typical of subduction zones. Damage is found to vary linearly with normalized hysteretic energy in a way that favors wall systems over frame systems. For the same normalized displacement demand, the index predicts lower damage in wall systems. Potential applications of the damage index include: (1) measuring damage accumulation over multiple earthquakes; (2) supporting the development of risk-targeted spectra that consider the duration and amplitude of strong-motion; and (3) generating regional damage estimates after an earthquake.