Damage-based Seismic Design of Structures

The influences of the ground motion and structural characteristics on damage potential of a 7-, a 13-, and a 20-story steel building are examined using four sets of 40 accelerograms each, classified as soil sites B, C, D, and E according to the 2003 International Building Code. The Park-Ang damage index that has been used extensively during the past two decades is examined. A new damage index based on ductility and stiffness degradation is proposed. Results indicate that the proposed index correlates strongly with the energy dissipated through inelastic action. The advantages and disadvantages of the strength-based design approach are discussed and a seismic design procedure based on damage is outlined.