Scaling Earthquake Ground Motions for Performance-Based Assessment of Buildings

March 30, 2011
Publication: Journal of Structural Engineering - ASCE v 137 n 3 p 311-321
Author(s): Ronald Hamburger Yin-Nan Huang Andrew S. Whittaker Nicolas Luco

The impact of alternate ground-motion scaling procedures on the distribution of displacement responses in simplified structural systems is investigated. Recommendations are provided for selecting and scaling ground motions for performance-based assessment of buildings. Four scaling methods are studied, namely, (1) geometric-mean scaling of pairs of ground motions, (2) spectrum matching of ground motions, (3) first-mode-period scaling to a target spectral acceleration, and (4) scaling of ground motions per the distribution of spectral demands. Data were developed by nonlinear response-history analysis of a large family of nonlinear single degree-of-freedom (SDOF) oscillators that could represent fixed-base and base-isolated structures. The advantages and disadvantages of each scaling method are discussed. The relationship between spectral shape and a ground-motion randomness parameter, å, is presented. A scaling procedure that explicitly considers spectral shape is proposed.

Services: Structural Design