Response spectrum analysis for floor acceleration

Matteo Pozzi, Armen Der Kiureghian

This project develops consistent methods for estimating Power Spectral Density of ground motion signals from response spectra, and for estimating Peak Floor Acceleration (PFA). PFA is a critical parameter influencing the performance of non-structural elements in buildings. The specific challenge related to PFA estimation deals with accounting for the rigid contribution of truncated higher modes and the cross-correlations between all pairs of modes.

The proposed method is able to provide a consistent estimation of the PFA along the entire structure, not only where the PFA is principally influenced by the first few flexible modes, but also where the PFA is mainly related to the rigid response of the structure, for example near its base.
Example of application of the developed approach to estimate peak floor acceleration for a cantilever structure. (a) Example cantilever beam; (b) selected mass-normalized mode shapes; (c) residual contribution of rigid modes for varying number of modes, (d) profile of estimated PFA using 3 modes: CQC with and without Rigid Contribution and SRSS without Rigid Contribution.


Pozzi, M., Der Kiureghian, A. "Response spectrum analysis for floor acceleration," Earthquake Engineering & Structural Dynamics, 44(12):2111–2127 | DOI: 10.1002/eqe.2583 (2015).

Pozzi, M., Der Kiureghian, A. "Response Spectrum Compatible PSD for High Frequency Range" in Transactions, SMiRT-22, San Francisco, CA – August 18-23 2013.

Pozzi, M., Der Kiureghian, A. “Response Spectrum analysis for floor acceleration,” 15th World Conference on Earthquake Engineering, 24-28 Sept. 2012, Lisbon, Portugal.