Earthquake ground motion characterization

Graduate researcher: Ting Lin

Project sponsor: U.S. Geological Survey, Pacific Earthquake Engineering Research Center

Figure from Baker (2009)

As nonlinear dynamic analysis becomes a more frequently used procedure for evaluating the demand on a structure due to earthquakes, it is increasingly important to understand which properties of ground motions are most strongly related to the response caused in the structure. A value that quantifies the effect of a record on a structure is often called an Intensity Measure (IM). Spectral acceleration at the first-mode period of vibration, Sa(T1), has frequently been used as an IM for predicting response of structures. But among records with the same value of Sa(T1), there is still significant variability in response of a multi-degree-of-freedom, nonlinear structural model. Here we consider a two-parameter (i.e., vector-valued) intensity measures which have greater potential to account for this variability in response.

A reference page for the ground motion parameter 'epsilon' is available here. It may be helpful to researchers investigating the effect of epsilon on their structures.

Selected publications:

 

	Baker, J.W. (2009). The Conditional Mean Spectrum: A tool for ground motion selection, ASCE Journal of Structural Engineering, (in press).
	Baker, J.W. and Lin, T. (2008). "Ground Motion Target Spectra for Structures Sensitive to Multiple Periods of Excitation: Conditional Mean Spectrum Computation Using Multiple Ground Motion Prediction Models." Final Technical Report for U.S. Geological Survey National Earthquake Hazards Reduction Program (NEHRP) External Research Program Award 08HQAG0115. 38 pp.
	Haselton C., Baker J.W., Goulet C., Watson-Lamprey J., and Zareian F. (2008). The importance of considering spectral shape when evaluating building seismic performance under extreme ground motions, in SEAOC Convention 2008, Kohala Coast, Hawaii 10 pp.
	Baker J.W. and Cornell C.A. (2006). Spectral Shape, Epsilon and Record Selection, Earthquake Engineering & Structural Dynamics, 35 (9) 1077-1095.
	Baker J.W. and Cornell C.A. (2005). A Vector-Valued Ground Motion Intensity Measure Consisting of Spectral Acceleration and Epsilon. Earthquake Engineering & Structural Dynamics, 34 (10), 1193-1217.

 

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