Graduate researcher: Shrey Shahi
Project sponsor: National Science Foundation
Additional details and software regarding this project are provided here.
Figure from Baker, 2007
Ground motions with velocity pulses caused by near-fault directivity have received a great deal of attention from engineers and seismologists because of their potential to cause severe damage to structures. Many studies have investigated the dynamic response of structures to these "pulse-like" ground motions, but the ground motions are typically identified using judgment rather than some classification procedure. The lack of a systematic, quantitative classification scheme has hindered progress in answering even seemingly simple questions such as the probability that a ground motion with a given magnitude, distance and source-site geometry will have a velocity pulse. In this project, a quantitative scheme for detecting pulses is being developed. The procedure uses a wavelet-based signal decomposition to identify and extract the largest velocity pulse from a ground motion, and if the extracted signal is large relative to the remaining signal, the ground motion is classified as a pulse-like motion. The identified pulse-like ground motions are then being used in dynamic nonlinear structural analyses to identify relationships between near-fault directivity effects and structural response.
|Spudich, P., Watson-Lamprey, J., Somerville, P. G., Bayless, J., Shahi, S. K., Baker, J. W., Rowshandel, B., and Chiou, B. S. J. (2012). “Directivity models produced for the Next Generation Attenuation West 2 (NGA-West 2) project.” Proceedings of 15th World Conference on Earthquake Engineering, Lisbon, Portugal, 9p.|
|Shahi, S., and Baker, J. W. (2011). “An empirically calibrated framework for including the effects of near-fault directivity in probabilistic seismic hazard analysis.” Bulletin of the Seismological Society of America, 101(2), 742-755.|
|Shahi, S. K., and Baker, J. W. (2011). “Regression models for predicting the probability of near-fault earthquake ground motion pulses, and their period.” 11th International Conference on Applications of Statistics and Probability in Civil Engineering, Zurich, Switzerland, 8p.|
| Shahi, S. K., and Baker, J. W. (2010). “Signal Processing and Probabilistic Seismic Hazard Analysis Tools for Characterizing the Impact of Near-Fault Directivity.” Proceedings, 7th International Conference on Urban Earthquake Engineering (7CUEE) & 5th International Conference on Earthquake Engineering (5ICEE), Tokyo, Japan, 6p.
|Green R.A., Lee J., White T.M., and Baker J.W., (2008) The significance of near-fault effects on liquefaction, 14th World Conference on Earthquake Engineering. Beijing, China. 8p.|
|Baker J.W. (2008). Identification of near-fault velocity pulses and prediction of resulting response spectra, in Geotechnical Earthquake Engineering and Soil Dynamics IV, Sacramento, California, 10 pp.|
|Baker J.W. (2007). Quantitative classification of near-fault ground motions using wavelet analysis, Bulletin of the Seismological Society of America, 97 (5), 1486-1501.|
|Tothong P., Cornell C.A., and Baker J.W. (2007). Explicit directivity-pulse inclusion in probabilistic seismic hazard analysis, Earthquake Spectra, 23 (4), 867-891.|