Location
San Diego, California
Presentation Date
30 Mar 2001, 1:30 pm - 3:30 pm
Abstract
For a given seismic source, ground motions at soil sites can be estimated using either soil attenuation relationships, or ground response analyses with input motions scaled to match spectral ordinates from rock attenuation relationships. Ground response analyses are performed with the expectation that accounting for nonlinear sediment response improves the accuracy and reduces the uncertainty in estimated motions. Discussed here are the benefits of ground response analyses as a function of site condition. This is accomplished by preparing statistical predictions of ground motions at 36 strong motion recording sites on soil. Two predictions are made, one using a modified soil attenuation relationship, the other using ground response analyses with a large suite of carefully selected and scaled input motions. Predictions from both methods are compiled as 5% damped spectral ordinates, and are expressed as medians and standard errors. These quantities can then be compared to the spectra of the recorded motion to evaluate the residuals of the estimates. For periods, T< 1 s, ground response analyses are found to improve the accuracy of ground motion predictions relative to soil attenuation. However, a positive bias in median ground response estimates is found that indicates a systematic underprediction of ground motion.
Department(s)
Civil, Architectural and Environmental Engineering
Meeting Name
4th International Conference on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Publisher
University of Missouri--Rolla
Document Version
Final Version
Rights
© 2001 University of Missouri--Rolla, All rights reserved.
Creative Commons Licensing
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.
Document Type
Article - Conference proceedings
File Type
text
Language
English
Recommended Citation
Stewart, Jonathan P. and Baturay, Mehmet B., "Uncertainties and Residuals in Ground Motion Estimates at Soil Sites" (2001). International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics. 12.
https://scholarsmine.mst.edu/icrageesd/04icrageesd/session03/12
Included in
Uncertainties and Residuals in Ground Motion Estimates at Soil Sites
San Diego, California
For a given seismic source, ground motions at soil sites can be estimated using either soil attenuation relationships, or ground response analyses with input motions scaled to match spectral ordinates from rock attenuation relationships. Ground response analyses are performed with the expectation that accounting for nonlinear sediment response improves the accuracy and reduces the uncertainty in estimated motions. Discussed here are the benefits of ground response analyses as a function of site condition. This is accomplished by preparing statistical predictions of ground motions at 36 strong motion recording sites on soil. Two predictions are made, one using a modified soil attenuation relationship, the other using ground response analyses with a large suite of carefully selected and scaled input motions. Predictions from both methods are compiled as 5% damped spectral ordinates, and are expressed as medians and standard errors. These quantities can then be compared to the spectra of the recorded motion to evaluate the residuals of the estimates. For periods, T< 1 s, ground response analyses are found to improve the accuracy of ground motion predictions relative to soil attenuation. However, a positive bias in median ground response estimates is found that indicates a systematic underprediction of ground motion.
