Location
Chicago, Illinois
Date
04 May 2013, 10:30 am - 11:30 am
Abstract
Recent earthquakes, the 2008 Wenchuan, 2009 L’Aquila, 2010 Haiti, and 2011 Christchurch and Japan in particular, have called attention to the probabilistic seismic hazard maps, particularly the ground motions with 10, 5, and 2 percent probabilities of exceedance in 50 years. As discussed in this paper, these ground motions are artifacts because they were produced from probabilistic seismic hazard analysis (PSHA). PSHA is a mathematical formulation derived from a rigorous probability analysis of the distribution of earthquake magnitudes, locations, and ground-motion attenuation. Some of the assumptions and distributions that PSHA is based on have been found to be invalid in earth science, however. In addition, PSHA contains a mathematical error, equating a dimensionless quantity (the annual probability of exceedance—exceedance probability in one year) to a dimensional quantity (the annual frequency of exceedance with the unit of per year [1/yr.]). Thus, PSHA is scientifically flawed, and the resulting seismic-hazard and seismic-risk estimates are artifacts. Use of the probabilistic ground-motion maps could lead to either unsafe or overly conservative engineering design. On the other hand, recent earthquakes, the 2010 Chile and 2011 Japan in particular, also showed that ground motions derived from deterministic seismic hazard analysis (DSHA) provided appropriate engineering design to prevent earthquake disaster.
Department(s)
Civil, Architectural and Environmental Engineering
Meeting Name
7th Conference of the International Conference on Case Histories in Geotechnical Engineering
Publisher
Missouri University of Science and Technology
Document Version
Final Version
Rights
© 2013 Missouri University of Science and Technology, 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
Wang, Zhenming, "Seismic Hazard Assessment and Design Ground Motion: Lessons Learned From Recent Earthquakes" (2013). International Conference on Case Histories in Geotechnical Engineering. 20.
https://scholarsmine.mst.edu/icchge/7icchge/session04/20
Seismic Hazard Assessment and Design Ground Motion: Lessons Learned From Recent Earthquakes
Chicago, Illinois
Recent earthquakes, the 2008 Wenchuan, 2009 L’Aquila, 2010 Haiti, and 2011 Christchurch and Japan in particular, have called attention to the probabilistic seismic hazard maps, particularly the ground motions with 10, 5, and 2 percent probabilities of exceedance in 50 years. As discussed in this paper, these ground motions are artifacts because they were produced from probabilistic seismic hazard analysis (PSHA). PSHA is a mathematical formulation derived from a rigorous probability analysis of the distribution of earthquake magnitudes, locations, and ground-motion attenuation. Some of the assumptions and distributions that PSHA is based on have been found to be invalid in earth science, however. In addition, PSHA contains a mathematical error, equating a dimensionless quantity (the annual probability of exceedance—exceedance probability in one year) to a dimensional quantity (the annual frequency of exceedance with the unit of per year [1/yr.]). Thus, PSHA is scientifically flawed, and the resulting seismic-hazard and seismic-risk estimates are artifacts. Use of the probabilistic ground-motion maps could lead to either unsafe or overly conservative engineering design. On the other hand, recent earthquakes, the 2010 Chile and 2011 Japan in particular, also showed that ground motions derived from deterministic seismic hazard analysis (DSHA) provided appropriate engineering design to prevent earthquake disaster.
