Is There a Logical Shortcoming in Ground Motion Attenuation Study


Abstract eng:
Attenuation relations, also known as ground motion prediction equations, have been developed and adopted to assess seismic hazard. In almost every attenuation relation, a distance term is used to describe the attenuation effect, and a magnitude term is used to describe the source effect. Although there are various definitions for earthquake magnitude (e.g., local magnitude, surface magnitude and moment magnitude etc.), they are estimated based on the amplitudes of ground motions recorded by monitoring networks. To estimate the magnitude, a calibration function taking into account the attenuation effect of motion is adopted to convert the observed amplitude to the value at a point with distance 100 km from the source. To predict ground motion, geometric and inelastic attenuation terms are adopted with different formula forms. The result of this inconsistency is that the ground motion measure (such as peak ground acceleration and spectral acceleration) predicted by the attenuation relationship may be different with that observed for the given distance and magnitude. This is a logical shortcoming in the attenuation relationship studies. Why the shortcoming exists for so long a time? First, the exchange of information between the people who determine the earthquake magnitude (mostly seismologists) and the people who develop attenuation relationships (mostly civil engineers) is limited. Second, and more importantly, the data used to determine the magnitude and to predict ground motion are often different. Effect of this inconsistency on the seismic hazard assessment is examined in this study; some preliminary results are presented to show the problem and a potential solution to overcome this problem is suggested.

Contributors:
Conference Title:
Conference Title:
16th World Conference on Earthquake Engineering
Conference Venue:
Santiago (CL)
Conference Dates:
2017-01-09 / 2017-01-13
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Text je chráněný podle autorského zákona č. 121/2000 Sb.



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 Record created 2017-01-18, last modified 2017-01-18


Original version of the author's contribution as presented on USB, paper 1177.:
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