UPDATING FRAMEWORK FOR SITE-SPECIFIC ATTENUATION RELATION OF SEISMIC GROUND MOTION IN THAILAND
Supervisor: Tsuyoshi TAKADA
We propose the attenuation relations for peak ground acceleration (PGA) and 5% damped spectral acceleration (Sa) applicable to the CMMT site which is located on rock. The CMMT site is located in Chiang Mai, the northern part of Thailand. Thailand has only a few ground motion data and most of peak ground acceleration are smaller than 1 gal. To overcome this difficulty, a Bayesian update technique was used to construct the attenuation relations for Thailand based on a past attenuation relation proposed by Idriss (1993). In this study, we added a correction term (site effect term) and error term to the Idriss attenuation relation using the Bayesian update technique. From the comparison of the prediction by the Idriss attenuation relation and the observed data, we found that the Idriss attenuation relation overestimates PGA but underestimates Sa. The prediction from the updated attenuation relation for PGA and Sa proposed by this study is much closer to the observations than those by the Idriss attenuation relation.
|Citation: ||Bulletin of IISEE, 44, 43-48.|