12/5(三)演講Multiple-Site (Areal) Characteristics of Seismic Hazard for Design and Risk Mitigation Purposes
|訊息內容||時間：2018年12月5日 (星期三) 上午10:00~12:00 (含討論)
主講人：Dr. Vladimir Sokolov
Prof. Sokolov specialized in site effect and seismic hazard of engineering seismology. He once was the Visiting Scholar of NCREE. Now he is the Seismic Hazard Expert, Saudi Geological Survey, Jeddah, Kingdom of Saudi Arabia. Dr. Sokolov will present his recent results in this speech.
MULTIPLE-SITE (AREAL) CHARACTERISTICS OF SEISMIC HAZARD FOR DESIGN AND RISK MITIGATION PURPOSES
Seismic Hazard Expert, Saudi Geological Survey, Jeddah, Kingdom of Saudi Arabia
Probabilistic seismic hazard assessment (PSHA) is widely used in earthquake engineering practice and seismic risk management. However, the results of classical point-wise (PW) PSHA contain no information about simultaneous ground motions during one earthquake at different sites located within a defined area. Such multiple-site (MS) estimations are very useful for the analysis of damage of various structures and corresponding losses in densely populated areas and for analysis of lifeline performance. Two characteristics of multiple-site seismic hazard are described in the presentation. The first characteristic is called as MS-PSHA value that is the annual rate of ground-motion level exceedance in at least one site of interest located within particular (e.g. urban or industrial) area (Sokolov and Ismail-Zadeh, 2016). The MS-PSHA estimations provide the higher ground-motion values than the PW-PSHA because they implicitly take into account the cases of extreme ground motions inside the given area. Both PW- and MS-PSHA estimations may be used in definition of several levels of design seismic loads in building codes. The second characteristic describes probability that specified ground motion level (e.g. design ground motion, DGM) will be exceeded at least once in at least fraction of the reference area during specified period of time (e.g. 50 years). The characteristic that was introduced by Wenzel and Sokolov (2018) is called as Fraction of Areal Exceedance (FAE). On one hand, the FAE could be useful for the risk management decisions because the characteristic provides a clue for the extent of potential damage. On the other hand, joint consideration of the PW- and MS-PSHA estimations, as the considered design ground motion levels for given annual frequency of exceedance, and estimations of FAE for given DGM would be useful for the selection of appropriate DGM given acceptable FAE.