000018364 001__ 18364
000018364 005__ 20170118182219.0
000018364 04107 $$aeng
000018364 046__ $$k2017-01-09
000018364 100__ $$aShimmoto, Shota
000018364 24500 $$aState-Dependent Fragility Curves for Aftershock Seismic Risk Assessment of Japanese Steel Frames

000018364 24630 $$n16.$$pProceedings of the 16th World Conference on Earthquake Engineering
000018364 260__ $$b
000018364 506__ $$arestricted
000018364 520__ $$2eng$$aProbabilistic seismic risk assessment of civil infrastructures has been attracting attention in Japan, especially after recent mega-earthquakes with a long-lasting series of aftershocks capable of accumulating building damage; e.g., the 2011 Tohoku earthquake. To this aim, it is valuable to be able to assess the failure probability of a particular structure and its evolution in time due to sequential earthquake events, which may cause a difficulty for stakeholders to perform consistent decision making to warrant business continuity. This kind of risk analysis may require state-dependent fragility curves, which in the study were developed for a Japanese steel frame. To construct the curves, a numerical model of a three-story steel moment-resisting frame was first constructed and calibrated according to the results of shake table tests for a typical Japanese steel structure. This model was subsequently transformed in an equivalent single degree of freedom (ESDOF) system, based on the results of the nonlinear static (pushover) analysis. The probabilistic damage model was then constructed via nonlinear dynamic analysis of the ESDOF system. The spectral acceleration of the elastic period of the ESDOF system was selected as the ground motion intensity measure while the drift angle was selected as response measure. All the records used in the analysis were selected from the Japanese strong-motion network, K-Net. Finally, the state-dependent fragility curves were developed for five levels of damage: As-New (AN), Immediate Occupancy (IO), Life Safety (LS), Collapse Prevention (CP) and Failure (F). The limit state value for each damage state (DS) was set in compliance with the results of the shake table tests. After computing the damage state probability due to the mainshock, the time-variant aftershock risk of the steel structure was quantified integrating the developed state-dependent fragility curves with the seismic hazard, following a Markov chain model already available in the literature, which makes use of aftershock probabilistic seismic hazard analysis (APSHA). Hazard was computed assuming that the structure was located in Osaka, a site that may be affected by a mega-earthquake at the Nankai Trough subduction-zone. In particular, in the considered exercise, the most probable damage state due to the considered mainshock scenario was found to be IO, followed, in probability terms, by LS, F, AN, and CP. Given the probability distribution of the mainshock-induced damage, the daily evolution of aftershock damage was computed, and it was found that the most likely DS after two months since the mainshock was still IO followed by F, LS, CP and AN.

000018364 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000018364 653__ $$ashake table test; performance-based earthquake engineering; Markovian modeling

000018364 7112_ $$a16th World Conference on Earthquake Engineering$$cSantiago (CL)$$d2017-01-09 / 2017-01-13$$gWCEE16
000018364 720__ $$aShimmoto, Shota$$iKurata, Masahiro$$iIervolino, Iunio$$iSuzuki, Akiko
000018364 8560_ $$ffischerc@itam.cas.cz
000018364 8564_ $$s1200411$$uhttps://invenio.itam.cas.cz/record/18364/files/1307.pdf$$yOriginal version of the author's contribution as presented on USB, paper 1307.
000018364 962__ $$r16048
000018364 980__ $$aPAPER