000018665 001__ 18665
000018665 005__ 20170118182235.0
000018665 04107 $$aeng
000018665 046__ $$k2017-01-09
000018665 100__ $$aNozu, Atsushi
000018665 24500 $$a“Anti-Catastrophe” Concept in Japanese Seismic Design Codes

000018665 24630 $$n16.$$pProceedings of the 16th World Conference on Earthquake Engineering
000018665 260__ $$b
000018665 506__ $$arestricted
000018665 520__ $$2eng$$aIn light of the serious tsunami disaster during the 2011 Tohoku earthquake and the subsequent severe accident at the Fukushima-Daiichi Nuclear Power Plant, the preparedness of infrastructures such as railway structures, highway structures and port structures to unexpected events became a big issue among civil engineers in Japan. In the conventional seismic design of these structures, basically two kinds of design ground motions, namely, the level 1 and 2 design ground motions are considered and the structures are designed so that they fulfill respective performance requirements through verification. In particular, significantly intense ground motions from shallow crustal and subduction earthquakes have been considered as the level 2 design ground motions. However, it is still necessary to consider the performance of structures to unexpected events and its consequences, mainly because of our insufficient knowledge of natural phenomena and of the performance of structures itself. Therefore, the authors proposed a new design concept called the “anti-catastrophe design concept”. In this concept, a structure is said to be “anti-catastrophe” when the structure or the structure-environment system does not exhibit catastrophic situation even in an unexpected event. In order to contribute to the establishment of the “anti-catastrophe” design concept of structures, the design standards for railway structures, highway structures, and port structures in Japan are reviewed. In all of these codes, the necessity to consider the performance of structures to unexpected events and its consequences are recognized. For the railway structures, devices have been developed for the anti-catastrophe design including the “dead weight compensation mechanism”. For the highway structures, “unseating prevention devices” have widely been used in the design of bridges. For the port structures, efforts are being made to improve the performance of breakwaters after they are affected by extreme tsunamis. One of the most important ingredients of the “anti-catastrophe design” is to understand the performance of a structure or a structure-environment system under extreme external forces to understand its consequences. In this respect, the “anti-catastrophe design” is oriented in the same direction as the “riskinformed design” proposed in the revised version of ISO2394. However, as mentioned above, the Japanese engineers seem to put more emphasis on the development of measures or devices to cope with this issue. It should be noted that our knowledge is quite limited in terms of the performance of a structure or of a structure-environment system subject to extreme events. Obviously more effort is needed to understand the performance of structures to extreme events. To this end, every kind of available tools should be used. For example, model tests and numerical simulations could be useful. On the other hand, it is not reasonable to think that the performance of such devices or measures should always be evaluated quantitatively. Sometimes, other human abilities such as intuition and insight could be useful in developing measures and devices. As an example, although we do not know the detailed stress history of unseating prevention devices during an earthquake, they have widely been used in the design of highway bridges in Japan and some of those devices performed well in the past earthquakes. After all, we should mobilize all kinds of human ability, ranging from intuition or insight to more sophisticated engineering skills, to cope with the issue of the preparedness of structures to unexpected events.

000018665 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000018665 653__ $$aAnti-catastrophe design; design code; unexpected event; extreme event; consequence

000018665 7112_ $$a16th World Conference on Earthquake Engineering$$cSantiago (CL)$$d2017-01-09 / 2017-01-13$$gWCEE16
000018665 720__ $$aNozu, Atsushi$$iMurono, Yoshitaka$$iTakahashi, Yoshikazu$$iAkiyama, Mitsuyoshi$$iKataoka, Shojiro$$iHonda, Riki
000018665 8560_ $$ffischerc@itam.cas.cz
000018665 8564_ $$s553246$$uhttps://invenio.itam.cas.cz/record/18665/files/1948.pdf$$yOriginal version of the author's contribution as presented on USB, paper 1948.
000018665 962__ $$r16048
000018665 980__ $$aPAPER