No abstract

To estimate the amplification characteristics of the ground motions in the heavlly damaged belt zone in Kobe City during山e I995 Byogo − ken Nanbu earthquake ， 3・ D wa ＞e propagation ana 【 yses ofa2 − D deep lrregular underground structure mode 【 wi 匸 h vertlcal discontinuity were perfbnned using the hyperelement method fbr incident plane waves expected from the wavefie ］ ds due to the source mechanism ． The incident waveform at bedrock is evaluatcd by deconvolution analys 且 s using 電 he observation record at Kobe University ． The ground motion at the surface of 【 he Osaka group layers and at ground surface are calculated． The effects ofthe deep irregular underground structure and sha］ ］ owsurface layers on the ground motion amplifica 【 10n are discussed ， The analytical results show that the ground motions in the heaviIy damaged belt zone were ampl ［ fied due to the fbcusing effect in 匸 he deep irregular undergreund sIructure as well as the shallow surface Iayers ， and that the catculated maximum acceleration dlstributions coi 口clde closely wi 宜 h the distribution of structural damage ．

This paper re-proposes a synthetic method of estimation of safety, reparability and serviceability for buildings from a viewpoint of seismic risk based on author etc (2010). The seismic risk curves regarding death rate, loss and building downtime are assumed to show safety, reparability, and serviceability in seismic performance. The effects of the interrelationship between the earthquake� motion and the building response characteristics on each seismic risk were analyzed in detail. The results showed that, because the contribution of the structural frame, nonstructural elements, and building equipments to seismic risk was greatly affected by the interrelationship, there was a tradeoff relationship among the abovementioned seismic risks that depends on the evaluation conditions. This suggests the usefulness of determining seismic performance based on multifaceted seismic risk assessment.

Currently used Japanese seismic intensity based on measurement value by mechanical instrumentation, which is called measurement seismic intensity and not always affects human body feeling and earthquake damage. The measurement seismic intensity represents local ground motion characteristics at an observation point due to the foundation and geology conditions and is difficult to evaluate the seismic intensity at a point between observation points. The questionnaire seismic intensity can be said to be very effective in the point. Therefore, in this research, the questionnaire survey to investigate areal ground motion characteristics in two cities in Miyagi prefecture during the 2011 off the Pacific coast of Tohoku Earthquake and its one of aftershocks on April 7, 2011. One is Ohsaki city of which central area was suffered from serious damage in the main shock. The other is Kurihara city including the Tsukidate area where serious damage in the main shock. The other is Kurihara city including the Tsukidate area where serious damage was not recognized even if the seismic intensity scale was 7 during the main shock.