• Nuclear Engineering and Technology
• /
• 제44권5호
• /
• pp.437-452
• /
• 2012

The Tohoku earthquake (Mw9.0) occurred on March 11, 2011 and caused a large tsunami. The Fukushima Dai-ichi NPP (F1-NPP) were overwhelmed by the tsunami and core damage occurred. This paper describes the overview of F1-NPP accident and the usability of tsunami PRA at Tohoku earthquake. The paper makes reference to the following current issues: influence on seismic hazard of gigantic aftershocks and triggered earthquakes, concepts for evaluating core damage frequency considering common cause failure with correlation coefficient against seismic event at multi units and sites, and concepts of "seismic-tsunami PSA" considering a combination of seismic motion and tsunami effects.

• Steel and Composite Structures
• /
• 제31권6호
• /
• pp.575-589
• /
• 2019

The main focus of this study is to numerically investigate the influence of strong earthquake and tsunami-induced wave impact on the response and behavior of a cable-stayed steel bridge with large caisson foundations, by assuming that the earthquake and the tsunami come from the same fault motion. For this purpose, a series of numerical simulations were carried out. First of all, the tsunami-induced flow speed, direction and tsunami height were determined by conducting a two-dimensional (2D) tsunami propagation analysis in a large area, and then these parameters obtained from tsunami propagation analysis were employed in a detailed three-dimensional (3D) fluid analysis to obtain tsunami-induced wave impact force. Furthermore, a fiber model, which is commonly used in the seismic analysis of steel bridge structures, was adopted considering material and geometric nonlinearity. The residual stresses induced by the earthquake were applied into the numerical model during the following finite element analysis as the initial stress state, in which the acquired tsunami forces were input to a whole bridge system. Based on the analytical results, it can be seen that the foundation sliding was not observed although the caisson foundation came floating slightly, and the damage arising during the earthquake did not expand when the tsunami-induced wave impact is applied to the steel bridge. It is concluded that the influence of tsunami-induced wave force is relatively small for such steel bridge with large caisson foundations. Besides, a numerical procedure is proposed for quantitatively estimating the accumulative damage induced by the earthquake and the tsunami in the whole bridge system with large caisson foundations.

• 한국지구과학회지
• /
• 제24권8호
• /
• pp.704-710
• /
• 2003

해일지진 및 해일유발지진의 특성을 기존의 연구결과인 규모, 모멘트, 에너지 그리고 단층의 길이 등의 자료를 이용하여 응력강하량 및 지체구조 관점에서 분석을 하였다. 해일지진(Tsunami Earthquake)은 일반 지진이나 해일유발지진(Tsunamigenic Earthquake)보다는 약 10bar 정도의 매우 낮은 응력강하량을 가지며 에너지/모멘트 비가 매우 작으며 주로 해구의 매우 낮은 경사의 스러스트 단층에서 발생하는 것으로 분석이 된다. 한편 동해에서 해일을 유발한 지진들은 약30${\sim}$50bar의 응력강하량로서 에너지/모멘트비가 세계평균과 비슷한 스러스트 단층에서 발생하는 것으로 유추된다. 따라서 응력강하, 에너지/모멘트 비, 그리고 스러스트 단층의 경사각은 지진해일 발생특성을 나타내는 인자로 대표될 수 있다.

• 한국방재학회 논문집
• /
• 제9권3호
• /
• pp.135-142
• /
• 2009

지진해일 초기 수면변위의 형상과 에너지는 지진해일 최대파고에 많은 영향을 주며, 이는 지진 매개변수에 의해 결정된다. 일본 서북부 연안에는 지진해일을 발생시킬 가능성이 높은 지진대가 분포되어 있는데, 이러한 지진의 지진 매개변수를 정확히 예측하는 것은 매우 어려운 일이다. 그러므로 이곳에서 일어나는 지진해일의 거동을 파악하고 가장 위험한 상황을 예측하기 위해서는 다양한 경우에 대한 검토가 필요하다. 그런데 지진 매개변수와 지진해일 최대파고의 상관관계를 명확히 알 수 있다면 이러한 지진해일을 검토하는데 많은 도움이 될 것이다. 본 연구에서는 이러한 상관관계를 분석하기 위하여 가상의 지진해일을 대상으로 지진 매개변수의 변화에 따른 지진해일 최대파고 변화양상을 검토하였다.

• 대한원격탐사학회지
• /
• 제28권2호
• /
• pp.255-266
• /
• 2012

2011년 3월 11일 14시 46분 (JST) 일본 센다이에서 동쪽152 km 지점에서 수심 32 km지점에서 ($38.222^{\circ}N$ $142.369^{\circ}E$) 진도 9.0의 대지진이 (공식명칭: The 2011 Tohoku Earthquake and Tsunami) 발생했다. 지진해일 발생 후 센다이를 포함하는 주변해역에서 해양환경의 변화를 모니터링 하기 위해서 해색위성인 GOCI 및 MODIS에서 추출된 클로로필과 Rrs(555)을 이용하여 2011년 3월에서 5월까지 모니터링을 실시 하였다. 지진해일 발생 전 센다이 주변해역 및 일본 동부 해안은 상대적으로 낮은 농도의 클로로필과 부유물질 농도를 보였지만, 지진해일 발생 후 지진해일의 영향은 일본 동부 남북방향의 긴 해안선을 따라서 전 지역에서 영향을 미쳤고, 수층이 교란되었다. 급격한 변화는 수심 30 m 이내의 얕은 수심에서 일어났고, 외해에서의 변화는 거의 없었다. 지진해일 발생 두 달 후 이전의 안정된 해양환경으로 복원된 것으로 관측되었다.

• 한국지진공학회:학술대회논문집
• /
• 한국지진공학회 1997년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 1997
• /
• pp.57-69
• /
• 1997

All of the Tsumami which affected severly the east coast of the Korean Peninsula in the years 1741-1993 are caused by earthquakes occurred along the boundary sea of Japan and norther Honshu. These earthquakes with magnitude greater than 7.0 are results of relative movement between the North American Plate and Urasian Plate. The active fault along the boundary of the two plates is attracted by many researchers since the 1983 May earthquake of magnitude 7.7. It is important to anticipate when the next large earthquake will occur and how much it affect the east coast of Korea. Among a few models of spatial seismic gap were proposed for earthquake occurrences accompanying Tsunami, Ishikawas' east-west seismic gap model is the most probable one. There is a tendency that the period between the activities of the active faults becomes shorter. It is expected that a large earthquake of magnitude 7.0 or above will occur along the eastern boundary of Japan Sea at the end of this century and produce Tsunami at the east coast of Korea.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2011년도 학술발표회
• /
• pp.7-7
• /
• 2011

On March 11 in 2011, off the Pacific coast of Tohokua huge earthquake of Magnitude 9.0 occurred. This presentation reports the earthquake, the ensuing tsunami and the devastating damages caused by them. The epicenter was approximately 72 km east of the Oshika Peninsula of Tohoku, with the hypo-center at an underwater depth of approximately 32 km. Owing to this earthquake, strong quakes were observed in eastern Japan with the levels 6 and 7 on the Japanese scale. The earthquake triggered extremely destructive tsunami wave, which attacked the very wide range of eastern Japan coast. The earthquake and ensuing tsunami caused severe damage to levees and embankment along the coasts and rivers. Those water-related damages are reported in this presentation. The Fukushima No. 1 Nuclear Power Plant was also damaged by the earthquake and ensuing tsunami. From the crippled nuclear power plant, appreciable quantities of radioactive material were emitted to the surrounding environment. Those substances which emitted to air may fall on the ground together with raindrops and runoff to rivers. Elucidation of those processes is the task which our hydrological society should undertake.

• 한국해안·해양공학회논문집
• /
• 제22권5호
• /
• pp.287-294
• /
• 2010

본 연구에서는 지진해일 실시간 정량 대응을 위해 발생원 위치 및 지진규모에 따른 해안침수예상도 작성 방법을 제안하였으며 그 방법은 다음과 같다. 관심지역에 지진해일 피해를 발생시킬 것으로 예상되는 발생원을 선정하고 지진규모에 따른 수치모의를 수행하여 각 발생원별 지진규모별 침수예상도를 작성하는 것이다. 본 연구에서는 시범적으로 동해안 임원항을 대상으로 일본 서안에 위치한 11개의 잠재 지진해일 발생원과 7개의 지진규모에 대하여 침수예상도를 작성하였다.

• 한국해안해양공학회:학술대회논문집
• /
• 한국해안해양공학회 1996년도 정기학술강연회 발표논문 초록집
• /
• pp.3-6
• /
• 1996

On July 12, 1993, a large earthquake (M=7.8) occurred off the south-west of Hokkaido, Japan. The tsunami generated by this earthquake caused a disaster which took a heavy toll of lives, more than 200 persons dead, by the flooding of tsunami in the area of Aonae district in Okushiri island. Investigation after the disaster made clear that southern lowland was flooded by the tsunami coming from west about 5 min after the shock and the second tsunami from the east attacked eastern lowland of the Aonae District about 10 min after the shock. (omitted)

• 한국지진공학회논문집
• /
• 제18권3호
• /
• pp.151-160
• /
• 2014

Probabilistic tsunami hazard analysis (PTHA) is based on the approach of probabilistic seismic hazard analysis (PSHA) which is performed using various seismotectonic models and ground-motion prediction equations. The major difference between PTHA and PSHA is that PTHA requires the wave parameters of tsunami. The wave parameters can be estimated from tsunami propagation analysis. Therefore, a tsunami simulation analysis was conducted for the purpose of evaluating the wave parameters required for the PTHA of Uljin nuclear power plant (NPP) site. The tsunamigenic fault sources in the western part of Japan were chosen for the analysis. The wave heights for 80 rupture scenarios were numerically simulated. The synthetic tsunami waveforms were obtained around the Uljin NPP site. The results show that the wave heights are closely related with the location of the fault sources and the associated potential earthquake magnitudes. These wave parameters can be used as input data for the future PTHA study of the Uljin NPP site.