• Title/Summary/Keyword: Seismic Event

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3D Finite Element Analysis of Fault Displacements in the Nobi Fault Zone, Japan

  • Choi, Young-Mook;Kim, Woo-Seok;Lee, Chul-Goo;Kim, Chang-Yong;Seo, Yong-Seok
    • The Journal of Engineering Geology
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    • v.24 no.3
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    • pp.323-332
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    • 2014
  • The Nobi fault zone, which generated the 1891 Nobi Earthquake (M8.0), includes five or six faults distributed in and around Gifu and Aichi prefectures, Japan. Because large cities are located near the fault zone (e.g., Gifu and Nagoya), and because the zone will likely be reactivated in the future, relatively thorough surveys have been conducted on the 1891 Nobi earthquake event, examining the fault geometry, house collapse rate, and the magnitude and distribution of earthquake intensity and fault displacement. In this study, we calculated the earthquake slip along faults in the Nobi fault zone by applying a 3D numerical analysis. The analysis shows that a zone with slip displacements of up to 100 mm included all areas with house collapse rates of 100%. In addition, the maximum vertical displacement was approximately ${\pm}1700mm$, which is in agreement with the ${\pm}1400mm$ or greater vertical displacements obtained in previous studies. The analysis yielded a fault zone with slip displacements of > 30 mm that is coincident with areas in which house collapse rates were 60% of more. The analysis shows that the regional slip sense was coincident with areas of uplift and subsidence caused by the Nobi earthquake.

A Comparative Analysis of Korea-Japan Seismic Recovery System (한일 지진 복구체계의 비교 분석)

  • Lee, JunBeom
    • Journal of the Society of Disaster Information
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    • v.16 no.3
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    • pp.458-471
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    • 2020
  • Purpose: In Korea, the frequency and frequency of earthquakes are increasing every year. Therefore, the purpose of this study was to compare and analyze the characteristics and examples of earthquakes in Korea and Japan, and to propose improvements to the earthquake prevention policy in Korea. Method: In this study, we investigate and evaluate Japan's response in two cases: the Kobe earthquake and the East Japan earthquake. After surveying and evaluating the nation's countermeasures in the two events, Gyeongju and Pohang, they were compared. Result: When comparing recovery systems in Korea and Japan, there were significant differences in plans for restoration of road transport networks, regional disaster prevention plans, and the introduction of Conclusion: considering the physical distance between Korea's earthquake-prone areas and the capital, the government should quickly come up with countermeasures to ensure that immediate earthquake response in the region is enhanced through the detailed establishment of the Functional Continuity Plan (COOP), and that administrative functions will function normally in the event of a disaster through the introduction of the administrative BCP concept.

Analytical Study on the Fire Resistance of Internally Confined Hollow CFT Column (내부 구속 중공 CFT 기둥의 내화 성능에 대한 해석 연구)

  • Won, Deok Hee;Han, Taek Hee;Park, Jong Sup;Kim, Young Jong
    • Journal of Korean Society of Steel Construction
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    • v.21 no.5
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    • pp.461-470
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    • 2009
  • A column resisting axial load and seismic load is one of the main members in a structural system. The heated column by event of a fire can lose its strength and it may damage its structural system or cause the collapse of the entire structural system. In this study, the fire resistance capacity of internally confined hollow concrete filled tube (ICH CFT) column was investigated. In an ICH CFT column, the yield strength of the external tube is important as a concrete filled tube (CFT) column because the external tube confines the filled concrete and the strength of the column depends on the confined effect. A study was performed by finite element analyses considering the confined effect and material nonlinearity as the temperature changes by the fire. The hollow ratio, the thickness of the external tube, and the strength of concrete were selected as the parameters for the analyses. The analyses were performed by using a commercial FEA program (ABAQUS) and nonlinear concrete model program. The analysis results showed that the hollow ratio and the strength of concrete mainly affect the fire resisting capacity of an ICH CFT column.

Loss Estimation in Southeast Korea from a Scenario Earthquake using the Deterministic Method in HAZUS

  • Kim, Kwang-Hee;Kang, Su-Young
    • 한국방재학회:학술대회논문집
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    • 2009.02b
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    • pp.43-50
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    • 2009
  • Strong ground motion attenuation relationship represents a comprehensive trend of ground shakings at sites with distances from the source, geology, local soil conditions, and others. It is necessary to develop an attenuation relationship with careful considerations of characteristics of the target area for reliable seismic hazard/risk assessments. In the study, observed ground motions from the January 2007 magnitude 4.9 Odaesan earthquake and the events occurring in the Gyeongsang provinces are compared with the previously proposed ground attenuation relationships in the Korean Peninsula to select most appropriate one. In the meantime, a few strong ground motion attenuation relationships are proposed and introduced in HAZUS, which have been designed for the Western United States and the Central and Eastern United States. The selected relationship from the ones for the Korean Peninsula has been compared with attenuation relationships available in HAZUS. Then, the attenuation relation for the Western United States proposed by Sadigh et al. (1997) for the Site Class B has been selected for this study. Reliability of the assessment will be improved by using an appropriate attenuation relation. It has been used for the earthquake loss estimation of the Gyeongju area located in southeast Korea using the deterministic method in HAZUS with a scenario earthquake (M=6.7). Our preliminary estimates show 15.6% damage of houses, shelter needs for about three thousands residents, and 75 life losses in the study area for the scenario events occurring at 2 A.M. Approximately 96% of hospitals will be in normal operation in 24 hours from the proposed event. Losses related to houses will be more than 114 million US dollars. Application of the improved methodology for loss estimation in Korea will help decision makers for planning disaster responses and hazard mitigation.

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Earthquake Resistant Performance of a High-rise Shear Wall Apartment Based on Nonlinear Time History Response Analysis (동적 탄소성 지진응답해석에 의한 고층 벽식 아파트의 내진성능 검토)

  • 박성수
    • Journal of the Earthquake Engineering Society of Korea
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    • v.3 no.1
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    • pp.1-8
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    • 1999
  • Dynamic elastoplastic LPM (lumped parameter mass) analyses are carried out in order to investigate the seismic resistant performance of a typical high-rise shear wall apartment subjected to several earthquakes. Three-dimensional nonlinear pushover analysis is adopted to estimate initial elastic stiffness, yielding strength and post-yielding stiffness of each story for the time history analysis of LPM shear model. For the hysteresis of each story, Clough and bilinear models are used with the input of four recorded earthquake ground motions of EI Centro 1940 NS, Taft 1952 EW, Hachinohe 1968 NS and Kobe 1995 NS, of which the amplitudes are scaled down to have the same maximum ground velocity of 12 kine. The result shows that yieldings take place in most storys of the building, i.e. the earthquake resistant capacity of this high-rise shear wall apartment is not sufficient at the event of earthquake M=5~6.

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A Simulation of Earthquake Loss Estimation for a Gyeongju Event (경주지역 발생 지진에 대한 지진손실예측 시뮬레이션)

  • Kang, Su-Young;Kim, Kwang-Hee;Suk, Bong-Chool;Yoo, Hai-Soo
    • Journal of the Korean Society of Hazard Mitigation
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    • v.8 no.3
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    • pp.95-103
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    • 2008
  • Knowledge of expected losses in terms of physical, economic, and social damages due to a potential earthquake will be helpful in the effort to mitigate seismic hazards. In this study, losses due to a magnitude 6.7 scenario earthquake in the Gyeongju area have been estimated using the deterministic method in HAZUS. The attenuation relation proposed by Sadigh et al.(1997) for site classes B, C, and D, which are assumed to represent the characteristics of the strong-motion attenuation in the Korean Peninsula, has been applied. Losses due to the hypothetical earthquake have been also calculated using other attenuation relationships to examine their roles in the loss estimation. The findings indicate differences among the estimates based on various attenuation relationships. Estimated losses of the Gyeongju area by a scenario earthquake using HAZUS should be seriously considered in the planning of disaster response and hazard mitigation.

Variation Analysis of Geomagnetic Data Observed Around the Event of Andong Earthquake (May 2, 2009) (안동지진(2009년 5월 2일) 발생 기간 지자기장 자료의 변동성 분석)

  • Oh, Seok-Hoon
    • Journal of the Korean earth science society
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    • v.30 no.6
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    • pp.683-691
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    • 2009
  • Geomagnetic variation around May 2, 2009 when Angdong earthquake broke out was analyzed using the data recorded at the Cheong-yang geomagnetic observatory, KMA. Firstly, we predict the geomagnetic variation by PCA analysis of geomagnetic data, and then compare the predicted value with the observed data to find any significant differences in residuals. Secondly, wavelet semblance technique is applied to compare the time series before and after the earthquake. Some meaningful change is detected in the Z-field. Thirdly, eigen value analysis for the 3 component geomagnetic data is performed. The location of the observatory was too far from the epicenter and the magnitude was too small to find decisive precursory phenomenon. Nevertheless we can detect some significant correlation between the earthquake and the variation of the geomagnetic field. Various signal processing methods applied in this study will give some opportunity to find precursory effects in the future.

Design of Real-Time Ground Motion Monitoring System using MMA data (MMA 데이터를 이용한 실시간 지진동 감시 시스템 설계)

  • Lim, In-Seub;Song, Myung-Won;Jung, Soon-Key
    • Journal of the Korea Society of Computer and Information
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    • v.12 no.5
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    • pp.29-37
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    • 2007
  • In this paper, we propose a new real-time ground motion monitoring system using MMA data which can be gathered more earlier than generic seismic data transmission method. Proposed system receives maximum, minimum and average data based on 20sps which is sent from station on every second continuously. And it calculates a PGA as a quantity of ground motion then visualizes that data to monitor the ground motion around whole country. To verify PGA data from MMA data, we checked Mu-dan-jang earthquake data of China on 2002/6/29. The proposed system was inspected by using log file of Oh-dae-san earthquake data on 2007/1/20. As results of experiment, the proposed system is proven to detect the event(earthquake) faster then existing method and to produce a useful quantitative information.

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A Study on the Necessary Spaces and Area Standards of Integration Facility for Early Childhood Education and Care (영유아 교육·보육 통합시설의 필요 공간과 면적기준에 관한 연구)

  • Cho, Jin Il;Choi, Hyeong Ju
    • The Journal of Sustainable Design and Educational Environment Research
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    • v.17 no.2
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    • pp.22-37
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    • 2018
  • This study suggests desirable disaster safety education curriculum through analyzing the operational status of the school disaster safety management training course and demand survey of school staff. First, the problem of the disaster safety training course of the school is not connected with the lack of law and system and the school disaster safety job. Second, improvement of law and system and variety of training should be made to acquire professional knowledge. Third, it is necessary to divide curriculum into the following four categories, according to educational needs of public officials ; Educational administration officers course focused on facility safety, maintenance and disaster countermeasure. Educational officials in technical post course addressing approval and permission of school facility projects, seismic reinforcement of school building, etc. Educational supervisors course covering roles and responsibilities of the school safety supervisors in the event of disaster. Teaching staffs course focused on safety instructions for students. Fourth, it is found that lectures and experiential learning methods are the most desirable methods of teaching and learning, and the major ranks are earthquake disaster, fire, gas, typhoon, school road, and electrical safety.

Study on Quantification Method Based on Monte Carlo Sampling for Multiunit Probabilistic Safety Assessment Models

  • Oh, Kyemin;Han, Sang Hoon;Park, Jin Hee;Lim, Ho-Gon;Yang, Joon Eon;Heo, Gyunyoung
    • Nuclear Engineering and Technology
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    • v.49 no.4
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    • pp.710-720
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    • 2017
  • In Korea, many nuclear power plants operate at a single site based on geographical characteristics, but the population density near the sites is higher than that in other countries. Thus, multiunit accidents are a more important consideration than in other countries and should be addressed appropriately. Currently, there are many issues related to a multiunit probabilistic safety assessment (PSA). One of them is the quantification of a multiunit PSA model. A traditional PSA uses a Boolean manipulation of the fault tree in terms of the minimal cut set. However, such methods have some limitations when rare event approximations cannot be used effectively or a very small truncation limit should be applied to identify accident sequence combinations for a multiunit site. In particular, it is well known that seismic risk in terms of core damage frequency can be overestimated because there are many events that have a high failure probability. In this study, we propose a quantification method based on a Monte Carlo approach for a multiunit PSA model. This method can consider all possible accident sequence combinations in a multiunit site and calculate a more exact value for events that have a high failure probability. An example model for six identical units at a site was also developed and quantified to confirm the applicability of the proposed method.