• Title/Summary/Keyword: 경주 지진

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Seismic Fragility Analysis based on Material Uncertainties of I-Shape Curved Steel Girder Bridge under Gyeongju Earthquake (강재 재료 불확실성을 고려한 I형 곡선 거더 교량의 경주 지진 기반 지진 취약도 분석)

  • Jeon, Juntai;Ju, Bu-Seog;Son, Ho-Young
    • Journal of the Society of Disaster Information
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    • v.17 no.4
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    • pp.747-754
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    • 2021
  • Purpose: Seismic safety evaluation of a curved bridge must be performed since the curved bridges exhibit the complex behavior rather than the straight bridges, due to geometrical characteristics. In order to conduct the probabilistic seismic assessment of the curved bridge, Seismic fragility evaluation was performed using the uncertainty of the steel material properties of a curved bridge girde, in this study. Method: The finite element (FE) model using ABAQUS platform of the curved bridge girder was constructed, and the statistical parameters of steel materials presented in previous studies were used. 100 steel material models were sampled using the Latin Hypercube Sampling method. As an input ground motion in this study, seismic fragility evaluation was performed by the normalized scale of the Gyeongju earthquake to 0.2g, 0.5g, 0.8g, 1.2g, and 1.5g. Result: As a result of the seismic fragility evaluation of the curved girder, it was found that there was no failure up to 0.03g corresponding to the limit state of allowable stress design, but the failure was started from 0.11g associated with using limit state design. Conclusion: In this study, seismic fragility evaluation was performed considering steel materials uncertainties. Further it must be considered the seismic fragility of the curved bridge using both the uncertainties of input motions and material properties.

A Study on Dissemination of Earthquake Response Technology and Improvement of Practicality through User Demand Surveys (사용자 수요조사를 통한 지진 대응기술의 보급 및 실용성 제고 방안 연구)

  • Choi, SeonHwa
    • Journal of Korea Society of Industrial Information Systems
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    • v.26 no.4
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    • pp.33-46
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    • 2021
  • In Korea 2016, the largest earthquake occurred in Gyeongju since the beginning of monitoring earthquakes. Consecutively the second-largest earthquake occurred in Pohang. At that time, immediately after the earthquake, citizens were not notified adequate information for evacuation. In consequence the response process was very confusing and citizens were not able to properly evacuate to shelter. For resolving these problems, it is needed of a service to inform quickly information which citizens want to know immediately after the earthquake. So, we have developed the customized information service model, the earthquake safety service which help citizens to escape safely using an earthquake shaking alert device. In this paper, we will introduce this model and present the future direction of R&D and strategic plans for technology dissemination and improvement of practicality through user demand survey.

Changes of Ionospheric Total Electron Content Caused by Large-scale Earthquakes and Recent Earthquakes Occurred Around the Korean Peninsula (국외 대규모 지진과 최근 발생한 국내지진에 의한 이온층 총 전자수 변화)

  • Kim, Byeong-Hoon;Seo, Ki-Weon
    • Geophysics and Geophysical Exploration
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    • v.19 no.4
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    • pp.228-235
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    • 2016
  • We investigated pre- and post- seismic total electron content (TEC) anomalies in ionosphere caused by recent large-scale earthquakes around the globe and additionally examined whether the similar phenomena are detected in connection with the earthquakes around the Korean Penisula. TEC anomalies associated with the large-scale earthquakes showed the similar results to previous studies. In addition, we newly found the similar TEC changes from the recent 2016 Ecuador earthquake (M7.8). However, the post-seismic TEC changes would be falsely interpreted as the pre-seismic TEC changes dependent on the post-processing of TEC observation. We also investigated the possibility of TEC responses from the recent domestic earthquakes including 2016 Gyeongju earthquake but could not find any anomalous TEC changes. This is probably because the domestic earthquakes release significantly smaller acoustic wave energy than that of large-scale earthquakes occurring in plate boundaries.

A Study of Hypocentral Depth of Pohang Earthquake (포항 지진의 진원 깊이 연구)

  • Chung, Tae Woong;Lee, Youngmin;Iqbal, Muhammad Zafar;Jeong, Jina
    • Geophysics and Geophysical Exploration
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    • v.21 no.2
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    • pp.125-131
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    • 2018
  • 2017 Pohang earthquake (M 5.4) was more disastrous than 2016 Gyeongju earthquake (M 5.8), partly because of its shallow focal depth. However, precise focal depth of Pohang earthquake is still controversial. Close crustal model showed 6 ~ 11.5 km in relocation depth, whereas other models showed almost surface range. Geothermal study indicated temperature of $300^{\circ}C$ at depth of 7.5 km. Related with observations of seismogenic layer, the focal depth of Pohang earthquake seems to be 7 km depth as obtained by close model.

Confidence Interval Estimation of the Earthquake Magnitude for Seismic Design using the KMA Earthquake Data (기상청 지진 자료를 이용한 내진설계 지진규모의 신뢰구간 추정)

  • Cho, Hong Yeon;Lee, Gi-Seop
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.29 no.1
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    • pp.62-66
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    • 2017
  • The interest on the potential earthquake magnitude and the request on the earthquake-resistant design examination for coastal structures are emerged because of the recently occurred magnitude 5.8 earthquake in Gyeoung-Ju, Korea. In this study, the magnitude and its confidence intervals with the return periods are estimated using the KMA earthquake magnitude data (over 3.5 and 4.0 in magnitude) by the non-parametric extreme value analysis. In case of using the "over 4.0" data set, the estimated magnitudes on the 50- and 100-years return periods are 5.81 and 5.94, respectively. Their 90% confidence intervals are estimated to be 5.52-6.11, 5.62-6.29, respectively. Even though the estimated magnitudes have limitations not considering the spatial distribution, it can be used to check the stability of the diverse coastal structures in the perspective of the life design because the potential magnitude and its confidence intervals in Korea are estimated based on the available 38-years data by the extreme value analysis.

초점 - 원자력연구원 하나로 건물 내진 보강 공사 현황

  • 한국원자력산업회의
    • Nuclear industry
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    • v.37 no.1
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    • pp.7-14
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    • 2017
  • 작년 경주 지진으로 원자력 안전에 대한 시민들의 촉각이 예민해져 있는 가운데 최근 대전 지역에서 원자력연구원의 하나로 원자로 건물 외벽 내진 보강 공사 방식에 대한 검증을 요구하는 여론이 일고 있다. 그 동안 원자력연구원에서 진행한 하나로 건물 내진 보강 공사 배경과 주요 일정, 설계 개념, 구조 성능 검증 실험, 공사 현황, 건물 성능 점검, 안전 관리, 정보 공개 및 검증, 향후 계획 등을 정리하여 종합했다.

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A Study for the Development Direction of Building Industry in Preparation for Earthquake Disaster (지진재난 대비를 위한 건축 산업의 발전방향에 대한 고찰)

  • Han, Dong-ho;Kim, Jong Kouk
    • The Journal of the Convergence on Culture Technology
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    • v.4 no.1
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    • pp.307-314
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    • 2018
  • It became clear that Korean peninsula is not a safe region anymore from an earthquake disaster after Gyeongju and Pohang Earthquake in 2016-2017. Unfortunately, building industry in Korea has not been well prepared for an earthquake disaster and the following problems exist. First, the rate of buildings with proper seismic performance is relatively low. Second, the number of piloti buildings which are vulnerable to earthquake and fire disaster has increased recently. Third, the proportion of small-scale buildings excluded from the application of the building law for securing safety is too high. Fourth, widespread corruption and poor construction impede safety. Therefore, measures to prepare for earthquake disaster are as follows. First, methods of reinforcing building structures and reducing the seismic load acting on a building should be utilized in order to secure the insufficient seismic performance of buildings vulnerable to earthquakes. Second, whistleblowers should be encouraged and protected to prevent defective construction due to corruption. To this end, whistleblowers should be recognized as an effective means of protecting public interest not the traitor to the organization.

Analysis of geotechnical Seismic Sensitivity in Kyeongju (경주 지역의 지반공학적 지진 민감도 분석)

  • 선창국
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2000.04a
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    • pp.130-140
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    • 2000
  • The earthquake hazard has been evaluated for 10km by 10km area around Kyeongju which is located near Yangsan fault and has abundant historical earthquake records. The ground motion potentials were determined based on equivalent linear analysis by using the data obtained from in situ and laboratory tests and the El centro eartqhuake record scaled to CLE and OLE of the region. The in situ tests include 9 boring investigations 2 crosshole 7 downhole 13 SASW tests and in the laboratory X-ray diffraction analyses and resonant column tests were performed. The peak ground accelerations range between 0.140g and 0.286g on CLE and between 0.051g and 0.116g on OLE respectively showing the good potential of amplification in the deep alluvial layer which is common in Kyeongju area. the response spectrum based on the Korea design guide was sometimes underestimate the motion. particularly near the natural period of the site and the importance of site-specific analysis and need for the improved site categorization method were introduced.

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Spectral Characteristics of the June 2, 1999 Kyeongju Earthquake (1999년 6월 2일 경주 지진의 스펙트럼 특성)

  • 신진수
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1999.10a
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    • pp.37-44
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    • 1999
  • Spectral characteristic of Kyeongju earthquake occurred on the June 2, 1999 with magnitude 3,4 is analyzed. It is guessed that the stress energy release of source within relatively short period caused the ground near the epicenter to vibrate with large amplitude for the magnitude and predominantly high frequency. The cumulative absolute velocity and average spectrum acceleration are 0.034 gsec and 0.118g, respectively lower than threshold values of potential earthquake damage which is consistent with the investigation of damage in field. The analysis of the acceleration records of Kyeongju earthquake shows the need to develop the ration criterion for the determining the operating basis earthquake of nuclear power plant.

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