• Title/Summary/Keyword: earthquake safety

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Evaluation of optimal ground motion intensity measures of high-speed railway train running safety on bridges during earthquakes

  • Liu, Xiang;Jiang, Lizhong;Xiang, Ping;Feng, Yulin;Lai, Zhipeng;Sun, Xiaoyun
    • Structural Engineering and Mechanics
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    • v.81 no.2
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    • pp.219-230
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    • 2022
  • Due to the large number of railway bridges along China's high-speed railway (HSR) lines, which cover a wide area with many lines crossing the seismic zone, the possibility of a HSR train running over a bridge when an earthquake occurs is relatively high. Since the safety performance of the train will be threatened, it is necessary to study the safety of trains running over HSR bridges during earthquakes. However, ground motion (GM) is highly random and selecting the appropriate ground-motion intensity measures (IMs) for train running safety analysis is not trivial. To deal this problem, a model of a coupled train-bridge system under seismic excitation was established and 104 GM samples were selected to evaluate the correlation between 16 different IMs and train running safety over HSR bridges during earthquakes. The results show that spectral velocity (SvT1) and displacement (SdT1) at the fundamental period of the structure have good correlation with train running safety for medium-and long-period HSR bridges, and velocity spectrum intensity (VSI) and Housner intensity (HI) have good correlation for a wide range of structural periods. Overall, VSI and HI are the optimal IMs for safety analysis of trains running over HSR bridges during earthquakes. Finally, based on VSI and HI, the IM thresholds of an HSR bridge at different speed were analyzed.

Analysis of Landslide Hazard Map during Earthquake with Various Degrees of Saturation and Cohesion Values (포화도 및 점착력 변화에 따른 지진시 산사태 위험도 분석)

  • Lee, Joonyong;Han, Jin-Tae
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.35 no.3
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    • pp.599-606
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    • 2015
  • Damage of landslide due to earthquake covers a considerable part of total damage due to earthquake. Landslide due to earthquake affects direct damage of human lives and structures, and social system can be paralyzed by losing functions of roads, basic industries, and so on. Therefore, systematic and specialized research examining the factors affecting the slope stability by earthquakes should be needed. However, method of evaluation of slope stability problems due to earthquake contains somewhat uncertainty since many soil properties are predicted or assumed. In this study, influences of change of soil properties such as degree of saturation and cohesion value are analyzed in factor of safety and displacement using seismic landslide hazard maps based on GIS. As the degree of saturation increases or cohesion decreases, it is found that seismic landslide hazard area marked with factors of safety or displacements tends to increase. Therefore, to draw more exact landslide hazard map during earthquake, it is necessary to obtain accurate soil property information preferentially from site investigation data in the field.

The relationship between time-varying eccentricity of load with the corner lateral displacement response of steel structure during an earthquake

  • Takin, Kambiz;Hashemi, Behrokh H.;Nekooei, Masoud
    • Steel and Composite Structures
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    • v.20 no.4
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    • pp.801-812
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    • 2016
  • In an actual design, none of the structures with shear behaviors will be designed for torsional moments. Any failure or damages to roofs, infills, shear walls, and braces caused by an earthquake, will inevitably result in relocation of center of mass and rigidity of the structure. With these changes, the dynamic characteristics of structure could be changed during an earthquake at any moment. The main objective of this paper is to obtain the relationship between time-varying eccentricity of load and corner lateral displacement. In this study, various methods have been used to determine the structural response for time-varying lateral corner displacement. As will be seen below, some of the structural calculation methods result in a significant deviation from the actual results, although these methods include the interaction effects of modes. Controlling the lateral displacement of structure can be performed in different ways such as, passive dampers, friction dampers, semi-active systems including the MR damper and active Systems. Selecting and locating these control systems is very important to bring the maximum safety with minimum cost into the structure. According to this study will be show the relation between the corner lateral displacements of structure and time-varying eccentricity by different kind of methods during an earthquake. This study will show that the response of the structure at the corners due to an earthquake can be very destructive and because of changing the eccentricity of load, calculating the maximum possible response of system can be carried out by this method. Finally, some kind of systems must be used for controlling these displacements. The results shows that, the CQC, DSC and exact methods is comply each other but the results of Vanmark method is not comfortable for these kind of buildings.

The Effects of Knowledge Management System for Earthquake disaster Management on the Disaster Management Job Performance (지진 재난관리를 위한 지식경영시스템이 재난관리 업무성과에 미치는 영향)

  • Shin, KwangSoon
    • Journal of the Society of Disaster Information
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    • v.16 no.2
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    • pp.353-363
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    • 2020
  • Purpose: The purpose of this study is to verify the effects of assessment and compensation system, information technology, knowledge quality, and knowledge management activities on the earthquake disaster management job performance. Method: Questionnaire survey was performed for the fire officials, and the multi-regression analysis for surveyed data was statistically performed by using SPSS 25.0 program. Result: Information technology, knowledge quality and knowledge management activities among the factors of the knowledge management system related to earthquake disasters have had significant positive effects on the earthquake disaster management job performance, but assessment and compensation system are found to have no significant effects on the earthquake disaster management job performance. Conclusion: It was confirmed that the higher the level of information technology, knowledge quality and knowledge management activities related to earthquake disasters, the higher the disaster management job performance.

Evaluation of the Actual Conditions for the Construction of a Firefighting Safety Management System in Domestic Power Plants (국내발전소 소방안전경영시스템구축을 위한 실태평가에 관한 연구)

  • Kang, Gil-Soo;Choi, Jae-wook
    • Fire Science and Engineering
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    • v.32 no.1
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    • pp.89-98
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    • 2018
  • Fire accidents in foreign countries, like the accident in a thermal power plant in Beijing, the accidents in domestic power plants, including Boryeong Power Plant in 2012 and Taean Power Plant in 2016, a disaster in a nuclear power plant in Fukushima in 2011 or the large-scale power failure in California in 2001 are safety accidents related to electric power, which caused losses in the people's stable lives and the countries. Electricity has an absolute impact on the people's life and the economy, so we can easily expect the serious situation affecting economic growth as well as direct damage to the protection of the people's lives and the losses of properties, if there are fire or explosion accidents or radioactive leak because of negligence in safety management, or problems because of natural disasters like an earthquake in power plants that generate electricity. In this study, it was drawn the improvement of the organizations exclusively in charge of firefighting, the operation of a program for the improvement of professional competency, the development of a customized firefighting management system for plants for systematic firefighting safety management and the improvement of the earthquake-proof correspondence system, which has recently become an issue, as measures for improvements through a survey of the actual conditions concerning the necessity of the construction of a firefighting safety management system for power plants with five power generation companies, including Korea Southern Power Co., Ltd., and the persons in charge of firefighting safety Korea Hydro & Nuclear Power Co., Ltd.

Optimum Intensity for Seismic Design of Major Man-made Structures in Korea (한반도내(韓半島內) 주요(主要) 인공구조물(人工構造物)의 적정(適正) 내진설계진도(耐震設計震度))

  • Kim, Sung Kyun
    • Economic and Environmental Geology
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    • v.19 no.4
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    • pp.297-304
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    • 1986
  • Earthquake disaster is dependent upon both site intensity and strength of structures. The higher the strength, structures become more safe, which in turn increases the construction cost. Therefore, it is necessary to decide an optimum design intensity in which the safety is balanced with the cost. Such an optimum design intensity for major man-made structures in Korea is determined in the present study from a simulation model as follows. 1) Hypothetical earthquake time series are generated from the probability distribution to represent appropriately the seismicity of Korea. 2) The strength of structures constructed with a certain design intensity is assumed to exponentially decrease with the elapsed time. The construction cost is also expressed as a function of design intensity. 3) Comparing the seismic intensity generated from the earthquake time series with the strength of structures, the safety of structures is examined. Then the time until the structure is damaged by an earthquake is obtained within the designed life time. 4) The above simulation is iterated several hundred times and hence the mean life time of structures having a certain design intensity is obtained. 5) After all, the optimum design intensity to minimize the annual mean loss, the ratio of construction cost to mean life time, is estimated. The major conclusions obtained from the above simulation model are as follows. 1) Depending upon the designed life time ($T_p$), the optimum design intensities are appeared to be 0. 05-0. 10g for $T_p=50yr$ and 0. 08-0.13g for $T_p=100yr$. 2) According to the sensitivity analysis, the optimum design intensity increases with the rapid strength decrease of structure and decreases with the increase of initial construction cost.

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A Shaking Table Test for Equipment Isolation in the NPP (II): FPS (원전기기의 면진을 위한 진동대 실험 II : FPS)

  • Kim, Min-Kyu;ZChoun, Young-Sun;Choi, In-Kil
    • Journal of the Earthquake Engineering Society of Korea
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    • v.8 no.5 s.39
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    • pp.79-89
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    • 2004
  • This paper presents the results of experimental studies on the equipment isolation effect in the nuclear containment. For this purpose, shaking table tests were performed. The purpose of this study is enhancement of seismic safety of equipment in the Nuclear Power Plant. The isolation system, known as Friction Pendulum System (FPS), combines the concepts of sliding bearings and pendulum motion was selected. Peak ground acceleration, bidirectional motion, effect of vertical motion and frequency contents of selected earthquake motions were considered. As a result, these are founded that the vertical motion of seismic wave affect to the base isolation and the isolation effect decreased in case of near fault earthquake motion.

A Study on inhabitants self-help scheme via sociotechnology for disaster safety of the smart city - Mainly on lessons of Kamaisi-city in Japan (스마트시티의 재난안전을 위한 사회기술기반의 주민 자조(自助) 방안 고찰 - 일본 가마이시시(釜石市) 교훈을 중심으로)

  • Chang, Hye-Jung;Kim, Do-Nyun
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.9 no.4
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    • pp.388-403
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    • 2016
  • On July 5, 2016, offshore magnitude 5.0 earthquake, Ulsan, Republic of Korea can anxiety not safe in the earthquake. The gas smell that occurred in Busan on July 20, 2016 did not understand a cause and spread by the ghost story for the earthquake to a citizen. Thus correct information about the disaster is important to the smart city and the quick correspondence for damage inhabitants and the community has an influence on the disaster resilience. This study is targeted for damage inhabitants, and it clarifies the importance of the evocation model of anxiety about the disaster in the smart city with social technology. In the case of the Great East Japan Earthquake, consider the self-help contents of Kamaishi-city inhabitants deeply and find out a proper application method. As a means of disaster response and recovery, suggest that the inhabitants and community will be able to practice self-help measures.