• Title/Summary/Keyword: Ground disasters

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Seismic performance evaluation of fiber-reinforced prestressed concrete containments subject to earthquake ground motions

  • Xiaolan Pan;Ye Sun;Zhi Zheng;Yuchen Zhai;Lianpeng Zhang
    • Nuclear Engineering and Technology
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    • v.56 no.5
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    • pp.1638-1653
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    • 2024
  • Given the unpredictability of the occurrence of the earthquake and other potential disasters into consideration, the nuclear power plant may be confronted with beyond design-basis earthquake load in the future. The containment structure may be severely damaged under such severe earthquake loading, increasing the risk of containment concrete cracking and potential radioactive materials leaking. Moreover, initial damage caused by the earthquake may significantly alter the pressure performance of the containment under follow-up internal pressure. To compromise the dangers of beyond design-basis earthquake to the containment, an alternative of replacing the conventional concrete with fiber-reinforced concrete (FRC) to upgrade the seismic resistance capacity of the containment is attempted and thoroughly researched. In this study, the influence of various fiber types such as rigid fiber and mixed fiber is regarded to constitute fiber-reinforced PCCVs. The physical properties of traditional and fiber-reinforced PCCVs under earthquake ground motions are scientifically compared and identified by using traditional and proposed evaluation indices. The results indicate that both the traditional evaluation index (i.e. top displacement, stress, strain) and the proposed damage index are greatly reduced by the practice of fiber strengthening under earthquake ground motions.

Shaking table tests on the seismic response of slopes to near-fault ground motion

  • Zhu, Chongqiang;Cheng, Hualin;Bao, Yangjuan;Chen, Zhiyi;Huang, Yu
    • Geomechanics and Engineering
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    • v.29 no.2
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    • pp.133-143
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    • 2022
  • The catastrophic earthquake-induced failure of slopes concentrically distributed at near-fault area, which indicated the special features of near-fault ground motions, i.e. horizontal pulse-like motion and large vertical component, should have great effect on these geo-disasters. We performed shaking table tests to investigate the effect of both horizontal pulse-like motion and vertical component on dynamic response of slope. Both unidirectional (i.e., horizontal or vertical motions) and bidirectional (i.e., horizontal and vertical components) motions are applied to soft rock slope model, and acceleration at different locations is reordered. The results show that the horizontal acceleration amplification factor (AAF) increases with height. Moreover, the horizontal AAF under unidirectional horizontal pulse-like excitations is larger than that subject to ordinary motion. The vertical AAF does not show an elevation amplification effect. The seismic response of slope under different bidirectional excitations is also different: (1) The horizontal AAF is roughly constant under horizontal pulse-like excitations with and without vertical waves, but (2) the horizontal AAF under ordinary bidirectional ground motions is larger than that under unidirectional ordinary motion. Above phenomena indicate that vertical component has limited effect on seismic response when the horizontal component is pulse-like ground motion, but it can greatly enhance seismic response of slope under ordinary horizontal motion. Moreover, the vertical AAF is enhanced by horizontal motion in both horizontal pulse-like and ordinary motion. Thence, we should pay enough attention to vertical ground motion, especially its horizontal component is ordinary ground motion.

Study of Optimization of Ground Vehicles Routes Aiming to Reduce Operational Costs and to Contribute to a Sustainable Development with the Reduction of Carbon Dioxide in the Atmosphere

  • Clecio, A.;Thomaz, F.;Hereid, Daniela
    • The Journal of Economics, Marketing and Management
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    • v.4 no.1
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    • pp.1-8
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    • 2016
  • The purpose of this paper is to discuss the methodology of optimizing delivery route scheduling using a capacity integer linear programming problem model developed to a previous case study. The methodology suggests a two-stage decision: the first, automatic, where the manager will obtain guidance generated by the solution of the linear programming model, later they could use post-optimization techniques to fine tune to the best operational solution. This study has the goal to reduce the size of service companies' ground transportation fleets, aiming not only to reduce costs and increase competitive advantages but also to lower levels of air pollution and its consequences, traffic and, therefore, the levels of carbon dioxide, allowing for a reduction in envir onmental disasters.

Application into Assessment of Liquefaction Hazard and Geotechnical Vulnerability During Earthquake with High-Precision Spatial-Ground Model for a City Development Area (도시개발 영역 고정밀 공간지반모델의 지진 시 액상화 재해 및 지반 취약성 평가 활용)

  • Kim, Han-Saem;Sun, Chang-Guk;Ha, Ik-Soo
    • Journal of the Earthquake Engineering Society of Korea
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    • v.27 no.5
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    • pp.221-230
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    • 2023
  • This study proposes a methodology for assessing seismic liquefaction hazard by implementing high-resolution three-dimensional (3D) ground models with high-density/high-precision site investigation data acquired in an area of interest, which would be linked to geotechnical numerical analysis tools. It is possible to estimate the vulnerability of earthquake-induced geotechnical phenomena (ground motion amplification, liquefaction, landslide, etc.) and their triggering complex disasters across an area for urban development with several stages of high-density datasets. In this study, the spatial-ground models for city development were built with a 3D high-precision grid of 5 m × 5 m × 1 m by applying geostatistic methods. Finally, after comparing each prediction error, the geotechnical model from the Gaussian sequential simulation is selected to assess earthquake-induced geotechnical hazards. In particular, with seven independent input earthquake motions, liquefaction analysis with finite element analyses and hazard mappings with LPI and LSN are performed reliably based on the spatial geotechnical models in the study area. Furthermore, various phenomena and parameters, including settlement in the city planning area, are assessed in terms of geotechnical vulnerability also based on the high-resolution spatial-ground modeling. This case study on the high-precision 3D ground model-based zonations in the area of interest verifies the usefulness in assessing spatially earthquake-induced hazards and geotechnical vulnerability and their decision-making support.

Economic analysis of Floodplain Forecast connected with GIS and MD-FDA (GIS와 MD-FDA를 연계한 예상침수지역의 경제성 분석)

  • Lee, Byung-Gul;Ahn, Chang-Whan;Choi, Hyun;Hong, Soon-Heon
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2007.04a
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    • pp.253-256
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    • 2007
  • Among natural disasters that lead to devastating damage, floods from heavy rains have been causing hundreds of victims and a great loss of their properties every year. Basically, there is no other way to deal with the problem considering it is a kind of natural disaster, but more specific studies for a preventive measure of flood has been in progress so far. However, the controversy over the problem is going on due to the objection of some environmental organizations or some economic reasons. The key important thing is select the most suitable area for a preventive measure of flood where a huge amount of national budget is put into, which is also the factor to judge it would be success or failure, therefore, in this study, it is made to be profitable to decide the priority order in a plan for preventing disasters by drawing more accurate data conveniently from the connection with GIS when you get some information of configuration of the ground and using them into the economic analysis for flood prevention industries.

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Development of Earthquake Damage Estimation System and its Result Transmission by Engineering Test Satellite for Supporting Emergency

  • Jeong, Byeong-Pyo;Hosokawa, Masafumi;Takizawa, Osamu
    • 한국방재학회:학술대회논문집
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    • 2011.02a
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    • pp.12-19
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    • 2011
  • Drawing on its extensive experience with natural disasters, Japan has been dispatching Japan Disaster Relief (JDR) team to disaster-stricken countries to provide specialist assistance in rescue and medical operations. The JDR team has assisted in the wake of disasters including the 2004 Indian Ocean Earthquake and the 2008 Sichuan Earthquake in China. Information about the affected area is essential for a rapid disaster response. However, it can be difficult to gather information on damages in the immediate post-disaster period. To help overcome this problem, we have built on an Earthquake Damage Estimation System. This system makes it possible to produce distributions of the earthquake's seismic intensity and structural damage based on pre-calculated data such as landform and site amplification factors for Peak Ground Velocity, which are estimated from a Digital Elevation Model, as well as population distribution. The estimation result can be shared with the JDR team and with other international organizations through communications satellite or the Internet, enabling more effective rapid relief operations.

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A Study on the Methods of Fire-Safety in Cultural Property Wooden Buildings (목조 문화재 건축물의 화재 방재를 위한 조사 연구)

  • Chang, Hyung-Soon;Cho, Won-Seok;Kim, Heung-Gee
    • Journal of the Korean Institute of Rural Architecture
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    • v.10 no.4
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    • pp.25-32
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    • 2008
  • The prevention of disasters in cultural property is very important management and historical duties. The reason can't be measured values with monetary scale of our contemporary. Therefore, this paper was considered fire-safety as one of terrible threat-disasters about the wooden buildings. This research deal with 47 cases cultural property wooden building by whole investigation(field survey and interview) in Gangnung province. The most buildings have basic fire extinguisher; ABC powder. A few buildings are rarely installed fire extinguishing equipments; outdoor fire hydrant, heat sensor, ground sprinkler, CO2-hose-reel. But these state is very insufficient for the fire-safety in cultural property wooden buildings. Specially as particular attention in province, forest fire of regional characteristic have close relation with cultural property fire. The majority of factor against forest and building fire is to provide monitoring and security system; CCTV, Fence, Sensor, Alarm and paid guard man against incendiary. Ultimately it is necessary to construct comprehensive disaster prevention system with the organic cooperation such as National Emergency Management Agency, Cultural Heritage Administration, Forest Service, local government officials and regional citizen.

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Disaster Assessment, Monitoring, and Prediction Using Remote Sensing and GIS (원격탐사를 이용한 재난 감시 및 예측과 GIS 분석)

  • Jung, Minyoung;Kim, Duk-jin;Sohn, Hong-Gyoo;Choi, Jinmu;Im, Jungho
    • Korean Journal of Remote Sensing
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    • v.37 no.5_3
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    • pp.1341-1347
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    • 2021
  • The need for an effective disaster management system has grown these days to protect public safety as the number of disasters causing massive damage increases. Since disaster-induced damage can develop in various ways, rapid and accurate countermeasures must be prepared soon after disasters occur. Numerous studies have continuously developed remote sensing and GIS (Geographic Information System)-based techniques for disaster monitoring and damage analysis. This special issue presents the research results on disaster prediction and monitoring based on various remote sensors on different platforms from ground to space and disaster management using GIS techniques. The developed techniques help manage various disasters such as storms, floods, and forest fires and can be combined to achieve an integrated and effective disaster management system.

A Study on the Improvement of the Disaster Prevention and Control System for Underpasses by Analytic Hierarchy Process (계층분석법을 통한 지하차도 재해 예방 및 제어 시스템 개선 연구)

  • Kim, Phil Do;Kim, Kyoung Soo;Moon, Yoo Mi
    • Journal of the Society of Disaster Information
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    • v.16 no.4
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    • pp.734-746
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    • 2020
  • Purpose: Increase in the size and number of underpasses rises occurrence of disasters such as fire and flooding inundation in underpasses. In the occurrence of disasters, the underpasses are more vulnerable to expose of crucial disasters than the general roads due to they are built underground. Therefore, The purpose of this paper is to derive system improvement items to prevent and control disasters in underpasses. Method: A hierarchical model of disaster impact factors and alternatives was developed based on prior researches and expert advices on disaster analyses and impact factors in the underpasses. The developed model was employed for surveys of pairwise comparison, and rankings of improvement were determined by applying the AHP method. Result: With a consistency of the surveys, results of relative weights of evaluation criteria(traffic accidents, fire, flooding inundation) and alternatives(law, system/planning, maintenance/human factor/environment) shows that improvement of laws and system related to the fire disaster is a top priority to prevent and control disaster of the underpasses. Conclusion: From experts' point of view, strengthening laws and systems related to disater prevention facilities such as water spray facilities, external(ground) exit in relation to fire in underpasses showed that it is an alternative to prevent disasters and minimize damage to underpasses.

Development of Image-map Generation and Visualization System Based on UAV for Real-time Disaster Monitoring (실시간 재난 모니터링을 위한 무인항공기 기반 지도생성 및 가시화 시스템 구축)

  • Cheon, Jangwoo;Choi, Kyoungah;Lee, Impyeong
    • Korean Journal of Remote Sensing
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    • v.34 no.2_2
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    • pp.407-418
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    • 2018
  • The frequency and risk of disasters are increasing due to environmental and social factors. In order to respond effectively to disasters that occur unexpectedly, it is very important to quickly obtain up-to-date information about target area. It is possible to intuitively judge the situation about the area through the image-map generated at high speed, so that it can cope with disaster quickly and effectively. In this study, we propose an image-map generation and visualization system from UAV images for real-time disaster monitoring. The proposed system consists of aerial segment and ground segment. In the aerial segment, the UAV system acquires the sensory data from digital camera and GPS/IMU sensor. Communication module transmits it to the ground server in real time. In the ground segment, the transmitted sensor data are processed to generate image-maps and the image-maps are visualized on the geo-portal. We conducted experiment to check the accuracy of the image-map using the system. Check points were obtained through ground survey in the data acquisition area. When calculating the difference between adjacent image maps, the relative accuracy was 1.58 m. We confirmed the absolute accuracy of the image map for the position measured from the individual image map. It is confirmed that the map is matched to the existing map with an absolute accuracy of 0.75 m. We confirmed the processing time of each step until the visualization of the image-map. When the image-map was generated with GSD 10 cm, it took 1.67 seconds to visualize. It is expected that the proposed system can be applied to real - time monitoring for disaster response.