• Title/Summary/Keyword: collapse risk

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A Study on the Risk Reduction of Distribution Line through Analysis of Electric Shock Accident (감전재해 분석을 통한 배전선로의 위험성 저감에 관한 연구)

  • Byeon, Junghwan;Choi, Sang-won
    • Journal of the Korean Society of Safety
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    • v.33 no.2
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    • pp.14-20
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    • 2018
  • In this study, we analyze the current status of major disasters in distribution works and propose safety measures through the distribution live-line work method and electric shock risk assessment. The result of analyzing the ratio of electric shocks to the occurrence of industrial accidents in the recent 13 years shows that the death rate is higher than other industries, especially the construction industry occupying most of the disaster, and it is higher than the collapse disaster. We analyze statistic data of 101 victims selected as core words of live work, distribution line, pole and 22.9 kV in the investigation report of major accident of electric shock fatal from 2001 to 2014. The safety measure was established through the risk assessment of the distribution method using the standard model of the risk assessment based on the results of electric shock analysis on the distribution line. In order to prevent the electric shock accident which is recently being discussed, the risk assessment procedure were carried out in the above-mentioned 22.9kV special high voltage live-line operation method. We derived the risk reduction plan for the distribution line from the results of the major accidents statistic and demonstration of the line works.

Seismic probabilistic risk assessment of weir structures considering the earthquake hazard in the Korean Peninsula

  • Alam, Jahangir;Kim, Dookie;Choi, Byounghan
    • Earthquakes and Structures
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    • v.13 no.4
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    • pp.421-427
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    • 2017
  • Seismic safety evaluation of weir structure is significant considering the catastrophic economical consequence of operational disruption. In recent years, the seismic probabilistic risk assessment (SPRA) has been issued as a key area of research for the hydraulic system to mitigate and manage the risk. The aim of this paper is to assess the seismic probabilistic risk of weir structures employing the seismic hazard and the structural fragility in Korea. At the first stage, probabilistic seismic hazard analysis (PSHA) approach is performed to extract the hazard curve at the weir site using the seismic and geological data. Thereafter, the seismic fragility that defines the probability of structural collapse is evaluated by using the incremental dynamic analysis (IDA) method in accordance with the four different design limit states as failure identification criteria. Consequently, by combining the seismic hazard and fragility results, the seismic risk curves are developed that contain helpful information for risk management of hydraulic structures. The tensile stress of the mass concrete is found to be more vulnerable than other design criteria. The hazard deaggregation illustrates that moderate size and far source earthquakes are the most likely scenario for the site. In addition, the annual loss curves for two different hazard source models corresponding to design limit states are extracted.

A Study on the Bow Collapse of High-Speed Passenger Craft in Collision with Bridge Pier (고속 여객선의 교각 충돌에 대한 연구)

  • 신영식;박명규
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.5 no.1
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    • pp.1-8
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    • 1999
  • During the last 10 years, the various type of high speed craft have been greatly developed, and since around of 1990 the large size of high speed passenger and/or cargo vessels are also introduced and took into the service in the various routes over the world. In a marine traffic way some bridge need to build across a rivers, cannals or a waterways. This one will be an obstruction and potential risk of collision in the way of high speed craft. Accordingly some of collision accident have been reported, which were caused by a lost control, wind and hydrodynamic forces, fog or human errors. In this paper a high speed craft having 40 m length is assumed to be collided with a circular type of bridge piers at right angle. The mode of deformation, penetration depth of collapse, impact forces, reduction of speed, loss of kinetic energy, and influence of scantlings, etc. have been calculated in each speed with a time variation to find a maximum values within a limit, and are graphically presented.

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Cause Analysis of Cone Roof Tank Collapse during Plant Construction (플랜트 공사 중 발생한 Cone Roof Tank 붕괴 사고 원인 분석)

  • Kim, Seung-Han;Kim, Byung-Suk
    • Journal of the Korea Safety Management & Science
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    • v.18 no.3
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    • pp.71-80
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    • 2016
  • This study is on safety improvement measures through analysis of accident cases during plant storage tank construction. Storage tank is a general term for artificial ground facility constructed to store oil, water, gas, and other chemicals. Some companies have clustered storage tanks (tank farm). The construction methods vary according to the component and types of fluids. Because most of the construction procedures include lifting heavy weight materials using heavy construction equipment and are carried out at high places, storage tank construction contains more risk factors than normal aerial construction. Recently, major accidents such as storage tank collapse have occurred often, and cost many lives due to the characteristics of the structure. In this study we would like to analyze the cause of these accidents and propose measures to improve safety.

New indices of structural robustness and structural fragility

  • Andre, Joao;Beale, Robert;Baptista, Antonio M.
    • Structural Engineering and Mechanics
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    • v.56 no.6
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    • pp.1063-1093
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    • 2015
  • Structural robustness has become an important design variable. However, based on the existing definitions of structural robustness it is often difficult to analyse and evaluate structural robustness, and sometimes not efficient since they mix structural robustness with several other structural variables. This paper concerns the development of a new structural robustness definition, and structural robustness and structural fragility indices. The basis for the development of the new indices is the analysis of the damage energy of structural systems for a given hazard scenario and involves a criterion to define an "unavoidable collapse" state. Illustrative examples are given detailing the steps and calculations needed to obtain values for both the structural robustness and the structural fragility indices. Finally, this paper presents the main advantages of the newly proposed definition and indices for the structural risk analysis over existing traditional methods.

A Study on the Strengthening effect of Concrete Reinforcement Bracket on the External Clay Brick Wall (외부치장적벽돌 벽체에 대한 콘크리트 보강브라켓의 보강효과에 관한 연구)

  • Kim, Sun-Woo;Kim, Yang-Jung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2020.06a
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    • pp.117-118
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    • 2020
  • The masonry structure is constructed by cement mortar binding material of brick objects and uses reinforced hardware (connected hardware or wall tie) together when building. However, over time, the corrosion of reinforced steel and the deterioration of joint mortar as well as bricks cause the risk of collapse. In particular, when the externally decorated brick wall is installed on the concrete girder for each floor, the angle bracket is not constructed or corroded, the full-layer weight load is applied to the wall of 0.5B, which is an example of full-scale or collapse. The purpose of this study is to provide numerical information on the reinforcement design by experimentally studying the structural performance of concrete reinforcement brackets that reinforce the vertical load of the exterior wall.

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Expected Damage Analysis of Risk Exposure Object by Violation Rate of Safety Distance in Explosion of Ground Type Magazine (지상형 탄약고 폭발 시 안전거리 위반율에 따른 위험노출대상의 피해 수준 분석 연구)

  • Ham, Tae Yuun;Lee, Jae Joon
    • Journal of the Korean Society of Safety
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    • v.37 no.4
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    • pp.92-100
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    • 2022
  • Of the Korean military's 3,959 ammunition depots, 1,007 - more than 25% - violate safety requirements for distance and equipment. There is a risk of explosion in old depots that are vulnerable to various interior and exterior accidents. This paper examines 10 scenarios, with varying values for ammunition amount and safety distance. The study calculated the overpressure that can be applied to risk-exposure objects, based on the safety distance; expected damage was predicted using constructed spatial information from 3D explosion simulations. The simulations confirmed that explosion overpressure increased the most when the safety distance violation rate increased from 80% to 90%. It also confirmed that secondary damage such as fire and explosion can cause casualties and property damage when the violation rate is 60% or higher. The results show that building collapse becomes a risk with a violation rate of 70% or higher. We conclude that taking ammunition depot safety distance violation into account when planning military facilities and their land utilization could better protect life and property.

Development of Seismic Strengthening Composite Method using Steel type CFT Frame (철골형 CFT 프레임을 활용한 내진보강 복합공법 개발)

  • Lee, Dong-Oun;Woo, Jong-Yeol;Park, Hyeon-Jeong
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2018.05a
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    • pp.101-102
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    • 2018
  • There is a risk that the damage caused by frequent earthquakes can lead to the risk of personal injury due to cracks in buildings and collapse of major structures. Although the seismic design of the new building is designed to be reinforced, the existing structure is not exposed to the risk of earthquake. Therefore, it is aimed to develop the steel frame type CFT composite method which can easily reinforce the CFT structural system with excellent seismic performance against the old non - seismic structure.

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High-rise buildings in the general direction of the Fire Safety Management Study (초고층 건축물 소방안전관리의 기본방향에 관한 연구)

  • Choe, Man-Cheol;Kim, Byeong-Seok
    • Proceedings of the Safety Management and Science Conference
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    • 2011.04a
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    • pp.79-93
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    • 2011
  • Unlike a general building high-rise buildings itself has a kind of risk. In this study, the risk of a number of high-rise buildings have fire safety management of the particular risks associated with looking for ways to minimize focused. Theoretical Study of the United States since the collapse of the WTC buildings, and be the center of the authentic country was. outside of the high-rise building fire safety and related issues, and measures were based on the theory of reference. Issues include voluntary arson. disaster management, building codes and fire regulations of the discrepancies, such as fire safety aspects are explained in terms of three kinds, and for it to take steps in the direction suggested an alternative for high-rise buildings. Although differences of opinion between departments will not be easy to fire and building regulations regarding conflicts of laws among other things, require immediate resolution, and high-rise buildings to create a standard for effective crisis management manual countermeasures will also be ensured.

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Risk Analysis Method for Deriving Priorities for Detailed Inspection of Small and Medium-sized Fill Dam (중소형 필댐의 정밀점검 우선순위 도출을 위한 간이 위험도 분석 방법)

  • Kim, Jinyoung;Kang, Jaemo
    • Journal of the Korean GEO-environmental Society
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    • v.21 no.10
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    • pp.11-16
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    • 2020
  • Korea's agricultural reservoir is one of the country's major infrastructures and plays an important role in people's lives. However, aging reservoirs are a risk for life and property. Currently, large and small dams and reservoirs have been constructed nationwide for more than 40 years of aging. Dams and reservoirs built nationwide are managed by various institutions. Therefore, it is difficult to manage all dams and reservoirs due to cost and time. Managers in the field with less management personnel and lack of expertise should be able to quickly identify risk factors for multiple reservoirs. In this study, risk factors such as seepage, leakage, settlement slide, crack and erosion were selected. To assess the risk of the items, we used the analytical hierarchical process (AHP), one of the Multi-Criteria Decision Making (MCDM) methods. The analysis showed that seepage has the greatest impact on reservoir collapse. It is judged that the priority of detailed diagnosis can be determined by evaluating the risk of dam reservoir collapse in a convenient way in advance using the calculated weight.