• Title/Summary/Keyword: Disaster and Safety

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An Optimal Design Algorithm of Pile Supported Foundations of Tower Cranes (타워크레인의 파일기초 최적설계 알고리즘 개발)

  • Ryu, Sang-Yeon;Seo, Deok-Seok;Kim, Sun-Kuk
    • Journal of the Korea Institute of Building Construction
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    • v.9 no.5
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    • pp.95-101
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    • 2009
  • As buildings increase in height, lifting plans are becoming increasingly important on construction sites. As a critical piece of load-lifting equipment, the tower crane deserves a well thought-out stability review, since it has a significant impact and is very vulnerable to structural safety disaster. To ensure the structural stability of a tower crane, its lateral support or pile supported foundation designs must include consideration for stability, and pile foundation must be used if site conditions prevent soil from providing the required bearing capacity, or prevent the foundation from being increased to the required extent. Pile supported foundation design requires thorough and systematic review, as more stability parameters need to be considered than with an independent foundation. This paper intends to develop an optimal design algorithm that can minimize associated costs while ensuring the fundamental stability of pile supported foundation design, limiting the scope of research to fixed-type trolley tower cranes using pile supported foundations. The findings herein on pile foundation stability review parameters, process and optimal design are expected to improve the operational efficiency of staff concerned, and reduce the time and efforts required for pile foundation design.

A Study on Fire Extinguishing Performance Evaluation of Compressed Air Foam System (압축공기포 소화설비의 소화성능 평가에 관한 연구)

  • Lee, Jang-Won;Lim, Woo-Sub;Kim, Sung-Soo;Rie, Dong-Ho
    • Fire Science and Engineering
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    • v.26 no.5
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    • pp.73-78
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    • 2012
  • This research is to evaluate the fire extinguishing performance of Compressed Air Foam System and this test was conducted using Foam Head System. Compressed Air Foam System adopt the methods of causing the foam by mixing compressed air in foam-aqueous solution, In Overseas, CAFS (Compressed Air Foam System) is generally used because long distance discharge is possible and the water damage can be minimized by reducing the water usage. In this study, Comparative analysis on fire extinguishing effect is done through test to compare the performance between Foam System applied existing air mixture method and Compressed Air Foam System applied AFFF 3 %, foam-extinguishing-agent based on UL162 standard. In Compressed Air Foam System, the volume proportion of air mixture to foam-aqueous solution is 1 to 1 and discharging flow rate is 140 L/min, 160 L/min, 180 L/min, 200 L/min each. As a result of the test, in terms of fire extinguishing performance, fire suppression time for Compressed Air Foam Systems is shorter than for General Air Mixture System in all flow conditions.

Abnormal Changes in Groundwater Monitoring Data Due to Small-Magnitude Earthquakes (지하수 모니터링 이상변동 자료를 이용한 소규모 지진 영향 유추)

  • Woo, Nam C.;Piao, Jize;Lee, Jae-Min;Lee, Chan-Jin;Kang, In-Oak;Choi, Doo-Houng
    • The Journal of Engineering Geology
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    • v.25 no.1
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    • pp.21-33
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    • 2015
  • This study tests the potential of detecting small-magnitude earthquakes (~M3.0) and their precursors using a long-term groundwater-monitoring database. In groundwater records from April to June 2012, abnormal changes in water level, temperature, and electrical conductivity were identified in the bedrock monitoring wells of the Gimcheon-Jijwa, Gangjin-Seongjeon, and Gongju-Jeongan stations. These anomalies could be attributed to the M3.1 earthquake that occurred in the Youngdeok area on May 30th, although no linear relationship was found between the scale of changes and the distance between each monitoring station and the epicenter, which is attributed in part to the wide screen design of the monitoring wells. Groundwater monitoring networks designed specifically for monitoring earthquake impacts could provide better information on the safety of underground space and on the security of emergency water-resources in earthquake disaster areas.

A study on use of quantitative risk analysis on life safety performance for the effect of fixed fire fighting system at road tunnel fires (정량적 위험성 평가를 활용한 도로터널 화재시 물분무 소화설비의 피난 안전 효과 연구)

  • Park, Kyung-Hwan;Yoo, Ji-Oh
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.14 no.1
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    • pp.1-22
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    • 2012
  • This paper tried to verify whether the fixed fire fighting system (FFFS) that is installed in road tunnel improves evacuation performance or not. Verification was performed according to the Disaster Prevention Facilities Installation and Management Guide at Road Tunnel. Twenty seven different fire scenarios were set up for the verification and the cases that FFFS was installed were compared with the cases that FFFS was not installed. The result of the comparison showed that the average equivalent death was reduced in 26 cases out of 27 cases when water spray extinguishing system was installed. It was confirmed that the risk when was not installed was unacceptable in Hong Kong and the Netherlands. On the other hand, it was confirmed that the risk was reduced to as low as reasonably practicable (ALARP) when was installed. The cumulative frequency of average death in case with FFFS was compared against the frequency of death without FFFS: death of one or more is about 50 times less; 10 or more is about 100 times less; and the death of more than 100 is four times less. It was verified that FFFS makes improved conditions to escape from the fires in road tunnel.

Experimental analysis of the sedimentation processes in the movable weir by changing the channel slope considering weir operation (가동보 운영 및 하상경사 변화에 의한 보 상류 퇴사과정의 실험적 분석)

  • Lee, Kyung Su;Jang, Chang-Lae
    • Journal of Korea Water Resources Association
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    • v.51 no.8
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    • pp.729-737
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    • 2018
  • This study investigates the sediment processes the Improved-pneumatic-movable weir through laboratory experiments considering changing channel slopes. Experimental results show that the delta migrates towards the weir and the delta height increases as time passes. Moreover, as the delta approaches the weir, the delta migration speed decreases. As the dimensionless delta location increases, the effective height of dimensionless delta and the dimensionless reservoir capacity increases. Therefore, under the same slope conditions, the sediment deposition volume of the delta is small as the channel slope is mild. This means that the channel slope affects the development of the delta in the upstream of the Improved-pneumatic-movable weir. At the beginning of the experiment, the foreset slope is mild. However, the foreset slope of the delta increases with water depth as the delta migrates downstream. Moreover, as the slope is mild, the ratio of delta front length to delta height is close to 1, and the dimensionless delta height and the dimensionless delta migration speed decrease. As the delta height increases, the water depth, the velocity approaching to the weir and the delta migration speed decrease.

Groping for Cooperative Space Activities in the Northeast Asia (동북아시아에서의 우주협력의 모색)

  • Rhee, Sang-Myon
    • The Korean Journal of Air & Space Law and Policy
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    • v.22 no.1
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    • pp.75-103
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    • 2007
  • The purpose of this paper is to suggest to tackle the problem of poor cooperation in space activities, by re-examining the nature of the competitive political environment, and by building up a normative overarching framework, One of the most acute problems that hampers regional cooperation is the U.S. influence as represented in the MTCR, a supplier's cartel, as was evidenced in the ill-fate of the 2001 launch contract between China and Korea the next year. Notably China, the third space power in the world, has not been allowed to join the MTCR despite her application in June 2004. A possible reconciliation between China and the MTCR over her application for a partnership would set a cornerstone in building up a cooperative environment in the Northeast Asia. Just as the Helsinki process was an overarching norm building framework, comprising human rights, security and environmental issues, it would be desirable that a future peace framework in Northeast Asia dealing with the pending issues of Korean peninsula should also comprise of such broad issues as one relating to cooperation in space activities in the region. South Korea could tap expertise from her neighbor China. When South Korea become an independent space power either with her own technology or otherwise, she would be in a better position to play a role as a balancer in coordinating between the two neighboring space giants. It is remarkable that the Japanese led APRSAT has contributed much in establishing Sentinel Asia as a part of the Disaster Management Scheme, in that each participant, whether it be a state agency, or a private entity like a university or a research institute, can tap the common data to contribute to the common good of safety.

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Groping for Cooperative Space Activities in the Northeast Asia (동북아시아에서의 우주협력의 모색)

  • Rhee, Sang-Myon
    • The Korean Journal of Air & Space Law and Policy
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    • no.spc
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    • pp.59-86
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    • 2007
  • The purpose of this paper is to suggest to tackle the problem of poor cooperation in space activities, by re-examining the nature of the competitive political environment, and by building up a normative overarching framework, One of the most acute problems that hampers regional cooperation is the U.S. influence as represented in the MTCR, a supplier's cartel, as was evidenced in the ill-fate of the 2001 launch contract between China and Korea the next year. Notably China, the third space power in the world, has not been allowed to join the MTCR despite her application in June 2004. A possible reconciliation between China and the MTCR over her application for a partnership would set a cornerstone in building up a cooperative environment in the Northeast Asia. Just as the Helsinki process was an overarching norm building framework, comprising human rights, security and environmental issues, it would be desirable that a future peace framework in Northeast Asia dealing with the pending issues of Korean peninsula should also comprise of such broad issues as one relating to cooperation in space activities in the region. South Korea could tap expertise from her neighbor China. When South Korea become an independent space power either with her own technology or otherwise, she would be in a better position to play a role as a balancer in coordinating between the two neighboring space giants. It is remarkable that the Japanese led APRSAT has contributed much in establishing Sentinel Asia as a part of the Disaster Management Scheme, in that each participant, whether it be a state agency, or a private entity like a university or a research institute, can tap the common data to contribute to the common good of safety.

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An Analysis on the Determinants of Mountainous and Coastal Area's Housing Value Caused by the Characteristics of the Natural Environment (자연환경 특성에 따른 산지형 및 해안형 아파트의 주거가치 상승 결정요인 비교 분석)

  • Choi, Yeol;Kim, Hyeong Jun;Kim, Su Jin
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.2
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    • pp.811-819
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    • 2013
  • This study aims to analyze determinants of mountainous and coastal area's housing value caused by the characteristics of the natural environment. As the current issue of housing value is throwing the spotlight on the climate change recently, environmental features are significantly important than before. There were a lot of studies on the influence of environmental characteristics to the housing price but these studies were mostly dealing with the housing price in especially apartments nearby Han-river in Seoul, South Korea. To have differences with existing studies, environmental characteristics estimating housing value are classified as 8 elements including the view, the wind speed, and the humidity. The result of this study is in following; there were few significant environmental variables in mountainous housing value growth model. This means people living in mountainous area recognize on environmental factors more such as housing or complex characteristics. People living in coastal area are much more sensitive environment variables in their residence value than mountainous area. Especially, the view for the ocean is the most important variable in housing value, and wind speed is second positively significant. Humidity and safety of disaster are negatively significant variables.

Direction of Emergency Rescue Education Based on the Experience of New 119 Paramedics for National Health Promotion (국민건강증진을 위한 응급구조학 교육의 나아갈 방향 -신임 119구급대원의 출동경험을 바탕으로-)

  • Kim, Jung-Sun
    • Journal of Korea Entertainment Industry Association
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    • v.15 no.1
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    • pp.207-220
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    • 2021
  • The purpose of the study is to investigate the application and utility of emergency rescue education and derive limitations, improvements and development directions of university education based on the field experience of 119 emergency medical technician(EMT)s. The research subjects were six new 119 emergency medical technician(EMT)s within three years of starting their first-aid service in the field. After conducting in-depth narrative interviews, the analysis was performed using Colaizzi method. The 82 formulated meanings were derived from significant statements. From formulated meanings, 23 themes, 4 theme clusters, 2 categories were identified. The four theme clusters were 'The effectiveness of university education', 'The limitations of university education', 'The direction of improvement in educational methodology' and 'The direction of improvement in educational contents. University education has been helpful overall, but limitations are observed at the same time, suggesting that it should be developed through the improvement of educational methodologies (i.e. problem-based learning, field case review, education through role-playing, simulation education, strengthening skill ect.) and educational content (i.e. training tailored to the field, education focused on trauma or cardiac arrest, expansion of triage education in disaster management, reinforcement of education on-site safety, education on special patients, diverse guidance and faculty for different perspectives).

Analysis of Response Characteristics According to Permanent Displacement in Seismic Slope (지진시 비탈면의 영구변위 발생에 따른 응답특성 분석)

  • Ahn, Jae-Kwang;Park, Sangki;Kim, Wooseok;Son, Su-Won
    • Journal of the Korean Geotechnical Society
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    • v.35 no.12
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    • pp.135-145
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    • 2019
  • The slope collapse can be classified into internal and external factors. Internal factors are engineering factors inherent in the formation of slopes such as soil depth, slope angle, shear strength of soil, and external factors are external loading such as earthquakes. The external factor for earthquake can be expressed by various values such as peak ground acceleration (PGA), peak ground velocity (PGV), Arias coefficient (I), natural period (Tp), and spectral acceleration (SaT=1.0). Specially, PGA is the most typical value that defines the magnitude of the ground motion of an earthquake. However, it is not enough to consider the displacement in the slope which depends on the duration of the earthquake even if the vibration has the same peak ground acceleration. In this study, numerical analysis of two-dimensional plane strain conditions was performed on engineered block, and slope responses due to seismic motion of scaling PGA to 0.2 g various event scenarios was analyzed. As a result, the response of slope is different depending on the presence or absence of sliding block; it is shown that slope response depend on the seismic wave triggering sliding block than the input motion factors.