• 제목/요약/키워드: structural fire analysis

검색결과 306건 처리시간 0.025초

Effect of glass powder on the behaviour of high performance concrete at elevated temperatures

  • Kadik, Abdenour;Cherrak, Messaouda;Bali, Abderrahim;Boutchicha, Djilali;Hannawi, Kinda
    • Advances in concrete construction
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    • 제10권5호
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    • pp.443-454
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    • 2020
  • In recent years, many studies have been done on the performance of concrete containing glass powder (GP). For the purpose of widespread use of GP in concrete mixes, a knowledge of the performance of such a mixture after a fire is essential for the perspective of structural use. This research work was carried out to evaluate the performance of High Performance Concrete (HPC) made with GP after being exposed to elevated temperature. The studied mixtures include partial replacement of cement by GP with up to 30%. The mechanical performance and structural alterations were assessed after high temperature treatment from 200℃ to 800℃. The mechanical performance was evaluated by testing the specimens to the compressive and tensile strength. In addition, the mass loss and the porosity were measured to notice the structural alterations. Changes in microstructure due to temperature was also investigated by the X-ray diffraction (XRD) and thermal gravimetric analyses (TGA) as well as porosity adsorption tests. The results of the concrete strength tests showed a slight difference in compressive strength and the same tensile strength performance when replacing a part of the cement by GP. However, after high temperature exposition, concrete with GP showed better performance than the reference concrete for temperature below 600℃. But, after heating at 800℃, the strength of the concrete with GP drop slightly more than reference concrete. This is accompanied by an important increase in mass loss and water porosity. After the microstructure analysis, no important changes happened differently for concrete with GP at high temperature except a new calcium silica form appears after the 800℃ heating.

그루브 조인트가 설치된 수계소화설비 입상배관계통의 지진거동분석을 위한 실험적 연구 (Experimental Study for Seismic Behavior Analysis of a Fire Protection Riser Pipe System with Groove Joints)

  • 김성완;윤다운;김재봉;전법규
    • 한국구조물진단유지관리공학회 논문집
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    • 제25권2호
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    • pp.35-42
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    • 2021
  • 본 연구에서는 NFPA 13을 참조하여 구조물 2층을 구현한 강재지그를 제작하였으며, 그루브 조인트의 배관연결재가 적용된 배관계통을 구성하고 정적 반복가력에 의한 지진모사실험을 수행하였다. 지진모사실험은 엑츄에이터로 건축물 내진설계기준의 최대허용 층간변위에 대한 반복가력실험을 수행하였다. 지진하중 발생 시 입상배관의 구조물에 대한 변형 또는 구조부재간의 상대변위에 의한 변위지배적인 거동에 따른 배관계통과 주요 배관요소의 지진거동을 분석하였다. 배관계통의 변형각은 기존의 센서를 이용하여 측정하기가 어려우므로 이미지측정시스템을 적용하였다.

구조물의 변위 변형 감지를 위한 변형률 센서를 장착한 커스터마이징 비콘 개발 (Development of a Customized Beacon Equipped with a Strain Gauge Sensor to Detect Deformation of Structure Displacement)

  • 김준경
    • 한국구조물진단유지관리공학회 논문집
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    • 제25권5호
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    • pp.1-7
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    • 2021
  • 본 연구에서는 대형 시설물의 재난 모니터링을 위해 시설물에서 발생 가능한 붕괴 및 화재 사고를 감지하고, 재난 상황 발생 시 IoT 기반의 시설물 내부 상황 인지를 위한 커스터마이징 비콘을 개발하고자 하였다. 기존 변형률 센서를 이용한 데이터 계측의 경우 유선으로 변형률 센서를 연결하여 계측하였지만, 본 연구는 이를 무선으로 변경하여 실시간으로 구조물 변형의 유·무를 모니터링이 가능하도록 하였다. 이 과정에서 휘트스톤 브릿지를 이용하기 위해 커스터마이징 비콘에 연결이 가능한 변형률 센서 모듈을 제작하였으며, 계측 데이터를 원격으로 확인하기 위한 시스템 구성을 진행하였다. 계측 데이터 검증을 위해 차세대융합기술연구원 15층 내에 10개의 커스터마이징 비콘과 2개의 게이트웨이를 설치하였으며, 계측 데이터 분석 결과 변형률 데이터값이 7~8 사이에 분포하는 것을 확인하였다.

방화범죄의 실태와 그 대책 - 관심도와 동기의 다양화에 대한 대응 - (The Reserch on Actual Condition of Crime of Arson Which Occurs in Korea and Its Countermeasures)

  • 최종태
    • 시큐리티연구
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    • 제1호
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    • pp.371-408
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    • 1997
  • This article is the reserch on actual condition of crime of arson which occurs in Korea and its countermeasures. The the presented problem in this article are that (1) we have generally very low rate concern about the crime of arson contrary to realistic problems of rapid increase of crime of arson (2) as such criminal motives became so diverse as to the economic or criminal purpose unlike characteristic and mental deficiency of old days, and to countermeasure these problems effectively it presentation the necessity of systemantic research. Based on analysis of reality of arson, the tendency of this arson in Korea in the ratio of increase is said to be higher than those in violence crime or general fire rate. and further its rate is far more greater than those of the U.S.A. and Japan. Arson is considered to be a method of using fire as crime and in case of presently residence to be the abject, it is a public offense crime which aqccompany fatality in human life. This is the well It now fact to all of us. And further in order to presentation to the crime of arson, strictness of criminal law (criminal law No, 164 and 169, and fire protection law No. 110 and 111) and classification of arsonist as felony are institutionary reinforced to punish with certainty of possibility, Therefore, as tendency of arson has been increased compared to other nations, it is necessary to supplement strategical policy to bring out overall concerns of the seriousness of risk and damage of arson, which have been resulted from the lack of understanding. In characteristics analysis of crime of arson, (1) It is now reveald that, in the past such crime rate appeared far more within the boundary of town or city areas in the past, presently increased rate of arsons in rural areas are far more than in the town or small city areas, thereby showing characteristics of crime of arson extending nation wide. (2) general timetable of arson shows that night more than day time rate, and reveald that is trait behavior in secrecy.(3) arsonists are usually arrested at site or by victim or report of third person(82,9%).Investigation activities or self surrenders rate only 11.2%. The time span of arrest is normally the same day of arson and at times it takes more than one year to arrest. This reveals its necessity to prepare for long period of time for arrest, (4) age rate of arson is in their thirties mostly as compared to homicide, robbery and adultery, and considerable numbers of arsons are in old age of over fifties. It reveals age rate is increased (5) Over half of the arsonists are below the junior high school (6) the rate of convicts by thier records is based on first offenders primarily and secondly more than 4 time convicts. This apparently shows necessity of effective correctional education policy for their social assimilation together with re-investigation of human education at the primary and secondary education system in thier life. The examples of motivation for arosnits, such as personal animosity, fury, monetary swindle, luscious purpose and other aims of destroying of proof, and other social resistance, violence including ways of threatening, beside the motives of individual defects, are diverse and arsonic suicide and specifically suicidal accompany together keenly manifested. When we take this fact with the criminal theory, it really reveals arsons of crime are increasing and its casualities are serious and a point as a way of suicide is the anomie theory of Durkheim and comensurate with the theory of that of Merton, Specifically in the arson of industrial complex, it is revealed that one with revolutionary motive or revolting motive would do the arsonic act. For the policy of prevention of arsons, professional research work in organizational cooperation for preventive activities is conducted in municipal or city wise functions in the name of Parson Taskforces and beside a variety of research institutes in federal government have been operating effectively to countermeasure in many fields of research. Franch and Sweden beside the U.S. set up a overall operation of fire prevention research funtions and have obtained very successful result. Japan also put their research likewise for countermeasure. In this research as a way of preventive fire policy, first, it is necessary to accomodate the legal preventitive activities for fire prevention in judicial side and as an administrative side, (1) precise statistic management of crime of arson (2) establishment of professional research functions or a corporate (3) improvement of system for cooperative structural team for investigation of fires and menpower organization of professional members. Secondly, social mentality in individual prospect, recognition of fires by arson and youth education of such effect, educational program for development and practical promotion. Thirdly, in view of environmental side, the ways of actual performance by programming with the establishment of cooperative advancement in local social function elements with administrative office, habitants, school facilities and newspapers measures (2) establishment of personal protection where weak menpowers are displayed in special fire prevention measures. These measures are presented for prevention of crime of arson. The control of crime and prevention shall be prepared as a means of self defence by the principle of self responsibility Specifically arsonists usually aims at the comparatively weak control of fire prevention is prevalent and it is therefore necessary to prepare individual facilities with their spontaneous management of fire prevention instead of public municipal funtures of local geverment. As Clifford L. Karchmer asserted instead of concerns about who would commit arson, what portion of area would be the target of the arson. It is effective to minister spontaveously the fire prevention measure in his facility with the consideration of characteristics of arson. On the other hand, it is necessary for the concerned personnel of local goverment and groups to distribute to the local society in timely manner for new information about the fire prevention, thus contribute to effective result of fire prevention result. In consideration of these factors, it is inevitable to never let coincide with the phemonemon of arsons in similar or mimic features as recognized that these could prevail just an epedemic as a strong imitational attitude. In processing of policy to encounter these problems, it is necessary to place priority of city policy to enhancement of overall concerns toward the definitive essense of crime of arson.

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반응표면법을 이용한 안전밸브의 최적화 (Optimal Design of the Safety Valve by Response Surface Method)

  • 이상우;신대영;변철웅
    • 한국전산구조공학회논문집
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    • 제20권5호
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    • pp.551-556
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    • 2007
  • 소화시스템에 사용되는 고압의 소화가스 저장용기에는 저장용기의 파손을 막아주는 안전밸브가 있다. 이러한 안전밸브의 내부에는 원형 박판의 파열 판이 들어 있는데, 저장용기의 내압이 위험수준에 도달하면 파열 판이 파손하여 내압을 배출하는 역할을 한다. 안전밸브의 설계인자는 파열 판의 두께, 안전밸브의 유로 직경, 플라스틱 패킹 링의 내부 직경 그리고 파열 판을 고정하는 볼트 안쪽의 필렛 반경이 있다. 이중에서 파열 판의 두께는 0.2mm로 고정을 하였다. 요인배치법을 사용하여 주효과를 결정하였고 회귀방정식을 유도하였다. 이러한 회귀방정식은 추후 안전밸브의 설계에 있어서 기초 설계 자료로서 활용할 수 있도록 실험 결과와 비교하여 검증하였다. 검증실험 및 회귀방정식에 의한 결과의 오차는 약 $2{\sim}5%$ 정도인 것을 확인하였다. 그리고 반응표면법을 사용하여 기밀테스트 압력인 25MPa에서 파열할 수 있는 안전밸브의 최적 모델을 결정하였다.

저탄장 자연발화 방지를 위한 압력용기의 응력 해석 (A Stress Analysis for Pressure Vessel to Prevent Spontaneous Ignition of Coal Stockpile)

  • 김영인;김승훈;지민석;염찬섭;최원혁
    • 한국항행학회논문지
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    • 제22권3호
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    • pp.205-212
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    • 2018
  • 자연발화의 문제는 심각한 경제적 손해뿐만 아니라 화재 시 발생하는 유해가스로 인해 환경오염을 발생시키는 대표적인 발전소 피해이다. 저탄장 자연발화 예방 및 조치하기 위해 드론을 이용하는 방법이 제시되었으나 외부의 측풍과 외란으로 인한 2차 사고의 발생위험이 존재하는 상황이다. 자연발화의 원인과 영향 인자는 매우 복잡하기 때문에 사전에 예방하기가 쉽지 않으며 일단 발생하면 소화하기도 어렵다. 따라서 저탄장 내부에서 직접적으로 온도 및 상태를 측정하고 자연발화 지점에 직접적으로 냉각 가스를 분출하여 소화하는 장치가 필요하다. 본 연구는 저탄장의 자연발화를 예방하기 위한 냉각볼 장치의 내부 압력과 외부 압력에 대하여 구조해석을 실시하고 구조적 안전성에 대하여 연구한다.

SPECTRAL ANALYSIS OF WATER-STRESSED FOREST CANOPY USING EO-l HYPERION DATA

  • Kook Min-Jung;Shin Jung-Il;Lee Kyu-Sung
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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    • pp.7-10
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    • 2005
  • Plant water deficiency during drought season causes physiological stress and can be a critical indicator of forest fire vulnerability. In this study, we attempt to analyze the spectral characteristics of water stressed vegetation by using the laboratory measurement on leaf samples and the canopy reflectance spectra extracted from satellite hyperspectral image data. Leaf-level reflectance spectra were measured by varying moisture content using a portable spectro-radiometer. Canopy reflectance spectra of sample forest stands of two primary species (pine and oak) located in central part of the Korean peninsula were extracted from EO-l Hyperion imaging spectrometer data obtained during the drought season in 2001 and the normal precipitation year in 2002. The preliminary analysis on the reflectance spectra shows that the spectral characteristics of leaf samples are not compatible with the ones obtained from canopy level. Although moisture content of vegetation can be influential to the radiant flux reflected from leaf-level, it may not be very straightforward to obtain the spectral characteristics that are directly related to the level of canopy moisture content. Canopy spectra form forest stands can be varied by structural variables (such as LAt, percent coverage, and biomass) other than canopy moisture content.

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청소년 지위비행의 인과적 경로 (Causal Pathway Analysis of Adolescence Status Delinquency)

  • 조영숙;신유선
    • 한국간호교육학회지
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    • 제7권2호
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    • pp.379-390
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    • 2001
  • The purpose of this study was to examine the actual condition of the adolescent status delinquency and to predict that family environments, the mother's rear attitudes and personal factors influence on the adolescent status delinquency among high school students in Busan(N=404). Under these purposes of the study, the preliminary study was performed to divided the criminal delinquency from the status delinquency, and on the basis of the result of the preliminary study, the analysis of causal pathway were performed. The data were surveyed using paper and pencil self-rating. Descriptive statistics and pathway analyses were conducted to answer research objectives. The result of this study was as follows. First, the status delinquency and the criminal delinquency are different dimensions with each other independently. Second, Contents of the status delinquencies were Drinking, Smoking, Cheating examination, Stopping out, Reckless running, Gang fighting, Reading lewdness and Watching lewd video, Sexual intercourse with the other gender, etc., The criminal delinquencies were Robbing of bicycle or auto-bicycle, Taking nalcotic drug, Robbing money of drunkard and women, Rape, Setting on fire, etc. Third, The factors of structural environments of the family and the factors of mother's rear attitude influenced on the status delinquency via adolescence's compulsivity. that is to say, if the mother's rear attitude is affective, it restrains the impulsivity of adolescence causing to the restraint of the status delinquency.

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PCITS에 의해 소손된 강이음쇠형 CSST의 특성 해석에 관한 연구 (A Study on the Properties Analysis of an Iron Fittings Type CSST Damaged by the PCITS)

  • 이장우;최충석
    • 한국화재소방학회논문지
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    • 제30권4호
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    • pp.121-127
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    • 2016
  • 본 논문에서는 대전류공급장치(PCITS)에 의해 소손된 강이음쇠형(iron fittings type) 금속플렉시블호스(CSST)의 구조 및 전기적 특성을 해석하였다. CSST는 보호 피막, 튜브, 너트, 클램프 링, 플레어 캡, 소켓, 볼 밸브 등으로 구성되어 있다. CSST의 내전압 평가는 전기 충전부와 비충전부 사이에 교류 전압 220 V를 1분간 인가하여 견뎌야 한다. 직류 500 V에 의한 절연 성능의 평가는 온도 상승 시험 전에 $1M{\Omega}$ 이상, 시험이 끝난 후에는 $0.3M{\Omega}$ 이상을 요구한다. 정상 제품의 평균 저항은 $11.5m{\Omega}$이었으나 PCITS로 130 A를 흘려 소손된 제품의 평균 저항 $11.50m{\Omega}$이었다. 또한 130 A가 약 10 s 흘렀을 때 튜브의 보호 피막이 일부 용융되었고, 검정색의 연기가 발생하였다. 60 s 경과되면 튜브의 대부분이 적색으로 발열되며, 전류가 120 s 흘렀을 때는 적열 범위가 넓어졌다. 95%의 신뢰 구간(CI)의 검증에서 P 값은 0.019로 정규 분포를 갖지 못하였으나 Anderson-Darling (AD) 통계량은 0.896, 표준 편차는 0.5573 등으로 양호한 특성을 나타냈다.

선박 화재시 승선자 피난동선예측을 위한 알고리즘 개발 기초연구 (Shipboard Fire Evacuation Route Prediction Algorithm Development)

  • 황광일;조소형;고후상;조익순;윤귀호;김별
    • 해양환경안전학회지
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    • 제24권5호
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    • pp.519-526
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    • 2018
  • 본 연구에서는 인명구조활동을 지원하기 위한 피난동선예측 알고리즘 개발의 첫 단계로 피난동선예측 알고리즘의 개념을 정립하고 그 타당성을 수치적으로 명확히 제시하였다. 제안하는 알고리즘은 평상시 선박내 모니터링 시스템으로부터 지속적으로 승객이동 데이터를 취득, 분석, 정형화하고, 재난발생시 이 데이터와 예측 툴을 활용해 도출한 승선자의 피난동선예측 정보를 구조자에게 제공하여 인명피해를 최소화시키는 프로세스로 요약할 수 있다. 피난훈련을 통해 피난특성 데이터를 취득하였고 이를 기존 인명피난예측 툴에 입력하여 피난특성을 예측한 결과, 예측 툴의 구조적 원인으로 인해 가시거리가 충분히 확보되고 피난경로를 충분히 숙지한 상황에서의 피난 시나리오(SN1)에서만 신뢰할 만한 예측결과가 도출되었다. 본 연구에서 제안하는 알고리즘의 타당성을 확인하기 위해 타 분야의 예측 툴을 사용하여 피난특성을 예측한 결과, 제안 알고리즘이 구현될 경우 평균피난시간예측값과 피난동선(지점경유)예측값이 각각 0.6 ~ 6.9 %, 0.6 ~ 3.6 % 범위의 오차에서 실측값과 매우 유사한 경향을 보였다. 향후 선내 모니터링 데이터를 분석하고 이를 활용한 예측성능이 우수한 피난동선예측 알고리즘을 개발할 계획이다.