• 한국안전학회지
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• 제19권2호
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• pp.93-97
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• 2004

Slab formwork consists of sheathing, stringer, hanger and shore. There are several types of adjustable individual shores. In constructions site, pipe supports are usually used as shores. The strength of a pipe support is decreasing as it is frequently being used at the construction site. In this study, 2857 pipe supports were bought to fine out the strength change of used pipe support and unused pipe supports according to aging. Among these pipe supports, 2337 pipe supports were lent to the construction companies free of charge. Compressive strength was measured by knife edge test and plate test at each 3 month. Test results show that the strength of unused pipe supports almost equaled to the strength of new pipe supports until 191 days, but the strength of used pipe supports at 191 days was lower than the strength of new pipe supports. So, the strength of used pipe supports at 191 days was not satisfied the specification of KS F 8001. According to these results, it shows that attention has to be paid to formwork design using used pipe supports. Therefore, the paresent study results will be able to provide a firm base to design slab formwork and test the performance of used temporary structure and prevent formwork collapses.

• 한국안전학회지
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• 제26권3호
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• pp.59-62
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• 2011

Among the accidents and failures that occur during concrete construction, many are formwork failures which usually happen when concrete is being placed. A system of formwork filled with wet concrete has its weight at the top and is not basically a stable structure. Slab formwork consists of sheathing, stringer, hanger and shore. There are several types of adjustable shores. In construction site, pipe supports are usually used as a shore of slab formwork. In this study, pipe support systems with/without horizontal connector were measured by buckling test. Buckling load of respective pipe support system was analyzed by structural analysis program(MIDAS). Buckling load of pipe support with/without horizontal connector was got by test and structural analysis. According to these results, we know that horizontal connector made pipe support system very safe. Buckling load of pipe support with horizontal connector is 56% higher than that without horizontal connector. So horizontal connector is important in slab formwork systems. Finally, the present study results will be used to design slab formwork system safely in the construction sites.

• 한국안전학회지
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• 제23권4호
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• pp.67-71
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• 2008

Formwork is a temporary structure that supports its weight and that of fresh concrete as well as construction live loads. Slab formwork consists of sheathing, stringer, hanger and shore. In construction site, pipe supports are usually used as shores which are consisted of the slab formwork. In this study, compressive strength of 80 pipe supports was measured by knife edge test and plate test. Buckling load of pipe supports was analyzed by structural analysis program(MlDAS). Theoretical buckling load with/without initial deformation was got by theoretical analysis. According to these results, buckling load which was analyzed by structural analysis program(MlDAS) was larger than compressive strength of knife edge test and plate test. Theoretical buckling load without initial deformation was larger than compressive strength of knife edge test and plate test. But Theoretical buckling load with initial deformation was lower than compressive strength of knife edge test and plate test. Initial deformation equation for test method according to the pipe support length was suggested. Therefore, the present study results will be used to design the slab formwork safely.

• 한국전산구조공학회논문집
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• 제28권4호
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• pp.361-368
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• 2015

최근 지진의 빈도가 증가하면서 전력 시설물에 대한 피해 역시 심각한 상황이다. 요즘 들어 Hanger, Brace, Snubber와 같이 주요기기들을 연결하는 배관지지 시스템의 중요성이 강조되고 있다. 배관의 손상은 발전소 가동에 전체적인 영향을 미치기 때문에 손상을 주는 요인으로부터 보호할지지 장치가 필요하게 된다. 이러한 장치들은 배관에 작용하는 직 간접적인 진동과 충격을 저감시키는 역할을 하기 때문에 배관의 손상을 방지할 수 있다. 본 논문에서는 마찰진자 원리를 이용한 기계식 댐퍼를 개발하고 특성시험을 통해 장치 성능을 검증한 내용을 기술하였다. 또한 자체 개발한 설계 프로그램을 통해 예상된 해석값과 시험값을 비교분석하였고 결과적으로 설계의 신뢰성을 향상시켰다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.886-891
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• 2000

One of the domestic co-generation plants have undergone excessive vibration problems of turbine attributed to external force for years. The root cause of turbine vibration may be shan alignment problem which sometimes is changed by thermal expansion and external farce, even if turbine technicians perfectly performed it. To evaluate the alignment condition from plant start-up to full load, a strain measurement of turbine and main steam piping subjected to thermal loading is monitored by using strain gages. The strain gages are bonded on both bearing housing adjusting bolts and pipe stoppers which. installed in the x-direction of left-side main steam piping near the turbine inlet in order to monitor closely the effect of turbine under thermal deformation of turbine casing and main steam piping during plant full load. Also in situ load of constant support hangers in main steam piping system is measured by strain gages and its results are used to rebalance the hanger rod load. Consequently, the experimental stress analysis by using strain gages turns out to be very useful tool to diagnose the trouble and failures of not only to stationary components but to rotating machinery in power plants.