• 한국구조물진단유지관리공학회 논문집
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• 제21권2호
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• pp.24-33
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• 2017

국내 도시철도 지하역사는 주로 개착식 공법으로 건설되었으며, 1970~80년대에 건설된 지하역사는 내진설계가 반영되지 않았다. 한반도 뿐 만 아니라, 전 세계적으로 지진 발생빈도는 증가하고 있는 추세이며, 내진설계가 적용되지 않은 기존 지하역사에 지진이 발생될 경우 막대한 인명 및 재산피해가 우려된다. 본 연구에서는 내진보강이 된 지하역사의 지반-구조물 상호작용과 보강효과를 검토하기 위해, Kobe 지진파 및 Northridge 지진파를 1/60축소모형에 적용하여 원심모형실험을 수행하였다. 내진보강은 주 부재인 기둥, 측벽, 슬래브의 강성을 증가시켜 내진보강 전후를 비교 검토하였다. 현장 조건에 따른 모형 지반을 모사하기 위해 공진주시험을 통해 실제 깊이 및 밀도에 따른 전단파 속도의 변화를 모사하였다. 지반과 구조물은 비교적으로 유사한 거동을 하였으며, 지표면으로 가까워질수록 상대변위가 증가하였다. 또한, 내진 보강전후의 지하역사 구조물의 슬래브에 비해 기둥과 측벽에서 상대변위와 모멘트 구조 거동을 통해 내진 보강 효과를 확인할 수 있었으며, 단주기인 Northridge지진파에 비해 Kobe지진파에서 구조물의 변형이 크게 발생하는 것을 통해 지진파는 주요 설계인자임을 확인할 수 있었다.

• 한국구조물진단유지관리공학회 논문집
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• 제19권2호
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• pp.40-51
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• 2015

콘크리트 구조물에서는 인장응력에 대한 저항과 콘크리트내의 하중전달을 위한 철근이음이 고려되어야 한다. 현재 사용되고 있는 철근의 이음방법으로는 전통적으로 사용되는 겹침이음과 함께 채움금속이음을 갖는 슬리브이음과 전조 평행나사 이음과 같은 기계적 철근연결방법 등이 사용되고 있다. 본 연구는 기존에 사용되고 있는 기계적 철근 이음의 시공성과 구조적 성능을 개선하기 위하여 전조 변단면 철근이음을 제안하고 이를 적용한 철근의 구조성능과 파괴거동을 평가하기 위하여 철근연결 종류 및 체결 특성을 고려한 인장강도 실험과 휨하중 실험을 실시하였다. 이를 통하여 제안된 전조 변단면 이음을 적용한 철근의 인장강도 및 휨성능을 비교 평가하였다. 본 연구결과 전조변단면 이음을 적용한 철근이 이음이 없는 철근과 비교하여 동일한 구조성능을 가지는 것으로 나타나 철근콘크리트 구조물의 철근 이음을 위하여 사용할 수 있을 것이다.

• 콘크리트학회논문집
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• 제23권2호
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• pp.235-244
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• 2011

세그멘탈 교량의 파괴는 부적절한 접합에 의해 파괴를 일으키게 되는데 이는 세그멘탈 접합부를 가로지르는 횡방향 텐던의 부식을 야기하게 된다. 이 연구에서는 현장 타설 접합 및 에폭시 접합 조건에 따른 초고성능 프리캐스트 콘크리트 접합부에서의 전단키 거동을 전단 및 극한거동 측면에서 평가하였다. 또한, PC 세그멘탈 교량 접합부의 전단 거동을 파악하기 위하여 전단키 접합부의 전단 거동과 전단강도 특성을 실험적으로 연구하였다. 이 연구를 통하여 접합부 형상에 따른 하중-변위 관계, 균열 거동, 파괴 모드, 전단 강도 등을 구명하고, 접합부의 역학적 거동에 영향을 미치는 여러 인자들에 대해 분석한다. 또한 이로부터 최적의 접합부 형상을 도출하고, 이에 따른 최적의 접합 방식을 검토함으로서 접합부 설계의 지침과 해석의 근거를 제시하도록 한다.

• Corrosion Science and Technology
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• 제3권2호
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• pp.39-46
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• 2004

Development and application of structural health monitoring system in Korea have become active since the early 1990's. In earlier applications, health monitoring systems were installed in several existing bridges in order to collect initial field data by full scale load capacity test for design verification and subsequently monitor long-term performance and durability of the bridge as part of an inspection and maintenance program. Recently, modem and integrated monitoring systems have been introduced in most of the newly constructed long-span bridges since the design stage. This paper outlines the progresses and applications of monitoring systems in Korea for both existing and newly constructed bridges and describes their aims and characteristics.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.959-964
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• 2001

This study investigates the seismic performance of bearing walls with rectangular sectional shape and specific details of reinforcements developed for 10 to 20-story apartment buildings in Korea. To investigate seismic behavior of structural walls, several specimens were experimented by author and laboratory test results by other researchers were collected and analysed. Structural behaviors of walls were evaluated by means of ductility, deformation, and strength capacities. For this purpose, thirty six specimens having different Properties such as aspect ratios and details were considered. Based on the results of this study, deformability of the walls with specific details is discussed. Also this study compares the response modification factor(R) for the bearing wall systems in seismic design provisions between Korea and United States.

• Communications for Statistical Applications and Methods
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• 제8권2호
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• pp.543-556
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• 2001

This study suggests integrated neural network modes for he stock price index forecasting using change-point detection. The basic concept of this proposed model is to obtain significant intervals occurred by change points, identify them as change-point groups, and reflect them in stock price index forecasting. The model is composed of three phases. The first phase is to detect successive structural changes in stock price index dataset. The second phase is to forecast change-point group with various data mining classifiers. The final phase is to forecast the stock price index with backpropagation neural networks. The proposed model is applied to the stock price index forecasting. This study then examines the predictability of integrated neural network models and compares the performance of data mining classifiers.

• 한국자동차공학회논문집
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• 제15권2호
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• pp.41-49
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• 2007

More diversified and strengthened safety regulations require higher safety vehicle with less weight. The structural foam can play a role for restraining section distortion of main body members undergoing bending collapse at vehicle crash. In this study, using structural foam modeling technology, validated in previous work, the bending collapse characteristics were evaluated for two types of circular and actual vehicle body frame sections. With changing the foam filling method, outer panel thickness and section shape, load carrying capability and absorbed energy were observed. The results indicate valuable design strategy for effectively elevating bending collapse performance of body members with foam filled.

• Architectural research
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• 제10권2호
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• pp.27-35
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• 2008

Because of several advantages of mortar-filled sleeve splice in reinforced concrete buildings, this method is being applied increasingly at construction sites and various methods of the splice have been developed in Korea and other countries. In order to apply this system in the field, studies on mortar-filled sleeve splice have been mainly experimental research focused on overall structural performance. However, for understanding the structural characteristics of this splice more accurately, we need to study the confining effect of sleeve, which is known to affect bond strength between filling mortar and reinforcing bar, the most important structural elements of the bar splice. Thus, in order to examine the confinement effect of mortar-filled steel pipe sleeve splice, the present study prepared actual-size specimens of steel pipe sleeve splice, and conducted a loading. Using the test results, we analyzed how the confining effect of steel pipe sleeve affects the bond strength of this splice and obtained data for developing more reasonable methods of designing the splice of reinforcement.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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• pp.477-480
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• 2006

Normally, with all ensuring the fire resistance structure as a method of setting the required cover thickness to fire, the RC is significantly affected from the standpoint of its structural stability that the compressive strength and elastic modulus is reduced by fire. Especially, high strength concrete and lightweight aggregate concrete is occurred serious fire performance deterioration by explosive spalling. Thus, this study is concerned with explosive spalling of lightweight concrete using structural lightweight aggregate. From the experimental test result, lightweight aggregate concrete is happened explosive spalling. The decrease of cross section caused by explosive spalling made sharp increasing gradient of inner temperature.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.1007-1013
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• 2004

A new type of girder named as Steel-Confined Prestressed Concrete Girder(SCP Girder) has been developed, which is composed of concrete, steel plate, and prestressing tendon. This girder may maximize structural advantages of these components, therefore it can be used to construct the middle or long span bridge with low-height girder. To verify the propriety of design, structural safety, and applicability of this girder, static load test was carried out. In this study, a design program was developed for practical design of railway bridge using SCP girder. And to verify the applicability of SCP girder to railway bridge, structural performance and economic efficiency based on the construction cost were compared with conventional railway bridges.