• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.568-573
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• 2005

To the installed CWR (Continuously Welded Rail) on steel plate girder bridges without ballast, shoes were replaced by the shoe for reduced axial force. During 9 months, from summer to winter, expansion by a temperature on girders, axial forces by a temperature on CWR, etc. are tested and the results are evaluated. Also, with the numerical analysis, the results - axial forces by a temperature on CWR, deformations of girders, etc. are compared and evaluated. From the longitudinal displacement on girders, occurred by run of trains, because of looking for the stability, the bearings for reducing axial forces are applied to the railway bridges. It is verified that the bearings for reducing axial forces disperse the axial forces by a temperature from the measurement of the forces on CWR of plate girder bridges,.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1998년도 창립기념 춘계학술대회 논문집
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• pp.466-473
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• 1998

LRV(Light Rail Vehicle) is one of the most useful way for urban transit. HDPIC has designed and manufactured the LRV train set for Manila Line 1 expansion. The LRV is composed of two carbody sections which are coupled by a articulated bogie. The articulated bogie and two motorized bogies have slewing rings in order to improve the curving performance and ride quality. Carbody structures are mainly made of low-carbon stainless steel (STS301L), and the carbody bolsters and draft sills are made of rolled steel for welded structures. The authority's specifications specified the design load conditions and weight limits. Design load conditions are vertical load, compressive load and diagonal jacking, and the maximum axle load is 10.7 ton. In order to meet those requirements, the stiffness and strength of carbody structure were predicted using finite element analysis during design stage. The half or full structure is modeled and analyzed with design load conditions, and critical areas are analysed in detail using sub-modeling method. The strength and strength of carbody structure was also verified by the load test. The analysis and test results show a good agreement.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1997년도 봄 학술발표회 논문집
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• pp.460-467
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• 1997

Compared to normal-strength concrete, high-strength concrete has the lower lateral expansion capacity caused by the higher elastic modulus and the lower internal crack characteristic. Therefore, the effect of the lateral confining action of hoops appears slowly and also in inefficient Nevertheless. it has been reported that the strength and deformation capacity of high-strength concrete is improved by well-distributed hoops. Due to that argument, this investigation has been compared and analyzed by the experimental works on the deformation capacity and the confinement mechanism of high-strength concrete shear wall of the high-rise building reinforced by rectangular steel tubes and rectangular hoops at both edges of the shear wall.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1439-1449
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• 2007

The challenging aspect of CWR (continuous welded rail) is the additional axial forces in rails, mainly due to the thermal expansion of steel plate girder and rail itself. It has been found that these axial forces are proportional to girder length, total bridge length and bolt tightening forces. Also these forces are dependent to girder support conditions, types of bearings and their arrangements. With CWR, the authors' previous studies show that performance improvements like noise reduce, fatigue resistances and bearing durability increment can be expected. In addition to these effects, secondary effects due to the semi integral behavior between rail and bridge girder also can be expected. Special bearings which can reduce the absolute maximum axial forces have been developed, and applied to real 100m span bridge. The performance improvements were verified through site measurements and numerical analysis. The purpose of this study is to confirm the expected performance improvement aspects of steel plate girder bridges with CWR. To verify these aspects, girder stiffness changes, rail axial force changes, girder displacements and noise level were thoroughly measured and compared.

• 한국추진공학회지
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• 제5권3호
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• pp.1-9
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• 2001

잠수함용 재료로 개발된 고강도 구조용강의 충격 시험이 수행되었다. 특히 샤르피 충격시험기를 이용하여 저온에서 구조용 강의 충격특성을 평가하였다. 최소흡수에너지, 최대흡수에너지, 연성 취성 천이온도를 결정하기 위하여 hyperbolic tangent curve fitting법을 이용하였다. 시험결과로부터 샤르피 충격에너지와 횡팽창량 사이의 비례 관계식을 산출하였다. 시험온도 변화에 따른 파단면 특성을 평가하기 위하여 SEM을 이용하여 파단면을 관찰하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.322-327
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• 2006

Banwol bridge with steel plate girder and Pyongtaek bridge with PSC bos girder have been operated maintenance measuring system by the Seoul-Chonan of Kyongbu express railway. By analyzing the theoretical and experimental values of design load for these two bridge, the establishment of reference maintenance for measuring items was deduced from research. Two materials, steel and concrete plates, were considered as the upper structure. Actual measurement data for the behavior under speed, structural analysis results, and the presented references were analyzed and used to set up the reference establishment. The measuring items are stress(strain), displacement, dynamic acceleration, expansion movement, and dynamic frequency. The maintenance reference was established by comparing analytical and measuring values of the five items with respect to structural state class.

• 한국해양공학회지
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• 제13권1호통권31호
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• pp.70-78
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• 1999

오늘날 기계공업 현장에서 심공드릴가공은 광범위한 응용과 양호한 생산성으로 인하여 그 요구가 증가 되고 있다. 그러므로, 본 연구는 난삭재인 SKD11고합금공구강을 여러가지 절삭조건하에서 BTA드릴가공하여 얻은 실험결과(표면조도, 진직도, 진원도, 원통도, 구멍확대량, 등)를 다루었으며 이들의 이론적 배경과 실험을 비교 분석하였다. 프레스금형 부품과 기계부품으로 사용되고 있는 SKD11고합금공구강은 기계가공이 힘든 난삭재료로서 그 어려움이 크므로 본 연구는 생산현장에 보다 나은 심공드릴가공결과와 관련 지식을 제공 할수 있다고 사료된다.

• 한국산학기술학회논문지
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• 제20권5호
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• pp.502-509
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• 2019

도로교의 신축이음장치 성능시험에 있어 최근에는 많은 연구가 진행되어 있지만, 항공기 활주로 연결 교량에 있어서 국내에 적용사례가 전무하고 성능시험에 대한 기초자료가 없는 상황이다. 본 연구는 활주로 연결 교량이 건설되어있는 인천공항 2단계 확장공사현장에 국내 최초로 적용된 강재형 모노셀 신축이음장치의 성능평가를 위해 전산해석과 KS F 4425기준에 근거하여 수축 신장 및 반복하중시험을 실시하였다. 시제품 제작 전 설계 문서에 기초하여 Midas 해석프로그램으로 전산 분석하였고 시제품을 제작하여 2001년 KS F 4425기준에 근거하여 완제품 성능시험을 시행하였다. 국내 교량의 하중재하시험에 대한 기술 기준은 대부분 차량에 대한 것이고 항공기에 대한 선례가 없어 인천공항공사에 출입하는 항공기 중에서 축하중이 최대치인 F급 $468.4kN/m^2$를 보수적으로 적용하여 200만회 반복재하시험을 진행하였다. 완제품 결과 제품에는 육안검사로 이상 유 무가 관찰되지 않아 충분한 사용성 및 내구성을 확보하였다고 판단된다. 수축 신장의 경우 2,500회 반복 시험 후 KS F 4425 기준에 따른 육안검사로 이상 유 무가 관찰되지 않아 충분한 신축성을 확보하였다고 판단된다. 본 연구의 결과는 선례가 없는 항공기에 대한 신축이음장치의 성능시험에 있어 유용한 현장 시험 자료 및 전산 해석 결과가 참고자료 활용에 가치가 있을 것으로 기대된다.

• 자원리싸이클링
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• 제21권6호
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• pp.12-22
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• 2012

본 연구는 제강용도로 사용하기 위해 돌로마이트를 하소후 남은 2 mm 이하의 경소백운석 부산물을 건축용 바닥 몰탈의 기존 팽창재로서 활용 가능성을 검토하고자 하였다. 경소백운석은 $600{\sim}800^{\circ}C$ 정도에서 하소하였을 때 반응성이 높은 준결정상태의 활성 마그네시아로 존재하게 되며, 이 활성화된 마그네시아는 수화초기 Brucite gel을 형성하여 수화물 비율을 상대적으로 줄여 치밀한 조직을 형성하는 원인으로 작용하고, 수화후기에는 결정질의 Brucite가 형성되어 수축 현상을 억제하며 부피가 2배 이상 팽창하여 화학적 수축균열 방지 역할을 하게 되는 것이다. 실험결과 경소백운석은 기존 사용 중인 팽창재 대비 동일량 적용시 압축강도는 우수하게 확인되었으나, 반응성은 기존 팽창재(생석회+무수석고)에 비해 다소 낮게 측정되었다. 하지만 팽창재로서의 역할은 충분한 것으로 확인되었으며, 공사기간 단축 등 부가적인 효과를 나타내었다.

• Structural Engineering and Mechanics
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• 제59권2호
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• pp.209-226
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• 2016

Integral bridges are typically designed with flexible foundations that include one row of piles. The construction of integral bridges solves difficulties due to the maintenance of expansion joints and bearings during serviceability. It causes integral bridges to become more economic comparing with conventional bridges. Research has been focused not only to enhance the seismic performance of newly designed bridges, but also to develop retrofit strategies for existing ones. The local performance of the pile to abutment connection will have a major effect on the performance of the structure and the embedment length of pile inside the abutment has a key role to provide shear and flexural resistance of pile-abutment connections. In this paper, a simple method was developed to estimate the initial value of embedment length of the pile for retrofitting of specimens. Four specimens of pile-abutment connections were constructed with different embedment lengths of pile inside the abutment to evaluate their performances. The results of the experimentation in conjunction with numerical and analytical studies showed that retrofitting pile-abutment connections with CFRP wraps increased the strength of the connection up to 86%. Also, designed connections with the proposed method had sufficient resistance against lateral load.