• Magazine of the Korea Concrete Institute
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• v.9 no.4
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• pp.57-65
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• 1997

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.655-658
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• 1999

An experimental investigation on the ruined RC bridge with 30 years old has been conducted to estimate the durabilities. The ruined RC bridge estimated in this study was located at Kyung-Bu Express Way. First, concrete strength and durability characteristics such as concrete resistivity, chloride content were estimated. Second, it was to test reinforcing corrosion embedded in slab of bridge. And, third, tensile strength and yield strength of reinforcing bar corroded and not corroded were estimated. This bridge inspection provides the most common cause of defects and deterioration and the results of this inspections give more specific information than those of laboratory inspections do.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.537-542
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• 1999

The design methodologies for carbon fiber sheet(CFS) strengthening of RC structures are not well established yet because the structural behavior of strengthened RC structures is more complex than that of unstrengthened ones. Even though the research for the methods using CFS has beed studied, the strengthening effects and structural behaviors of strengthened structures are not systematized yet. The purpose of this study is to carry out the experimental studies on three kinds of half scale RC slab bridges and to investigate the behavior of RC slab bridges from the experimental results. Typical flexural failure occurs in the non-strengthening slab like general RC slab bridges, and also the flexural failure occurs in the all area strengthened slab with sudden rip-off failure of strengthening material by punching shear. For the case of strip type strengthened slab, flexural failure occurs, with rip-off of second strip at the base of loading point. Strengthening effect on the slab using CFS is that the strength is increased upto 7~15 percent and the crack pattern is changed.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.621-626
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• 1997

Recently, TYFO glassfibers have been used for strengthening n aged RC bridge slabs because of low material cost and easy repairing work. The purpose of this study is to experimentally and analytically investigate the effect of TYFO glassfibers for enhancing the capacity of aged RC bridge slabs. Tes result shows that yield and ultimate strength of RC slabs with TYFO are increased as 11~18% and 25~35% comparing with those for RC slabs without TYFO, respectively, Also, ductility of RC slabs strengthened with TYFO have been significantly increased. Further tests have been performing on aged RC bridge slabs strengthened with carbon fiber strips.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.93-96
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• 2006

This study represents results of performance-based fragility analysis of reinforced concrete (RC) bridge. Monte carlo simulation is performed to study nonlinear dynamic responses of RC bridge. Two-parameter log-normal distribution function is used to represent the fragility curves. These two-parameters, referred to as fragility parameters, are estimated by the traditional maximum likelihood procedure, which. is treated each event of RC bridge pier damage as a realization of Bernoulli experiment. In order to formulate the fragility curves, five different damage states are described by two practical factors: the displacement and curvature ductility, which are mostly influencing on the seismic behavior of RC bridge piers. Five damage states are quantitatively assessed in terms of these seismic ductilities on the basis of numerous experimental results of RC bridge piers. Thereby, the performance-based fragility curves of RC bridge pier are provided in this paper.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.615-620
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• 1997

Further to static test on aged RC bridge slabs strengthened with TYFO glassfibers, fatigue tests have been done on aged RC bridge slabs with and without glassfibers. It can be seen from the test that fatigue behaviors of aged RC bridge slabs stiffened with TYFO glassfibers have been by and large improved comparing with those of aged RC bridge slabs without TYFO, but fatigue failure modes have not been changed become of bonding failure between tensile reinforcements and concrete. It is in particular noted from the test that bonding failure between concrete surface and TYFO have been observed. Further tests are strongly necessiated to develop appropriate anchoring method for improving fatigue life of aged RC bridge slabs strengthened with TYFO glassfibers.

• Journal of the Earthquake Engineering Society of Korea
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• v.5 no.3
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• pp.29-36
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• 2001

Same as-built drawings in national roadway bridges in Korea were examined. As a result, many bridge piers were found whose aspect ratios are in the vicinity of 2.5. These columns are expected to do shear-flexure behaviour, but the previous research works considered flexure behaviour columns only. In the study, therefore, a shear-flexure behaviour column was selected as the model pier, and quasi static test on the full and 1/2 scale models was carried out. From the test results, the scale effect on the seismic performance evaluation was analyzed, and the seismic performance of the model bridge pier without seismic details was evaluated by the capacity spectrum method.

• Journal of the Earthquake Engineering Society of Korea
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• v.5 no.2
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• pp.49-57
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• 2001

본 연구의 목적은 유사동적실험에 의한 섬유보강 원형 RC교각의 내진성능평가를 위한 연구로서 수원시에 위치한 내진교량인 하길교를 대상모델로 하였으며, 도로교 표준시방서의 내진설계규정이 적용되지 않은 비내진교각시험체 2본 및 내진성능향상을 위한 섬유보강시험 4본, 즉 총 6본에 대하여 유사동적실험을 수행하였다. 보강공법으로는 유리 탄소섬유 보강공법을 사용하였으며, 실험변수로는 입력지진동, 섬유고방유무로 하였다. 그리고 내진성능평가 방법은 입력 및 소산에너지, 변위 연성도가 분석되었다. 본 실험의 결과 유리 섬유로 보강된 비내진시험체의 변위연성도 KHC인공지진파에 대하여 7.7~9.0정도의 값으로 충분한 내진성능을 확보하고 있는 것으로 평가되었다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.5
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• pp.757-767
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• 2016

The power spectral density (PSD) for the road surface roughness on the bridges of minor roads in Wonju city and Hoengseong-gun, Gangwon-do is presented. To obtain the PSD, the road surface roughness on 18 different bridges with various superstructure type and span is measured by GPS at every 10 to 30cm interval. Assuming the PSD as the stationary normal probability process with zero mean value, the PSD of measured road surface roughness is obtained by applying the Maximum Entropy Method (MEM). A simple formula in evaluating the PSD of RC slab bridge, Rahmen bridge and PSC I-girder bridge which is applicable to the dynamic response analysis of bridges considering the road surface roughness is proposed. Using the calculated PSD curves, the road surface conditions on the 18 bridges are evaluated. The statistical relationship between the PSD and the IRI is presented by applying linear regression and correlation analysis.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.5
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• pp.23-30
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• 2009

According to Korea Highway Bridge Design Code the bridge deck is designed by the strength design method and is regarded as a beam possessing the unit width based on the bending theory. By many researches it is revealed that the existing bridge deck is failed by punching shear. For evaluating the ultimate capacity of bridge deck it is important to estimate the behavior of bridge deck under the punching shear. For the punching strength it is difficult that the existing research results are applied to the simplified composite deck. In this study for comparing characteristics on punching shear the punching shear tests on simplified composite deck and RC deck are performed. The punching shear strength of simplified composite deck is compared with several bridge design codes.