• Water for future
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• v.56 no.11
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• pp.59-64
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• 2023

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.4
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• pp.469-475
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• 2019

A long-term bridge monitoring system has been introduced and is under operation for long-term safety management of the structure. However, it is difficult to assess the condition of the quantitative structural system as it only measures responses and does not measure input loads. To overcome these shortcomings, FBG (Fiber Bragg Grating)-based input load measurement sensors were developed in this paper for measuring highway bridge input loads and their validity was verified through laboratory tests.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.2A
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• pp.391-399
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• 2006

Plate girders with variable depths have been often used at piers considering not only the economy but also an aesthetic aspect. Tapered plate girders exhibit more complicated behaviors than prismatic girders especially under shear. However, a comprehensive design method for the determination of the shear strength has yet to be developed mainly due to lack of study. In this study, investigated is the buckling and ultimate behaviors of tapered plate girders subjected to shear through finite element analyses. From the analysis results, a simple design formula is suggested for the evaluation of the shear strength of tapered plate girders.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.1C
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• pp.53-63
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• 2010

Since the water retention curve is considered as a major parameter to evaluate the unsaturated ground or soils, overburden pressure and clay content on soils underneath ground surface have not been considered for estimating water retention characteristics. Therefore, a need exists that the effect of overburden pressure and clay content on water retention characteristics was assessed in typical weathered soils found in Korea. Soil-Water Characteristic Curve and the unsaturated hydraulic conductivity were estimated using water retention characteristics under the condition of different overburden pressure, clay content, and de-saturation path. Then, these effects are evaluated with the results of SWCC tests from the laboratory. In addition to that, the unsaturated moisture capacity and diffusivity of each case is discussed.

• Journal of Wetlands Research
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• v.20 no.4
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• pp.446-457
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• 2018

Forecasting of flood wave travel time is very important in terms of river management and operation. Recently, the hydrological environment of has changed due to the construction of multi-function weir in the river. It is necessary to analyze flood wave travel time, including hydraulic structures in the channel. The flood wave travel time according to the discharge and downstream water level operating conditions was analyzed using HEC-RASver5.0.3 which is capable a two-dimentional analysis. This study showed nonlinear characteristics of flood wave travel times due to increase of discharge and operating conditions. The results of this study will be helpful for the operation of multi-function weir as well as the river operation.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5B
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• pp.483-491
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• 2009

In this study, a jetty construction is taken into account for the reduction of sediment diffusive concentration incoming from the upstream river due to the urbanization and industrial development and to minimize the effects on the coastal ecosystems. The field observation and numerical calculation are conducted to analyze the diffusion zone of sediment concentration in the small estuary and coastal area. The specification of the installed jetty which is able to control the sediment concentration was decided based on the prediction of the dispersion area changes in space and time. The selected size and layout for the jetty design were examined for the dispersion zone by numerical calculation and field observation. As a result, the jetties constructed in the estuary retarded the dispersion rate of sediment concentration, so that the effect area of sediment dispersion was obviously decreased. In addition, the measured field data indicated that the sediment deposition in the inside of dikes could be controlled and the right side area of jetties could be preserved without influx sediment diffusion.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.20-20
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• 2022

최근 국내 기후변화와 산업화로 인한 오염물 배출량 증가로 인해 하천 및 호소에 남조류 과대 성장이 빈번히 발생한다. 과거에 비해 녹조현상의 빈도가 잦아졌으며, 지속기간이 증가하였다. 조류 발생 시 현장에서 채수한 샘플을 통해 검경 및 chlorophyll-a 분석을 진행하여 조류의 정성·정량적 평가를 진행한다. 이러한 분석결과는 녹조 발생에 대한 기초자료로 활용되고 있다. 하지만 현장 시료 샘플을 통한 조류 검경의 경우 단일지점에 대한 분석으로 인해 하천 및 호소의 전체적인 대표성을 나타내기엔 한계가 있고, 많은 인력과 시간이 소요된다. 또한 chlorophyll-a는 녹조류와 높은 관련성이 있어 유해남조류에 대한 집중 분석에는 한계가 발생한다. 이러한 한계점을 통해 국내·외로 조류 연구에 분광 스펙트럼을 활용한 원격탐사 기법 적용되고 있으며, 남조류 농도를 분석하기 위해 남조류의 보조 색소인 phycocyanin을 활용한 연구가 진행되고 있다. 본 연구에서는 분광스펙트럼을 활용한 phycocyanin 분석을 진행하였다. 분광 스펙트럼을 측정하기 위해 점(point) 단위의 고해상도 분광방사계를 활용하였으며, phycocyanin 측정을 위해서 형광 센서를 활용하였다. 현장에서 형광센서 및 분광방사계를 동시에 측정하여 데이터를 취득하였으며, 분광 스펙트럼 특성상 노이즈 및 이상치가 발생하기 때문에 전처리 과정을 통해 이를 보완하였다. phycocyanin 분석을 위해 다중 스펙트럼을 활용한 분광지수를 활용했으며, 이를 통해 phycocyanin 분석에 있어 최적의 분광지수를 제시하고자 한다. 본 연구 결과는 고해상도 점(point)단위 분석으로 향후 선단위, 면단위 하천 조류-스펙트럼 분석에 있어 기초자료로 활용될 것으로 판단된다.

• Proceedings of the Korean Fiber Society Conference
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• 1998.10a
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• pp.356-359
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• 1998

지오텍스타일은 수분차단을 제외한 분리, 보강, 여과 배수등의 기능을 가지며, 현재 제방공사, 해안ㆍ하천의 호안공사, 간척공사 또는 도로, 철도 노상 안정 등의 분야에 광범위하게 이용되고 있다. 또한 지오텍스타일은 모래, 흙, 자갈 등의 환경에 노출, 사용되는 고분자 재료로서 토목공사의 시공기술과 밀접한 관계를 가지는 토목용 섬유제품이다. (중략)

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2019.10a
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• pp.113-113
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• 2019

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2020.10a
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• pp.114-114
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• 2020