• 한국산학기술학회논문지
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• 제13권8호
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• pp.3719-3725
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• 2012

최근, 건설공사의 급증으로 인한 양질의 하천모래의 고갈로, 콘크리트용 대체골재로서 바다모래, 부순모래 및 순환잔골재 등의 사용이 증가하고 있다. 그러나, 미세척 바다모래는 함유된 염화물로 인하여 철근콘크리트 구조물에 사용할 경우, 철근부식 유발로 구조물의 내구성에 악영향을 미치고, 부순모래는 미립분이 많고 입도조정이 어려워서 철근콘크리트 구조물에 널리 사용되지 못하고 있는 실정이다. 한편, 낙동강 세사는 낙동강 중 하류에 대규모로 분포하고 있고, 입도를 제외하면 콘크리트용 잔골재로서 품질이 우수하므로 이에 관한 연구가 시급히 요구되고 있다. 따라서 본 연구의 목적은 콘크리트 잔골재로서 낙동강 세사를 적극적으로 활용하기 위하여 그것의 물성을 평가하는 것이다. 이를 위하여 낙동강 본류 대표위치별로 시료를 채취하여 이들의 절건밀도, 입도, 단위용적질량 등의 물성을 평가하였는데, 그 결과 낙동강 세사는 입도를 제외하면 잔골재로서의 물성이 우수한 것으로 나타났다.

• 한국건설순환자원학회논문집
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• 제2권3호
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• pp.265-271
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• 2014

It is strongly needed to investigate the fine sand as an alternative fine aggregate of well-graded river sand because the fine sand which is being enormously distributed in the midstream and downstream of Nakdong-River in Korea has a poor grading but good quality as a fine aggregate for concrete. Thus, the purpose of this experimental research is to evaluate the durability of concrete using the fine sand to utilize it actively as a fine aggregate. For this purpose, the concrete specimens using different fine sand were made for the specified concrete strength of 35MPa, and then their durability such as the resistance to freezing and thawing and carbonation, and drying shrinkage were evaluated. It was observed from the test results that the resistance to freezing and thawing and carbonation of concrete using the fine sand was similar to that of concrete using reference sand, but the drying shrinkage of concrete using the fine sand with small fineness was comparatively lager than that of concrete using reference sand.

• 한국산학기술학회논문지
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• 제14권3호
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• pp.1481-1488
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• 2013

지속적인 경제성장에 따른 콘크리트 구조물의 급증으로 양질의 하천모래가 고갈됨에 따라 콘크리트용 대체 골재 개발이 필요한 실정이다. 따라서 이 연구의 목적은 낙동강 세사를 콘크리트용 대체골재로서 적극적으로 활용하기 위한 기초자료를 제시하는 것이다. 이를 위하여 세사 분포지역인 낙동강 본류의 중 하류에서 세사 시료를 채취한 후, 이들의 밀도, 입도, 단위용적질량 및 0.08mm체 통과량 등의 물성 평가와 세사를 사용한 콘크리트의 배합특성으로 설계기준강도에 대한 단위수량 및 단위시멘트량을 평가하였다. 그 결과, 세사를 사용한 콘크리트의 설계기준강도에 대한 단위수량 및 단위시멘트량은 입도가 좋은 기준모래를 사용한 콘크리트의 경우보다 크게 증가하지 않는 것으로 나타나, 전자와 후자 사이의 배합특성은 별 차이가 없는 것으로 나타났다.

• 한국재난정보학회 논문집
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• 제9권4호
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• pp.493-502
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• 2013

이 연구의 목적은 낙동강에 대규모로 부존되어 있는 세사를 콘크리트 잔골재로서 적극적으로 활용하기 위하여 이를 사용한 콘크리트의 건조수축 및 내구성을 평가하는 것이다. 이를 위하여 낙동강 본류의 중 하류에서 하천세사를 채취한 후 강도수준에 따라 콘크리트 배합실험을 수행하였다. 그 결과로부터 압축강도와 시멘트-물비의 상관식을 도출한 후 하천세사 종류별로 설계기준강도 35MPa에 대해서 콘크리트 공시체를 제작하여 이들의 건조수축과 동결융해 및 탄산화 저항성과 같은 내구성을 평가하였다. 그 결과, 하천세사를 사용한 콘크리트의 내구성은 기준모래를 사용한 콘크리트의 경우와 유사한 것으로 나타났으나, 하천세사의 건조수축은 조립률이 작은 경우 기준모래를 사용한 콘크리트보다 비교적 큰 것으로 나타났다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회 2차
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• pp.68-75
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• 2010

Around the Nakdong River which is one part of the repairing business of 4 Grand Rivers currently being constructed, sandy ground is distributed throughout the wide area. Many civil engineering structures such as small and medium sized dams, flood control basins, and redevelopment of reservoirs and retention reservoirs are scheduled to be constructed, so the prevention measures for liquefaction are surely needed. To identify such liquefaction, a lot of factor affecting the strength of liquefaction were studied through laboratory investigation. Most of the conducted study was about clean sands, but in the case of the real ground the sand can exist not in the clean conditions but in the conditions mostly including sand of fine grained soil. The sand of fine grained soil has become a significant factor to assess liquefaction because many cases of liquefaction happened in the silty and clayer soil. In this study, un-drained tests of plasticity index of fine grained particles were conducted with the sands from Nakdong River. In result, the study shows that dynamic shear strength characteristics differ according to the plasticity index.

• 한국환경과학회지
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• 제27권6호
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• pp.411-423
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• 2018

To investigate the distribution characteristics of grain size and organic matter of surface sediments from the Nakdong-Goryeong Mid-watershed, surface sediments were collected and analyzed. The samples were collected from six sited at four different times between May 2013 and May 2014. The were analyzed for grain size, water content, ignition loss, chemical oxygen demand, total organic carbon and total nitrogen. The surface sediments were mainly composed of medium sand (mean 44.7%) and coarse sand (mean 32.8%) and became coarser in May 2014. Fine sediments at the site NG-2 were poorly sorted and positively skewed, and occur in a tributary environment that is relatively low-energy compared with the other sites. The water content at the studied sites (15.3 ~ 34.9%) averaged 20.25%, and ignition loss (0.4 ~ 5.8%) and total nitrogen (274 ~ 2493 mg/kg) averaged 1.33% and, 696 mg/kg, respectively. These values indicated that the sediments were not seriously contaminated when compared with the sediment pollution evaluation standard of the National Institute of Environmental Research. The chemical oxygen demand (mean 0.17%) was at the non-polluted level compared with United States Environmental Protection Agency sediment quality standards. The total organic carbon (mean 0.18%) at all sites except site NG-2 (lowest effect level) was the no effect level of the Ontario sediment quality guidelines. The COD/IL (0.02 ~ 0.20) and C/N (0.73 ~ 6.76) were less than 1 and 10, respectively. Organic matter in the study area produced naturally from aquatic organisms. Results of principal component analysis showed that fine sediments (very fine sand and silt) were significantly affected by organic matters (ignition loss, chemical oxygen demand, total organic carbon and total nitrogen). In addition, the highest organic matters content in the study area occurred at the site with the finest sediments (NG-2).

• 한국수산과학회지
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• 제34권3호
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• pp.268-278
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• 2001

다양한 퇴적환경이 존재하는 낙동강 하구 및 주변 연안역에서 총 40개의 정점을 선정하여 채취한 표층 퇴적물 시료에 대해 입도분석, 유기물, 탄산염, 점토광물 및 금속원소 함량 분석을 실시하여 표층 퇴적물의 특징적인 퇴적상 및 특성을 파악하고 하구둑 건살이후 활발히 진행되고 있는 낙동강 하구역의 퇴적환경 변화를 살펴보았다. 연구지역 표층 퇴적물의 퇴적상은 퇴적물의 지역적 분포특성 및 퇴적물 특성에 따라 사질 퇴적상 분포역 (TYPE I),니질 퇴적상 분포역 (TYPE II), 그리고 이 두 퇴적상의 중간적인 특성을 나타내는 사니질 혼합 퇴적상 분포역 (TYPE III)의 세 가지 형태로 분류된다. 이러한 두 퇴적상의 경계에 위치하는 사니질 혼합 퇴적상은 퇴적물의 특성으로 보아 낙동강으로부터의 직접적인 공급뿐만 아니라 흥수나 폭풍시 진해만에서의 재부유된 부유성 세립 퇴적물의 공급에 의해 형성된 복합기원의 퇴적상으로 판단된다. 낙동강 하구둑이 완공된 이후 연안사주를 벗어난 지역까지 계속해서 사질 함량이 증가한 것으로 나타난 하구 지역의 퇴적환경 변화는 낙동강 상류로부터의 니질 퇴적물 유입량 감소, 하구지역의 수력학적 에너지 변화, 그리고 이 지역 주변에서 실시된 인위적인 작업에 의한 영향 등의 요인 때문에 발생한 것으로 생각된다.

• 한국환경과학회지
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• 제30권6호
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• pp.487-500
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• 2021

To evaluate the geochemical characteristics and assess the pollution in surface sediments of the Nakdong River estuary, two sites adjacent to the estuary bank (Hh1 and Hh2) and one site at the upper part of the estuary bank (Hh3) were investigated. The surface sediments were analyzed for their contents of metals (Cu, Pb, Ni, Cr, Zn, and Al), organic matter (IL, COD, TOC, and TN), and grain size from 2018 to 2020. As a result of the pollution assessment, there was little anthropogenic contamination by most of the metals. The surface sediments in Hh2 had comparatively abundant silt and clay, whereas the other sites were mainly composed of sand. The organic index and contents of organic matter were highest at Hh2. Multivariate statistical analyses (cluster analysis and Pearson correlation analysis) showed that the contents of organic matter and pollution were associated with fine sediment. These results suggest that the geochemical characteristics were changed by the estuary bank built in the research area and that the increase in fine sediment attributable to the low-energy environment resulted in an increase in organic matter pollution.

• 한국환경과학회지
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• 제26권3호
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• pp.311-324
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• 2017

To certificate change in the geochemical characteristics of surface sediments in the main stream of the Nakdong River, surface sediments from 12 sampling sites during the first and second half year (total 24 sampling sites) were collected and analyzed for grain size, ignition loss, total organic carbon and heavy metal content. Surface sediments mainly composed of sand (coarse and medium sand) and fining changed from the first half to the second half of the year. Ignition loss, total organic carbon and heavy metals content increased in the second half of the year. Some heavy metals (Zn, Ni and Cu) were found to be at the lowest effect levels according to Ontario sediment quality guidelines. Additionally, most heavy metals were found to be at the non polluted level and level I according to USEPA sediment quality standards and National Institute of Environmental Research sediment pollution evaluation standard, respectively. The enrichment factor (< 1) and index of geoaccmulation (< 0) were non polluted in the study area. The correlation analysis results showed that ignition loss, total organic carbon and heavy metal content were highly correlated with grain size. Regarding changes in geochemical characteristics of surface sediments in the study area, grain size fine and organic matter and heavy metal content increased in the second half year. Nonetheless these results indicated pollution levels that did not adversely affect the benthos.

• 한국환경과학회지
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• 제24권8호
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• pp.969-980
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• 2015

In order to certificate the distribution and pollution of heavy metal of surface sediments in Nakdong River were collected and analyzed for grain size, water content, ignition loss and heavy metal content. Surface sediments mainly composed of sand(avg. 94.6%) and water content and ignition loss were 20.46%, 1.53% on average. Grain size were relatively fine and organic matter content were relatively high in the Hoichun and Sunakdonggang. Most of heavy metal content(Zn > Cr > Pb > Ni > Cu > Hg) in the Deokcheongang and Sunakdonggang were higher than the other streams. The Igeo were non polluted(less than 0) in all streams and the EF were relatively high in the small stream and PLI were non polluted(less than 1). In addition, organic matter, heavy metal content and pollution were highly correlation with grain size. Surface sediments in study area, heavy metal pollution of the Sunakdonggang were relatively high compared to the other stream but these results were not serious pollution that exceed the sediment pollution evaluation standard of river and lake in Korea and pollution levels adversely affected the majority of benthos were not.