• 한국패류학회지
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• 제25권2호
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• pp.97-103
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• 2009

본 연구에서 바지락 부유 유생은 저질입경이 클수록 착저율(${\Omega}_b$)이 높았으며, 생물적으로도 저질을 선택하고 있다는 것을 확인할 수 있었다. 또 침투류의 발생에 의한 유동장에 있어서는 유속이 10 cm/s, 저질 중앙입경 1.211 mm, 침투 유속 0.3 cm/s일 경우, 3.1-5.1 배의 부유 유생 착저 효과 $\alpha$ (=${\Omega}_b/{\Omega}_{b0}$)가 증가되는 것을 확인하였다. 부유 유생에 있어서 저질입경의 선택성은 생물적인 요인에 의존하고, 유동장에 있어서 착저 촉진 효과는 물리적인 안정 조건에 지배되어 있었다. 그리고 이번 새롭게 도입한 안정 지표(${\lambda}p$)에 의해 통일적으로 평가할 수 있는 것을 확인하였다. 유생의 안정 지표(${\lambda}p$)에 의하면, 유속이 작용했을 경우의 부유 유생은 저질입경에 영향을 받지 않고 거의 일정 값을 가지며, 초기 이동한계유속 및 전면 이동 한계유속에 대응하는 ${\lambda}p$값은 각각 0.14, 1.06 이였고, 새롭게 제안한 안정 지표(${\lambda}p$)의 타당성이 검증되었다. 따라서 본 연구 결과에 의해 어떤 해역의 바지락 부유 유생의 부유 밀도, 저질 입경, 유동 조건이 명확할 때, 바지락 부유 유생의 착저율을 추측할 수 있는 결과를 얻을 수 있었다.

• 한국환경과학회지
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• 제24권8호
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• pp.1065-1073
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• 2015

Urbanization can be significantly affected the hydrologic cycle by increasing flood discharge and heat flux. In order to mitigate these modifications in urban areas, Low Impact Development (LID) technique has been designed and applied in Korea. In order to estimate runoff reduction rate using SWMM LID model, the characteristics of five LID techniques was firstly analyzed for water balance. Vegetated swale and green roof were not reduce flood discharge nor infiltration amount. On the other hand, porous pavement and infiltration trench were captured by infiltration function. The flood reduction rate with LID is substantially affected by their structures and properties, e.g., the percentage of the area installed with LID components and the percentage of the drainage area of the LID components.

• 상하수도학회지
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• 제28권1호
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• pp.33-45
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• 2014

In this study, current sewer infiltration/Inflow(I/I) computation and application method was examined about improvement and adequacy relating to the main issues raised by the field for practitioners. The results of review about infiltration calculation method were considered to be in need of improvement at 'standards of minimum sewage calculation'. Furthermore, the results of review about I/I application method were considered to be in need of improvement at 'standards of seasonal infiltration application' and 'the relative decrease in the Annual evaluation standards'. In addition, annual I/I analysis at JC County for the four years(2009~2012) in respect of operation flow and rainfall data was conducted. The result of annual infiltration analysis, compared average daily sewage generated average infiltration rate was found in 21.95 %, infiltration by unit was found in $0.31m^3/day/cm/km$ and $0.12m^3/day/day$, respectively. The result of annual inflow analysis, average rainfall - Inflow equations was found $y=5.499{\times}$($R^2$ 0.793), and the average Inflow quantity by sewer extension was predicted to $0.66m^3/mm-km$.

• 한국농공학회논문집
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• 제53권6호
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• pp.121-128
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• 2011

Long-term water treatment performance analysis was conducted for the constructed wetland treating agricultural tailwater. Studied wetland was established in 2001 and operated from June, 2002 to November, 2010. Wetland vegetation cover was shown over 90 % coverage after 2005. According to vegetation development, accumulation of sediment nutrient was observed; Organic Carbon, T-P and T-N. In addition, DO concentration and temperature was decreased in the constructed wetland output. An infiltration rate also significantly decreased due to compaction of wetland soil. A runoff coefficient was increased due to the low infiltration rate after 2005. A T-N, TSS and Chl.a removal rate was maintained constantly. However, the T-P removal rate was slightly decreased along to wetland operation because low DO concentration could increase elution of phosphorus from sediment. After constructing open water, the T-P removal rate was increased. This is because open water could accelerate the reaearation process. Consequently, over three years of vegetation development could be helpful for wetland performance. In addition, DO concentration is important factor to maintain the T-P treatment.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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• pp.225-232
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• 2009

Infiltration of rainfall causes railway slopes to be unstable and may result in failure. Basic relationship between the rainfall and stability of railway embankment is defined to analyze its stability by rainfall. An experimental study for defining of infiltration rate of rainfall into slope is conducted in the lab. The results of Rainfall infiltration show that rainfall infiltration is not equal to infiltration as like reservoir because rate of rainfall infiltration is controlled by slope angle. Based on these results, boundary condition of rainfall is altered and various numerical analysis are performed. The variation of shear strength, the degree of saturation and pore-water pressure for railway slope during rainfall can be predicted and the safety factor of railway slope can be expressed as the function of rainfall amount, namely rainfall index. And suggested rainfall index is compared with the rail transport operation control which is used in KORAIL. It is judged that this rainfall index can be a good tool for the rail-transport operation control.

• 상하수도학회지
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• 제34권3호
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• pp.191-200
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• 2020

This study is to improve the efficiency of BTL (Build Transfer Lease) project operation by comparing the infiltration rate based on the data of 5 years of infiltration of the separate sewer system and combined sewer system. In the survey site, the separate sewer system area consists of eight flowmeters in seven treatment basins, and the combined sewer system area consists of eight flowmeters in five treatment basins. The infillration rate was analyzed by night-time domestic flow evaluation method, and the average infiltration rates of the separate sewer system and combined sewer system were 13% and 16%, respectively. Combined sewer system was about 1.3 times higher than the separate sewer system. The average BOD of separate sewer system was 233 mg/L, which was about 2.4 times higher than the combined sewer system was 107 mg/L. In the comparison of the average pipe diameter-length infiltration of separate sewer system and combined sewer system, the separate sewer system and the combined sewer system were about 0.150 ㎥/d/mm/km and about 0.109 ㎥/d/mm/km, respectively. The floating population in mixed residential and commercial areas has been identified as the cause. Therefore, we propose a method to calculate the infiltration rate in consideration of the margin ratio in the area where the night active population is concentrated.

• 한국조경학회지
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• 제31권6호
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• pp.95-103
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• 2004

A turfgrass rootzone foundation is one of the important iufluences on the growth of cool-season turfgrass such as Kentucky bluegrass, which is usually grown on korean golf courses and athletic fields in Korea. This study was carried out to evaluate the growth of Kentucky bluegrass on 4 types of turfgrass root-zone foundations: a 2cm thickness of Sand 90%+Peat humus 8%+Zeolite 2% mixture on a subsoil base (C), a 20cm thickness of Sand 90%+Peat humus 8%+Zeolite 2% mixture (S), a 20cm thickness of Sand 45%+fine sand(a sort of Bomyungsa) 45%+Peat humus 8%+Zeolite 2% mixture (S+F), and a 20cm thickness of Sand 45%+fine sand(a sort of Bomyungsa) 45%+Peat humus 8%+Zeolite 2% mixture on a 20cm thick drainage layer (S+F(G)). Visual ratings of Kentucky bluegrass on the C foundation were low throughout the experiment when compared to S, S+F, and S+F(G) foundations, which contained high contents of sand with a high water infiltration rate. However, poor growth of Kentucky bluegrass in the summer of 1991 on the S foundation was likely to be caused by a too high water infiltration rate (185.8cm/hr). The growth of Kentucky bluegrass on the S+F(G) was good while the growth was a little weak at the developing stage on the S +F foundation. If the cost had to be considered when constructing golf courses and athletic fields, The S+F foundation without the drainage layer would be the best choice in terms of low cost and good quality of Kentucky bluegrass compared to the S+F(G). In this result, the infiltration rate was regarded as the most influential factor to the growth of Kentucky bluegrass on rootzone foundations.

• Geomechanics and Engineering
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• 제34권2호
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• pp.125-138
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• 2023

To improve the understanding of infiltration characteristic of modified slurry and the support efficiency of filter cake in silty sand strata, the slurry infiltration (SI) and filter cake formation (FCF) were investigated in a laboratory apparatus. The water discharge and the excess pore pressure at different depths of silty sand strata were measured during SI. The relationship between permeability coefficient/thickness ratio of filter cake (k_c/ΔL) and effective slurry pressure conversion rate of filter cake (η) were analyzed. Moreover, the SI and FCF process as well as the modification mechanism of CMC (carboxymethyl cellulose) were clarified. The experimental results indicate the formation of only external filter cake in the silty sand strata. The slurry particles obtain thicker water membrane after being modified by CMC, which blocks partial water path in filter cake and decreases the water discharge significantly. The silty sand excavated from tunnel face also contributes to the water discharge reduction. The k_c of the external filter cake ranges from 3.83×10^-8 cm/s to 7.44×10^-8 cm/s. The η of the external filter cake is over 96%, which decreases with increasing k_c/ΔL. A silty sand content within 10% is suggested during construction to ensure the uniformity of the filter cake.

• 한국물환경학회지
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• 제24권1호
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• pp.107-117
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• 2008

Infiltration facilities are effective instruments to mitigate flood and can increase base runoff in urban watersheds. In order to analyze effects of infiltration trenches physical model experiments were conducted. The physical model facility consists of two soil tanks, artificial rainfall generators, tensiometers, and piezometers. The experiment was conducted by nine times and each case differed in rainfall intensity, rainfall duration and the type of ground surface. Measured quantities in the experiments are as follows: surface runoff, subsurface runoff, trench pipe runoff, groundwater level, water content, etc. The following resulted from the model experiment: The volume of subsurface runoff at trench watershed was maximum 78.3% compared with rainfall. This value is bigger than that of ordinary rate of subsurface runoff, and shows a groundwater recharge effect of trench. The time of runoff passing through the trench became earlier and the volume of runoff became larger with the increase of inflow into the trench, while trench exfiltration into ground became relatively smaller. The results of this study presented above show that infiltration trenches are effective instruments to increase base runoff during dry periods.

• 한국토양비료학회지
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• 제13권1호
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• pp.1-6
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• 1980

강우강도가 100mm/hr인 인공강우기(人工降雨器)를 이용(利用)하여 밭토양의 강우침투성(降雨浸透性)을 조사(調査)하고, 침투수(浸透水)의 토양중재분포를 Youngs의 이론식(理論式)에 의(依)하여 추정(推定)한 것과 비교(比較)한 결과(結果)는 다음과 같았다. 1. 토양별 한계강우침투속도(限界降雨浸透速度)는 강우강도 100mm/hr 조건하(條件下)에서 식양토 내지(乃至) 식토(埴土)에서 10mm/hr 이하(以下), 양토에서 10~20mm/hr, 사양토에서 20~30mm/hr, 및 사토(砂土)에서 30mm/hr 이상(以上)으로 나타났으며, 한계강우침투속도(限界降雨浸透速度)에 도달(到達)하는 시간(時間)은 15~20분(分) 이었다. 2. 토양별 표토(表土)의 포화투수계수는 삼각사양토에서 0.47mm/min, 송정식양토에서 0.16mm/min, 그리고 전남미사질식양에서 0.14mm/min로 나타났다. 3. 강우후(降雨後) 토양수분의 재분포상양(再分布相樣)은 Youngs 이론식(理論式)에 의(依)하여 추정(推定)된 것과 거의 비슷한 경향이었다.