非均質 帶水層에서의 地下水 流動에 대한 2차원 數植模型에 관한 硏究

宋在優,金智鎬,鄭祐昌 弘益大學校 科學技術硏究所 1996 科學技術硏究論文集 Vol.7 No.1

The role and importance of groundwater are increased with the deficiency of surface water and contamination of river on the development and management of water resources. But in recent, imprudent development gave the negative impact on the aspect of the quantity and quality of groundwater. For example, the excessive pumping leads to exhaution of groundwater, and waste materials bring about contamination of groundwater. On the contaminant problem, the groundwater flow is the important media of pollutant transport and its phase is different hydraulic conductivity. Therefore, 2-D numerical model using FEM is developed. To verify this numerical model, it is compared with Theis's analytical solution for unsteady groundwater flow and existed model(used FDM). In this study, numerical model(used FEM) gives good agreement between analytical solution and existed model(used FDM). In this numerical simulation, homogeneous aquifer is supposed to use coarse sand, heterogeneous aquifer is supposed to consist of coarse sand and coarse gravel, and coarse sand and silt. The result of numerical simulation generally shows good agreements with real groundwater flow through homogeneous and heterogeneous aquifer.

비대칭 원환을 이용한 교각주위 세굴 방지 효과

宋在偶,沈遇培 弘益大學校 科學技術硏究所 1998 科學技術硏究論文集 Vol.9 No.1

Laboratory flume experiments to investigate the characteristics of the flow and local scour around circular shapes of bridge pier in a straight channel are performed. This study examines the effect of a asymmetry circular collar devices for controlling the depth of scour. As the ratio of asymmetry increased, the scour depth decreased. In addition, the maximum reduction of scouring is about 67% for CASE3 and CASE4. The prevention of scouring is most effective when the asymmetry collar for all case is placed at 0.1h below river bed.

河川空間의 效率的인 活用에 關한 硏究

宋在偶 弘益大學校 科學技術硏究所 1994 科學技術硏究論文集 Vol.4 No.-

The function of riverine-space is classified, in general, in to function as riverine-space use, geographical division and others. Riverine-space development is an integrated development of riparian part of river and high water river site. They can be converted public park, play ground, parking lots, etc. The results of this study are summarized briefly as follows 1. The river regime coefficient is very different between Korean rivers and continental ones. It is hydraulic and spatial characteristics of Korean rivers so Korea has broad open space as the riverine-space. 2. The most important function of riverine-space is free flood flow and previous to plan, this have to be brought to mind without fail. 3. For the effective use of riverine-space, regional properity is considered surely and synthetic plan of all over the river side including branch river is needed at any cost. 4. Natural space must be preserved as possible. The study and examination for the image of future river means a lot to plan up of rivers.

동적세굴에 의한 교각주위 세굴특성

宋在偶,李尙度 弘益大學校 科學技術硏究所 2000 科學技術硏究論文集 Vol.11 No.-

Laboratory flume experiments to investigate the characteristics of scour around bridge pier by live-bed scour condition are performed. This study examines the comparison of maximum scour depth on clear-water condition and live-bed condition at the circular shape of bridge pier. The experiments were conducted in a 0.9m-wide, 0.45m-deep flume with 8m-length in a straight channel. An approximately 15cm layer of sand with a median diameter of 0.2mm formed the bed. Both the water and the sediment transported were recirculated throughout the flume and return curcuit by a centrifugal pump. For the sake of live-bed condition, sediment supply apparatus utilized. The results show that clear-water condition is larger maximum scour depth than live-bed condition. The aspect of scour depth also appeared that clear-water condition is longer time of scour depth because bed material grain is big and velocity is slow.

未計測 小河川流域의 計劃洪水量 算定에 관한 硏究

宋在偶,丁榕泰 弘益大學校 1988 弘大論叢 Vol.20 No.2

The objective of this paper was to find best method of the synthetic unit hydrograph arbitrary small watershed. The following results were analyzed from the four methods. 1) For the development of more accurate peak discharge, the size and shape of the watershed need be considered. 2) The peak discharge of SCS method rather than that of Nakayasu's method was affected by drainage area and time of concentration. this is due to watershed characteristics. 3) kajiyama's and Nakayasu's method leave something to be desired for the evaluation of the accurate design discharge.

流路彎曲部 橋脚주위의 洗掘 및 保護工

宋在偶,李鎔桓,崔仁鎬 弘益大學校 科學技術硏究所 1997 科學技術硏究論文集 Vol.8 No.-

Laboratory flume experiments to investigate the characteristics of the flows and local scour around circular shapes of bridge pier in a curved channel are performed. This study examines the effect of a circular collar devices for controlling the depth of scour. The scour depth due to a collar is about 40% of the scour depth without collar in a straight course of the flume while it is about 44% of the scour depth without collar at the location of 150˚in a curved channel. when the collar is placed yd/h=-0.2 for which the diameter of a collar is twice of the pier diameter, reduction o scour depth is very effective in a straight channel but when the collar is placed at yd/h=-0.1, the reduction of scour depth is very effective in a curved channel.

東海岸 河口 閉塞 要因 考察 : A Study on the Causes of River Mouth Closing Along the East Coast

宋在偶 연세대학교 대학원 1975 원우론집 Vol.3 No.1

The east coast seems to have remarkably different features from the west arid south coast in the geographical, geomorphological, and oceanographical senses. In this paper the auther wishes to introduce some results of investigation the causes of river mouth closing along the east coast. There are various closing form in river mouth by many causes, but the east coast has the same closing form(the ratio of closing; roughly 0.18), as well known, by the sand spit, and has not hyd-rological but littoral drift background. The river of the east coast is proved mature age from hypsometric analysis. The wave and longshore current must be principal factor to be considered, in the analysis of the closing phenomenon owing to littoral drittoral drift. The research of the blown sand is considered valuable for the next study of this subject.

推計學的 模型에 의한 河川流量의 模擬發生

宋在偶,白景元 弘益大學校 1986 弘大論叢 Vol.18 No.2

The purpose of synthetic generation of river flows based on the stochastic theory is to make possible a better design of water resources systems by generation of long term data which have the same statistical characteristics of historical discharge data. This study included the generation of monthly and annual discharges by Thomas- Fiering model and Monte Carlo model, the comparative study with the historical data and genreated data, and the change of monthly generated discharges into annual discharges. Discharges at Yeoju were characterized by log-normal distribution, and the annual discharges were identified as a time series of persistence absent. The statistical characteristics of the historical data were maintained in the generated data, but the small differences between historical and generated data were produced by the errors in the random number generation. And fit distribution type of the annual discharges could be seen from the annual discharges obtained from the generated monthly discharges.

Coir Roll을 이용한 자연형 호안의 수리학적 특성

宋在偶,李尙度 弘益大學校 科學技術硏究所 2001 科學技術硏究論文集 Vol.12 No.-

Laboratory flume experiments to investigate the hydraulic characteristics by using close-natured element "coir roll" are carried out. This study examines the comparision if mean velocity and roughness coefficient in the case of spread the coir roll and plant the vegetation on the coir roll. The experiments was conducted using a 0.9m-wide, 0.45-deep flume with 8m-length and a radius if 2.5m in 180℃ An approximately 5cm thickness coir roll spread the flume bottom, 10cm in length and a 0.5cm in diameter vegetation planted at intervals of 9cm on the coir roll. The water was recirculated throughout the flume and return curcuit by a centrifugal pump. The results show that spread the coir roll and plant the vegetation on the coir roll are smaller each 43 percent and 46 percent than not spread the coir roll in the case of mean velocity. In the case of roughness coefficient, spread the coir roll and plant the vegetation on the coir roll are larger each 2.54 times and 2.37 times than not spread the coir roll.

東津江 水系의 計量形態學的 特性

宋在偶,李元熙 弘益大學校 1987 弘大論叢 Vol.19 No.2

This paper analyzed the correlation among the stream morphological characteristics and correlation between the hydraulic geometrical characteristics and frequency of discharge for Dongjin river. The purpose of this study was to provide the informations for stream development projects. The stream morphological characteristics were analyzed by the Horton's three laws. This river basin was well developed very closely to the pattern described by Horton's laws. The concept of proportional stream ordering system was employed to describe continuously the longitudinal variation of the stream morphological characteristics. The flow duration curves obtained with the daily stream flow data of 1090% frequency occurences at the gauging stations in this river basin, were expressed an exponential functions. But relationship with frequency of discharge, morphological characteristics and hydraulic geometrical characteristics were not analyzed because of lack of data. Also the result of regression analysis of meander belt and meander length showed power curve for Dongjin river