• International Journal of Highway Engineering
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• v.14 no.2
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• pp.109-116
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• 2012

This study is aiming to separate highway entrance ramps from impact zones which are considered the characteristics and real traffic situations in each lane and section. The results of this study can be applied to Lane Control System and control the traffic flow for highway more efficiently. Based on earlier studies which analyzed impact zones in entrance-ramp junction using the standard deviation of speed, this study divides more segmentalized impact zones according to the degree of turbulences. As a result of this study, about 800m of intervals, from 500m of upper flow (1,2,3 lane) to 300m of lower flow(2, 3 lane), shows similar traffic characteristics influenced by entrance ramp directly.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.2D
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• pp.167-173
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• 2009

In general, an influenced area of merging section is defined as 500 m including 100 m upstream and 400 m downstream. However, from an observation of the actual traffic flow, it is found that merging effect influences more on downstream than upstream. In this study, an influenced area of merging section on freeway is analyzed by using turbulence which is defined as conflicts between vehicles. In order to overcome the limits of existing traffic flow detection system established with intervals of about 500 m, this study uses raw data collected from the detectors which are established in entrance ramps with similar road conditions. To divide data of each point into similar road conditions, the data of total 72 hours is sorted by Level of Service. An influenced area analyzed by standard deviation of speed is 700 m section of highway, including 300 m upstream and 400 m downstream, for both right and left ramps. It is the result including upstream 200 m more than previous studies.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3D
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• pp.287-293
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• 2008

Density is used as the measure of effectiveness within the ramp junction influence area suggested in the KHCM 2005 in the LOS analysis of the ramp junction, and also density predictive models suggested in the KHCM 2005 is constructed based on the expressway with the speed limit of 100km/h or 110km/h in Korea. So, the density predictive models suggested in the KHCM 2005 are needed to verify if the models could be applied to the urban freeway with the speed limit of 80km/h or less, because the speed limits on most of the urban freeways in Korea are 80km/h or less. The purpose in this study is to construct and verify the appropriate density predictive model within the on-ramp merge influence area of the urban freeway by comparing with the USHCM 2000 and KHCM 2005 models.

• Journal of Korean Society of Transportation
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• v.31 no.5
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• pp.71-78
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• 2013

This paper investigated the influences of ramp traffic flow on the lane utilization for signalized intersection approaches which are adjacent to an off-ramp-street junction. The statistical test showed a correlation between lane utilization and the ramp traffic flow. As the ramp traffic flow increases, the left lanes are less utilized and the right lanes are more utilized. The lane utilization factors are calculated by applying traffic data collected from the Seoul Metropolitan area. The utilization factors are 1.113 for 2 lanes, 1.124 for 3 lanes, and 1.131 for 4 lanes. The lane utilization factors proposed in the paper show higher values than those in current Korea Highway Capacity Manual (KHCM) under the conditions that the number of lanes is 2 or 3. However, the lane utilization factor for 4 lanes in the paper shows lower value than in KHCM. The ramp traffic flow causes more utilization of the right lanes than at normal signalized intersections and the extent gets larger as the number of lanes decreases. Based on the results of the paper, the lane utilization factors at signalized intersection approaches should be revised and reasonable capacity should be recalculated if the signalized intersection is adjacent to an off-ramp-street junction.

• Journal of Korea Water Resources Association
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• v.37 no.8
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• pp.623-630
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• 2004

In this paper, the hydraulic model tests are conducted for the hydraulic characteristics at channel junctions. The experiments are examined through the variation of approaching angle, discharge in the upstream main channel and the discharge ratio between the main channel and the tributary. The experiments are conducted in the channel model having the length of 450cm, the widths of 40cm and 32cm. Four water tanks and pumps are installed in the experimental channel. The length of stagnation zone is increased by Increasing of approaching angle and the discharge in the upstream channel. The length of stagnation increase with the discharge ratio between the main channel and the tributary. However, the variation of the stagnation zone near the channel junctions is little at the same approaching angles and the discharge ratioes between the main channel and tributary. However, the variation of the stagnation zone near the channel junctions is little at the same approaching angles and the discharge ratioes between the main channel and tributary. Accelerating zone of the velocity is occurred in the middle of the channel in the small approaching angle. However, the influence zone of the accelerating velocity is increased by increasing the approaching angle.

• Journal of Navigation and Port Research
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• v.26 no.1
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• pp.95-100
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• 2002

The first version of KHCM was Published in 1992 and is currently used in engineering Practice extensively. The study of new manual was initiated by Korea Institute of Construction Technology 1998 and is intended to be ready for publication by the year 2002. According to the field survey, the action of the individual merging vehicle creates turbulence in the vicinity of the ramp-freeway junction area. The purpose of this paper is to develop the model for Predicting the for entering the lanes 1 and 2($V_{12}$) and the density function at the influence zone by comがring the research works on the ramp junction in the USHCM 2000. The methodology has two major steps : the determination of the flow entering Lanes 1 and 2 immediately upstream of the merge influence area: and the density of the flow within the ramp influence area As a result of this paper the specific functions for such models are suggested through the regression analysis of data collected at four freeway fields in Korea.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.6
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• pp.47-54
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• 2021

The number of freeway traffic accidents in Korea is about 4,000 as of 2020, and deaths per traffic accident is about 3.7 times higher than other roads due to non-recurring congestion and high driving speed. Most of the accident types on freeways are side and rear-end collisions, and one of the main factors is hazard traffic flow caused by merge, diverge and accidents. Therefore, the hazard traffic flow, which appears in a continuous flow such as a freeway, can be said to be important information for the driver to prevent accidents. This study tried to classify hazard traffic flows, such as the speed change point and the section where the speed difference by lane, using individual vehicle information. The homogeneous segment of speed was classified using spatial separation based on geohash and space mean speed that can indicate the speed difference of individual vehicles within the same section and the speed deviation between vehicles. As a result, I could extract the diverging influence segment and the hazard traffic flow segment that can provide dangerous segments information of freeways.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.359-359
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• 2016

본 연구에서는 최근 기후변화에 따른 가뭄으로 어려움을 겪고 있는 충청남도 서부권의 물 부족을 해결하기 위하여 금강 본류로부터 보령댐으로 일정 유량을 도수(diversion)하는 계획이 금강 본류에 미치는 수리적 영향을 검토하였으며 특히 금강 본류의 농공용수 취수에 제한을 초래할 수 도 있는 수위에 미치는 영향을 중심으로 분석하였다. 본 연구의 공간적 범위는 금강 하굿둑으로부터 하류 외해 방향으로 약 9km 지점에 위치한 금강 하구로부터 상류 방향으로는 금강 하굿둑으로부터 약 76km 지점에 위치한 공주시 반포면 검상동의 검상천 합류지점까지 총 85km에 이르는 구간에 대한 1차원 수리 모형을 구축하였으며, 시간적 범위는 보령댐으로의 도수가 갈수기에 이루어지는 것으로 가정하여 2015년 2월 1일부터 5월 31일까지 진두수위표의 시간별 유량과 8개 지천의 유입 유량, 장항검조소의 시간별 조위, 농공용수 취수시설 취수량 및 회귀수, 금강 배수갑문 운영 등을 고려하여 모형의 보정을 실시하였고, 유황분석에 따른 2016년 갈수기 예측 유량을 추정하여 보령댐으로의 도수에 따라 금강 본류 내 주요 구간의 수위에 미치는 영향을 분석하고자 하였으며, 서해안 조위에 따른 금강하굿둑 배수갑문의 운영에 직접적인 영향을 받는 배수위 구간임을 감안하여 비정상류 해석(unsteady flow analysis)을 수행하였다. 갈수기 예측 유량 추정 결과 2015년과 같은 가뭄이 지속될 경우, 2016년의 유황은 2015년 대비 21%로 분석되었으며 이는 보령댐 도수 여부에 관계없이 물 부족이 발생할 수 있는 상태인 것으로 분석되었고, 하천유지유량 정도의 유황이 유지되는 상태에서 보령댐으로 도수를 실시할 경우, 도수시 금강호 최저 수위는 각각 EL(+)0.94m와 EL(+)0.72m로 모의되어 농업용수를 비롯한 기존 취수시설 뿐만 아니라 보령댐 도수시설의 운영에도 어려움이 생길 것으로 예상되었다. 2016년 갈수기 동안 과업 대상 구간인 금강 하류부의 유황은 농업용수 취수가 본격화되기 이전인 2월에는 하천유지유량 정도의 유황을 유지하는데 별 어려움이 없지만 3월 이후농업용수 취수가 본격화되면 농업용수 취수시설이 집중된 입포수위표 ~ 금강 하굿둑 사이 구간은 하천유지유량 이하로 유량이 크게 감소할 것으로 예상되었다.

• Journal of the Korean Society of Hazard Mitigation
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• v.6 no.1 s.20
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• pp.69-81
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• 2006

The purpose of this study is to identify the downstream influences due to the dam discharge by using 2-dimensional model, SMS(Surface water Modeling System). RMA-2 and SED-2D in SMS were applied to Yongdam multipurpose dam watershed located in Gum river basin. Through the simulation, erosion and deposit quantitative analysis of sinuous channels and scour pattern analysis of bridges have been done. A differences erosion depths between deposit are simulated as $-102.4 mm{\sim}54.2 mm$ at No.176(1.4 km) and $-104.1 mm{\sim}28.9 mm$ at No.146(7.4 km), sinuous channel. The river bed at Kamdong bridge in straight channal is simulated as uniform erosion. However, the river bed at Dumdul bridge in sinuous channal has been shown as different erosion depths at each sides. Consequently, the parts that could not be simulated on the existing 1-dimensional model, can be improved results by using a 2-dimensional model, about weakness points for hydraulic modeling such as extreme bend, tributary confluence.

• Journal of Korea Water Resources Association
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• v.56 no.1
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• pp.53-62
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• 2023

Recently, due to the influence of climate change, the occurrence of damage to heavy rain is increasing around the world, and the frequency of heavy rain with a large amount of rain in a short period of time is also increasing. Heavy rains generate a large amount of outflow in a short time, causing flooding in the downstream part of the mountainous area before joining the small and medium-sized rivers. In order to reduce damage to downstream areas caused by flooding, it is very important to calculate the outflow of mountainous areas due to torrential rains. However, the sewage network flooding analysis, which is currently conducting the most analysis in Korea, uses the time and area method using the existing data rather than calculating the rainfall outflow in the mountainous area, which is difficult to determine that the soil characteristics of the region are accurately applied. Therefore, if the rainfall is analyzed for mountainous areas that can cause flooding in the downstream area in a short period of time due to large outflows, the accuracy of the analysis of flooding characteristics that can occur in the downstream area can be improved and used as data for evacuating residents and calculating the extent of damage. In order to calculate the rainfall outflow in the mountainous area, the rainfall outflow in the mountainous area was calculated using MIKE SHE among the MIKE series, and the flooding analysis in the downstream area was conducted through MIKE 21 FM (Flood model). Through this study, it was possible to confirm the amount of outflow and the time to reach downstream in the event of rainfall in the mountainous area, and the results of this analysis can be used to protect human and material resources through pre-evacuation in the downstream area in the future.