• Journal of Korea Multimedia Society
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• v.17 no.4
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• pp.478-489
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• 2014

Recently, flood damage by frequent localized downpours in cities are on the increase on account of abnormal climate phenomena and growth of impermeable area by urbanization. In this study, we are focused on flooding on roads which is the basis of all means of transportation. To calculate real-time accumulated rainfall on a road link, we use the Coefficient of Correlation Weighting method (CCW) which is one of the revised methods of missing rainfall as we consider a road link as a unobserved rainfall site. CCW and real-time accumulated rainfall entered through the Internet are used to estimate the real-time rainfall on a road link. Together with the real-time accumulated rainfall, flooding history, rainfall range causing flooding of a road link and frequency probability precipitation for road design are used as factors to determine the Flood Risk Index on roads. We simulated two cases in the past, July, 7th, 2009 and July, 15th, 2012 in Busan. As a result, all of road links included in the actual flooded roads at that time got the high level of flood risk index.

• Journal of Korean Society of Disaster and Security
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• v.12 no.4
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• pp.53-61
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• 2019

Occurrences of debris flow are a serious danger to roads and residential located in mountainous areas and cause a lot of property loss. In this study, two basins were selected and spatial data were constructed to simulate the occurred debris flow from mountainous areas. The first basin was to use the Terrestrial LiDAR to scan the debris flow occurrence section and to build terrain data. For the second basin, use drones the sediment in the basin was photographed and DSM (Digital surface model) was generated. And to analyze the effect of the occurrence of debris flow on downstream side, FLO-2D, two-dimensional commercial model, was used to simulate the flow region of the debris flow. And it was compared with the sedimentation area of terrestrial LiDAR and drone measurement data.

• Tunnel and Underground Space
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• v.25 no.3
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• pp.275-283
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• 2015

Excavation of underground space in soft ground implicate to the structure, such as subsidence. As a result, it has been acting as a serious risk to the stability of the roads and facilities. Therefore, in order to stabilize the soil stabilization and reinforcement of the structure, we have been using a number of methods and injecting material. In this study, we compared and analyzed the amount of subsidence regarding the ground reinforcement during underground excavation in soft ground by performing model test. And three-dimensional numerical analysis was performed using FLAC 3D. The subsidence was simulated numerically according to the tunnel excavation. The subsidence results of the model tests and numerical analyzes were relatively consistent. Thus comparing the ground subsidence by varying the reinforcement area on the numerical analysis was analyzed. As a results, three-dimensional numerical simulation could be regarded to simulate better on the ground subsidence by various kinds of underground excavation and it can be used as a material of subsidence prevention methods.

• Journal of Korean Society of Transportation
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• v.25 no.1 s.94
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• pp.23-35
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• 2007

Freeway diverging areas are very vulnerable to traffic accidents due to abrupt vehicle speed changes and geometric changes. Therefore, in designing diverging areas, much attention should be Paid to safety The Present design criteria about freeway diverging areas regulate transition sections for lane changes, deceleration lanes, transition corves for direction changes. and other similar items. However, the design criteria were often violated in implementation because of ambiguities in the criteria. This study aims at clarifying and improving the present design criteria for freeway diverging areas. For this, field survey data and traffic accident data for diverging areas were analyzed.

• Journal of Korean Society of Transportation
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• v.27 no.4
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• pp.137-143
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• 2009

It is necessary to develop driving assistant information in order to prevent a rear-end collision with a crashed car which is at the blind curve on highway. Laboratory experiments were performed using a driving simulator to keep the traffic environment constant. This research was evaluated the effect of driver behavior according to providing collision avoidance information which was consisted of advisory, caution, and warning information by the dangerous degree of traffic situation. Driver behavior was evaluated to analyze the collision avoidance with a crashed car, and glance behavior was examined to measure the eye movements to the display on which provided the collision avoidance information. After experiment, the significance was evaluated on provided collision avoidance information. As the result of this research, the number of collision accident is reduced when the phased information was provided. In addition, it is clear that auditory information is more important than visual information in the case of providing the second information.

• Proceedings of the KOR-KST Conference
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• 1998.10b
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• pp.311-311
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• 1998

일반적으로 교차로에서의 보행자 사고는 대부분이 횡단보도에서나 횡단보도 주변에서 발생하는 것이 많다. 이것은 운전자의 안전의식부족뿐만 아니라 보행자들이 교통법규를 지키지 않기 때문이다. 교통사고는 운전자나 보행자를 막론하고 안전의식 수준 및 안전시설의 질적 수준과 밀접한 관련이 있다. 특히 횡단보도 위치와 관련한 정지선에 대한 기준이 없어서 횡단보도 전후에 정지선이 2개가 설치된 곳이 많아 차량간의 사고를 유발하고, 보행자는 보행동선을 단축하기 위해 횡단보도 주변횡단이라는 위험한 행태를 유발하지만 이에 대한 연구나 대안제시가 이루어지지 않고 있다. 본 연구는 요인분석법이란 다변량 통계기법을 통해서 사고기록과 형태자료를 분석하였다. 사고기록은 정지선이 2개에서 1개로 변경된 25개 교차로에 대한 보행자와 차량의 유형별, 위치별, 피해정도별 사고기록을 조사 분석하고 행태분석은 현재 정지선이 2개인 곳과 기하구조가 유사한 정지선 1개인 곳을 하나의 쌍으로 해서 모두 8쌍(16개의 교차로 횡단보도)를 조사 분석하였으며, 마지막으로 설문조사를 통해서 보행자의 교통법규 준수와 인식정도에 대한 조사를 통해 보행자들의 인식과 행태조사를 통한 교통법규 준수 정도를 알아보았다. 사고자료의 분석을 통해서 첫째, 정지선이 2개인 교차로는 교차로내 차량사고, 접근부의 후면 추돌사고, 횡단보도에서 보행자사고가, 둘째, 정지선이 1개인 교차로는 유출부 차량사고가 많은 것으로 나타났으며, 행태자료의 분석을 통해서는 첫째, 정지선이 2개인 곳은 횡단보도를 이탈 또는 진입하면서 횡단하는 보행자, 점멸신호에 횡단 시작하는 보행자의 행태와 보행자 신호에 횡단보도를 통과하는 차량, 둘째, 정지선이 1개일 때는 횡단보도를 침범해서 정지하는 차량, 도로에 내려서서 기다리는 보행자가 많은 것으로 나타났다. 마지막으로 설문조사와 행태조사를 종합하면, 보행자들의 인식으로는 약 71%의 응답자와 점멸신호의 의미를 알고, 전체 응답자의 약 58%가 점멸신호에 건너지 않고 기다린다는 응답(교통법규준수)을 했으며, 실제 행태에서는 약 12.4%가 위반하는 것(87.6% 법규준수)으로 나타났다. 보행자들이 응답한 것보다 실제 행태에서는 더 많은 보행자가 교통법규를 준수하는 것으로 나타났으며, 횡단보도를 이용하는데 있어서 횡단보도를 침범하는 차량과 신호시간이 적다는 의견이 많았다.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.527-531
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• 2007

하천내에서 작은 물고기의 국지적인 회유 또는 이동 습성은 먹이를 구하고, 산란 및 성장과 집단에서 분산하고, 위험으로부터 도피하는 것에 밀접한 연관이 있다. 하천의 합류부와 연결부에 제방(levee), 도로(road) 등이 설치되는 경우 일반적으로 암거형태의 인공수로로 상 하류를 연결되는데, 암거내 수리특성상 평수시 저유량, 고유속, 저수심의 수리특성을 보인다. 이러한 수리특성은 물고기가 이동하는데 장애(barrier)가 되어 생태적으로 하천내 종다양성 감소와 일부 어종의 멸종을 초래한다. 어도 설치시 설계기준에서 가장 주목할 부분은 어도를 이용할 대상어종의 범위와 유영능력이다. 하천설계기준(2005, 한국수자원학회)에서 제시된 물고기의 유영능력은 대부분 국외 어종을 대상으로 외국에서 실험한 결과를 이용하고 있다. 그러므로 이러한 기준이 국내 어종에 대해 적합한지에 대한 검토가 필요하다. 본 실험의 목적은 국지회유성인 피라미와 각시붕어가 인공수로를 통과할 때의 유영행동 중 소상성공율과 유영속력을 평가하고자 함이다. 유영행동의 실험방법은 Brett(1967)에 의해 제안된 2가지 방법인 증진유속방법과 고정유속 방법중에서 물고기의 이동경로와 소상능력을 확인하기에 용이한 고정유속방법을 사용하였다. 또한, 효과적인 실험을 위해 실험어종(피라미 100마리, 각시붕어 100마리)이 실험 중에 최적의 건강상태를 유지할 수 있도록 물고기의 적응 기간(24시간)과 실험 중 휴식기간을 두었다. 실험결과 체형이 방추형(fujiform)인 피라미의 경우 평균유속 $0.7{\sim}0.8m/s$구간에서 소상성공율이 61%에서 26%로 급격하게 하락하는 현상이 나타났다. 그리고 측편형(compressiform)의 체형을 가진 각시붕어의 경우 평균유속 0.4m/s에서 소상성공율이 25%로 나타났으며 그 이상의 유속에서는 10%이하로 나타났다. 실험어종의 이동경로를 분석한 결과 대부분 수로바닥에 밀착하여 최저유속구간을 이용하여 이동하는 것으로 나타났으며, 이동경로의 지점유속은 평균 유속의 70%정도로 나타났다. 실제 하천에 설치된 인공수로가 생태통로의 기능을 유지하기 위해서는 평상시 수리특성이 대상어종의 유영능력을 초과하지 않도록 설계되어야 한다. 특히, 하천에 설치된 인공수로의 길이가 $5{\sim}10m$정도일 경우라면 피라미의 소상 가능성을 50% 이상 확보하기 위해서는 평수시 설계유속이 0.7m/s를 초과하지 않아야 할 것으로 판단된다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.1
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• pp.48-58
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• 2014

In this study, quasi-static according to the displacement-controlled (strain control) method tests on RC columns for seismic reinforcement performance in accordance with the provisions of the seismic design and construction before 1992 design code for highway bridges in korea. Used reinforcement that improves the performance of Inorganic Helical Bar, a kind of alloy steel, circular columns were tested outside the seismic reinforcing. In the experiment, fracture behavior, lateral load-displacement relation, ductility and energy assessment evaluation was performed through tests. The variables in experimental are section force of reinforcement, spiral reinforcement spacing, reinforcement method. Improved seismic performance and effect were confirmed through quasi-static test experiments. The results of study confirmed determination the appropriate size of reinforcement, reinforcement forces, spacing and selection of the type required, furthermore, not only mechanical reinforcement but also substitution of high-strength concrete reinforced with concrete cover improved seismic performance.

• Computational Structural Engineering
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• v.7 no.2
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• pp.89-99
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• 1994

The nonlinear dynamic behaviors of guardrail established on the local or high way have been investigated using BARRIER VII program with respect to four design variables such as section type of beams and posts, impact angle, impact velocity and vehicle weight. Computer simulation programs are sophisticated analytical models for analyzing dynamic vehicle/barrier interactions and provide a relatively inexpensive alternative to full scale crash testing. This study has been focused on the structural adequacy, occupant risk, and vehicle trajectory. For this purpose, the maximum defection and impact force have been calculated to design the clear zone and to analyze effect of impact attenuation. Also, the acceleration of vehicle and exit angle after collision have been computed to estimate the occupant risk. From this study, it is suggested that we should strengthen the design criteria of guardrail to prevent from disastrous traffic accidents.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.6
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• pp.1937-1944
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• 2014

In recent years, common ducts have been installed and operated in the sidewalls of tunnels to prepare for emergencies in tunnel construction and maintenance. The installation of common ducts is done mainly by humans. Problems with cost increases are inherent in tunnel construction by humans due to the safety risks and the economic inefficiency of humans performing construction activities. Among the problems that arise are poor illumination due to the use of temporarily installed electricity, the risk of accidents due to the confined workspaces, and workers avoiding work tasks because of the poor environment in tunnel. Ideas for solving these problems were developed using a value engineering (VE) process, and mechanized construction was identified as a promising solution. To verify the effectiveness of mechanized construction of a common duct in tunnels, experimental construction work was carried out, and mechanized construction was proven to directly improve the constructability and economic efficiency of common duct construction. In addition, reducing human involvement in common duct construction in tunnels is expected to improve safety, and because of the continuous concrete placement technique used, the finish and appearance of the ductwork are improved.