• Journal of Korean Society of Transportation
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• v.20 no.2
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• pp.117-124
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• 2002

새로 개발한 철재 교량용 방호울타리는 기존 시설에 비해 충격흡수기능과 조망권 확보, 융설작업, 유지보수가 용이하도록 설계되었다. 본 연구는 새로 개발한 철재 교량용 방호울타리를 건설교통부의 $\ulcorner$도로안전시설 설치 및 관리지침 - 교량용 방호울타리 편. 1999$\lrcorner$ 의 설계기준에 따라 기존 고속도로에 사용하고 있는 F형 콘크리트 교량용 방호울타리와 성능비교를 통해 평가하고자 하였다. 비교평가는 S2급 교량용 방호울타리의 시험기준으로 실시하였으며 결과는 다음과 같이 나타났다. 첫째, 소형승용차를 대상으로 한 운전자의 안전도 평가에서는 두가지 시설 모두 강도성능, 충돌 후 차량 안전성능 구성 부재 비산 억제 성능 등 세 가지 기준을 만족하였으나, 가속도 기준에 있어서는 철재 교량용 방호울타리는 기준인 20g 이하인 18.2605g로 나타나 안전기준을 만족하였고, F형 콘크리트 교량용 방호울타리는 20.1791g로 나타나 기준을 약간 상회하는 것으로 나타났으나 안전기준의 범위에 있는 것으로 평가하였다. 둘째. 대형차량을 대상으로 한 방호울타리의 구조적 안정성 평가에 있어서는 F형과 철재 교량용 방호울타리 모두 평가기준에 적합한 것으로 나타났다. 새로 개발한 철재 교량용 방호울타리는 국내 최초로 모의충돌시험과 실물차량 충돌시험을 통해 개발하였다는 의의를 가지고 있으며 성능측면에서도 기존의 시설에 비해 충분히 안전하다는 것을 증명하였다. 그러나 측정시설의 미비로 충돌후의 차량의 이탈속도나 이탈각도에 대하여 만족할 만한 수준의 결과를 제시하지는 못하였다.

• Computational Structural Engineering
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• v.10 no.4
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• pp.12-21
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• 1997

차량충돌에 대하여 운전자의 안전확보를 위하여 새로 개발한 철재 중앙분리대에 대한 안전성 분석을 위하여 인체모형을 탑재한 실물차량 충돌실험을 실시하였다. 인체모형의 두부와 흉부, 대퇴부 및 차량의 무게중심점에서 가속도와 충격하중을 계측하여 철재 중앙분리대 방호울타리에 차량충돌시 운전자의 안전성을 검증한 결과 다음과 같은 결론을 도출하였다. 1) 철재 중앙분리대 방호울타리는 콘크리트 중앙분리대 방호울타리에 비해 운전자의 신체 상해치와 차량파괴 등에 있어서 뛰어난 충격흡수성능을 보여주었다. 2) 철재 중앙분리대 방호울타리는 콘크리트 중앙분리대 방호울타리의 경우 빈번히 발생하는 차량전복과 같은 2차사고의 유발 가능성이 전혀 없는 구조적 안정성을 보여주었다. 3) 경량의 차량충돌에 대하여 자체 탄성영역내에서 충격을 흡수하여 유지보수 측면에서 유리함을 나타냈다. 4) 충돌 수 충돌차량에 대한 차량유도성능이 뛰어났으며, 차량의 충돌후 이탈각도는 충돌각도의 60% 이내로 나타났다. 5) 철재 중앙분리대 방호울타리로부터 분리된 파편이 거의 없어 도로소통에 지장을 초래하지 않는다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.1
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• pp.93-102
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• 2021

This paper describes the process of developing a concrete median barrier of SB4 grade with anti-glare function. The development section has a height and width of 1,270mm and 560mm, respectively. A wire mesh is placed in the center of the cross section to improve the protection performance. Collision analysis predicted that this section satisfies the strength and occupant protection performance, and that no damage to the barrier occurs. In the actual collision test, it was confirmed that this section satisfies the strength and occupant protection performance. However, damage was observed on two concrete barrier when the truck crashed. In order to improve the accuracy of the collision analysis of the concrete barrier in the future, it is considered that a study on the model development and continuous collision analysis method for domestic commercial vehicles should be carried out.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5558-5565
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• 2012

Roadside barriers are facility for preventing cars from out of path, and 7 classes of barrier are prescribed in criteria of road grades and speed limit, etc. However, overload and overspeed are increased according to improvement of vehicle performance, and falling over frequently occur in vehicle accident related in barriers. Therefore, enhancement of the existing design criteria of roadside barriers is demanded. In this research, vehicle crash simulation was carried out, and the condition for fracture of roadside barriers and vehicle overturn was evaluated in order to verify the defence performance of the barriers, which are SB5 steel barrier and SB6 concrete barrier adapted mainly to highway.

• Korean Journal of Culture and Social Issue
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• v.17 no.1
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• pp.51-62
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• 2011

This study focused on the effects of median type on drivers' subjective sense of speed and the changes in this sense by driver age. Participants were 61 drivers: 20 young (aged 20-39 years), 19 middle-aged (40-59 years), and 22 older drivers (60+ years). The participants watched each of two driving scenarios, showing either a guardrail-equipped or a concrete median. The participants were asked to push a button when they perceived speeds of 60 km/h, 80 km/h, or 100 km/h. All drivers perceived higher speeds in the guardrail condition than in the concrete condition. Perceived speeds increased with driver age in both guardrail and concrete conditions. These results mean median type affects drivers' subjective sense of speed even as driver age increases, and that drivers' subjective sense of speed tends to increase with age.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.2
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• pp.49-57
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• 2012

Recently, in field of bridge construction, modular technology has been studied to reduce construction period. However, main stream of the study is limited to the pier, girder and deck of bridge, which are huge or main members. Studies on incidental facilities like concrete barrier is out of sight. Thus, in this study, connection system of concrete barrier was developed to apply to modular bridges and static experiment was performed in order to verify structural capability of proposed system. Variables of experiment are composed of bolt direction such as vertical and horizontal. The experimentation due to the designed variables was conducted by comparison with a standard concrete barrier, which is a traditional barrier. As a result, vertical joint way of the bolt showed nearly identical structural performance and healthy to standard specimen's. it can be applied to modular bridges.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.4
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• pp.2414-2418
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• 2014

This study carried out three-dimensional finite element analysis and structural safety evaluation of attachable roadside barriers. The effects of diaphragm distance and the number of bolts on displacements and maximum stresses for various parameters are studied using the LS-DYNA finite element program for this study. In this study, the existing finite element analysis of barriers using the LS-DYNA program is further extended to study static behaviors and structural safety of the barrier with module structures connected by anchor bolt inserted through concrete bridge decks. The numerical results for six parameters are verified by comparing different models with displacements and stress distribution occurred in the barrier and shows good structural performance.

• Journal of Korean Society of Transportation
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• v.21 no.1
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• pp.115-125
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• 2003

The concrete median barriers are the most popular safety appurtenance that can be installed on narrow medians and are effective in keeping uncontrolled vehicles from crossing into opposing lanes of traffic. It is necessary to install and maintain median barriers because it is very difficult to reserve enough room required for medians in KOREA. Also, concrete median barriers are accepted as the actual alternatives for median barriers, mostly because they require almost no maintenance even after serious collisions. Typical concrete median barriers are 810mm high and have 596mm high glare screens on top of them. However we have experienced a number of "climb" and "roll-over" accidents of heavy vehicles and most of all, there have been some serious accidents caused by the part of broken glare screens. So the improvement study of concrete median barriers started. Prior to this study, a new type of concrete median barrier was suggested which is 1,270mm high and has no glare screens on top of it. So it was required to compare the properties of various types of concrete median barriers including the new type to find the optimal type of concrete median barrier. In this study, we have evaluated the characteristics of four types of concrete median barriers (New Jersey type, F type, constant slope type, and wall type). We have performed many computer simulations for the evaluation of the crashworthiness of them, and through the simulations we have tried to find a proper type of concrete median barrier. Through the computer simulations, we evaluated the structural stability and safety of the four types of concrete median barriers. We confirmed the structural stability and safety of them But in regard to the probability of "roll-over" of heavy vehicles, the higher concrete median barriers showed better performances than the lower. As the result of this study a new type of concrete median barrier was recommended.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.113-116
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• 2008

According to a domestic provision, test levels of the barrier are divided into seven categories(SB1 to SB7) and the corresponding crash conditions are specified. Meanwhile, standard types of concrete barriers with different dimensions have been constructed nation wide. Some studies aimed at finding a proper test level of each type of the concrete barrier have been carried out, but the reliable and consistent results have not been fully established yet. The purpose of this study is to find out the test level corresponding to the concrete barrier of type-2 through static test. AASHTO LRFD was referred to for the loading pattern and a magnitude of the load that simulate a vehicle crash assumed. The test results show that the ultimate strength of the type-2 satisfies the load level required for SB5. However, it seems that the type-2 does not comply with SB6, showing some differences in results from previous analytical studies. In order to take advantage of the static test in establishing the test level of the domestic barrier, more detailed provisions should be specified.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.134-137
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• 2006

In this paper, performance verification of connection between bridge rail and FRP decks are performed by static test. Also, the effect of flexible bridge rail failure to behavior of FRP deck are examined. Commercial products of flexible bridge rail are applied to test specimen, and 6 types of FRP deck-to-bridge rail connection system are considered. By the test results, 6 types of connection system by the connection method have similar structural capacity and have enough safety margin. Therefore, it is determined that 6 kinds of bridge rail considered in this study can be applied to bridge effectively by the cases of bridge field condition.