• 한국공간구조학회논문집
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• 제15권2호
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• pp.79-86
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• 2015

This study investigated the embedded depth of guardrail posts through 3-D soil material model and carried out evaluation of the dynamic performance of guard rail. In order to calculate for embedded depth of sloping ground, displacement of guardrail posts is analyzed according to the embedded depth of experiment variables. Through the static test of guardrail posts, the maximum deflection was found to decrease the interval. By performing the dynamic test using the Bogie Car, that is confirmed the elastic modulus of the soil occuring the maximum deflection. Guardrail posts is considered to need for further reinforcement in the larger slope than the plains. This study researched about maximum displacement and deviation velocity through dynamic performance of guardrail system and conducted analysis about protection performance evaluation of passenger.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1998년도 가을 학술발표회 논문집
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• pp.117-124
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• 1998

New Thrie-Beam guardrail section has been developed. The Characteristic of its geometry, energy absorbing capability and response to impact has been studied and compared with those of conventional W-Beam guardrail system. To compare the response to impact computer simulation using Barrier Ⅶ program was made. Stretch tests and static loading tests were conducted for the performance verifications.

• International Journal of Automotive Technology
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• 제4권1호
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• pp.31-40
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• 2003

W-beam guardrail system has been the most popular roadside safety device around the world. Through large plastic deformation and corresponding energy dissipation, a W-beam guardrail system contains and re-directs out-of-control vehicles so as to reduce the impact damage on the vehicle occupants and the vehicles themselves. In this paper, our recent experiments on 1 : 3.75 downscaled W-beam and the beam-post system are reported. The static and impact test results on the load characteristics, the global response and the local cross-sectional distortion are reveled. The effects of three different end-boundary conditions for the beam-only testing are examined. It is found that the load characteristics are much dependent on the combined contribution of the local cross-sectional distortion and the end-supporting conditions. The energy Partitioning between the beam and the supporting Posts in the beam-Post-system testing were also examined. The results showed that the energy dissipation partitioning changed with the input impact energy. Finally, a simple mass-spring model is developed to assess the dynamic response of a W-beam guardrail system in response to an impact loading. The model's prediction agrees well with the experimental results.

• 한국안전학회지
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• 제35권4호
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• pp.23-31
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• 2020

In the construction sector, there were 99 fatalities from falls associated with steel tube and system scaffolds for three years from 2016 to 2018 and out of which 27.3 percent (27 workers) were found to have occurred during installing and dismantling procedure. To erect scaffolding which is installed for the work at height, the work platforms are generally installed first and the safety guardrails are installed and vice versa to dismantle. As a result, workers are exposed to the risk of falling because they erect and dismantle scaffolding without guardrails. To minimize the risk of falling, it is necessary to study a new construction method that can erect or dismantle scaffolding while guardrails are installed (called advanced guardrail system). This study analyzed advanced guardrail system in terms of safety regulation, workability and economic efficiency by investigating the domestic situation on the use of scaffolding, reviewing domestic and foreign standards for guardrails and conducting economic feasibility study. The results of this study is expected to greatly contribute to preventing falls in scaffolding installation and dismantlement procedure. As a follow-up study, empirical research is required including physical test of scaffolding with advanced guardrail system and effectiveness analysis after trial applications.

• 한국멀티미디어학회논문지
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• 제25권6호
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• pp.833-843
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• 2022

Based on the problems of untimely Expressway fire rescue and backward traditional fire rescue methods, an emergency fire fighting and inspection robot riding on expressway guardrail is designed. The overall mechanical structure design of emergency fire fighting and inspection robot riding on expressway guardrail is completed by using three-dimensional design software. The target fire detection is realized by using the target detection algorithm of Yolov5; By selecting a variety of sensors and using the control method of multi algorithm fusion, the basic function of robot on duty early warning is realized, and it has the ability of intelligent fire extinguishing. The BMS battery charging and discharging system is used to detect the real-time power of the robot. The design of the expressway emergency fire fighting and inspection robot provides a new technical means for the development of emergency fire fighting equipment, and improves the reliability and efficiency of expressway emergency fire fighting.

• 한국강구조학회 논문집
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• 제13권4호
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• pp.381-393
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• 2001

최근 교통상항은 교통량의 급격한 증가와 차종의 다양성에 그 특성이 있다. 우리나라에서 가장 많이 사용되고 있는 W형 보를 사용한 가드레일은 $14ton-60Km/h-15^{\circ}$ 의 충돌조건에 대하여 구조물의 강성이 충분치 못한 반면에, 보다 현실적인 충돌속도에 대하여 소형차의 탑승자 안전을 충족시키지 못하는 것으로 나타났다. 대형차에 대응하기 위하여 구조물의 강성을 증가시키는 일과 소형차에 대하여 탑승자의 안전을 도모(에너지 소산)해야하는 두 가지의 서로 상반된 목표를 달성하기 위하여, 두께 3.2mm의 강판을 이용한 보의 고무로 만든 충격 흡수재를 이용한 트라이-빔 가드레일 시스템을 고안하여 정적 실내실험, 컴퓨터 시뮬레이션 및 실차 충돌실험을 통하여 거동 및 성능을 조사하였다. 2%의 무게증가로 기존의 W형 보에 비하여 보의 높이가 약 100mm 증가된 트라이-빔(450mm)가드레일 시스템은 범퍼 높이가 다른 다양한 차종에 보다 좋은 수용능력을 보였고 강성과 충격흡수 능력 또한 W-보 가드레일 시스템에 비하여 크게 향상되었다. 그리고 실차 충돌실험을 실시한 결과 NCHRP 350의 Test 3-10 충돌시 성능 요건을 만족시켰다.

• 한국지반공학회논문집
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• 제35권11호
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• pp.25-36
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• 2019

차량이 도로를 이탈하여 성토부로 추락하는 것을 방지하기 위해 설치되는 연성 차량방호울타리는 사면부 시작점 근처에 도로방향으로 일렬로 근입된 무리말뚝과 무리말뚝 위에 부착되는 가드레일로 구성되어 있다. 차량방호울타리에 차량 충돌 시, 충돌에너지의 일부는 가드레일의 변형에 의해 흡수되며, 나머지 에너지는 가드레일을 지지하는 말뚝과 지반의 상호작용으로 저항하게 된다. 본 논문에서는 충격하중에 대한 말뚝과 지반의 상호작용을 원심모형실험을 수행하여 분석하였다. 풍화토로 다져진 경사지반에 설치된 단말뚝의 충격하중에 대한 극한지지력 및 거동특성을 분석하고자 하였다. 이를 위해 말뚝에 충격하중을 모사할 수 있는 하중재하시스템을 설계 및 구축하였다. 구축된 원심모형실험체 및 하중재하시스템을 이용하여 하중 및 지반조건에 대한 매개변수연구를 수행하였다. 최종적으로, 말뚝의 하중재하점에서 나타나는 하중-변위 곡선을 계측하여 충격극한지지력을 분석하였다. 또한, 휨모멘트 분포도로부터 산정된 지반반력 분포도를 도출하였고, 선행 연구결과와 비교하여 차량 방호울타리 지지말뚝의 지지거동을 분석하였다.

• 한국안전학회지
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• 제35권5호
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• pp.49-58
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• 2020

In domestic construction sites, when installing steel pipe scaffolding and system scaffolding, the guardrails are installed after the installation of the work platforms. This conventional guardrail system (CGS) is always exposed to the risk of falls because the safety railing is installed later. In order to prevent fall disasters during erecting and dismantling scaffolds, it is necessary to introduce the advanced guardrail system (AGS) which installs railings in advance of climbing onto a work platform. For the introduction of the AGS, the structural performance of the system scaffolding applying the CGS and the AGS was compared and evaluated. The structural analysis of the system scaffold (height: 31 m and width: 27.4 m) with AGS confirmed that structural safety was ensured because the maximum stress of each element of the system scaffolding satisfies the allowable stress of each element. As a result of performance comparison of CGS and AGS for each element, the combined stress ratio of vertical posts in AGS was 6.4% lower than that of CGS. In addition, in the case of ledger and transom, the combined stress ratios of AGS and CGS were almost the same. The compression test of the assembled system scaffolding (three-storied, 1 bay) showed that the AGS had better performance than the CGS by 9.7% (8.91 kN). The cross bracing exceeds the limit on slenderness ratio of codes for structural steel design. But the safety factor for the compressive load of the cross bracing was evaluated as meeting the design criteria by securing 3 or more. In actual experiments, it was confirmed that brace buckling did not occur even though the overall scaffold was buckled. Therefore, in the case of temporary structures, it was proposed to revise the standards for limiting on slenderness ratio of secondary or auxiliary elements to recommendations. This study can be used as basic data for the introduction of AGS for installing guardrails in advance at domestic construction sites.

• 대한안전경영과학회지
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• 제25권3호
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• pp.73-81
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• 2023

This study uses FMECA (Failure Modes, Effects, and Criticality Analysis) and HAZOP (Hazard and Operability), which are widely applied in industrial areas, among risk assessment methods, and applies them to the same system. While FMECA evaluates system failure conditions and analyzes risks, HAZOP evaluates the system comprehensively by evaluating operational risks that may occur based on system parameters. According to data released by the Ministry of Land, Infrastructure and Transport, as of December 2021, the length of roads in Korea is 113,405 km, and the repair of guardrails that have expired must be fixed urgently in terms of traffic safety. Replacing all of these guardrails with new ones requires a very large cost, but if the guardrails are repaired with a vehicle equipped with the G-Save method, carbon emissions are reduced, the repair period is shortened, and great economic benefits can be obtained. However, risk assessment for guardrail coating vehicles has not been done so far. Focusing on this point, this study aims to evaluate the risk of these coating vehicles and describe the results. Finally, we found that the Risk Priority Numbers(RPN) in the FMECA risk assessment were greatly reduced, and 6 risk factors from HAZOP risk assessment and actions were taken.

• 한국재난정보학회 논문집
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• 제12권3호
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• pp.279-285
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• 2016

차량방호울타리는 교통사고 발생 시 마지막 안전장치이다. 차량방호울타리의 구조적 성능이 기대 수준 이상으로 유지가 되어야지만 운전자 혹은 차량 탑승자의 생명을 보호해 줄 수 있게 된다. 단부처리시설은 방호울타리의 끝단에 설치되며 차량 충돌 시 가드레일이 차량에 관통하는 현상을 방지함과 동시에 충격을 흡수하는 형태의 시설물이다. 이러한 차량방호울타리의 개발을 위하여 컴퓨터 시뮬레이션을 통한 반복해석을 수행함으로서 다양한 변수에 적절히 대응하는 방호울타리를 개발할 수 있을 것이다.