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Abstract
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An increase in the number of traffic accidents in tunnel emergency stop areas has been recored in the last two years in many countries with long road tunnels. In most cases, the collisions of passenger cars into the emergency stop area walls were fatal, which presents an even bigger obligation for the road management authorities to find a solution to the problem. Even though the tunnel emergency stop areas tunnels are designed and built according to the valid legislation, it has turned out that the current implementation of the emergency stop area wall in the driving direction presents a serious potential traffic safety risk.
With the purpose of determining the most suitable method of protecting the SOS tunnel niche wall in the event of vehicle impacts, comparative numerical analysis of vehicle impacts has been performed in accordance with the SIS - EN 1317 standard. For the emergency-stop-area wall-impact protection, two different designs were considered: the H2 safety railing and the crash cushion composed of eight cylindrical steel sheet tubes. The tube diameter is 500 mm and the sheet thickness is 3 mm. Both designs were subject to collision simulations in accordance with EN 1317 parts 1 and 2 (EN 1317-1 - -4). As the safety of passenger cars was being studied, the tests TB 11 (vehicle mass 900 kg and vehicle velocity 100 km/h) and TB 21 (vehicle mass 1300 kg and vehicle velocity 80 km/h were simulated with a finite-element-model-based explicit dynamic analysis. The kinematic values of the vehicles just prior to the collision were determined by simulating the driving dynamics several seconds before the collision in PC-Crash. Based on the FEM analysis results in LS-Dyna for each crash scenario, a comparative analysis of the two protection systems was performed in order to determine their efficiency and suitability for installation in the existing tunnel emergency stop areas.
Based on comparative analyses of the values of the Acceleration Severity Index (ASI), Theoretical Head Impact Velocity (THIV) and values of the Post-Impact Head Deceleration (PHD), the crash cushion provides the best results for the events of impacts of TB 11 vehicles and TB 21 vehicles into an SOS tunnel niche.
Language: en |