Optimized Design of Safety Boards with Adjustable Spacing for Subway Platforms

Introduction: The domestic subway industry has introduced various policies and facilities through a steady interest in safety facilities as an effort to reduce accidents. Consequently, safety facilities, such as platform screen doors and wheelchair elevators, are currently installed in subway stations. However, according to the Ministry of Land, Infrastructure, and Transport, an average of 65 trip accidents continued to occur annually. Tripping accidents in the gap between the train door and platform continue to occur because of problems with the platform structure and the occurrence of steps. Objectives: The purpose of this study is to analyze the physical properties of safety boards to select a basic design and optimize it. Methods: We analyzed of the internal crystal structure according to the material, material surface composition elements, and material tensile strengths. Based on these analyses, we conducted the following sub-studies: 1) Understanding the operating status by searching and organizing the latest domestic data installed and operated on the platform. 2) Analysis of the operating principles of existing safety steps and identification of the current status based on domestic patent searches for fixed, sliding, and foldable safety steps. 3) Analysis of the limitations of the existing safety boards. In other words, because safety board installation is highly expensive, it is difficult to install them at all stations. Therefore, by analyzing the advantages and disadvantages of the three methods, we conducted a structural analysis of the adjustable-interval safety step platform safety board and optimized its design. Results: Considering the limitations and problems of existing safety steps, new ideas were proposed and the optimal safety step was selected through comparative analysis. In addition, referring to the platform safety step standards, the maximum allowable vertical distribution load of the frame was set to be 1,000 kgf or more, and the maximum allowable vertical distribution load of the movable step was set to be 500 kgf or more. After creating the basic model, the design was changed by changing the number of supports and balls. Conclusions: The purpose of this design is to consider safety while supplementing the economic efficiency, which is the disadvantage of the existing safety steps currently installed. It can be installed at different intervals for each platform, and it was designed with safety as the top priority, preventing unexpected collisions and being safe even under high loads. In order to verify safety under load, the optimal design was selected through a comparison of deformation values between models during the ANSYS analysis process.