Postearthquake Function Level Evaluation of Railway Station Considering the Seismic Fragility of the Station Signal Equipment

The railway station is a critical node in the transportation network. Accurately evaluating the postearthquake functional level of railway stations not only facilitates functional recovery but also provides a scientific basis for formulating emergency plans in earthquake-stricken areas. This paper analyzed the operation modes and functional implementation methods of railway stations, categorizing postearthquake functional levels into three categories: complete function, basic function, and functional failure. Based on state tree theory and focusing on the impact of signal equipment, the fragility index of signal equipment was established, and the basic components of each subfunction and the functional logic relationships between components were analyzed. A new state tree-based method for evaluating the postearthquake functional level of railway stations was first proposed. Using this method, a typical railway station was evaluated. The research results indicated that under seismic action, the hanging lamps, elevators, ceilings, and signal equipment in railway stations were more prone to failure, and the overall functional redundancy of the railway stations was relatively low. Therefore, it was recommended to enhance the seismic design of the railway station’s layer, strengthen the seismic structural measures of hanging lamps, elevators, and signal cabinets, and place important signal cabinets on the lower mezzanine of the railway stations. Addressing these weaknesses could significantly enhance the postearthquake functional level of railway stations.