Study on Maintenance and Safety Management of Subway Viaducts Based on the Life Cycle

To effectively control the safety risk of existing subway viaducts and extend the service lives of subway viaducts, damages investigation of subway viaducts was implemented and the main causes of damages were analyzed. Based on investigation results and theory analysis, the functions degradation states of subway viaducts, which were divided into five stages of their lifetime, were put forward. To support the elementary object of sustaining subway viaducts' life, the modes of maintenance and safety management(MSM) of subway viaducts were discussed, and a closed mode of MSM, which is similar to the PDCA circle and can continuously improve the performance of subway viaducts, was set up. Further, the mode of MSM was promoted to manage and maintain the rail traffic facilities in the life cycle. The proposed new thought of MSM can provide reference for discussing MSM of other engineering structures.