ABSTRACT
In recent years several long-span bridges have been constructed and put into service in China’s high-speed railway lines. These bridges usually cross the major rivers of China which serve as vital shipping channels. The long-span structure becomes the superior and sometimes even sole scheme to carry high-speed tracks over the rivers without impacting the water transportation at the bridge site. High-speed trains require stable and smooth geometries of the tracks on long-span bridges to achieve successful and safe passages. Nevertheless, the above mentioned track geometries can be threatened by multiple stressors, e.g., high-speed trains, wind, temperature, among others. Structural health monitoring (SHM) systems have been applied to the long-span bridges, aiming to collect real-time information about both the stressors and structure responses. This information can be used to investigate the performance of bridge structures, and eventually to ensure the running safety of high-speed trains. In this context, the present paper examines the acceleration responses of a long-span steel arch bridge, i.e., the Nanjing Dashengguan Yangtze River Bridge, under operating high-speed train loads. This unique long-span railway bridge and its SHM system are introduced. A coupled dynamic model of the high-speed vehicle and b ridge structure system is subsequently developed. Acceleration responses at the typical locations resulting from the coupled dynamic analysis are compared to the SHM data. It is found that at several specific velocity values the maximum accelerations of the bridge produce respective peaks through the parametric study on train speeds. This interesting phenomenon calls for more detailed investigation on the concerned topic in the future.
