IDENTIFICATION OF HIGH-ORDER LOCAL VIBRATION PROPERTIES OF RC VIADUCT

In order to sustain the development of high-speed trains, it is necessary for railway bridges to grasp the dynamic behavior of bridge members precisely, by identifying not only whole bridge vibration properties but also local ones, and low-order to high-order mode vibration properties. Actually, there are common concerns over resonance and noises caused by the vibration of bridge members due to high-speed trains. However, there have been few vibration measurement experiments for carrying out identification of high-order member vibration properties. In this circumstance, the authors conducted the passing train experiment, measuring vibration concurrently at several points on the intermediate and projecting slabs of a RC viaduct for high-speed trains. Through the vibration measurement experiment, the authors verified the possibility of detection of high-order vibration modes of members and identified the outstanding vibration mode when a high-speed train passes. This paper also includes a few discussions about the relation between vibration properties and the outstanding frequency induced by the multi-axle load of trains. By accumulating the data of actual measurements of local vibration, it would be possible to contribute to the sophistication of finite element analysis, etc.