Vibration Analysis of Bridges Under Moving Vehicles and Trains

Abstract

This chapter discusses the vibration of bridges under moving vehicles and trains, which is of great theoretical and practical significance in civil engineering. The chapter describes some recent developments in the vibration analysis of girder and slab bridges under the action of moving vehicles or trains. A bridge-track-vehicle element is developed for investigating the dynamic interactions among a moving train, its supporting railway track structure, and the bridge structure. The effect of track structure on the dynamic response of the bridge structure and the effect of bridge structure on that of the track structure are identified. The proposed bridge-track-vehicle element can be easily degenerated to a vehicle-beam element, which is employed to study the effects of the random road surface roughness and the long-term deflection of concrete deck on the dynamic response of a girder bridge. The chapter also describes the plate-vehicle strip for simulating the interaction between a rectangular slab bridge and moving vehicles. It also explains two kinds of plate finite strips—namely, the plate-vehicle strip and the conventional plate strip, which are employed to model a slab bridge. In the analysis, each moving vehicle is idealized as a one-foot dynamic system with the unsprung mass and sprung mass interconnected by a spring and a dashpot. A train is modeled as a series of moving vehicles at the axle locations. The efficiency and accuracy of the proposed methods are demonstrated in the chapter by numerical examples.