STOCHASTIC ANALYSIS OF STRUCTURE VIBRATION INDUCED BY SIMPLE SUPPORTED HIGHWAY BRIDGE

An analytical method for calculating the power spectral density(PSD) of the traffic-induced force acting on the ground,ground vibration,and dynamic response of building induced by the viaduct systems is presented.The vehicle is modeled as a two-DOF system with linear suspensions and tire flexibility,the bridge as a continuous Euler-Bernoulli beam simple supported at both ends,and the ground as an elastic half space.The effect of road surface roughness is also considered.The theory of a stationary random process is used to obtain expressions for the PSD of traffic-induced force,ground vibration and building vibration,when the PSD of road surface roughness is given.The obtained numerical results show that the PSD of a traffic-induced force has three peak values,the vehicle determines the first two peak values and the vertical stiffness of pier determines the third one.The amplitude of the PSD of a ground vibration decreases as the distance between the loading position and response point increases,and this reduction is obvious particularly in the high frequency region.In addition,the influence of structural properties on the propagation of an environmental vibration inside building is obvious.