Random Vibration Response Analysis Of Bridges Under The Action Of Frequent Earthquake

The structural response analysis with the traditional method of stochastic response analysis needs to transform random excitation as a stochastic process into a series of random variables, it needs a great amount of calculation, so we need an improved method. The influence of the randomness of the structure and the site soil parameters need to be considered in the process of structural response analysis, in this way can the result accords with the actual. Taking a railway bridge as example, random vibration response of bridges under the action of frequent earthquake is analyzed by adopting a method that combines theoretical analysis and numerical simulation. The following studies are mainly involved:(1) The research status of seismic response analysis of Bridges is introduced, several kinds of stationary random models of seismic oscillation are introduced, through the analysis of parameters, the variation coefficients of the structure and the site soil parameters are got, the spectral density of power spectrum of the Kanai-Tajimi model under the action of frequent earthquake also is got;(2) A random pseudo excitation method is derived through the pseudo excitation method, then through analyzing the random response of single particle linear oscillator, the accuracy of random pseudo excitation method is validated, the feasibility of the feasibility of the Response Surface Method with Monte Carlo sampling is proved;(3) Based on the above method, the influence which cannot be neglected of the random of parameters is validated by studying the displacement response of bridges which consider the random excitation conditions and random parameters under the action of frequent earthquake. With response surface function, a analysis method of sensitivity coefficient of random variables is defined, the influence of the random of parameters on structural response is got.(4) effects of variation coefficient of each parameter on structural response are analyzed, the influence which cannot be neglected of variation coefficient of parameters is validated.