Research On Dynamic Response Of Self-anchored Suspension Bridge Under Moving Vehicular Load

In recent years, load of the operating vehicles is gradually developing in thedirection of increasing more and more heavy, at the same time, new materials andnew methods are used to build a bridge of light quantity more and more often.Those result in the problem of coupling vibration between vehicles and highwaybridges more and more prominent increasingly. Based on this background, thisarticle selected a self-anchored suspension bridge case and carried on thevehicle-bridge coupling vibration issues.There are many ways to study vehicle-bridge coupling vibration, the modalsynthesis method is chosen in this paper. First, independent dynamic equilibriumequations of the vehicle system and bridge system is deduced; second, a unifiedcoupled vibration equation is set up considering the impact of the bridge deckroughness with the coupling condition; third, solve the equation by numericalanalysis method; finally get the dynamic response of the vehic le and the bridgeduring the whole time. According to this calculation process, the paperprogrammed a calculating application named VBCCP, based on Matlab. Bridgevibration feature analysis is the use of finite element software Ansys.Combined with a real bridge, this article analyzes the influences of differentfactors on vibration response in different parts of the bridge structure (mainlyabout beam, boom and the main tower), and gets some conclusions. DifferentDynamic Amplification Factors (DAF) are discussed through the vibrationresponse in different parts of the bridge structure, and the DAFs are comparedwith the impact factor in the specification. It finds out that the current existingspecification still has considerable improvements on provision of the impactfactor. The specification should make clear the differences in the calculation ofdifferent bridges, and the differences in sensitivity of vehicular load in variousparts of the same bridge structure should be taken into consideration at the sametime.In addition, the paper also discusses driving comfort according to theresponse of the vehicle. The evaluation criteria used is ISO2631, promulgatedby the International Standards Organization. Evaluation results of vehicle driving comfort are calculated in different driving situations in the article, and theinfluences of different factors are discussed, some conclusions have been listedat the end.