The dynamic effect of the moveng loads on bridges

This work deals with the dynamic effect of movingvehicles on highway bridges. The aim of this work is to makea comparison between the dynamic and static responses ofhighway bridges under the effect of moving vehicles. Hence,exact values for the dYnamic magnification factor fordifferent cases are determined and compared with the impactfactor obtained from the empirical formula given in theEgyptian code of practice.For this purpose, a complete analysis has been made todetermine the dynamic response for beams when traversed bymoving loads. The natural frequencies and mode shapes forsimply supported and continuous beams with constant andvariable inertia are determined using the finite elementmethod. The mode superposition method is used to carry outthe dynamic analysis for beams considered. A computerprogram is prepared to achieve this analysis and toinvestigate various cases of actual bridges. The importantfactors affecting the dYnamic response of these bridgessuch as the velocity and acceleration of the moving vehiclesare studied.