DYNAMIC RESPONSE CHARACTERISTICS OF PLATE GIRDER BRIDGE SUBJECT TO MOVING MOTOR VEHICLE

The dynamic responses of highway bridges to moving vehicles are investigated theoretically and experimentally taking account of the road surface roughness. To verify the rationality of both theoretical analysis and analytical models of bridges and moving vehicles, the analytical results are compared with the experimental ones obtained by dynamic field tests on a simple girder bridge with span length of 22.2m. With strict regard for the influence of eccentricity of moving vehicles on dynamic response of bridges, the simultaneous differential equations for the coupling vibration of bending and torsion are derived by means of modal analysis. It can be considered that the two-degree-of-freedom sprung-mass system with one front axle and two rear axles is more realistic as a model of heavy dump truck than the one-degree-of-freedom system usually used.