ANALYSIS OF INTERACTION BETWEEN VEHICLE AND BRIDGE WITH CURVED BOX GIRDERS
Against the curved box girder bridges in highway bridges and urban viaducts,the curved grillage model of the multi-cells curved box girder is built in terms of the shear-flexible grillage method,and the analysis for the vehicle-bridge interaction is performed.The trigonometric function is introduced as element's displacement function,and a novel curved beam element is derived using equilibrium equation.Based on the force-displacement equations of curved beam,both the stiffness matrix and consistent mass matrix of spatial curved beam element in polar coordination are deduced.A spatial vehicle model with seven degrees of freedom is established according to the Lagrange principle.The inverse Fourier transforms is used to generate four grades of road irregularity according to power spectral density of road roughness.The dynamic character and vehicle-bridge interaction of a concrete continuous curved box girder are numerically simulated,and the influence of the vehicle position,vehicle speed,road roughness and curvature radius on the impact factor is investigated.The results show that the curved beam element has more powerful computational efficiency and practicality.The interaction between vehicle and bridge with the curved box girder can be exactly simulated by the curved grillage model developed in the paper.