Analysis of Mechanical Property of Steel Plate Composite Girder Bridge

To examine the mechanical property of the steel plate composite girder bridge in the construction process, the viaduct on the main line of Xiangfu Road Upgrading Project in Changsha is taken as a case. The spatial finite element model of the steel plate composite girder bridge with four equal spans of 30 m was built by MIDAS Civil, to analyze the construction stages and study the influence of concrete shrinkage and creep and thermal effect on the load bearing behavior of the structure. The results show that the stresses in the construction stages can meet the code requirements. The shrinkage and creep of concrete slabs cause continuing deflection of the composite girder, resulting in redistribution of internal forces and stresses in the cross section of the composite girder. Therefore, the proportion of variation amount of deformation, internal forces and stresses caused by shrinkage and creep should not be ignored in the total amount, the influence of which must be considered in design. Systematic temperature variation and temperature gradients exert minimal influence on the geometry of the composite girder, but the effect of temperature gradients is more distinctive than systematic temperature variation. The increment of temperature stresses should not be ignored and the action of temperature effect on safety of the structure needs rational analysis. © 2020, Journal Press, China Railway Bridge Science Research Institute, Ltd. All right reserved.