Analysis of Main Girder Mechanical Property of Main Bridge of Qingshan Changjiang River Highway Bridge in Wuhan

The main bridge of Qingshan Changjiang River Highway Bridge in Wuhan is a hybrid girder cable-stayed bridge with a main span of 938 m. The bridge deck is 48 m wide, with integral steel box girders in the central span and steel box-concrete composite girders in the side spans. To study the mechanical property of the very wide main girder of long-span bridge under heavy vehicle loads, the finite element model of the fish-bone-shaped girder of the full bridge was built to analyze the global load bearing condition of the bridge. The local models of main girder sections were established to analyze the local load bearing conditions of the central span deck, steel girder in the steel-concrete joint section in the side spans and hybrid joints. The uniformity coefficient of longitudinal stresses in main girder was calculated and the stress distribution traits of the very wide main girder were analyzed. The fatigue performance of the orthotropic steel deck under heavy vehicle loads was analyzed. The results demonstrate that the overall stiffness of the main girder is big and the calculation indexes of both the global and local models can meet the code requirements. The portion of shear force in the edge and central webs of side-span main girder is in low correlation with the web area. The uniformity coefficients of longitudinal stresses in cross-sections at different locations of the main girder are of wide difference. The design of fatigue-sensitive details of main girder can meet the service requirements in the design life cycle of the bridge. © 2020, Journal Press, China Railway Bridge Science Research Institute, Ltd. All right reserved.