Effect of Flexural Stiffness of Stiffening Girder on Mechanical Performance of Hybrid Cable-Stayed Suspension Bridge

This study presents the effect of flexural stiffness of stiffening girder on the mechanical properties of the hybrid cable-stayed suspension bridge. The Xihoumen Rail-cum-Road Bridge of Ningbo-Zhoushan Railway is used as a case. The finite element models -were built up in MIDAS Civil to analyze the variation of indicators of the mechanical performance of the bridge under nine different flexural stiffnesses of the stiffening girder, including vertical displacement, vertical rotation, longitudinal movement at expansion joints, main cable forces, longitudinal bending moment at the bottom of the towers and the tension ranges of end hanger cables under live loads. The results demonstrate that when the flexural stiffness of the stiffening girder is improved to 1 0 times of its original value, the above mentioned indicators would reduce by 38. 9 % > 50.0%, 13.5%, 0.4%, 13.2% and 56.4%, respectively. The effect of flexural stiffness of stiffening girder in the hybrid cable-stayed suspension bridge is distinctive on vertical rotation of the stiffening girder and tension ranges of end hanger cables under live loads, and weakens on the vertical displacement of the stiffening girder, longitudinal movement at expansion joints, and the longitudinal bending moment at the bottom of the towers, and is minimal to the maximum tension of main cables. © 2023 Wuhan Bridge Research Institute. All rights reserved.