Sensitivity Analysis of the Main Structural Parameters of the Four-Tower Partially Cable-Stayed Bridge

Abstract

We established a structural finite element model based on a four-tower partially cable-stayed bridge. We performed a study to determine the appropriate settings of several main parameters of the four-tower partially cable-stayed bridge. Given changes in the stiffness of the main girder, stayed cable and length of cable-free zones in the span, a three-parameter coupling coordination model was constructed. The coupling degree and coordination degree between different parameters are calculated and compared, the primary and secondary parameters affecting the structural performance of some cable-stayed bridges are determined, and a more suitable parameter composition interval is proposed. The sensitivity analysis of the main structural parameters of the four-tower partial cable-stayed bridge has not been published in the literature, and there is no coupling study on the length of the cable-free zone and the stiffness of the main girder and stay cable. The overall structural stiffness was improved by increasing the main girder’s stiffness and stayed cable, with the main girder stiffness being the primary parameter. The increase in uncoupled zone length in the span improved the utilization rate of the line within a specific range; however, too long a length led to a reduction in overall structural stiffness. The main girder stiffness was set between EG′IG/EGIG = 1~3, while stayed cable stiffness was set between ECAC′/ECAC = 0.8~1.4. The length of the cable-free zone in the span was set between l1/l0 = 0.08~0.15, while the coupling coordination degree was medium to high coordination. The structural performance of the background engineering bridge was improved. However, the conclusion of this paper is more applicable to low-pylon cable-stayed bridges, and it has not been verified whether it applies to traditional cable-stayed bridges.