Geometry Calculation Method for Main Cables of Completed Suspension Bridge with Irregular Spatial Cable Planes

In the suspension bridge with irregular spatial cable planes, the main cables are constrained by the forces of hanger cables in three directions. Due to the existence of interaction of spatial hanger cables and main cables, geometry calculation of the main cables in the completed bridge state is very complicated. To facilitate the calculation, the concept of planarizing spatial issue and reversely resolving two-dimensional issues in spatial domain is put forward, based on the segmental catenary theory. The formulas to calculate the main cable geometry of suspension bridge with irregular spatial cable planes in the completed bridge are derived, which takes into account the interactions of main cables and hanger cables. The iterative analysis program for the main cable geometry in the completed state of the suspension bridge with irregular spatial cable planes was compiled by MATLAB software, and a verifying subsystem to analyze the balancing condition of the main cables was established using APDL (ANSYS Parametric Design Language). Two existing suspension bridges of this type, the Yeongjong Bridge in South Korea and the Luohe River Bridge (the part of Junma Avenue over Luohe River) in Yiyang County, Henan Province, were applied as the cases for the study, to examine the method proposed. The results show that the geometry calculation method proposed in this paper is of high precision and fast convergence, which can be applied to analyze the main cable geometry of suspension bridges with various cable planes in the completed state. © 2020, Journal Press, China Railway Bridge Science Research Institute, Ltd. All right reserved.