Abstract: Based on the cable space slope as the basic parameter of cable system equation, the calculation method of design position of inclined busbar saddle of spatial cable suspension bridge was discussed. Based on the geometrical and mechanical relations between the main cable and the cable saddle of the spatial cable suspension bridge, a set of binary non-linear equations with the spatial slope of the left and right tangent points of the cable saddle as the unknown parameters were derived, and the design position of the inclined busbar saddle could be obtained by solving the equations with dichotomy method, which simplified the complicated calculation process caused by too many variables in the traditional method. Numerical examples show that the improved method has good accuracy.

Key words: bridge engineering; the saddle position; lean busbar; space slope; dichotomy

摘要： 在以缆索空间斜率作为缆索系统方程基本参数的基础上，讨论了空间缆索悬索桥倾斜母线鞍座设计位置的计算方法。从空间缆索悬索桥主缆与索鞍几何、力学关系出发，推导出以索鞍左、右切点空间斜率作为未知参数的二元非线形方程组，用二分法求解方程组即可得到倾斜母线鞍座设计位置，简化了传统方法因过多变量导致得复杂计算过程，且无需初值。通过算例表明：改进后的方法精度良好。

关键词: 桥梁工程；鞍座位置；倾斜母线；空间斜率；二分法