Set the parameters of catenary element on the basis of analysis result of main cable shape and the principle that the unstressed length of main cable between suspenders is constant.

• 基于成桥线形的分析成果，根据空缆时索夹间主缆的无应力长度应等于成桥时索夹间的无应力长度这一原则设置悬链线单元的参数。