景观悬索桥装饰缆索的找形与内力计算

景观悬索桥的装饰缆索不参与主结构受力,但却是桥梁不可分割的一部分.为保证其成桥后主缆及吊杆线形,必须有一定的内力与主桥相匹配.提出了一种针对悬索桥装饰缆索的找形及内力计算方法,首先建立主缆模型,并将各吊杆作用简化为竖向约束,计算各区段缆索拉力及吊杆的张力,进而通过主缆及吊杆的适宜张力计算其下料长度.结合新疆某景观悬索桥实例,利用MIDAS/Civil建立主缆局部有限元模型,计算主缆、吊杆张力及理论下料长度,并对其进行风振激励下的动力特性验算.按该方法计算的下料长度及拉力进行施工,成桥后各方面均可满足要求.

Form Finding and Internal Force Calculation of the Cable in Ornamental Suspension Bridge

As an inseparable component， the decorative cable of ornamental suspension bridge does not carry loads with the main structure. The main cable and hanger rods should have certain internal force that matches with the main bridge so as to keep their line-shapes. An approach was proposed for such bridge to calculate the blanking length and tensile force of the cable and rods. Firstly， a model for the main cable was built with hanger rods simplified as vertical constraints. Secondly， the tensile force of main cable in each section and the constraining force of rods were calculated. Finally， the blanking length of each member can be obtained. With a project in Xinjiang， a partial FE(finite element) model of main cable is established by the MIDAS/Civil to calculate the theoretical tensile forces and blanking lengths of the cable and rods， and check its dynamic characteristics. The as-built bridge meets all requirements.