索穹顶张拉过程中环索滑移分析的驱动索单元法

Analysis of hoop cable slippage during tensile process of cable domes based on driving cable element method

索穹顶结构在张拉过程中一般采用分批分级张拉斜索的方式.由于索穹顶结构的环索通常采用连续布置方式,当相邻分批张拉索的内力差作用在环索节点上的分量超过环索与索夹间的最大静止摩擦力后,会引起环索与环索夹之间的滑移.由于环索往往是索穹顶结构中预应力最大的构件,其滑移会对整体结构的内力分布和位形产生严重影响.在准确计算分析的基础上优化张拉方案,控制环索滑移对整体结构的影响是索穹顶结构能否张拉成形且满足设计要求的关键问题.本文提出基于向量式有限元的驱动索单元法进行索穹顶张拉全过程模拟,分析环索滑移对结构内力和位形变化的影响.

The step-by-step tensile of stay cables in batches is the most common method in the construction of cable domes.As the hoop cable is usually set continuous,when the value difference of internal force component in the hoop direction between adjacent tensile cables exceeds the maximum static friction force between the hoop cable and the cable clip,the relative slippage between the cable and the clip will occur.The slippage of hoop cable will cause magnificent influence on structural initial force distribution and configuration.Therefore,optimizing the tensile construction scheme based on accurate simulation analysis and controlling the influence of hoop cable slippage are the key points for successful construction of cable domes.The driving cable element method based on VFIFE is proposed to simulate the whole construction process of cable domes and analyze the influence of hoop cable slippage on structural internal force and configuration variation.