在弦支穹顶结构工程中,环索通常连续贯通。为了能够准确、便捷地分析摩擦力在贯通环索张拉成型过程中的影响,该文利用一个4节点4单元算例,对张拉过程中单元内力的变化与分布进行了详细的阐述,并利用贯通环索在张拉滑动前后其无应力长度相等的原则,提出了贯通环索在张拉过程中摩擦力的计算方法。并利用这一摩擦力的计算方法,以摩擦系数、张拉点数、张拉力为参数对葵花1型与肋环1型弦支穹顶的环索贯通张拉成型进行了分析。分析结果表明:由于摩擦力的存在,当采用较少的张拉点张拉环索成型时,葵花型与肋环型弦支穹顶结构分别会产生下部索杆内力分布不均匀、撑杆倾斜等现象。建议在实际弦支穹顶结构的张拉过程中不宜采用以较少的张拉点张拉环索成型的施工方法。
Hoop cable is generally continuous in suspend-domes. To assess the influence of friction during the construction procedure of tensioning continuous hoop cable of suspend-dome, the paper utilized an example of four nodes and four elements. The change and distribution of element force during tension were examined. The method of calculating friction during tensioning continuous hoop cable was presented according to the fact that the non-stress length of the continuous hoop cable is fixed after slippage. Then, the paper analyzed the construction of sunflower 1 type and rib 1 type suspend-domes considering the change of friction coefficient, tension element and tension force. The results displays an asymmetric distribution of cable-strut force, and strut slant would occur in suspend-dome after construction by tensioning continuous hoop cable because of friction. So it is unfavorable that tensioning continuous hoop cable by fewer tension elements in the practical project.