以具有多个整体自应力模态的 Kiewitt 型索穹顶结构为研究对象，对单整体自应 力模态索穹顶结构找力分析的比值更新法进行改进，提出了适用于 Kiewitt 型索穹顶结构 的找力分析新方法，并以算例进行了验证． 通过指定关键组件，分别对其施加预应力进行 迭代计算，应用基于最小二乘的模态误差分析方法，将计算结果与奇异值分解法所得结果 进行对比，发现:改进的比值更新法精度高，相比奇异值分解法，其得出的结果均为整体可 行的自应力模态，即索受拉、杆受压，力学意义明确，为该结构的预应力确定提供了新的思 路和解决方法．

By taking the Kiewitt cable domes which contain multiple overall selfstress modes as the research objects，this paper deals with the improvement of ratio-updating method for forcefinding analysis of cable domes with single overall selfstress mode and proposes a new approach to forcefinding analysis of Kiewitt cable domes，with its applicability being validated by examples later． Moreover，the key members are designated and prestressed to perform an iterative computation，and，by using the mode error analysis method based on the leastsquares，a comparison of the results respectively obtained by the proposed method and the singular value decomposition method is carried out． The results show that，as compared with the singular value decomposition method，the proposed improved ratio-updating method possesses high accuracy and helps to obtain overall feasible selfstress modes with clear meaning in the mechanical concept of cables in tension and struts in compression，thus providing a new idea and solution for the prestress determination of cable domes．