中文摘要：

对频率法计算竖直拉索索力的原理和方法进行分析与评价，指出工程实际拉索与理想匀质拉索模型的区别，强调端部性质对频率法测量竖直拉索索力的影响。根据实际拉索两端一般具有锚杯和连接筒的构造特点，提出“三段式、两端刚接”振动模型；延用匀质拉索索力计算公式模型，考虑对匀质比例变量进行修正从而获得实际比例变量；采用有限单元法对端部性质进行参数影响分析，深入研究了比例变量修正系数九随长度修正系数九和刚度修正系数丑的变化规律。比例变量修正系数λ与长度修正系数λL=PL成正比例函数关系，其函数方程斜率为刚度修正系数λI；根据刚度修正系数λI随刚度比PI增大而增大，随索力T增大而减小等变化规律，构造刚度修正系数九函数方程；并最终建立可计入端部性质影响的修正索力计算公式。数值分析和工程实例计算结果均表明：当长度比PL≥0．08时，端部性质对计算索力的影响随索长的减小而迅速增大；当长度比PL≥0．14时，匀质索力计算公式已经不能正确计算索力，其计算偏差可达50％以上；而本文建立的修正索力计算公式始终能够对长度比PL≤0．5拉索做出正确的计算索力，其计算精度能够满足工程要求。

英文摘要：

The theory and method for calculating the force of vertical cables by a frequency-based method were analyzed. The difference between a practical cable and the model of a theoretical uniform cable and the significance of the extreme properties for calculating the cable force of vertical cables were pointed out. According to the structural characteristic of a practical cable, the vibration model consisting three segments and the rigid constraints at the two ends was proposed, which could obtain the practical proportion variable by modifying the uniform proportion variable using the formulas of calculating the cable force with the uniform properties. With the finite element method, the parameter influence of extreme properties were analyzed, and the changing regularization of the proportion variable amending coefficient （PVAC） against the length amending coefficient （LAC） and the stiffness amending coefficient （SAC） was researched. The following results were drawn： i） The PVAC was directly proportional to the LAC, and the slope of the functional equation was SAC; ii） The SAC increased with the stiffness ratio and decreased with cable force respectively. Based on above results, the functional equation of the SAC was constructed and the amending formulas of calculating cable force were created finally, which could effectively reckon in the extreme properties affections. The results of numericalanalysis and engineering examples showed that a） the effect of the extreme properties on the calculation of cable force rapidly increased with respect to the length ratio when the length ratio was bigger than 0.08, b） the uniform formulas of calculating cable force cannot obtain a correct cable force when the length ratio was bigger than 0. 14, and the calculating error could be over than 50%; c） the amending formulas of calculating cable force proposed could throughout obtain a correct cable force when the length ratio was less than 0.5, and the calculation accuracy satisfied the engineering requirements