索道桥施工控制参数的精细数值解析算法

Fine numerical analysis calculation for construction control parameters in cableway bridges

为了提高索道桥施工控制参数的计算精度,在分析既有近似解析算法原理的基础上,基于全桥主索无应力索长不变量,统筹考虑锚跨和主跨缆索架设过程中索段的相互转换影响,提出了精细数值解析算法。通过算例对比分析了近似算法和精细算法的计算精度差异,结果表明:施工过程中钢索无应力索段长度在主、锚跨之间相互转换和温度变化的影响不容忽视。锚索倾角对主索受力、线型的影响相对较小。忽略锚索垂度,对于无应力索长计算精度的影响甚微;而忽略锚索倾角,则影响很大。近似解析法得到的主跨钢索垂度值的误差较大,而索力值和索长值的误差较小。精细数值解析算法的计算结果高精度地满足了构件变形协调条件,计算效率高。

In order to improve the calculation for construction control parameters of cableway bridges, the principle of the existing approximate analytic algorithm was firstly analyzed. A fine numerical analysis method for calculating erection parameters was put forward, based on the quantity of total unstressed length of a cableway bridge and the influence of the transformation of cable sections between the anchor spans and the main span in erecting cables. Calculating precisions of the two methods were compared by an engineering example. The results demonstrate that the effects of temperature variation and mutual shift of unstressed length of cables between the anchor spans and the main span should not be ignored. Angles of cables in anchor spans produce relatively little effects on the axial forces and line shape of main cables. Neglection of cable sags in anchor spans exerts slight influences on computing precision for unstress length of steel cables, but dip angles of cables in anchor spans causes unacceptable errors. The computation by the approximate analytic algorithm results in great errors for cable sags in the main span, but it results in negligible errors for parameters of cable forces and length. The calculating results of this method satisfy the deformation compatibility condition of structural elements in very high precision, and its calculating efficiency is high.