马新大桥索力测试及调索计算方法

The Cable Force Test and Cable Adjustment Calculation Method of Ma Xin Bridge

以国内首座斜独塔单索面钢-砼组合斜拉桥(60+65+220)m为工程背景,运用频率法测索原理,通过实测拉索自振频率得到实际索力,运用精细的有限元模型计算理论索力与实测索力进行对比。该桥二次索力调整时如何做到按施工方便的顺次,一次调整到设计值,是本桥施工监控核心技术之一。应用桥梁常用软件MIDAS/CIVIL得到23阶调索影响矩阵,运用大型数学计算软件Matlab进行调索矩阵运算,解决了23阶线性方程组的求解难题;可方便获得每根拉索经一次张拉即可达到该桥成桥设计索力的施调索力增量,施调过程实时进行理论与实测索力偏差对计算模型的修正。方法简单易行、可操作性强、精度高,可为同类工程提供参考。

In oblique single tower and single cable plane steel-concrete composite cable-stayed bridge（ 60 ＋ 65＋ 220） m engineering background,using the principle of frequency method and founding natural frequency to calculate cable force,using sophisticated finite element model to calculate the theoretical cable force and comparing with calculated cable force. How to accord to sequentially of facilitating the construction during the second bridge cable force adjustment and finding the design value by an adjustment were one of the core technical monitoring during construction. Application bridge software-MIDAS / CIVIL got 23 impact matrix of adjustment,using large-scale mathematical software-Matlab made matrix operations,the solving problems of 23 order linear equations were solved. So the cable force increment of adjustment was got,which each cable can be achieved by a tension force to bridge cable,calculation model was corrected by deviation comparison of theoretical and measured cable force during adjustment. This method was simple,workable,precise and could provide reference for similar projects.