基于拉索静态线形的索力测定

TENSION CALCULATION OF CABLE BY ITS STATIC PROFILE

为了充分利用现代测量技术解决索力的精确测定问题,作者基于索段的解析式建立了一种索力测定方法。测得索上三点的相对位置后,就可通过求解非线性方程组得到索力。激光测量仪器可在一个测站对多根索实现快速测量,从而保证了该方法的快速和高效,并且本方法避免了常用的索力测定方法的一个重要不足,即精度受拉索端部条件影响较大。数值算例表明,不考虑索的弹性、由于索的微振动等原因引起的相对位置测量误差等,对索力值的影响都可忽略不计。某斜拉桥工程算例也证明了本方法的微精确性和实用性。本方法可精确测定处于施工过程中和处于使用状态的拉索的索力。

In order to calculate cable tension more precisely with the help of modern measuring technology, a new method is proposed in this paper based on cable segment抯 static analytical formula. After the coordinates of three points on a cable are measured, cable tension can be calculated by solving the corresponding non-linear equations. The precise laser measuring instruments can measure many cables from one site quickly, and therefore the effectiveness of this new method is guaranteed. Moreover, it overcomes the shortcomings of the comnonly used methods, whose results are affected by the end condition of cable. Numerical example indicates it is precise enough even if the cable抯 elasticity is neglected, and the cable tension error resulting from measurement and cable vibration is ignorable. The application to one cable-stayed bridge has verified the precision and practicability of the present method. It can be used during the construction and the service of cable-stayed bridge, suspension bridge, cable-suspended roof and other cable structures, whenever the cable is static or vibrating with small amplitude.