影响矩阵法在南京长江三桥状态识别中的应用

Application of effect matrix method in condition identification of Nanjing Yangtse River No.3 Bridge

南京长江三桥是钢塔钢箱梁斜拉桥,斜拉索是该桥最容易发生损伤的构件。根据内力重分布原理,斜拉索的索力变化量是判断其损伤的主要参考指标。由于实际测量精度的原因,需要用测得的主梁挠度来识别斜拉桥的索力。利用传统的柔度法,首先在模型计算的基础上建立影响矩阵,然后利用影响矩阵方程求解拉索的实际索力。反算出索力后即可确知整个桥梁的内力状态,进而可以对桥梁进行评估和预后。对南京长江三桥数值模拟的计算结果表明,该方法具有简单、适用的特点,并且具有较好的数值稳定性。

Nanjing Yangtze River No. 3 Bridge is a cable stayed bridge with steel tower and steel box girder, and the cable is easier to damage for the bridge. According the theory of the internal force redistribution, the cable force＇s increment is important index for estimation cable＇s damage. The cable force need be identified using displacement in practice. Based on traditional flexibility method. In the first place, effect matrix is calculated. And then, the effect matrix equation is used to estimate the cable force, the bridge condition can be known, Finally, the bridge will be evaluate and prognosis, Results of analyses indicate that the effect matrix method is simple and convenient in practice.