基于定期检测与遗传算法的大跨度斜拉桥损伤识别

Damage identification of long-span concrete cable-stayed bridge based on periodic detection and genetic algorithms

为了对运营中的斜拉桥进行安全性评估,首先需要根据实桥测试结果对结构损伤进行初步识别。在斜拉桥定期索力检测与主梁关键截面的应力监测结果的基础上,提出斜拉桥损伤识别的遗传算法,并编制了复杂结构损伤识别的遗传算法程序,通过各期结构检测结果之间的变化来反演检测期间结构参数的变化,据此识别结构损伤位置与程度,保证了在结构参数化有限元模型存在识别误差的情况下也能得到正确的损伤识别结果。宁波招宝山大跨度预应力混凝土独塔斜拉桥的损伤识别仿真结果表明,本文方法和程序具有较高的识别精度,并可推广应用于其它复杂结构的损伤识别。

The primary damage identification based on in-situ test results constitutes an ＇important process for the safety assessment of in-service cable-stayed bridges. Application of Genetic Algorithms to damage identification of cable-stayed bridges, based on the monitored data of cable forces and strains in key sections of the main girders, is conducted.A Damage Detection computer code for complex civil structures developed by the authors is employed to identify the location and extent of damages. The deterioration of structures is calculated according to the monitored data, to make the results of damage identification immune to the errors in the parametric FEM analysis of bridges. The method is tested for a long-span concrete cable-stayed bridge in Ningbo, which has been in-service for four years. The results indicate that the proposed method and the computer code are accurate and reliable.