在役桥梁结构损伤位置识别的综合指标方法研究

In-service bridge structural damage location identification with a combination index method

在役桥梁结构的健康状况关系到人们生命财产的安全,了解其损伤状况极为重要。目前,在役桥梁结构的损伤识别经常要中止桥梁的运营,造成巨大的经济损失。为此,提出了一种不影响其运营的在役桥梁损伤位置识别方法。曲率模态方法是识别结构局部损伤位置比较理想的方法,该方法具有操作简便,灵敏度高的优点。同时,频率指标具有测试简便,精度高的优点,由此,提出了一种综合考虑曲率和频率变化率的综合指标法。为了在测试中不影响在役桥梁的运营,该方法中引入了随机子空间方法。最后采用一简支钢梁对所提方法进行试验验证。试验结果表明,基于频率和曲率变化率的综合指标法与随机子空间方法相结合能够有效地识别在役桥梁结构的损伤位置,而不会影响桥梁结构的运营。

The health status of in-service bridge structures is related to the safety of people＇s lives and property,therefore,it is extremely important to understand their damage status.At present,the damage identification usually has to suspend the operation of an in-service bridge,causing a huge economic impact.In order to solve this problem,Here,an in-service bridge damage location identification method without interrupting its operation was presented.Curvature mode method was an ideal method to identify the structural local damage,with advantages of easy operation and high sensitivity to damage location,meanwhile the frequency index was easy to test with high precision.An improved structural damage identification method was proposed,based on the change rate of structural curvature and frequency.In order to avoid interrupting the operation of an in-service bridge,the stochastic subspace identification method was introduced.Finally,the combination method proposed was verified with a simply supported steel beam testing in laboratory.The test results showed that the improved combination index method can effectively identify the bridge damage location without interrupting the in-service bridge operation.