基于响应灵敏度的桥梁下部结构损伤识别方法研究

Research on Damage Identification Method for Bridge Substructure Based on Response Sensitivity

为实现桥梁下部结构横、竖向状态的同步识别,以多跨简支梁桥下部结构为研究对象,提出了基于响应灵敏度的桥梁下部结构损伤识别方法。首先,基于车桥耦合动力分析理论推导了桥梁下部结构响应灵敏度方程;其次,基于响应灵敏度模型修正算法和数值算例对所提方法的有效性和抗噪性进行了验证。结果表明:当梁体、墩身、基底约束同时受损时,所提算法可准确、有效地识别墩身单元刚度和基底约束刚度值;所提算法具有较强的抗噪性,在5%噪声影响下仍能有效识别墩底弹性支承的损伤,并能准确定位损伤桥墩单元位置和识别损伤值。

To achieve the synchronous identification of the horizontal and vertical states of the bridge substructure,taking the substructure of a multi-span simple-supported beam bridge as the research object,a damage identification method for the bridge substructure based on response sensitivity is proposed.Firstly,based on the theory of vehicle-bridge coupling dynamic analysis,the sensitivity equation of the bridge substructure response is derived.Secondly,the effectiveness and noise resistance of the proposed method are verified based on the response sensitivity model correction algorithm and numerical examples.The results show that when the beam,pier,and foundation constraints are simultaneously damaged,the proposed algorithm can accurately and effectively identify the stiffness of pier element and the stifness value of foundation constraint.The proposed algorithm has the strong noise resistance and can effectively identify the damage to the elastic support at the bottom of the pier under the influence of 5%noise,and accurately locate the damaged pier unit position and identify the damage value.