基于泄流响应的高拱坝模态参数辨识与动态监测

Modal parameter identification and dynamic monitoring of high arc dam under vibration response induced by flow discharge

模态参数的准确辨识是对在线结构进行损伤诊断和状态监测的难点和核心之一。以二滩高拱坝原型测试为背景,结合随机子空间算法与改进的稳定图对泄流激励下的拱坝模态参数进行辨识,并实现对高坝振动状态的长期在线监测,为结构的安全评估提供依据。针对时域法所面临的模型定阶困难和噪声干扰以及由它们所引起的虚假模态辨识与剔除问题,利用改进的稳定图方法对模态参数进行更为精确辨识,并与ERA算法的识别结果进行对比。研究结果表明,该方法具有良好的品质与较高的计算精度,具有良好的工程应用前景。

Based on the prototype test of Ertan arc dam,combining with stochastic subspace identification algorithm and improved stabilization diagram,the modal parameters of arc dam under flow discharge were identified effectively,and the long-term online monitoring of the high dam was realized.All these result in offering evidence for structural health evaluation.Aiming at the difficult problems of noise reduction,false modal parameters identification and elimination,as well as model order determination in time domain methods,an improved stabilization diagram was put forward to achieve more precise results.The results obtained were compared with the results by ERA method.The study shows that the new approach is of excellent performance and fine precision,and also has good prospect to be applied in engineering.