【摘要】 为了研究大跨斜拉桥拉索振动频率的环境时变特征,本文对苏通大桥斜拉桥的拉索振动响应进行了模态频率识别,并详细地考察了日常运营条件下实测模态频率的环境变异性。分析结果表明,温度的变化对斜拉桥拉索各阶振动频率的影响很小,相反,交通荷载与拉索实测模态频率存在较为明显的相关关系,即拉索各阶振动频率基本随车流量增大而线性增大。在此基础上,本文建立了基于模糊模式识别的拉索异常状态预警方法,实现了对拉索振动频率异常的在线监测与预警。更多还原

【Abstract】 In order to investigate the environmental variability in the modal frequencies of stay cables of long-span cable-stayed bridges,the modal frequency identification of stay cables of Sutong Cable-stayed Bridge is performed using the measured acceleration responses.The environmental variability of the modal frequencies is discussed in detail under daily traffic conditions.The analysis results reveal that the environmental temperature has little influence on the modal frequencies of stay cables,whereas the traffic loadings have remarkable correlations with the measured modal frequencies of stay cables.The modal frequencies are observed to increase with the increase of traffic loadings,on the basis of which the damage alarming method for stay cables based on fuzzy pattern recognition is proposed.更多还原