轨道交通基础结构振动响应监测和分析

依托某轨道交通线路结构监测系统的长期数据,分析城市轨道交通基础结构在列车荷载作用下的振动加速度空间分布及其随时间的变化情况。同时,提出一种基于能量谱密度的车致动力响应信号损伤敏感特征提取方法,并采用累积和控制图及Haar滤波,对上述特征的长期变化情况进行度量。结果表明:对基础结构振动响应进行监测可以较好地实现其状态的长期监测和评价。在基础结构正常状态下,车致振动响应数据的时、频特征值在一日之内具有随机性,但均值较为稳定;在监测期内,以能量谱密度、累积和控制图及Haar滤波可以反映出基础结构在较长的监测时间内均处于正常的状态,其年度频率特征值和最值可以用于评价后续的基础结构状态情况。

Monitoring and Analysis of Rail Transit Infrastructure Vibration Response

With the support of an extensive dataset, the spatial distribution and temporal evolution of urban rail transit infrastructure vibration acceleration in the long term is analyzed. The dataset is collected by an infrastructure monitoring system deployed on a metro line, with the coverage of 1 year. An energy spectrum density (ESD) based method of damage -sensitive feature extraction, dedicated to the examination of the dy namic response caused by passing trains is designed. Meanwhile, cumulative sum (CUSUM) and haar filtering are applied to the measurement of long-term variation of feature value. The results show that the vibration monitoring system fits the demand of structural health monitoring well. When operational infrastructure is at a steady health state, its dynamic response excited by passing trains is to some extent randomly distributed whereas its mean value is stable. It shows that the proposed analysis methods can clearly characterize the well-operating infrastructure during a long service time. In addition, the calculated feature value and its CUSUM & the haar filtering value can be referred to, when the assessing of other track structures'' health state is demanded in the future.