基于InSAR的南京大胜关大桥纵向位移监测与分析

InSAR-based longitudinal displacement monitoring and analysis on Nanjing Dashengguan bridge

为解决传统桥梁位移监测方法传感器数量有限、监测信息不全面以及监测成本高等问题,以京沪高铁南京大胜关大桥为对象,研究了基于合成孔径雷达干涉(In SAR)的大跨桥梁结构纵向位移监测方法.利用欧空局Sentinel-1A卫星IW模式影像,建立了适用于大跨桥梁纵向位移监测的In SAR时间序列分析方法,得到了全桥1 723个相干目标的纵向位移信息.分析结果表明,大桥纵向位移主要由热膨胀引起,采用In SAR技术可以准确识别全桥纵向位移,且支座处纵向位移与结构温度的相关性模型与该桥支座位移传感器建模结果吻合.

To resolve the problem of the traditional bridge displacement monitoring methods,such as the limited numbers of the monitoring sensors,the incomprehensive monitoring information,the high costs and so on,a monitoring method for the longitudinal displacement of long-span bridges based on the interference of the synthetic aperture radar(InSAR)is proposed by taking the Nanjing Dashengguan bridge as the research subject.The InSAR time series analysis method for longitudinal displacement monitoring of the long-span bridges is established by using the interferometric wide(IW)model image of the Sentinel-1A satellite of the European Space Egency(ESA),and the longitudinal displacement information of1723coherent targets is obtained.The results show that the longitudinal displacement of the bridge is mainly caused by the thermal expansion of the bridge structure.The InSAR technique can accurately identify the longitudinal displacement of the whole bridge.Furthermore,the correlation model between the longitudinal displacement of the bridge and the structural temperature is in agreement with the modeling results of the bridge displacement sensors.