基于时序In SAR技术的芜湖市长江大桥一桥变形监测与分析

Deformation Monitoring of the First Bridgeof the Yangtze River Bridge in Wuhu City Using InSAR Data

为保障人民群众生命财产安全,建立健全桥梁监测体系,以芜湖市长江大桥一桥为例,利用SBAS-InSAR(Small Baseline Subset In SAR)技术处理2018年7月至2019年10月的Sentinel-1A数据,并将In SAR监测结果与桥梁上主桥的挠度仪进行对比。结果表明,桥面整体形变范围在13 mm以内,桥梁构件的沉降变化在时间上表现出一定的季节性变化规律。其中西侧简支梁桥在冬季呈现沉降趋势,在夏季呈现抬升趋势;位于东侧的斜拉桥部分在冬季呈现抬升现象,在夏季呈现沉降现象。针对这一现象,分析了测点形变量与温度之间的关系,其中西侧桥面形变与温度成正相关,东侧桥面形变与温度成负相关,并进一步根据监测数据建立了桥梁温度-竖向位移模型。研究结果证实了In SAR监测微小形变的可能性,可为对桥梁等大型工程监测提供数据。

In order to ensure the safety of people’s lives and property,a bridge monitoring system has been established and improved.This paper takes the first bridge of the Yangtze River Bridge in Wuhu city as an example,using SBAS-InSAR technology to process Sentinel-1A data from July 2018 to October 2019,and the results are compared with the deflection meter of the main bridge on the bridge.The results show that the overall fluctuation of the bridge is within 13 mm,and the settlement change of the bridge follows a certain law with time.Among them,the simple-supported girder bridge on the west shows a subsidence trend in winter and an uplift trend in summer;the cable-stayed bridge on the east shows uplift in winter and subsidence in summer.For this phenomenon,the article analyzes the relationship between the measuring point and the temperature.The west side is positively correlated with temperature,and the east side is negatively correlated with temperature.Based on the monitoring data,this paper establishes a temperature-vertical displacement model.Experiments have proved the possibility of InSAR to monitor small deformations,in order to provide data for the monitoring of large-scale projects such as bridges.