PS-InSAR技术在桥梁形变监测的应用及降雨影响分析

Application of PS-InSAR Technology to Bridge Deformation Monitoring and Analysis of Rainfall Impacts

摘要: 针对传统桥梁监测方法难以实现大范围、长时序形变获取的问题，本文采用PS-InSAR技术，利用2023年12月至2025年8月的20景Sentinel-1A卫星数据，对彩虹桥开展时序形变监测与分析。通过选取桥梁两端及跨中共4个典型PS点，分析其累计沉降特征，并结合降雨数据探讨环境因素对桥梁形变的影响机制。结果表明：监测期内桥梁整体形变幅度较小，累计形变控制在±10 mm范围内，未出现显著不均匀沉降，结构运行状态良好；不同部位形变存在明显空间差异，桥台及引桥区域波动较大，对外界扰动更为敏感，而跨中区域形变相对平缓；降雨作为重要外部因素，在降雨集中时段会引起桥梁形变波动增强，且桥台区域响应最为显著，同时形变变化相较降雨存在一定滞后性，总体来看，降雨对桥梁形变的影响主要表现为短期扰动，未引发持续性累积沉降。研究结果表明，PS-InSAR技术可有效获取桥梁长时序形变信息，可为桥梁健康监测及环境荷载作用分析提供技术支撑。

Abstract: To address the difficulty of acquiring large-area and long-term deformation information using conventional bridge monitoring methods, this study applies persistent scatterer interferometric synthetic aperture radar (PS-InSAR) technology to conduct time-series deformation monitoring and analysis of Caihong Bridge using 20 Sentinel-1A satellite scenes acquired from December 2023 to August 2025. Four representative persistent scatterer (PS) points, located at both bridge ends and at the mid-span, were selected to analyze cumulative settlement characteristics. Rainfall data were further incorporated to investigate the mechanisms by which environmental factors influence bridge deformation. The results show that the overall deformation of the bridge during the monitoring period was relatively small, with cumulative deformation controlled within ±10 mm. No significant differential settlement was observed, indicating that the structure remained in a favorable operational state. Clear spatial differences were observed among the bridge components: the abutment and approach-bridge areas exhibited greater fluctuations and were more sensitive to external disturbances, whereas the mid-span area showed relatively gentle deformation. As an important external factor, rainfall intensified short-term deformation fluctuations during concentrated rainfall periods, with the most pronounced response occurring in the abutment area. Meanwhile, bridge deformation showed a certain lag relative to rainfall. Overall, rainfall’s influence on bridge deformation was mainly manifested as short-term disturbances and did not induce cumulative settlement. The findings indicate that PS-InSAR technology can effectively acquire long-term bridge deformation information and provide technical support for bridge health monitoring and analysis of environmental loading effects.