地基InSAR技术在昌吉赣高速铁路路基边坡监测中的应用研究

Application Study on Ground-based InSAR Technology for Monitoring Subgrade Slope of Nanchang-Ganzhou High-speed Railway

针对昌吉赣高速铁路某边坡在抗滑桩治理后仍存在变形问题,本文采用地基InSAR技术对其进行高精度监测试验。结果表明:(1)在参数合理设置情况下,地基InSAR雷达回波信号较强,能够获取该边坡毫米级微小形变场;(2)该抗滑桩加固边坡在监测期间变形趋势较为平缓,大部分形变累积量在3mm以内,部分区域形变累积量达到5-6mm,说明该边坡整体相对稳定;(3)地基InSAR与全站仪监测结果较为吻合,但相比全站仪单点位移观测相比,地基InSAR技术具有监测范围大、时间和空间分辨率高等优势,可有效监测分析边坡形变空间特征及变化趋势。本文监测结果为该边坡稳定性评价提供了重要基础资料,初步验证了地基InSAR在高铁边坡稳定性监测中的可行性及其应用潜力。

Although a slope of the Nanchang-Ganzhou High-speed Railway embankment was protected by anti-slide piles, the deformation could result in slope failure due to the slope instability. In this study, we utilize ground-based InSAR (GB-InSAR) to obtain very high-resolution displacement fields for evaluating the stability of the slope. Our experimental results show :(1) the signal of a radar echo is strong on the slope body when parameters are reasonably set, which enables us to monitor small deformation with a high accuracy.( 2 ) During the observation period, the very gentle deformation signals are detected, most of accumulative displacements being smaller than 3 mm and only some regions experiencing 5 ~ 6 mm of displacement, which suggests that the slope is relatively stable.(3) The ground-based InSAR deformation results agree well with the total station measurements, demonstrating the validity of the GB-InSAR measurements. Since GB-InSAR has some advantages such as a large extent, high temporal and spatial resolutions, the deformation results could provide some important information for evaluating the stability of this slope and demonstrating the great potential of GB-InSAR for monitoring slope failures of the high-speed railway embankments.