Surface deformation of a high slope of Yuxi-Yuanjiang Expressway based on time-series InSAR technology

The landslide disaster caused by the deformation and instability of the high slope of the expressway in mountainous area seriously threatens the safety of the expressway transportation. Therefore, it is of great significance to carry out long-term deformation monitoring on high slope of expressways. Compared with the traditional deformation monitoring technology, such as leveling and GPS, InSAR (Interferometric Synthetic Aperture Radar) technology has the advantage of high precision and weather free, which can obtain more effective surface deformation data. In this paper, taking the high slope at the exit of Luoziqing tunnel of Yuxi-Yuanjiang expressway in Yunnan Province as the research area, we use 45 scenes of Sentinel-1A SAR data in ascending orbit from January 2017 to December 2019 to obtain the surface deformation of the high slope by SBAS (Small baseline subset) technology. The results show that the slope is uplifted as a whole, and the uplift of the middle part of the slope is larger than that of the two sides. The deformation velocity and cumulative deformation is relatively low in winter and spring, while the deformation velocity and cumulative deformation is relatively large in summer and autumn. Different positions of the slope show different deformation characteristics, which shows that the SBAS InSAR technology is a promising method for high slope deformation monitoring in mountainous area.