InSAR monitoring and evaluation study on the safety and stability of high-altitude limestone dumps

Abstract

Abstract The conventional method of monitoring the stability and safety of slopes at high-altitude dumps is associated with a high financial investment and poses a risk for personnel involved in the deployment of monitoring instruments. In order to mitigate the challenges posed by conventional monitoring methods, including high investment and potential risks to personnel, we employed Synthetic Aperture Radar Interferometry (InSAR) technology for the evaluation of slope stability at a high-altitude dumps in Sangri County, Shannan, Tibet. The utilization of Synthetic Aperture Radar Differential Interferometry (D-InSAR) technology was employed to observe the deformation of the dumps over the course of the rainy season, spanning from 2019 to 2022. A four-year (Nov 2018 to Oct 2022) deformation rate assessment of the dumps was performed utilizing the Small Baseline Subset⁃Interferometric Synthetic Aperture Radar (SBAS-InSAR) technology. The accuracy of InSAR monitoring in high-altitude slope areas was verified through correction with the results obtained from GNSS RTK monitoring. The state of stability and safety of the slope at the dumps was evaluated based on the results obtained from deformation monitoring. The D-InSAR monitoring results indicated that when the rainfall surpassed 300 mm, the slope deformation of the dumps exhibited a maximum displacement of 20 mm, necessitating intervention. The results of SBAS-InSAR monitoring indicate that the slope of the dumps underwent substantial deformation changes during the rainy season, yet remained stable during the dry periods. However, the results of our SBAS-InSAR monitoring indicate that the deformation and displacement curves of the dumps did not correspond entirely with changes in rainfall, and exhibited a hysteresis phenomenon in terms of deformation magnitude. The application of InSAR technology allows for the comprehensive and dynamic monitoring of the slopes at high-altitude dumps, offering reliable long-term assessments of safety and stability and ensuring secure and stable operations.