Study of dynamic characteristics of ground collapse caused by mining in Gaojialiang coal mine, Inner Mongolia, using SBAS-InSAR technology

Ground collapse due to mining activities is a prevalent issue in underground coal mining processes. Without timely monitoring and control, it can adversely affect the surrounding structures and the environment. Addressing the challenges of traditional subsidence monitoring methods in the mining areas with uneven hilly terrain, this study focuses on the 20314, 20313, and 20312 working faces within the 203 panel of Gaojialiang coal mine area, Inner Mongolia. It employs 12 images of Sentinel-1 radar from April 2018 to December 2020 processed using the small baseline subset differential interferometry InSAR (SBAS-InSAR) technique to derive average displacement velocities and temporal subsidence data in the study area. The study analyzes the dynamic characteristics of subsidence in the area. The results show that the overall subsidence rate is higher in the northern part of the study area compared to the south, with the maximum subsidence rate of approximately −17.2 mm/a observed in the northern third of the 20313 working face. The subsidence pattern generally progresses from south to north and from west to east, corresponding to the actual mining sequence. Major subsidence areas are concentrated in the northern portions of the 20314 and 20313 working faces, with maximum subsidence reaching about −106 mm. The application shows that SBAS-InSAR technology has effective results and significantly technical advantages in monitoring land subsidence in hilly mining areas, thereby providing certain method support for land subsidence monitoring in mining areas.