PS-InSAR and UAV technology used in the stability study of Ankang expansive soil airport

Abstract

Expansive soil is a natural geological body with obvious expansion and contraction, multiple fissures and other undesirable properties. The deformation monitoring of expansive soil in high-fill areas under the combined action of wet expansion and dry contraction has become a hotspot of related research. to large-scale soil disasters. Time-series Interferometric Synthetic Aperture Radar (InSAR) technology is widely used in the monitoring of various geological hazards due to its advantages of wide coverage, high monitoring accuracy, and all-weather operation. This study takes Ankang Airport (AKA) expansive soil airport as an example. First, the ground digital elevation model (DEM) of the airport filling area was obtained by using UAV; secondly, the deformation rate and deformation time series of the expansive soil airport were obtained by using the persistent scatterer InSAR (PS-InSAR) technology; third, for the coherence In poor areas, artificial corner reflectors (CR) are arranged to increase stable scattering points; Finally, the deformation time series of feature points are extracted, combined with regional precipitation data analysis, the relationship between the periodic deformation of the airport expansive soil slope and rainfall. There is a subsidence trend along the LOS direction in the dry season, which is consistent with the expansion and contraction characteristics of expansive soils. Finally, the deformation rate is proportional to the depth of the expansive soil fill. It is judged that the existing small surface deformation and its periodic deformation distribution are caused by the combined action of the settlement after construction of the expansive soil filling area and the expansion and contraction characteristics of the expansive soil.