Deformation and evolution of large dumping bodies based on SBAS-InSAR and optical remote sensing images

Abstract

Objective Deep unstable slopes develop in the Minjiang River Basin, and revealing their deformation evolution characteristics is of great significance for stability evaluation and disaster prevention. Methods In this study, taking the large-scale dumping deformation body of the ladder slot in Maoxian as an example, and the method of combining SBAS-InSAR monitoring and optical remote sensing interpretation was used to obtain the historical time series deformation field of the deformable body surface. Results The research shows that the leading edge of the collapsed deformed body of the ladder trough exhibits a composite failure mode of collapse failure and bulging cracking, and the collapse area has experienced a failure process from increasing deformation to weakening; in the increasing stage, the deformation amount on the north side of the dump deformer is much larger than that on the south side. After the deformation weakened, a tensile stress settlement zone (-70.17 mm/a) formed on the trailing edge of the south side, and the leading edge bulged and cracked (-45.94 mm/a) due to the concentration of compressive stress. After the deformation weakened, the deformed body was in a creep state (the maximum annual settlement was less than 80 mm), but the deformation of the south trailing edge collapse area and the north leading edge collapse area responded obviously to rainfall and earthquakes, showing a sudden increase of 5-15 mm deformation and a rebound phenomenon. Conclusion The surface displacement monitoring method in this paper can provide a reference for the evolution analysis of unstable slopes with large deformation level spans.

Keywords

• dumping deformable body
• sbas-insar
• optical remote sensing image tracking interpretation
• seismic rainfall sensitivity