关键词: 大厚度挖方区回弹变形, PS-InSAR, TerraSAR-X, 变形规律分析

Abstract: This paper takes a collapsible loess large-thickness excavation foundation project in northern Shanxi as the research object, and uses PS-InSAR technology to process 16 TerraSAR-X satellite images acquired from October 2018 to November 2019. Obtained rebound deformation information for the subsidence area of collapsible loess. The characteristics of time series rebound deformation of large thickness cut-out area are summarized. The results show that due to the stress unloading of the upper soil body, there is a phenomenon of rebound deformation of the foundation soil in the excavation area. The selected high-density PS point deformation information reflects the true deformation of the study area. The rebound deformation range is consistent with the excavation boundary. The greater thickness of the excavation, the more rebound deformation caused by the excavation of the soil. During the monitoring period of 1 year after the excavation is completed, the amount of deformation in the rebound zone changes linearly with time. At the maximum excavation thickness, the maximum rebound amount is 29.3 mm. In addition, the deformation amount monitored by PS-InSAR technology is in good agreement with the field level results, which shows that the technology has a good application effect in the rebound deformation monitoring of large thickness cut areas of loess.

Key words: rebound deformation in large thickness cutout area, PS-InSAR, TerraSAR-X, analysis of deformation law