Research On Surface Deformation Process Based On PS-InSAR Technology

In recent years,there have been many catastrophic events caused by the process of surface deformation,which have had a significant impact on human social life,property security,and urban infrastructure construction.Therefore,the research of the surface deformation process has gradually attracted people's attention.This paper uses PS-InSAR technology to study the surface deformation process of Zhuxianzhuang mining area and Hefei area.The specific contents and results are as follows:(1)For Zhuxianzhuang coal mine,this paper mainly uses PS-InSAR technology to analyze the surface deformation caused by curtain grouting in this area.We collected 45 Sentinel-1 A satellite ascending SAR data from May 2017 to December 2018,and used StaMPS and stacking method to obtain the average surface deformation velocity of Zhuxianzhuang coal mine and its surrounding area.The results show that the subsidence velocity is about 10mm/yr near Suzhou City.Near Zhuxianzhuang coal mine,the de-formation is not obvious,but there is a circular collapse area in the east with a diameter of about 5.5km.Based on the field survey and the time series results of the nearby PS points,the deformation processes of the three PS points located in the circular collapsed area all changed drastically during the same period.This period of changes coincided with the period of the groundwater level decline,indicating that there is a causal re-lationship between ground deformation and changes in groundwater level.Therefore,we believe that the circular collapse area may be caused by the water inrush control of Zhuxianzhuang coal mine.Although the deformation of mining area is small,the risk of ground subsidence is still very high and needs to be given sufficient attention.(2)For Hefei area,based on PS-InSAR technology,52 Sentinel-1A satellite as-cending SAR data from October 2017 to August 2019 were processed and the average deformation velocity map were obtained.The results show that the northeast part of Hefei city and the area around Chaohu Lake are mainly subsidence areas,and the maxi-mum velocity is about 12mm/yr.The west and southeast of Hefei city are mainly uplift areas,and the maximum velocity is about 15mm/yr.In addition,based on the Bayesian theory,the regional deformation of the Xishanyi shear zone,Feidong fault and Feizhong fault were inversed.The results show that the Xishanyi shear zone is an active fault that the strike is NNE and the dip is SE.Its motion characteristics are mainly right-lateral strike-slip with partial extension components.The Feidong fault's strike is NW and the dip is NE.The movement characteristics are mainly right-lateral strike-slip with partial thrust components.And the Feizhong fault is a left-lateral strike-slip with thrust fault that the strike is approaching EW and the dip is south.Comparing the theoretical defor-mation derived from the fault model with the observed deformation,it is found that the two have good agreement.Based on the tectonic and motion characteristics of the three faults,we find that the triangular block formed by them is under the combined influence of the activities of the Tanlu fault and the extrusion force from the north-west directions.Therefore,there is a slight rotation trend on the whole,which may be the reason for the occurrence of small earthquakes in this area.