Monitoring Of Surface Subsidence In Mining Aera Based On SBAS-InSAR Method Combined With Okada Dislocation Model

Coal is the most important energy source in China.It seriously affects people's living standards and the development of the national economy,and provides sufficient energy security for the country.Coal mining is very easy to induce various geological disasters,which will have a serious impact on the lives and property safety of people in the mining area.Therefore,monitoring the surface deformation of the mining area and inversion of its mining surface parameters to obtain the deformation law and realize the deformation prediction can effectively prevent the occurrence of geological disasters in the mining area.Conventional coal mine deformation monitoring methods and methods usually choose to use level gauges,GPS and other methods.Although the monitoring accuracy is higher than the InSAR method,the deformation monitoring range is smaller,which will generate a lot of work.The measured points obtained by the monitoring are discrete points.There is not enough density to effectively reflect the overall deformation of the mining area,which hinders the application and research of coal mine deformation monitoring to a certain extent.Since the late 1980 s,Synthetic Aperture Radar Interferometry(InSAR)technology has gradually developed into a new geodetic survey method and method.A series of sequential InSAR methods have been proposed successively to overcome many limitations of DInSAR and are widely used in mining areas.Monitoring and forecasting of surface deformation.In order to analyze the impact of coal mining in Shanxi Province on the surface deformation,the Stacking time series InSAR method was used to initially obtain the year-long time series surface deformation results of Shanxi Province based on Sentinel-1A data.The results indicate that coal mining caused Shanxi.The biggest cause of surface deformation in the province,the experimental results also explain the degree and scale of the surface deformation caused by coal mining in Shanxi Province to a certain extent,which has certain significance for the formulation of reasonable mining plans and coal mine safety warnings in Shanxi Province.The law of surface deformation caused by mining of different coal seam types is different.The SBAS time series InSAR method was used to obtain the time series surface deformation results for the 9-209 and 110 working faces of the Dianping Coal Mine in Shanxi Province and the 5-101 working face of the Fenyuan Coal Mine.After comparison,it is found that:(1)The degree of surface deformation caused by coal mining is proportional to the length of coal mining.When the length of coal mining reaches a certain level,the surface settlement funnel caused by coal mining gradually changes from one to two,and the deformation center It gradually shifts from the center of the working face to the two ends of the working face;(2)The degree of surface deformation caused by the mining of steeply inclined thick coal seams is greater than the degree of surface deformation caused by nearly horizontal thin coal seams,and it is easier to cause surface collapse.After that,using the above-mentioned SBAS time series InSAR results as observations,the mining parameters of 5-101 working face of Fenyuan Coal Mine were inverted based on the Okada dislocation model,and the inversion results were compared with the measured parameters,and the forward modeling results were compared with the InSAR results A comparison was made to verify the feasibility and reliability of the inversion of coal face parameters based on the surface deformation obtained by the time-series InSAR method and the Okada model.Finally,based on the SBAS time series InSAR deformation results of different mining stages of Fenyuan Coal Mine 5-101 face,the Okada dislocation model and Gaussian fitting curve are used to initially realize the prediction of coal mining parameters,and a new feasible coal mine deformation is proposed.Prediction method,the results show that as the coal seam mining progresses,the absolute value of the dislocation opening value first increases,then decreases,and finally tends to 0.When the mining length reaches a certain value during the mining process,the dislocation opening is absolutely The value reaches the peak and the deformation acceleration reaches the maximum.After that,with the end of mining,the absolute value of the dislocation opening gradually decreases,and the deformation acceleration also gradually decreases,and after a period of time after mining ends,it tends to 0,and the surface deformation also tends to be gentle.At the same time,it also verified the feasibility and reliability of the Okada rectangular dislocation model combined with Gaussian fitting curve to realize coal seam parameter prediction,which is a new scientific method of coal mine surface deformation prediction,which has certain significance for deformation prediction and safety warning in mining area.