Deformation Monitoring Of Datong Mining Area Based On InSAR And Okada Model

Coal mine as one of the main energy of our country,with its price economy and abundant reserves,has played a pivotal role in power generation,metallurgy and chemical industry,which promotes the national advance and economic prosperity.As the social economy develops,some mineral resources have been over-exploited,thus breaking the stress balance on the ground.It leads to a series of geological disasters around the mining area and has a significant impact to people’s production and life.So,the comprehensive dynamic monitoring of mining subsidence is extremely vital in the safe mining for coal mine and avoiding mining damage.Traditional measurement methods are laborious to realize actual time monitor in a large range of mining areas,while radar interferometry technology has been widely applied with its fast and large-scale merits.Nevertheless,since the magnitude of subsidence and serious temporal and spatial incoherence,it is difficult to exploit InSAR to monitor.The time-series InSAR technology can reduce the problem of spatiotemporal incoherence to a certain extent,and extract a large number of deformations in mining areas.Traditional InSAR technology can only obtain one-dimensional surface deformation in the direction of LOS,which can’t complete raction the real surface deformation state.In this paper,the two-dimensional deformation field of mining area is solved by combining with lifting rail data.In order to monitor mining in mining area,based on InSAR monitoring results,Okada dislocation model was used to invert mining area parameters,and parameters such as length,width,depth and fracture component of fully mechanized mining face in mining area were obtained,providing scientific and powerful method for coal mining.For each research content,the conclusions obtained can also be briefly discussed:(1)The SBAS-InSAR technology was used to process the sentry data of 40-litre track and120 descending track covering Datong mining area from 2017 to 2021,and the average annual deformation rate during this period were obtained.Then,the annual average subsidence rate of the mining area is decomposed in two dimensions based on the spatial geometry relationship of the satellite,and the vertical deformation rate and the east-west deformation rate for the research area.We can get there’s a lot subsidence zones in the research area,as well as the vertical deformation in the subsidence area is generally larger than the east-west deformation.(2)Combined with InSAR monitoring results,parameters of fully mechanized mining face in two mining areas of Datong mining area were inverted by using Okada rectangular dislocation model in uniform space.Parameters of mining area were inverted by simulated annealing method in geodetic inversion method,and finally the simulated values that best fit the observed values were obtained,and the best mining parameters,including length,width,mining depth and fracture component,were obtained,and the posterior probability density of the parameters was estimated.