Study Of The Subsidence-monitoring In Dragon Head Mine Area With Time Series Insar Technology

Because of the high mining intensity,deeply buried and rock breaking,mining deformation and damage was serious in Jinchuan dragon head mine.At this stage,the deformation monitoring of the dragon head mine mainly adopted layouting GPS observation network and leveling.But there were shortcomings including it was easily damaged,energy-consuming,time-consuming and laborious.The monitoring cycle is 2 times per year.Timeliness was relatively inadequate.Synthetic aperture radar interferometry(InSAR)could solve the difficulities.Although,the using of InSAR technology improved the monitoring precision and efficiency,it could cause the reduction of the accuracy in solving the north-south displacement.According to these problems,this paper have done some researches and got the following knowledgements.(1)First,we used ALOS 1 data for SBAS-InSAR treatment and obtained the shape variables of the line of sight in dragon head mine in2009-2011.At the same time,we used the GPS observation point in 2009-2011 to get the same area as the ALOS1 deformation through interpolation.According to helmer variance algorithm,we built up fusion model of SAR monitoring data and GPS data to get the fusion of ALOS-GPS data of the three dimensional deformation monitoring.The monitoring results showed that the accuracy was higher among that vertical deformation of the mining area was in the scope of-239.243 and 109.414 mm/year.We looked from the displacement map,finding that mine pit had the deformation tendency from sides of the slope to the central area and mine pit existed weak uplift in northern slope position.(2)Then,we used the data from Sentinel 128,33 and 135 bands for the deformation in the line of sight of dragon head mine in 2015-2016.We extracted azimuth angle and angle of sight in satellite imaging and used three parameter equation to calculate three-dimensional deformation of the mining area.In order to further improve the precision of data,prior condition adjustment theory was introduced to indirectly solve three-dimensional shape variables.Finally we obtained three-dimensional deformation of the dragon head mine using the theory of mean square error to do the precision analysis.The results showed that the indirect method based on prior knowledge of the variable precision was better than the direct method to solve the three dimensional deformation,so the north-south precision ascended to the highest.The root mean square error of 8.6042 was obtained by the direct method,the indirect method was 4.825,the values of three-dimensional deformation range of north-south,east-west and vertical direction was:-41.429?194.373 mm/year,-295.511?100.374 mm/year and-208.585?64.435 mm/year.There was no fundamental change in the deformation characteristics of the whole area.(3)Besides,we used the 42 pictures from Sentine133 data which had good image quality.We got the deformation data about 42 areas of dragon head mine based on SBAS-InSAR algorithm for the scene in 2014-2017.we calculated the vertical displacement and analyzed deformation characteristics.The monitoring results showed that the change of oblique mouth and settlement of new no.1 well presented a linear correlation with time.But mining wells had small fluctuations with poor correlation with time;After conducting profile analysis in vertical line,line 34,line 16 and line 2,we got results that a large subsidence zone existed in 1775.52 m to 3240 m and subsidence volume in the subsidence center had accumulated to 174 mm.At last we got the overall subsidence tendency of the mining area obtained by the surface analysis of the subsidence area.(4)In conclusion,we did comprehensive analysis about subsidence factors in dragon head mine.We thought that mining subsidence was mainly caused by mining activities.On the one hand,construction played a role in controlling,especially in F1 and F8 faultage.On the other hand,the structure of rock mass and joint fissure development caused subsidence difference.The subsidence difference of east-west slope tended to decrease gradually with proceeding subsidence activities.