Dynamic Monitoring and Analysis of Mining Land Subsidence in Multiple Coal Seams in the Ehuobulake Coal Mine Based on FLAC3D and SBAS-InSAR Technology  
[PERSON]  
1 College of Geology and Mines Engineering, Xinjiang University, Urumqi 830046, China; [EMAIL_ADDRESS] (S.Z. ); [EMAIL_ADDRESS] (H.L. ); [EMAIL_ADDRESS] (G.L.) [PERSON]  
1 College of Geology and Mines Engineering, Xinjiang University, Urumqi 830046, China; [EMAIL_ADDRESS] (S.Z. ); [EMAIL_ADDRESS] (H.L. ); [EMAIL_ADDRESS] (G.L.) Chengfang Shan  
3 Kaya Nushinha Coal Mine Coal  
areas [5; 6; 7]. The rapid development of remote sensing methods allows exploring the possibilities of their use for monitoring ground surface deformation. Among these methods, differential synthetic aperture radar interferometry (DInSAR) has proven to be particularly useful to monitor mining subsidence [8; 9; 10; 11; 12]. SBAS is a DInSAR algorithm and allows maps to be obtained with deformation time series corresponding to around 35 days using ERS-1/2 and ENVISAT datasets [13]. The Short Baseline Subsets (SBAS) technique [14] allows the generation of maps of average deformation and monitoring on the prone areas with precision to 1 cm or below [15]. The SBAS algorithm reduces the atmospheric artefacts and topographic errors in time-sequential interferograms. The algorithm uses only interferograms with small baselines that overlap in time to reduce spatial decorrelation. The method uses the most highly correlated areas to derive the deformation signal from multiple-examined interferograms, which reduces speckle and improves the phase estimate [13; 14; 16]. SBAS-InSAR has been successfully applied for monitoring volcanic activity, (e.g., [PERSON] et al. on Augustine Volcano (Alaska) [17]) and seismic activity (e.g., [PERSON] et al. in San Francisco Bay [18]). In summary, SBAS-InSAR technology has the advantages of all-weather, all-sky time, low cost, large coverage area, and high spatial resolution. At the same time, the technology can reduce the impact of spatiotemporal loss correlation and atmospheric delay, and apply a limited number of images to obtain millimeter-level temporal settlement [14; 19; 20]. FLAC3D can set a variety of numerical analysis models under different geological conditions to meet the complexity of the actual engineering geological environment. It can intuitively analyze the change process of stress field and deformation state in mined-out areas, and deeply analyze the deformation mechanism and development trend of overburden rock in mined-out areas. The combination of FLAC3D and SBAS-InSAR can give full play to their respective advantages and realize the dynamic monitoring and analysis of land subsidence law in mining area. At present, scholars at home and abroad have conducted a series of studies on the law of mine land subsidence using various methods. Turkish scholar [PERSON] et al. conducted numerical simulation research on Omerler Coal Mine in Turkey and proposed to use shield support to reduce surface movement and deformation, as well as increase mining safety [21]. Indian scholar [PERSON] et al. conducted numerical simulation research on sharply inclined coal seam, analyzed risks, and proposed prevention and control measures [22]. [PERSON] (1996) et al. first monitored the settlement of coal mines near Cardanne in France using DInSAR technology [8]. [PERSON] (2003) et al. used DInSAR technology [23]. [PERSON] (2008) et al. obtained the deformation results of the coal mines in Gangwondo, South Korea from 1992 to 1998 [24]. [PERSON] (2018), [PERSON] (2019), [PERSON] (2017), and [PERSON] (2016) et al. [25; 26; 27] all carried out the quantitative research of InSAR technology in long-term deformation disasters in mining areas. Fast Lagrangian analysis of continua in three dimensions (FLAC3D) is a numerical simulation software for rock and coal mines [28]. [PERSON] et al.