甘智慧, 尚慧, 杜荣军, 占惠珠. 基于FLAC3D和DEM数据的缓倾斜煤层开采沉陷分析[J]. 煤田地质与勘探, 2021, 49(3): 158-166. DOI: 10.3969/j.issn.1001-1986.2021.03.020
引用本文: 甘智慧, 尚慧, 杜荣军, 占惠珠. 基于FLAC3D和DEM数据的缓倾斜煤层开采沉陷分析[J]. 煤田地质与勘探, 2021, 49(3): 158-166. DOI: 10.3969/j.issn.1001-1986.2021.03.020
GAN Zhihui, SHANG Hui, DU Rongjun, ZHAN Huizhu. Mining subsidence analysis of gently inclined coal seams based on FLAC3D and DEM data[J]. COAL GEOLOGY & EXPLORATION, 2021, 49(3): 158-166. DOI: 10.3969/j.issn.1001-1986.2021.03.020
Citation: GAN Zhihui, SHANG Hui, DU Rongjun, ZHAN Huizhu. Mining subsidence analysis of gently inclined coal seams based on FLAC3D and DEM data[J]. COAL GEOLOGY & EXPLORATION, 2021, 49(3): 158-166. DOI: 10.3969/j.issn.1001-1986.2021.03.020

基于FLAC3D和DEM数据的缓倾斜煤层开采沉陷分析

Mining subsidence analysis of gently inclined coal seams based on FLAC3D and DEM data

  • 摘要: 宁夏石嘴山矿区位于西部黄河流域,其煤矿采空区沉陷导致地表生态和环境问题频发,对其采煤沉陷分析将对西部黄河流域煤矿区的环境修复有一定的积极作用。为研究缓倾斜煤层采空区围岩应力与位移场演化特征,以宁夏石嘴山矿区为对象,基于FLAC3D数值模拟软件,建立缓斜煤层开采三维数值模型,计算分析采空区围岩应力、塑性区及位移变化规律,并基于两时相DEM叠加统计分析地表位移变化,与数值模拟结果进行相互验证。结果表明:地下开采引起应力重分布,采空区顶板及煤柱出现明显的应力集中现象,最大主应力呈现从煤层顶板向地表递减的变化趋势;越靠近采空区顶部的岩层垂直位移越大,随着远离采空区逐渐减少,开采完成后地表垂直位移最大值约12 m;随着采空区面积的不断增大,采空区四周及角隅处塑性区逐步延伸扩大,且以剪切破坏为主;地面沉陷盆地不对称,2个沉降中心均发生在沉陷盆地中部且偏下山方向,下山方向比上山方向影响范围更大;数值模拟计算的沉降量与两时相DEM叠加统计分析的变化量结果及趋势基本一致,研究成果可为煤炭安全开采提供参考依据,为地表沉降监测提供新方法。

     

    Abstract: Shizuishan Mining Area in Ningxia Province is located in the western Yellow River. The subsidence of the mined-out area causes frequent surface ecological and environmental problems. The analysis of coal mining subsidence will play a positive role in environmental remediation the Yellow River Basin. Taking Shizuishan Coal Mine as an object to study the evolution characteristics of surrounding rock stress and displacement field of gently inclined coal seam, a three-dimensional numerical model of the gently inclined coal seam based on the numerical simulation software FLAC3D was established. The variation of stress, plastic zone, and displacement in the surrounding rocks in goaf were calculated and analyzed, and the surface displacement variation of the coal mining area was obtained from the bi-temporal images DEM superposition statistics which was verified with the numerical simulation results. The results showed that mining activities destroyed the stress balance of the surrounding rocks and causes stress redistribution. An obvious stress concentration appeared in the roof and coal pillar of the goaf. The maximum principal stress decreased gradually from coal seam roof to surface. The vertical displacements of the rock formation near the mining area were larger, and gradually decreased as it moved away from the mining area. After the end of three level coal seam mining, the maximum vertical displacement of the surface was about 12 m. With the increasing area of the mined-out area, the plastic zone around the mined-out area and corners gradually extended and expanded, which was mainly shear failure. The surface subsidence basin was asymmetric. The two subsidence centers occurred in the middle of the subsidence basin and downhill direction, and the influence range on downhill direction was larger than uphill direction. The settlement results and trends were basically consistent with both the numerical method and two-phase DEM overlay statistical analysis. The research results can provide a reference for safe mining activities and a new method for ground subsidence monitoring.

     

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