上覆煤层开采后下伏煤层渗透性变化规律研究Research on Permeability Change Law of Underlying Coal Seam after Overlying Coal Seam Mining
冯辉,高杰,胡钦涛
摘要(Abstract):
上覆煤层开采后,掌握下伏煤层渗透率的变化规律是瓦斯抽采的关键。采用FLAC3D对上覆煤层开采进行数值模拟,模拟结果显示:当膨胀变形为正时,下伏煤层煤体被加载压缩;当膨胀变形为负时,下伏煤层煤体被卸载拉伸。采用瞬态压力脉冲法测定下伏煤层的渗透率,由实验室加载-卸载实验得到渗透模型:加载过程中渗透率与轴向应变成负指数函数关系;卸载过程中渗透率与轴向应变成正指数函数关系。最终得出膨胀变形值与渗透率方程关系,以此分析上覆煤层开采后下伏煤层渗透率的演化规律。
关键词(KeyWords): 下伏煤层;渗透率;瓦斯;加载-卸载
基金项目(Foundation):
作者(Author): 冯辉,高杰,胡钦涛
DOI: 10.13532/j.cnki.cn11-3677/td.2016.03.031
参考文献(References):
- [1]Yi J,Akkutlu I Y,Karacan C,et al.Gas sorption and transport in coals:A poroelastic medium approach[J].International Journal of Coal Geology,2009,77(1-2):137-144.
- [2]Ying-ke L,Fu-bao Z,Lang L,et al.An experimental and numerical investigation on the deformation of overlying coal seams above double-seam extraction for controlling coal mine methane emissions[J].International Journal of Coal Geology,2011,87(2):139-149.
- [3]哈秋舲.岩石边坡工程与卸荷非线性岩石(体)力学[J].岩石力学与工程学报,1997,16(4):386-391.
- [4]哈秋舲,刘国霖.长江三峡工程岩石边坡卸荷岩体工程地质研究[M].北京:中国建筑工业出版社,1997.
- [5]哈秋舲,张永兴.三峡船闸岩石陡高边坡稳定与控制研究[M].重庆:重庆大学出版社,1997.
- [6]吴刚.复杂应力状态下完整岩体卸荷破坏的损伤力学分析[J].河海大学学报,1997,25(3):44-49.
- [7]黄润秋,黄达.卸荷条件下岩石变形特征及本构模型研究[J].地球科学进展,2008,23(5):441-446.
- [8]黄达,金华辉,黄润秋.拉剪应力状态下岩体裂隙扩展的断裂力学机制及物理模型试验[J].岩土力学,2011,32(4):997-1001.
- [9]Chen HD,Cheng YP,Zhou HX,Li W.Damage and permeability development in coal during unloading[J].Rock Mech Rock Eng,2013(46):1377-90.
- [10]Brace,W.F.Walsh,J.B.Frangos,W.T.Permeability of granite under high pressure[J].Journal of Geophysical Research,1968(73):2225-2236.
- [11]Wang,S.G.Elsworth,D.Liu,J.S.Permeability evolution in fractured coal:The roles of fracture geometry and water-content[J].International Journal of Coal Geology,2011,87(1):13-25.