控制爆破局部切槽放顶机理的三维渗流有限元分析

提出了处理缓倾斜采空场的新方法———控制爆破局部切槽放顶技术。简述了三维渗流有限元分析 (EPSCA3D)的力学原理 ,应用EPSCA3D研究了该方法的力学特性 ,并与二维有限元分析结果进行了比较。结果表明 :应用该联合法能引起顶板应力向有利于安全生产的方向重分布 ,不会引起地表发生明显的岩体移动 ;二维和三维有限元分析的切槽位置基本相同 ,应力分布和地表岩移趋势基本一致 ,但三维有限元分析的结果更接近实际。三维分析表明 :在走向方向间隔一定距离沿倾向同样地实施切槽放顶 ,既可以改善局部地压 ,又可以减小地表沉降 ;渗流引起放顶前深部水平的应力增加 ,隔离墙处的拉应力增加、压应力减小 ,放顶前后的岩移量微弱减小。

EPSCA3D ANALYSIS ON LOCAL GROOVING AND TOP-CAVING OF ABANDONED STOPE BY CONTROLLED BLASTING

A new method,the technique for local top-caving of an abandoned stope by controlled blasting,is proposed to treat gently-inclined abandoned stope The mechanical principle of EPSCA3D is outlined and the mechanical character of the top-caving method is studied by EPSCA3D The comparison between the analytical results obtained by two-dimensional finite element analysis or EPSCA3D is actualized The study results show that when the united method is used,the roof stress will redistribute to keep safety production,and obvious surface subsidence and rock movement can be prevented The grooving location is basically same,and the trend of stress distribution and surface subsidence and rock movement is basically consistent for two-dimensional finite element analysis and EPSCA3D,but the results of EPSCA3D is further close to practice EPSCA3D shows that local grooving top-caving at a distance in strike and along incline can not only meliorate local ground pressure,but also decrease surface subsidence and rock movement For the seepage tension,the stress of lower levels and the tension stress at insulation wall increase,and the compression stress at insulation wall decreases before roof cutting And the rock movement of top-caving and non-dilapidated roof decreases faintly