钻孔应力分布特征及卸压增透技术的数值模拟

Numerical simulation on characteristics of borehole stress distribution and technique of pressure relief and permeability improvement

对钻孔的应力分布进行了系统研究,采用FLAC3D软件建立三维模型,综合考虑巷道和钻孔的共同影响,分析了不同原岩应力、钻孔深度、钻孔直径及钻孔数目条件下钻孔围岩的应力分布情况,并对水平多孔随钻孔间距变化的应力分布规律进行分析。采用卸压增透技术消除多孔间的应力集中区,对煤体进行卸压增透,消除突出危险性,最后利用数值模拟和现场工业性试验对效果进行验证。

The stress distribution of borehole was investigated systematically. The 3D model was established by using FLAC3D software, and the common influence of roadway and borehole was comprehensively considered. Moreover, the stress distribution under different rock stresses, borehole depths, borehole diameters and borehole numbers, and the stress distribution law of horizontal multiple boreholes varied with the borehole spacing were analyzed. The technique of pressure relief and permeability improvement was employed to eliminate the stress concentration area among multiple boreholes, relieve the pressure and improve permeability of coal seam, as well as remove the outburst danger. Finally, the results were confirmed by using numerical sim- ulation and industrial field tests.