深部巷道钻孔卸压对巷道稳定性的影响及钻孔参数确定

Impact of Pressure⁃Relief Borehole on Stability of Deep Roadway and Determination of Drillings Parameters

研究了大直径卸压钻孔布孔方式及钻孔参数对深部巷道稳定性的影响。结果表明,与单排钻孔方式相比,双排钻孔能较好地转移应力和控制巷道变形;与未布置卸压钻孔相比,单排钻孔和双排钻孔巷道帮部变形量分别减小了6.05%和15.44%,原最大应力处的应力值由39.61 MPa分别降至33.50 MPa和32.70 MPa。钻孔应尽量布置在巷道帮部的中间位置;钻孔深度应穿过塑性区,达到应力最大值位置;钻孔间距选取钻孔水平方向塑性区的距离;钻孔排距不应大于钻孔上下产生的应力降低区范围。

The impact of large⁃diameter pressure⁃relief borehole arrangement and drilling parameters on roadway stability was studied.It is found that arrangement of boreholes in a two⁃row pattern,compared to boreholes in a single⁃row pattern,can benefit stress shift and control of roadway deformation.By adopting the arrangement of boreholes in a single⁃row pattern and a two⁃row pattern,the deformation at both sides was reduced by 6.05%and 15.44%respectively,and the original maximum stress was reduced from 39.61 MPa to 33.50 MPa and 32.70 MPa respectively.It is also found that boreholes should be arranged,as much as possible,near the center of two sides,penetrating the plastic zone to the place with the maximum stress.And the spacing between boreholes should be determined based on the horizontal distance of the plastic zone of boreholes,and the burden spacing should be less than the height of stress⁃relaxed zone.