软岩巷道全断面锚注支护技术应力分布特征研究

Research on Stress Distribution Characteristics of Soft Rock Roadway Full Section Anchor Grouting Support Technology

针对软岩巷道分析其失稳变形破坏过程,提出全断面锚注支护技术,采用数值模拟方法研究赵固一矿在原支护方案和全断面锚注支护方案下的塑性区分布及垂直应力情况。结果表明:在原支护方案下,底板塑性区破坏深达4 m,两帮处的集中应力分布明显,最大集中应力系数为1.48。当采用全断面锚注支护方案后,巷道围岩形成统一整体,底板塑性区范围减小至1 m以内,两帮处的集中应力基本消失。结合现场监测发现,顶板离层在支护后期基本趋于稳定,巷道日均表面变形量约为2 mm/d,巷道围岩状态整体稳定,支护效果明显。

Based on the analysis of the instability,deformation and failure process of the soft rock roadway,the full section anchor grouting support technology is proposed,and the distribution of the plastic zone and the vertical stress under the original support scheme and the full section anchor grouting support scheme in Zhaogu No.1 coal mine are studied by using the numerical simulation method.The results show that under the original support scheme,the failure depth of the plastic zone of the floor is up to 4 m,the concentrated stress distribution at the two sides is obvious,and the maximum concentrated stress coefficient is 1.48.When the full section anchor grouting support scheme is adopted,the surrounding rock of the roadway will form a unified whole,the plastic area of the floor will be reduced to less than 1 m,and the concentrated stress at the two sides will basically disappear.Combined with the field monitoring,it is found that the roof separation layer basically tends to be stable in the late support period,and the daily average surface deformation of the roadway is about 2 mm/d,which is in a stable state as a whole,and the support effect is obvious.