基于无支护条件下深埋圆形洞室塑性区半径的经典求解公式,导出了塑性区半径与围岩单轴抗压强度和黏聚力之间的关系式,进行了围岩体内摩擦角和黏结强度对塑性区半径的影响敏感性对比分析,得出黏聚力对塑性区半径的影响比内摩擦角对其影响敏感性强。基于国内外学者对黏结式锚杆加固机理研究成果,导出了深埋圆形洞室锚杆支护条件下塑性区半径的近似计算公式,通过具体算例进行分析,结果表明:开挖半径一定情况下,锚杆支护下深埋圆形洞室的塑性区半径的大小不仅跟岩石本身特性有关,而且跟锚杆的规格、力学性能及布置情况都存在关系。
According to the elastic and plastic theory, an elastic-plastic solution for a deep circular tunnel with no support was obtained. With the boundary condition, the radius of the plastic zone was determined. Based on the reference formulas, the relational expression between uniaxial compressive strength and cohesion were established separately and the sensitivity was analyzed. Through analyzing the action mechanism of a grouted anchor, an evaluation formula for the radius of plastic zone of a deep circular tunnel under a supporting anchor was deduced. The results show that the radius of the plastic zone of deep circular tunnels under a supporting anchor relates to the inherent rock character, and to the specifications, mechanical property, and layout of anchors.