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针对黏弹-塑性岩体中深埋圆形隧洞锚注、衬砌联合支护问题,导出开挖、锚注加固和衬砌支护阶段位移、应力的解析解。在开挖段,用随时间变化的半径函数模拟扩孔式断面开挖过程,并同时考虑纵向开挖的空间效应,给出黏弹区和塑性区应力、位移及塑性区半径随时间变化的解答。某时刻施加锚注支护后,将锚注岩体等效为弹塑性材料,用圆柱型正交各向异性体现锚杆对径向刚度加强,用强度指标的增强体现锚注的加固作用,分别对锚注区完全弹性和部分达到塑性的情况导出了锚注和衬砌支护阶段应力、位移的解答,并给出判断再次出现塑性的条件和塑性区半径的表达式。根据解答,分析了不同位置应力和位移随时间变化情况;不同加固程度、锚注时刻对洞口应力、位移的影响。该文的解答可用于相似条件下隧洞初步设计。
Aiming at the problems of anchor injection and lining support in deep round tunnel in viscoelastic - plastic rock mass, the analytical solutions of displacement and stress at excavation, anchorage and reinforcement and lining support stage are derived. In the excavation section, the excavation process of the reaming section is modeled by the radius function changing with time, and the space effect of longitudinal excavation is also taken into account. The changes of the stress, displacement and plastic zone radius in the viscoelastic region and the plastic region with time are given answer. After the anchoring and bolting support is applied at a certain moment, the bolting-grouting rock mass is equivalent to the elastoplastic material, and the cylindrical orthotropic anisotropy is used to reinforce the radial rigidity of the bolting rod. The strengthening of the anchoring bolting is reflected by the enhancement of the strength index, The solutions of the stress and displacement of the bolt - grouting and the lining support are deduced when the anchorage zone is fully elastic and partly plastic. The expressions of the plastic condition and the plastic zone radius are also given. According to the solution, the changes of stress and displacement at different positions with time are analyzed. The influence of different reinforcement degree and anchor injection time on the stress and displacement of the hole is analyzed. The solution of this paper can be used for the preliminary design of tunnel under similar conditions.