围岩-锚固体流变控制机制及支护最优化设计

Rheology control mechanism of surrounding rock mass and anchorage body and its support design optimization

针对巷道围岩的流变特性及其控制理论,通过黏弹性理论和非线性最优化原理,在考虑开挖面空间效应的基础上,研究围岩-锚固体的耦合作用机制,并建立巷道支护最优化设计模型。通过算例分析了支护时间、锚固体厚度、巷道半径以及原岩应力对围岩-锚固体流变特性和巷道支护最优化设计的影响。结果显示,支护时间、锚固体厚度、巷道半径以及原岩应力都与巷道围岩的稳定性有着密切的联系。巷道位移随着支护时间的增长、锚固体厚度的减小、巷道半径和原岩应力的增大而增大;当锚固体受力处于临界状态时,锚固体厚度随着支护时间的增大而减小,且当锚固体厚度较小时,锚固体厚度与支护时间近似呈线性关系。

The aim of this paper is to improve the control theory for the theological behavior of the surrounding rock around roadway. Based on the theory of viscoelasticity and nonlinear optimization principle, a time-dependent viscoelastic model of coupling action between the surrounding rock mass and the anchorage body is developed considering the space effect of tunnel face advancement; and then an optimization model of roadway support is established. The influences of the support time, the thickness of anchor, the original rock stress and the road radius on the deformation of surrounding rock mass are analyzed; and then the optimal design parameters of the roadway support are discussed in detail by a case study. The results show that the support time, the thickness of anchorage body, the original rock stress and the road radius have certain impacts on the stability of tunnel. With the increases of the roadway support time, the original rock stress and the road radius, and the decrease of the thickness of the anchor body, the displacement increases. The optimal design parameters of the roadway support are obtained; when the force acted on the support body reaches a critical state, the thickness of anchorage body decreases with the support time elapsing, and when the thickness of anchorage body is smaller, they show an approximately linear relationship with time.