陡倾岩层隧道开挖力学特性研究

陡倾岩层隧道由于层状结构的存在,在开挖过程中,围岩的破坏机理与方式、围岩与结构的变形、受力等特征明显不同于其它岩体隧道。本文在陡倾岩层隧道开挖破坏机理探讨的基础上,通过三维数值模拟,对不同陡倾角条件下围岩与结构的变形、受力特征进行了计算,分析了隧道开挖力学特性与倾角的关系,提出了陡倾岩层隧道设计施工建议。计算结果表明:倾角越大,隧道发生顺层滑移破坏的概率越大,地表沉降、拱顶位移、围岩主应力随倾角的增大而增大,但拱脚位移、围岩剪应力、喷射混凝土内力与倾角并非一致性关系。

Research on Mechanical Behavior for Tunnel Excavation in Steeply Inclined Strata

In the process of tunnel excavation in the steeply inclined strata, the mechanism and mode of surrounding rock failure, the deformation, stress characteristics of surrounding rock and structure are different from those of other rock tunnel due to the layered structure. Based on the study of failure mechanism of tunnel excavation, in the steeply inclined stratathrough three-dimensional numerical simulation, the deformation and stress characteristics of surrounding rock and structure under conditions of different steep dip were calculated, the relationship between tunnel excavation mechanical behavior and steep dip was analyzed, and the design and construction suggestions for tunnel in steeply inclined strata were put forward. The calculation results show that: the bigger steep dip, the consequent layer slip failure probability of tunnel is bigger, and the ground surface settlement, crown displacement and the principal stress of surrounding rock increase with the increase of steep dip, but the relationship of the arch foot displacement, shear stress of surrounding rock and internal force of spray concrete with the steep dip is not in consistent relation.