节理岩体中隧洞开挖的渐进破坏模式

节理岩体中隧洞的破坏模式与节理属性密切相关．基于一个能描述多组节理的岩体模型，采用数值模拟技术研究了节理倾角和侧压力系数对节理岩体中隧洞破坏模式的影响结果表明，节理岩体中隧洞的破坏模式受节理倾角控制．在较小节理倾角下，主要表现为肩部岩体的弯曲断裂、节理之间的分离和边墙岩体的压碎；在较大的节理倾角下，主要以边墙岩体的压碎和节理之间层状岩体的滑移为主侧压力系数亦影响隧洞破坏模式，在较小的侧压力系数下，隧洞破坏主要受节理倾角影响；随着侧压力系数的增大，其破坏主要受构造应力影响．这些结论可为隧洞支护设计和施工提供参考

Gradual Failure Mode of Tunnel After Excavation in Jointed Rock Mass

The failure mode of tunnel in jointed rock mass has close relationship with joint characteristics. Based on a jointed rock mass model that can describe properties of several joint sets ,a numerical simulation technology was employed to study the effects of the dip angle of joints and the lateral pressure coefficient on the failure mode of tunnel in jointed rock mass. The results indicate that the dip angle of joints has significant impacts on the failure mode of tunnel in jointed rock mass. At smaller dip angle,the failure mode is mainly shown through the crush of sidewall and the detaching,flexing and breaking of layered rock mass;at bigger dip angel ,the failure mode is displayed as the crush of side wall and sliding of layer rock mass between joints. The lateral pressure coefficient has obvious effect on the failure mode of tunnel. With smaller coef- ficient,the failure mode depends largely on the dip angle of joints;with the increase of coefficient,the tectonic stress will show dominant effect on the failure of tunnel. These results can offer a guideline for design and construction of tunnel support.