中文摘要：

工程中连拱隧道围岩松动范围的确定对采取合理的支护手段和方法具有重要的理论价值和实际意义。以埋深100 m的公路连拱隧道为研究对象,利用室内模型试验,对软弱破碎围岩松动区的发展过程及范围进行研究,并采用压力盒量测围岩不同部位的应力,分析围岩松动区的应力场特征。利用FLAC软件对模型试验进行数值模拟,通过应力分析法和极限拉应变法判别松动区范围,并与模型试验结果进行对比分析,发现松动区内围岩切向应力大于径向应力,深埋条件下围岩更容易形成压力拱,应力分析法所得的松动区与模型试验结果更为接近,建议深埋隧道采用应力分析法判断松动区范围。

英文摘要：

In the field of multi-arch tunnel,determining loose zone of surrounding rock has important theoretical value and practical significance for taking appropriate method for support in actual projects. By taking highway multi-arch tunnel with overburden depths of 100 m for example,a model test based on similar principle is implemented to study loose zone of the soft and fractured surrounding rock,and the characteristics of stress field in loose zone are analyzed through measuring pressure of different locations by pressure cells. FLAC software is applied to simulate model test. The range of loose zone is identified by stress analysis method and ultimate tensile strain method. Comparing with results of model test shows that tangential stress is greater than radius stress in loose zone,surrounding rock is more likely to form pressure arch under deep overburden condition. The range of loose zone decided by stress analysis method is closer to the results of model test,identifying loose zone is feasible for deep overburden tunnel by stress analysis method.