交通荷载作用下超浅埋隧道洞口段变形及控制研究*

为研究交通荷载作用下超浅埋隧道施工的安全性及其控制方法，利用功效系数法分析隧道施工时的风险程度，结合有限元软件模拟交通荷载作用下隧道的变形特征，并探究不同开挖方法及支护条件下隧道变形情况，最后与现场实际监测数据进行对比。研究结果表明:交通荷载对隧道施工影响较大，施工时应采取管制措施；隧道下穿段施工风险较大，应采用双侧壁导坑法开挖；单层大管棚加小导管注浆的超前支护措施可以保证隧道施工安全进行。

Research on deformation and control of entrance section in ultra-shallow buried tunnel under traffic load

In order to study the safety and control method of ultra-shallow buried tunnel construction under the traffic load,the efficacy coefficient method was used to analyze the risk degree of tunnel construction.The deformation characteristics of tunnel under traffic load were simulated with the finite element software,and the deformation situation of tunnel under different excavation methods and support conditions were studied.Finally,the results were compared with the actual monitoring data on site.?The results showed that the traffic load had great influence on the tunnel construction,and the control measures should be taken during construction.The construction risk of the underpass section of tunnel was great,and the tunnel construction safety could be guaranteed when the excavation of double side heading method and the advanced support of single-layer large pipe shed and small pipe grouting were adopted.