寒区隧道衬砌结构冻胀破坏规律研究

摘要

冻胀力是造成寒区隧道冻害时常发生的主要原因.通过对寒区隧道衬砌结构冻胀力产生机理进行研究,认为冻胀力是围岩整体冻胀和局部冻胀共同作用的结果,并采用弹性力学计算方法推导了冻胀力的计算公式.利用有限元分析软件TRAS研究了青沙山隧道衬砌结构冻胀破坏规律及防治措施,研究发现:拱顶和拱脚处衬砌结构安全系数较低,容易发生冻胀破坏;增加衬砌厚度来预防冻胀力效果不明显,建议采用钢筋混凝土结构.%Frost-heaving force is the main reason for frequent frost-heaving damage of tunnel in cold regions.Through the research on the mechanism of frost-heaving force which acts on the tunnel lining structure in cold regions,frost-heaving force is considered to be the result of the interaction of the overall and local frost-heaving of surrounding rock,and the calculation formula of frost-heaving force is derived by using the elasticity method.The law of frost-heaving damage of Qingshashan tunnel lining structure and prevention measures are also studied by using finite element analysis software TRAS,the study found that the safety factor of lining structure in the vault and arch foot is low and prone to frost-heaving damage,the effect is not obvious just by increasing the thickness of lining layer to prevent frost-heaving force,so the use of reinforced concrete structure is recommend.