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对寒区隧道冻害进行了分类并探讨了其成因,特别是对衬砌结构因冻损伤的原因进行分析,并将其分为衬砌结构因壁外冻胀损伤和因壁内冻胀损伤两种类型。分析表明,前者对结构的影响较小,后者对结构的威胁较大。针对寒区隧道衬砌结构容易发生裂缝的现象,提出了减少温变过程中的不利约束,预防衬砌出现较大温度应力,进而预防衬砌裂缝发生发展的工程措施。在寒区采用背贴式止水带预防衬砌施工缝渗漏的方法存在不足,宜以中埋式可排水止水带取代。环向排水管应直通中央排水管,在围岩富水且衬砌壁后中、下段环向排水管易冻的隧道区段,沿环向排水管宜设置条带状局部保温层。在隧道潜在冻害威胁较大的区段,通过在衬砌壁后设置电热带穿线管,可提供电热融冰的隧道防冻预案。试验工程表明,可排水止水带、直通中央排水管的环向排水管、电加热融冰等技术在寒区隧道中应用效果良好。
The cold damage of tunnel in cold region was classified and its causes were discussed. In particular, the cause of frozen damage of lining structure was analyzed and divided into two types of lining structure due to frost heaving injury outside wall and frost heaving injury inside wall . The analysis shows that the former has less influence on the structure and the latter poses a greater threat to the structure. Aiming at the phenomenon that the tunnel lining structure in the cold region is prone to be cracked, the engineering measures to reduce the unfavorable constraint in the temperature changing process, to prevent the lining from having larger temperature stress and prevent the lining crack from developing are proposed. In the cold area using the back-mounted water-stop to prevent lining construction joints leakage there is a shortage, should be buried in the drainage can replace. Central to the drainage pipes should be through the central drain pipe in the surrounding rock water-rich and lining wall, the lower section of the ring to the frozen section of the tunnel, along the vertical drainage pipe should be set to strip the local insulation. In tunnels where there is a great threat of potential frost damage, an anti-freezing tunneling scheme of electrothermal melting ice can be provided by arranging the electric heating pipe threading pipe behind the lining wall. Experimental project shows that the drainage of water-stop, through the central drain to the drainage pipes, electric heating and melting ice technology in the cold zone tunnel effect is good.