寒区隧道冻害成因与若干防治新技术  

Causes of Tunnel Frost Damages in Cold Region and Several New Technologies to Prevent Them

作　　者：吕康成[1] 吉哲[1] 马超超[1] 许鹏[1] 

机构地区：[1]长安大学公路学院,西安市710064

出　　处：《公路》2012年第7期297-301,共5页Highway

基　　金：国家西部交通建设科技项目;项目编号:2007 318 812 67

摘　　要：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。Tunnel frost damages in cold region are classified and their causes are discussed.Especially the structural damages caused by freezing are seriously analyzed,and they are classified into two categories.One of them is caused by the outer freezing of lining,the other from the inner freezing of lining.The results show that the former has little affects to the structure,but the latter may cause severe damages to the lining.For the phenomenon that cracks frequently occur in the linings of cold region tunnels,a few technical measures to prevent cracks are presented,through which constraints can be released during the temperature changes,and the stresses due to the temperature difference will be reduced.In cold region,it is unsuitable to adopt back paste-typed water-stoppers to prevent the leakage from lining construction joints,and a good choice is to utilize the drainable water-stoppers.To achieve a better drainage effect in ring direction,the ring drainage pipe mast directly connect with the central drainage pipe.If the surrounding rock is water-rich one,and the lower part of the ring drainage pipe is easily frozen,the ring drainage pipe had better been covered with thermal insulating layer with belt shape.In the tunnel section with high tendency of freezing threat,through installing electro-thermal wires between the water-proof layer and the lining,a kind of plan to melt the ice electrically is experimented.The test engineering shows that the above techniques have good effects in cold region tunnels.

关 键 词：公路隧道 防冻 防渗 保温 技术 

分 类 号：U457.5[建筑科学—桥梁与隧道工程]