Research On The Structure Of Insulation Tunnel In Cold Region

Having suffered one or several freezing and thawing cycles, generally, highwaytunnel in cold region will appear some damages, such as cracking or spalling in innerlining layer and water penetrating and freezing in pavement structure etc., which notonly affect the durability of the tunnel structure，but also threaten severely to drivingsafety of vehicles in tunel.For that purpose, based on the field inspection on Suiman Highway (GZ15)Wusongling tunel and Harbin Ring Expressway Tianhengshan tunel, and combinedwith tunel data in home and abroad, insulation design should consist of severalprocedures as follows:（1）By analyzing the differences of design details and construction schemes ofinsulating course between Wusongling tunel and Tianhengshan tunel, and bycomparing in performances between the spraying liquid polyurethane in site withprefabricating and installing hard polyurethane board, the later was regarded as thefirst choice of insulating course of tunel engineering in cold region.（2）The thickness of insulating course was calculated separatly by equivalentthickness conversion method, meteorologic analysis method and finite elementanalysis, the thickness of Wusongling tunel and Tianhengshan tunnel are determine.（3）By analyzing and comparing the differences of computational resultsbetween with the “Kurokawa Xifan formula” and with the “meteorologic analysismethod”, this dissertation suggests that the computation method of length ofinsulating course adopt the “Kurokawa Xifan formula”.（4）By testing circumstance temperature in tunnel, temperatures inside andoutside insulating course and temperature in inner lining layer of Wusongling tuneland Tianhengshan tunel, and the distribution rules of temperatue patterns in radial,trasversal and circumferential directions have been acquired.It has been also certifiedthat the temperature in boundary position is a constant value and the design ofinsulating course is correct, furtherly, this dissertation puts forward that internal andexternal insulating courses should be designed for the opening and shallow buriedsection of a tunel.The procedures of thesis areused for reference to design and construction ofinsulating course of tunnel.