寒区公路隧道保温层设置的数值分析

Numerical analysis of insulating layer setting of highway tunnel in cold regions

针对东西部寒区隧道出现的冻害工程问题,结合哈尔滨天恒山公路隧道现场监测数据,提出考虑相变的平面瞬态温度场计算模型,利用有限元软件对隧道温度场进行了数值模拟.计算得到隧道运营期内保温层的设防厚度,考虑隧道贯通后会在当地形成新的季节冻结层的实际情况,计算了三种不同工况相同厚度保温层的设置方式,结果表明分层设置保温层具有有效防治冻害的效果,同时结合传热学理论,对隧道结构设置保温层和不设置保温层两种工况进行热-应力耦合分析,发现温度场对隧道结构应力场有较大影响,因此在寒区进行隧道设计时,应考虑热-应力相互作用的影响.

According to the frost damage to the eastern and western cold region tunnels, this paper, combining with the TianHengshan highway tunnel and the temperature field data monitored in the job-location, creates the plane and transient temperature model considering the phase change and simulates the temperature field of the tunnel . The results show that the thickness of the insulating layer can effectively protect the tunnel from frost damage. Considering the local region will form a new frozen layer because of the tunnel, the paper also caleulates the three different working conditions which insulating layer with the same thickness is set by different methods. The result reveals that the insulating layer set by layering can more effectively stop the frost damage. According to the theory of heat transfer, this paper has researched on hotstress field coupling analysis about tunnel structure in two different kinds of working conditions where insulation layer is not set and insulation layer is set. The result reveals that the temperature field has a major effect on the stress field. So when the tunnel in cold regions is designed, the influence of thermal stress must be considered.