风火山隧道温度特性非线性分析

Nonlinear analysis on temperature characteristics of Fenghuo Mountain tunnel

风火山隧道是青藏铁路的控制性工程之一,全隧道位于多年冻土之中,这种特殊隧道的温度分布将直接影响隧道结构的稳定性。根据带相变瞬态温度场问题的热量平衡控制微分方程,应用Galerkin法推导出了三维有限元计算公式。根据风火山隧道内的实测大气温度,利用三维有限元计算公式,计算分析了该隧道在未来50 a的温度特性,并与现场实测围岩温度进行了对比分析,分析表明计算理论、模型、参数和条件是可靠的,风火山隧道在未来50 a内不会出现季节性融化。从而为寒区工程设计提供理论依据和计算方法。

Fenghuo Mountain tunnel, lying in permafrost, is a key project in Qinghai-Tebit Railway. The temperature distributions of this special tunnel will directly affect the stability of tunnel structure. Based on the governing differential equations of the problem of temperature field with phase change, the finite element formulae of three-dimensional temperature fields are obtained from the Galerkin＇s method. Three-dimensional temperature fields of Fenghuo Mountain tunnel in coming 50 years are forecast on the basis of the air temperature measured inside the tunnel. A comparison between the numerical results and the measured temperature of the rock surrounding the tunnel is made. The results show that the theory, model, parameters and conditions are all credible, and that there will not occur a seasonally thawed range in the rock surrounding Fenghuo Mountain tunnel in coming 50 years. It can provide theory basis and a numerical method for actual engineering design in cold regions.