青藏铁路风火山隧道设计难点探讨

Discussion on the Difficulties in Design of Fenghuoshan Tunnel in Qinghai-Tibet Railway

研究目的:青藏铁路风火山隧道处于高海拔、高寒及冻土的特殊环境中,这使得隧道的设计面临着许多特殊的问题,如冻融圈的控制、冻胀力的作用、防排水设计等问题,解决以上问题是风火山隧道成功修建的关键。研究结论:文章通过对风火山隧道主要技术问题的分析,探讨在高寒、高海拔及冻土地区隧道设计的思路和方法,为今后类似工程的修建提供借鉴。多年冻土隧道的主要设计思路是围绕着"保护冻土"的要求采取了隧道隔热保温技术、复合防冻胀技术及综合防排水设施,有效控制冻融圈的范围,消除产生冻胀和冻害的根源。

Research purposes： Fenghuoshan tunnel is located in a special area featured with high altitude, cold and permafrost. Several special difficulties, such as control of freeze - thaw cycle, action of frost heave force, waterproof and drainage technology have to be solved in design of the tunnel, which are key points in the tunnel construction. Research conclusions ：The paper discusses considerations and methods for the design of tunnels in high altitude, cold and permafrost area by analyzing the technical solutions for Fenghuoshan tunnel, and presents references for the similar project. The general design idea for the permafrost tunnel is ＂protecting permafrost＂ with multi -technique measures, including heat insulation ,complex frost heave resistance, integrated waterproof, etc. , to effectively restrict freeze -thaw cycle development and to eradicate the root causes of frost heave.