摘要
【目的】探究气候变暖对寒区隧道温度场的影响规律。【方法】以某寒区隧道洞口段断面为研究对象,采用COMSOL软件建立了水—热耦合数值模型,考虑未来50 a气温升高2.6℃,分析冻结期与融化期隧道温度场演变特征。【结果】结果表明,地表附近围岩温度随环境温度持续升高,而衬砌背后围岩因开挖扰动引发融化—回冻过程,温度呈“先降后升”趋势,最低值均出现在第10年(冻结期-3.8℃,融化期-1.2℃)。多年冻土上限由基准年的2.6 m下移至第50 a的3.9 m,累计下移1.3 m。至第50年融化期,衬砌背后局部围岩温度接近0℃,形成小范围季节冻融圈。【结论】温度升高与冻土上限下移将劣化围岩力学性质,加剧隧道融沉塌陷风险,研究成果可为寒区隧道防冻设计提供理论依据。
[Purposes]To investigate the impact of climate warming on the temperature field of cold-region tunnels.[Methods]A hydro-thermal coupled numerical model was established using COMSOL software for a tunnel portal section.Considering a temperature rise of 2.6℃over the next 50 years,the evolution characteristics of the tunnel temperature field during freezing and thawing periods were analyzed.[Findings]The results show that the temperature of the surrounding rock near the surface continuously increases with the rising ambient temperature.However,behind the lining,the temperature of the surrounding rock exhibits a"decline followed by rise"trend due to the thaw-refreeze process induced by excavation disturbance,reaching its lowest values in the 10th year(-3.8℃during the freezing period and-1.2℃during the thawing period).The permafrost table descended from 2.6 m in the baseline year to 3.9 m in the 50th year,with a total displacement of 1.3 m.By the 50th year during the thawing period,the temperature of the localized surrounding rock behind the lining approached 0℃,forming a small seasonal freeze-thaw circle.[Conclusions]Rising temperatures and the descending permafrost table will deteriorate the mechanical properties of the surrounding rock,intensifying the risks of thaw settlement and collapse.The research findings can provide a theoretical basis for frost-prevention designs in cold-region tunnels.
作者
王伟
曲范乾
康常乐
WANG Wei;QU Fanqian;KANG Changle(Jiuquan Transportation Energy Development Co.,Ltd.,Jiuquan 735000,China;Gansu Construction Traffic Construction Co.,Ltd.,Lanzhou 730050,China)
出处
《河南科技》
2025年第22期72-77,共6页
Henan Science and Technology
