冻土区公路隧道洞口段热融规律  

Law of thermal thaw of highway tunnel portal in Permafrost Region

作　　者：富志鹏[1] 李博融[1] 韩常领[1] 董长松[1] FU Zhi-peng;LI Bo-rong;HAN Chang-ling;DONG Chang-song(Shaanxi Key Laboratory of Road Disaster Prevention,CCCC First Highway Consultants Co.,Ltd.,Xi’an 710065,Shaanxi,China)

机构地区：[1]中交第一公路勘察设计研究院有限公司,陕西省公路交通防灾减灾重点实验室,陕西西安710065

出　　处：《长安大学学报（自然科学版）》2020年第6期86-96,共11页Journal of Chang’an University(Natural Science Edition)

基　　金：西藏自治区科技厅重点研发与转化计划项目(XZ201801-GB-07);国家重大科学仪器设备开发专项项目(2017YFF0108705,2017YFF0108706)。

摘　　要：为明确在地质、环境、气候及施工开挖等因素共同影响下的洞口段热融规律,进一步完善寒区公路隧道洞口段边仰坡热融稳定性防治技术,依托青海省境内共玉(共和—玉树)高速公路姜路岭隧道,通过现场监测、数值模拟及理论分析,对洞口段洞内地温响应过程及变化规律进行深入研究,根据温度场的模拟计算结果,分析影响边仰坡及隧道内热融范围的主要因素,并判断控制温度场的方法。结果表明:坡面浅埋土体地层中的温度变化相对地表有着一定的滞后性,这种滞后性与深度成正比;太阳辐射对依托工程洞口段边坡热融的影响较大,即使是阴坡面也极有必要施做一定的遮阳措施来减小冻土热融;洞内围岩融化圈在施做二次衬砌之前增长和发育的速度较快,在施做一次衬砌前,围岩热融圈也已形成较大的规模,这对于还未受到强支护的洞室稳定性十分不利,应当注重二次衬砌施做前的洞内保温措施;施工开挖阶段坡面热融对洞内围岩热融的影响随着隧道埋深的增长迅速减小,应当注意对埋深特浅断面的拱顶围岩热融范围的影响,特别是对大范围热融贯通现象的防范。In order to clarify the law of thermal melting in the portal section under the joint influence of geological, environmental, climate and construction excavation, and further improve the prevention and control technology of thermal melting stability in the front slope of the portal section of highway tunnels in cold regions, based on the Jiangluling Tunnel of Gongyu(Gonghe to Yushu) Expressway in Qinghai Province, through on-site monitoring, numerical simulation and theoretical analysis, the temperature response process in the tunnel portal section was analyzed. Based on the simulation results of the temperature field, the main factors affecting the slope and the range of the thermal fusion in the tunnel were analyzed, and the method of controlling the temperature field was determined. The results show that the temperature change in the shallow soil layer on the slope has a certain lag, compared with the surface, which is proportional to the depth, the solar radiation has a huge impact on the thermal melting of the slope at the entrance of the supporting project, even on the shady slope, it is necessary to take some sunshade measures to reduce the thermal melting of the frozen soil, the growth and development of the melting circle of the surrounding rock in the tunnel before the secondary lining speed is fast. Before the construction of the first lining, the surrounding rock thermal melting circle has formed a large scale, and very unfavorable to the stability of the tunnel which has not been strongly supported, so we should pay attention to the thermal insulation measures in the tunnel before the construction of the second lining. During the construction and excavation stage, the influence of the slope thermal melting on the surrounding rock thermal melting in the tunnel decreases rapidly with the increase of the tunnel buried depth, and pay attention to the burial influence of the thermal melting range of the surrounding rock of the deep and extra shallow section vault, especially the prevention of the large-sca

关 键 词：隧道工程 冻土区 数值分析 热融规律 水化热 热学参数 

分 类 号：U453.1[建筑科学—桥梁与隧道工程]