摘要
裂隙以及渗流作用对寒区隧道温度场的影响不可忽视。以延庆—崇礼高速公路河北段棋盘梁特长隧道为依托,建立考虑渗流的随机裂隙模型,探究不同因素对隧道冻结深度的影响,从而构建保温层厚度计算公式。研究结果表明:(1)隧道进口最冷月负温段的长度为172 m,最低温度负温段的长度为273 m;出口处最冷月负温段的长度为238 m,最低温度负温段的长度为292 m,洞口段300 m范围内应为抗防冻重点。(2)裂隙的存在对温度场的分布有不可忽视的影响,受裂隙“阻隔”作用影响,隧道断面包络线呈现不均匀性,冻深以拱顶处最大。(3)冻深与孔隙率、渗透率、比热容和围岩初始温度呈负相关,与导热系数和传热系数呈正相关。冻结深度对各因素的敏感性排序为:初始地温>比热容>孔隙率>导热系数>传热系数>渗透率。(4)构建的保温层厚度计算公式考虑了裂隙以及渗流作用的影响,得到棋盘梁隧道进口段保温层厚度为4.2 cm,出口段保温层厚度为4.8 cm。
The impact of fissures and seepage on the temperature field of tunnels in cold regions cannot be neglected. Based on the Qipanliang Extra-long Tunnel in the Hebei section of the Yanqing-Chongli Expressway, a random fissure model considering seepage was built and the impact of various factors on the depth of tunnel freezing was explored so as to establish the calculation equation of insulation layer thickness. The research results showed that(1)the negative temperature section at the inlet of the tunnel in the coldest month was 172 m long, and the negative temperature section at the minimum temperature was 273 m;the negative temperature section at the outlet in the coldest month was 238 m, and the negative temperature section at the minimum temperature was 292 m;anti-freezing shall focus on the range of 300 m in the inlet section.(2) The existence of fissures had a non-negligible impact on the distribution of temperature fields, and due to the influence of "separation" of fissures, the tunnel section envelopes were nonuniform, and the maximum depth of frost appeared at the crown.(3) The depth of frost was negatively correlated with porosity, permeability, specific heat capacity and initial temperature of surrounding rocks and was positively correlated with heat conductivity coefficient and heat transfer coefficient. The sensitivity of the depth of frost to various factors was ranked as follows: initial ground temperature > specific heat capacity > porosity > heat conductivity coefficient > heat transfer coefficient > permeability.(4) In the established calculation equation of insulation layer thickness, the impact of fissures and seepage was considered to get the insulation layer thickness(4.2 cm) in the inlet section and the insulation layer thickness(4.8 cm) in the outlet section.
作者
于建游
姜逸帆
林铭
刘建其
蔡李斌
蒋新政
王志杰
周平
YU Jianyou;JIANG Yifan;LIN Ming;LIU Jianqi;CAI Libin;JIANG Xinzheng;WANG Zhijie;ZHOU Ping(Yanqing-Chongli Expressway Preparatory Office of Hebei Expressway Group Limited,Zhangjiakou 075400;Key Laboratory of Transportation Tunnel Engineering of the Ministry of Education,Southwest Jiaotong University,Chengdu 610031)
出处
《现代隧道技术》
CSCD
北大核心
2022年第4期108-117,共10页
Modern Tunnelling Technology
基金
河北省交通运输厅科技项目(YC-201904)
中央高校基本科研业务专项资金(SWJTU11ZT33)。
关键词
公路隧道
保温层厚度
数值模拟
随机裂隙模型
寒区隧道
Highway tunnel
Insulation layer thickness
Numerical simulation
Random fissure model
Tunnels in cold areas
