寒区隧道不同排水系统结构形式下保温层作用效果及适用性研究

Study on Effectiveness and Suitability of Thermal Insulation Layer of Different Tunnel Drainage System Structures in Cold Region

以哈牡高速铁路鲜丰隧道为例,探究施作保温措施后洞内环境温度以及隧道围岩温度等变量综合影响下的隧道温度场。基于不同的围岩初始温度以及洞内温度,提出相应的寒区隧道排水系统结构形式选择建议,以保障寒区隧道排水系统的安全与稳定。研究表明,同一条件下,设置保温层后排水系统各测点的温度值均有不同程度的提高;设置保温层后,对衬砌背后水管保温效果较好,而对侧边水沟及纵向水管保温作用效果有限;排水系统结构形式的主要区别体现在中心(深埋)水沟内的温度;根据洞内环境温度以及隧道围岩温度,可将寒区隧道排水系统结构形式选择划分为3个区域,分别为A区(无保温)、B区(中心水沟-保温)以及C区(中心深埋水沟-保温)。

By using the Xianfeng Tunnel of Harbin-Mudanjiang High-speed Railway as an example,this paper is meant to investigate the tunnel temperature field under the combined effect of the variables such as in-tunnel ambient temperature and tunnel surrounding rock temperature after installation of thermal insulation layer.Based on the specificrock initial temperature and in-tunnel temperature,an appropriate drainage system structure is recom⁃mended for the tunnel in cold region,to ensure safety and stability of the drainage system.Under the same condi⁃tion,according to this study,the temperature values at the measuring points of the drainage system have increased to various extents after thermal insulation layer is installed.Installation of thermal insulation layer will render excel⁃lent thermal insulation effect on the water pipe behind the lining,but have limited thermal insulation effect on the side ditch and vertical water pipe.The main difference in drainage system structure is indicated by the temperature in the center(deep)ditch.Depending on the in-tunnel ambient temperature and tunnel surrounding rock tempera⁃ture,the drainage system structure of tunnel in cold region can be divided into three zones,including Zone A(with⁃out thermal insulation),Zone B(center ditch-thermal insulation)and Zone C(center deep ditch-thermal insulation).