摘要
文章通过建立三维CFD数值模型,研究了单向通风条件下高海拔寒区隧道洞内纵向温度场的分布规律及不同因素对温度场的影响。结果表明:当洞口平均温度高于-2℃,洞口风速小于1.2 m/s时,隧道衬砌表面会呈现出正温状态,可以不采取保温防冻措施;在同一洞口风速作用下,随洞口温度的降低,洞内纵向负温长度虽有所增加,但在围岩对洞内空气加热作用下,增加幅度逐渐减弱;在同一洞口温度作用下,随着洞口风速增大,进风一侧冬季0℃点位置会向洞内纵向延伸,增大隧道可能出现冻害的段落长度;基于正交试验,得出寒区隧道纵向温度场影响因素的敏感度排序为洞口风速>洞口气温>隧道长度;合理确定高海拔隧道保温层设防长度,需考虑洞口风速情况,寒区隧道选线应避免洞口轴线与风向平行的情况,应尽量与风向垂直或大角度相交。研究成果可为寒区隧道的建设与防冻设计提供科学参考。
A three-dimensional CFD numerical model was established in this paper to study the distribution law of longitudinal temperature field and the influence of different factors on temperature field in a tunnel in high-altitude cold area under unidirectional ventilation.The results indicate that the tunnel lining surface might present a positive temperature state and the thermal insulation and anti-freezing measures might not be taken when the average temperature is higher than-2℃and the wind speed is less than 1.2 m/s at the tunnel entrance.Although the longitudinal length under negative temperature in the tunnel increases along with the decrease of portal temperature under the same wind speed at the portal,the increase amplitude is decreasing gradually under the heating effect of surrounding rock on the air in the tunnel.The position of 0℃point on the inlet side in winter might extend longitudinally into the tunnel along with the increase of wind speed at the portal under the same temperature action at the portal,which might increase the length of the section where freezing damage would possibly occurre in the tunnel.It could be concluded from the orthogonal test that the sensitivity order of influencing factors in the longitudinal temperature field of the tunnel in cold area is wind speed at the portal>air temperature at the portal>tunnel length.The wind speed at the portal should be considered to reasonably determine the fortification length of thermal insulation layer in the high-altitude tunnel.So,during tunnel routing in a cold area,it is required to avoid the situations that the axis of the portal is parallel to the wind direction or perpendicular to or intersected at a large angle with the wind direction as far as possible.The research results could provide scientific reference for the construction and anti-freezing design of tunnels in cold regions.
作者
郑波
方林
郭瑞
ZHENG Bo;FANG Lin;GUO Rui(National Engineering and Researeh Center for Mountainous Highways,Chongqing 400067;China Railway Southwest Research Institute Co.,Ltd.,Chengdu 611731;Sichuan Provineial Engineering Technology Researeh Center of Tunnel Safety,Chengdu 611731;China Merchants Chongqing Communications Technology Research&Design Institute Co.,Ltd.,Chongqing 400067)
出处
《现代隧道技术》
CSCD
北大核心
2021年第S01期349-358,共10页
Modern Tunnelling Technology
基金
国家山区公路工程技术研究中心开放基金(GSGZJ-2017-01)
四川省科技计划项(2018GZ0359)
关键词
单向通风
高海拔隧道
温度场
影响因素
敏感度
防冻设计
Unidirectional ventilation
High-altitude tunnel
Temperature field
Influencing factors
Sensitivity
Antifreeze design
作者简介
郑波(1980-),男,博士,正高级工程师,主要从事隧道及地下工程科研与技术咨询工作,E-mail:my1390@126.com.
