Temperature field distribution characteristics in cold region tunnels and surrounding rock and analysis of influencing factors
There are more and more tunnels in high latitude and high altitude areas in China,and different degrees of frost damage problems have occurred during the actual operation of the tunnels,which bring hidden dangers to the tunnel structure and public transportation,and the prevention and control of frost damage should not be delayed.A three-dimensional tunnel heat transfer model was established to study the distribution of temperature fields in cold region tunnels,and the effects of initial ground temperature,surrounding rock density,thermal conductivity,and specific heat capacity on the temperature field as well as the degrees of their effects were discussed and compared.The results show that the low-temperature air outside the tunnel is the main factor causing significant changes in the temperature field inside the tunnel,leading to radial warming circles in the tunnel surrounding rock.The depth of warming of the tunnel surrounding rock with an initial ground temperature of 10℃ reaches 8 m under the effect of natural winds(2 m·s-1,-10℃).The initial ground temperature has a direct influence on the temperature field of the tunnel.The initial ground temperature increases by 5℃,the temperature of the surrounding rock increases by 2.5℃ during the operation period.The temperature of surrounding rock in tunnel is positively correlated with the specific heat capacity and density of the surrounding rock,but the relationship with the thermal conductivity is related to the radial distance,when the radial distance is less than 1.3 m,they are positively correlated,and vice versa,they are negatively correlated.Finally,the gray correlation analysis was used to compare the sensitivity of their effects on the tunnel temperature field.The order of sensitivity influence from large to small is:initial ground temperature(1),density of the surrounding rock(0.74),surrounding rock thermal conductivity(0.71),specific heat capacity of the surrounding rock(0.68),which shows that the initial ground temperature has the greatest influence on the temperature field.The research results can support the anti-freezing design of tunnels in cold re-gions.
cold region tunneltemperature fieldnumerical simulationCFDinitial ground temperaturethermal physical parameter of surrounding rock
万方数据
维普
