Analysis of Influencing Factors of Temperature Field in Freezing Construction of Metro Connecting Passage

With the development of underground space and the continuous development of subways, the emergence of artificial freezing method has solved the problem of how to ensure the safety of excavation and damage the environment during subway construction. This paper relies on the horizontal freezing method of the connecting passage between Zhengzhou Airport and Xuchang City Railway Yingbin Avenue Station~Xinzheng Airport Station. The flow rate and direction of the seepage field, the influence of phase change and heat transfer boundary conditions are controlled based on the heat transfer of porous media. And seepage theory and practical engineering use COMSOL Multiphysics to establish a numerical model of the coupling of the seepage field and the temperature field in the connecting channel. The model is used to simulate the influence of groundwater velocity, freezing pipe diameter, and initial ground temperature freezing pipe spacing on the temperature field development under single-row freezing, and the sensitivity formulas of the above factors on the freezing wall thickness and freezing time are given. Through the sensitivity analysis and comparison of various factors, the results show that the influence of the four factors on the freezing temperature field in descending order is groundwater flow rate, freezing pipe spacing, freezing pipe diameter, and initial ground temperature. In this case, it can effectively offset the influence of groundwater velocity on the freezing temperature field.