盾构出洞水平冻结加固冻土温度场发展规律研究

Study on Temperature Field Development Law of Horizontal Freezing Reinforcement for Shield Tunneling Terminal

盾构隧道端头井冻结法加固的重点在于形成稳定封闭的冻结壁。以杭州地铁4号线江北风井盾构出洞工程为例,考虑相变潜热及端头井地下墙与冻土之间的热交换,通过数值模拟与冻结实测数据对比,分析了盾构出洞过程中的冻土温度场发展规律,提出了水平冻结加固风险控制措施。

A reinforcement key of ground freezing method for a shield tunnel terminal shaft would be to form a stable and closed freezing wall.Based on a shield tunneling terminal engineering of Jiangbei ventilation shaft in No.4 Line of Hangzhou Metro System as a case,in consideration of the phase transition latent heat as well as a heat exchanging between the underground wall of the terminal shaft and freezing soil,with a comparison between the numerical simulation and the freezing measured data,the paper analyzed the development law of the freezing soil temperature field during the process of the shield tunneling terminal and provided the risk control measures of the horizontal freezing reinforcement.