关键词: 富水砂层, 盾构隧道, 联络通道, 冻结法施工, 热固耦合, 地层温度

Abstract: In order to study the feasibility of freezing method in water-rich sand stratum and its influence on surrounding strata, based on the hydrogeological conditions and specific freezing construction schemes of projects, a three-dimensional thermo-solid coupling numerical model is established through ANSYS. The calculation results are corroborated by actual monitoring data, and the ground temperature diffusion distribution law and ground deformation response characteristics in frozen construction are proved. The results show that: (1) In the first 0~7 days, the soil temperature around freezing pipes drops significantly; as the freezing time increases to 20 days, the temperature change increases, and the cooling range expands further; when it has been frozen for 30 days, the cooling range no longer changes significantly. (2) After 30 days of freezing, the thickness of the freezing curtain around connecting passage has reached 2.4 m, which meets the design requirements. (3) Analyzing the on-site monitoring points and the numerical simulation results, it can be seen that their surface subsidence variation trend and value are consistent overall.

Key words: water-rich sand stratum, shield tunnel, connecting passage, artificial freezing method, thermosolid coupling, ground temperature