水泥土杯型冻结加固盾构隧道端头温度场发展规律研究

Research on the development rule of temperature field at the end of shield tunnel strengthened by cement modified soil cup

盾构隧道端头冻结法施工的关键是形成稳定封闭的冻结壁。为掌握水泥改性土杯型冻结温度场的发展规律,以杭州地铁4号线某盾构隧道端头冻结工程为例,考虑地层温度与相变潜热,对水泥改性土冻结温度场进行了三维数值模拟。研究表明其中水泥土降温规律分为快速降温、相变阶段、降温、趋于平缓4个阶段;砂土水泥土、黏土水泥土、砂土、黏土这四种土体中砂土水泥土降温速度最快,研究结果为类似工程提供参考。

The key of shield tunnel end well freezing method is to form a stable and closed freezing wall.In order to master the development law of the cup type freezing temperature field of cement modified soil,taking a shield tunnel project of Hangzhou Metro Line 4 as an example,considering the formation temperature and latent heat of phase change,the three-dimensional numerical simulation of the freezing temperature field of cement modified soil is carried out.The results show that the cooling law of cement soil can also be divided into four stages: rapid cooling,phase change,cooling and flattening;among the four types of soil,sand cement soil,clay cement soil,sand and clay,the cooling speed of sand cement soil is the fastest and that of clay is the slowest.The research results provide reference for similar projects.