地铁联络通道冻结法施工数值模拟分析-岩土工程专业论文.docxVIP

ABSTRACT Artificial freezing method is widely used in mine construction projects, in recent years, with the development of underground engineering, artificial freezing method has been commonly used in the construction of connecting passage of the subway tunnel. In the past artificial frozen wall design is mainly based on the construction of the mine, but there is a big difference between the urban underground engineering and mines in depth, construction method and construction stress, so the related design calculation method is also different. So far research on the temperature field and displacement field of frozen soil freezing and thawing in the construction of the subway connecting passage by the artificial freezing method is rare. In addition, the numerical simulation of connecting passage construction by the artificial freezing method rarely takes the phase change process of soil into consideration. However, the process of soil freezing is a thermodynamic coupling process, considering the interaction of temperature field and displacement method is an inevitable requirement of further development. Aiming to solve the above problems, this paper establishes a numerical model of a connecting passage in tianjin subway construction. In the process of artificial frozen, coupling effect of the temperature field and displacement field is simulated, and the freezing temperature field distribution and development are also studied. Method to determine the average temperature of the frozen wall with a certain thickness range is proposed, also method to determine the freezing time that is used to attain the temperature is proposed; Based on the research of the displacement field in the process of freezing, the impact on the surrounding environment of the artificial freezing method construction is evaluated. The main research contents and conclusions are as following: Based on the thermodynamics, thermal elastic mechanics theory and the assumption of the temperature change