Characteristics Of Artificial Freezing Temperature Field And Inverse Heat Conduction

In this paper, a number of theories have begun to freeze construction on the system are described, for example, made of artificial freezing,freeze some of the temperature field theory, permafrost thermal conductivity and Inverse Problems.Then use the above theory, combined with a specific construction plan Guangzhou subway, the subway freezing temperature field were measured analysis. Very typical 5.4m mucky silty sand soil at the same time to take the subway tunnel, the soil test, soil parameters get changed. On an experimental basis, to change the soil thermal conductivity and inverse analysis were studied, and the use of the current domestic and international mainstream very finite element analysis software ANSYS, freezing temperature field simulation and analysis. Finally, subway construction freeze in the development of the frozen wall made a prediction and gives some reasonable suggestions.Thermal conductivity is an important parameter to study the temperature field of thermal conductivity carried out experiments, the thermal conductivity and dry density, moisture content of the relevant conclusions, dry density, moisture content is the most important factor, artificial freezing mucky fine powder the thermal conductivity of sand when the average growth rate of about -10℃ increase per 0.1g/cm3 0.06W/ m.K, the average growth rate of artificial freezing Muddy fine sand -10℃ when the thermal conductivity is about 5 percent of every moisture content increase thermal conductivity 0.04W/m.K. On the basis of the theory of least squares on the test set several thermal conductivity, and its analysis and optimization, the final thermal conductivity corresponds to the minimum objective function value is 30.77, then the corresponding thermal conductivity of 1.35 W/m·K, the thermal conductivity of the corresponding temperature field simulation results closest to the measured value. This value is then simulated temperature and thermal conductivity under the measured temperature value for comparison, the temperature of the simulated and measured values of the four holes for measuring temperature of less, which means that the authenticity and reliability of anti-analysis tests.In the article last ANSYS software layers of soil 5.4m temperature, freezing wall thickness was simulated, and on that basis to make a post lap times prediction forecast at 5.4m soil for the first 60 days,and transfer a temperature-related cloud temperature simulation.Results of this study as permafrost anti-analysis provides a new method for the construction of underground frozen method provides empirical reference has important significance and value of the works.