Study On Freezing Temperature Field Of Cross Passage Considering Freezing Pipes’ End-effect

Frozen method has been widely used when constructing subway cross passage inChina. In the construction process frozen pipes are relatively short and these anglesare very different in each parts. And these lead to that the freezing pipes’ end-effects’influence on freezing temperature field can’t be ignored. In current study oftemperature field in the end of freezing pipe is not comprehensive when constructingthe cross passage. In this paper, numerical simulation and physical simulation testmethod will be used in the study of freezing temperature field of cross passageconsidering freezing pipes’end-effect for depth research.Firstly, the numerical simulation of the freezing temperature field has beencarried out. The law of freezing temperature field under the designed conditions hasbeen analyzed in the calculations. Considering the soil properties, the initialtemperature, freezing tube wall temperatures, freezing tube diameter, tube spacingfreeze, frozen pipes distance from the tube sheet, tube and tube sheet angle freeze andother factors’ impacting on the freezing temperature field. Single factor and multiplefactors orthogonal experiment has been carried out to analyze the impact on thetemperature field of various physical and geometric factors and their remarkablerelationship. And the non-dimensional regression formula of width, averagetemperature of frozen wall and the coefficient of temperature drop on the junction ofsegment and soil have been put forward by using multiple regression theory.Secondly, according to similar criteria, physical simulation experimental studyhas been carried out. The variation of the freezing temperature field on the soilbetween the freezing pipes’ end and the segments of cross passage and the junction ofsegment and soil at the test conditions has been discovered. And the fitting variancesaccording to the variation curves have been obtained.Finally, with the results of physical experiment and numerical calculation undertypical parameters compared, it was confirmed that the law of physical experimentwas consistent with the law of numerical simulation.The contents of this thesis will provide some references on the construction ofcross passage by using frozen method and the design and construction on actualengineering in the future.