Analytical determination of the soil temperature distribution and freezing front position for linear arrangement of freezing pipes using the undetermined coefficient method

Abstract When on-site tests are performed in artificial ground freezing projects, the conventional analytical method for determining the soil temperature field often presents significant error under certain conditions, particularly when the temperature-measuring pipe is far removed from the freezing front. This paper proposes a new method—called the undetermined coefficient method (UCM)—that more accurately predicts the actual soil temperature field and position of the freezing front. The UCM comprises a new mathematical formula developed based on a series of model tests performed under three different conditions—no seepage, constant seepage, and sudden seepage—and a multiple data regression analysis-based method for determining the coefficients in the developed formula. The proposed UCM was compared to a conventional analytical method based on the results from model tests and from the construction of the cross-channel of Guangzhou Metro Line 11. The results indicated that the UCM presented higher stability and practical value than conventional alternatives and could accurately predict the actual soil temperature field and position of the freezing front. Therefore, the UCM is expected to be of high practical value in artificial ground-freezing operations.