Experimental and modeling investigation of freezing characteristic curve of silty clay using TDR: Fid-Bau Portal

Experimental and modeling investigation of freezing characteristic curve of silty clay using TDR

Xin, Quanming / Su, Yanjun / Cao, Yang / She, Xiaokang / Wang, Zhihui / Ling, Xianzhang / Yang, Tianhong

Abstract The soil freezing characteristic curve was investigated using TDR, and the freezing point model was established based on measured temperature-time curve. A modified model was established based on developed relationships between model parameters and total water content ωtotal. The freezing degree was defined to describe the freezing process. The freezing point increased hyperbolically with increasing ωtotal and decreased linearly with increasing dry density. A critical water content ωcr was proposed, the growth rate of unfrozen water content gradually decreased with increasing ωtotal when ωtotal < ωcr, and it was almost unaffected by ωtotal and dry density when ωtotal > ωcr. The three parameters that were related to initial phase transition position, residual unfrozen water content and phase transition intensity in the modified model changed with ωtotal rather than fixed constants, thereby overcoming the limitation that unfrozen water content continuously increases with increasing ωtotal in the original model, which is suitable and important for changing total water content in multi-field coupling analysis of freezing soil. Comparison between predicted and measured results showed a satisfactory agreement.

Highlights • The unfrozen water content of silty clay was investigated using time-domain reflectometry (TDR) during freezing process. • A critical water content ωcr was proposed, and the freezing degree was defined to describe the freezing process. • A modified SFCC model with new developed relationships between model parameters and total water content was established.