3D numerical simulation of melting temperature field of cement-improved soil cup-shaped frozen soil wall

To investigate the thawing law of cement-improved cup-shaped frozen soil wall, this paper performs 3D numerical simulation on the melting temperature field of cement-improved cup-shaped frozen soil wall and presents a comprehensive study of various influential factors, namely, thermal conductivity, specific heat and latent heat of the temperature field. This study was based on the horizontal freezing reinforcement project of shield tunnel of Nanjing Metro Line 10. It was found that initial temperature has little effect on the thawing rate of freezing cement soil while the location of frozen soil had larger influence on it. During the thawing process, the temperature of non-frozen soil at the outer wall of 1 m frozen soil decreased in the beginning stage and then increased, but there was an constant decrease in the soil temperature at the outer wall of 3~7 m frozen soil. The thawing time prolonged with the decrease of thermal conductivity, the increase of latent heat and the specific heat capacity. The effect of specific heat capacity was mainly reflected in the heating stage and the latent heat had main impact on the phase change of frozen soil. Thermal conductivity affects not only the heating stage but also the phase change.