Temperature field study of forced thawing by pipe curtain freezing method in Sanya submarine tunnel

Compared with other construction methods, artificial freezing technology has the advantages of good anti-penetration performance and zero pollution to the surrounding environment, and is widely used in tunnel construction under complex environment, in which the thawing temperature field during the construction period has been the focus of attention in the actual construction.Taking the freezing of the tube curtain of the undersea tunnel in the Sanya estuary waterway as the engineering background, the finite element software was used to establish a model to analyse the development of the thawing temperature field, the 0 degrees C isotherm and the warming curves at the observation points.The results show that: when the circulating hot water temperature reaches more than 30 degrees C, the effect of shortening the thawing time is not obvious, which means that the thawing time is gradually stabilised when the circulating hot water temperature rises to a certain value. The thawing time decreases with the increase of seepage velocity, and the effect of shortening the thawing time is not obvious when the head difference exceeds 4m, which indicates that the thawing time is gradually stabilised when the head difference increases to a certain value. The results obtained provide reference for similar projects.