Study on Thaw-Settlement Effect of Sandy Cobble Ground under Freezing Construction

The whole freezing process construction of the metro liaison channel is simulated using the indirect method to realize thermal-mechanical coupling by ANSYS to highlight the thaw-settlement characteristics in the freezing structure of the liaison channel on water-rich sandy cobble ground. The discussion of the surface settlement, deformation, and stress characteristics in the thaw-settlement stage of segment structure and liaison channel structure of the double-line tunnel in water-rich sandy cobble ground provides a valuable reference for the construction of the practical project. The results show that the surface settlement increases gradually with the thawing of sandy cobble ground. However, the thaw-settlement effect of sandy cobble ground is small, and the thaw-settlement deformation of the stratum is only 1.85 mm. The settlement value of the segment and the liaison channel structure increases gradually with the thawing of sandy cobble ground. At the same time, the tensile stress of the segment and the liaison channel structure decreases, and the compressive stress increases. The settlement deformation at the top of the connection between the segment structure and the liaison channel structure, the segment’s compressive stress at the bottom of the connection, and the settlement deformation and compressive stress at the floor of the liaison channel should be well-monitored in actual construction.