The Simulation Study of Thawing Settlement of Ground Surface in Horizontal Freezing Construction of Metro Tunnel

摘要

The paper is based on the prototype project with underground tunnel adopted horizontal freezing in Dabeiyao station of Beijing. The study focuses on the effect of freezing and thawing on the deformation of ground surface in freezing construction by simulation tests. The study shows; During the thawing stage, the temperature appears ladder-type distribution along the direction of depth; the internal stress of soil body suddenly drops when the temperature reaches -4 deg C - 0 deg C. While adopting horizontal freezing construction, the ground surface deformation does not drop suddenly in thawing stage, but continuous. The frost heave in vertical direction is smaller than the thawing settlement in the same direction; meanwhile, an experimental formula is presented which coincides basically with the prototype project.