Features of the Temperature Cracks in a Tunnel Final Lining

Cast-in-place concrete lining, which is the major structure of a tunnel with composite or monolithic lining, requires high safety, durability and waterproof performance. The prevention and control of lining concrete cracks are of great concern. However, the temperature and shrinkage cracks in the arch and wall of a cast-in-place concrete lining are common construction quality defects in practical cases. This contribution presents the changing features of temperature crack widths in responding to the temperature variation with seasons in several cast-in-place final ling panels, where there are no waterproof and drainage sheets in their composite linings. The crack width changing features imply that the constraints to the temperature drop and shrinkage deformation of the concrete in its arch and wall in construction stage still work in the period of post-construction. Considering the cracks beyond the planned allowable values, the information on the width changing features presents clue to determine the rule on the occurring and developing of the temperature and shrinkage cracks in the cast-in-place lining concrete, as well as crack resistance design and construction quality control.