Freezing Large Shaft Design of about One Kilometer Deep

The freezing depth(955 m) of Hetaoyu coal mine auxiliary shaft is the deepest one in the world,25 m more than that of Balby Potassium Salt Shaft No1,UK,(930m in depth).The shaft has met obstacles in the construction process,and has been forced to use freezing construction.Therefore,the design is very difficult.This paper focuses on the characteristics of the shaft freezing scheme,difficulties and problems to be solved,and makes a comparison with Balby Potassium Salt Shaft No.1.Aiming at the engineering difficulties,large diameter(Φ 168 mm) freezing tube is put forward,together with concentric double fluid supply tube and temperature control tube to control freezing wall development to solve the problems in design.Good effects are obtained.It is useful for the similar engineering in the future.