Abstract: In response to the problem of low shaft wall temperature of the frozen shaft in the deep thick alluvial layer area,taking the freezing of a certain ventilation shaft as an example,a freezing scheme design was carried out based on the characteristics of the shaft being located in the strata dominated by viscous soil and a high flow rate of Neogene groundwater.The design focused on freezing holes in the outer annulus.By comparing the predicted shaft wall temperatures,measures such as adjusting the temperature of brine,initiating and stopping the circulation of brine in the inner annulus,and intermittent circulation were taken to control the shaft wall temperature in the alluvial section to not be below -12 ℃,and good results were achieved.Shaft wall displacement monitoring conducted during shaft excavation indicated that when the template height was not higher than 4 m and the high excavation time for a single circulation section did not exceed 32 h,the average shaft wall displacement on one side did not exceed 26.5 mm.However,when the high excavation time for a single circulation section was extended from 32 h to 34 h,about 22 % of the shaft wall experienced a one-side displacement exceeding 50 mm.