Based on the assumptions of exponential fluid and narrow plate model

formulas for calculating the climb height of grout in shaft base post grouting was deduced. It is shown that the climb height of grout is mainly related to the grouting pressure

the shaft length

the shaft diameter and the mudcake thickness. With the theoretic analysis and case study

it is indicated that thicker mudcake

higher grouting pressure and shorter shaft length would lead to larger climb height and larger risk of overflow. The overflow of grout would be prevented by reducing the grouting pressure

the mudcake thickness and debris thickness. The overflow of grout can also be prevented by increasing the strength of mudcake. For the overflow shafts

intermission grouting would be employed. Compared with the ordinary shafts

the former has higher bearing capacity than the latter

resulting from the grout upwards along the shaft soil interface.