Abstract:Field measurements were carried out in order to obtain the variation laws of the strains of the shaft lining during drainage and grouting. Research results are as following:the shaft lining is vertically compressed during dewatering aquifer in alluvium,and relative tensile strain is caused by Poisson¢s effect. Compared with the strain state at the beginning of each grouting operation,the shaft lining is vertically stretched in the period of grouting,and the inner margin of the shaft lining is tangentially stretched or compressed at the same time. There are two tension zones and two compression zones in the inner margin,and one of the tension zones is nearest to the grouting hole,with the other being farthest from the grouting hole. The central angle of the compression zone or tension zone is about 90°,the soil layers around the shaft lining are uplifted by grouting,and the vertical compression stress in the shaft lining is reduced. The above results are very useful and important for the operation of grouting.