Analysis of stratum grouting influence on shaft lining stress with the methods of simulation and in site measurements

According to the principle that stratum grouting can effectively release and restrain the vertical additional stress on the shaft lining, based on the actual measurement results of a project, we established a model for calculating the stress on the shaft lining during stratum grouting, studied the impact of grouting pressure change on shaft lining stress during shaft curing, obtained a quantitative result, compared the actual measurement data about the shaft lining stress increase and the shaft top settlement condition with the numerical simulation result, and finally proved the accuracy of the numerical simulation result. The results indicated that the parameters like shaft lining stress, shaft deformation, and grouting pressure must be under effective monitoring in the project of preventing and curing shaft-lining rupture through intermittent stratum-grouting under low pressure; the safety of shaft during grouting is tightly related with grouting pressure, especially the circumferential stress and radial stress with grouting pressure. The circumferential and radial stress increase by 0.96 MPa and 4.3 MPa respectively when the grouting pressure increases by 1 MPa. The results can be applied to similar shaft lining treatment projects.