Influence of lateral grouting points on deformation of shield tunnels under loads

As a deformation treatment technology for on-excavated tunnels, the rectification grouting of shield tunnel has been applied in engineering, but there is no basis for the layout of rectification grouting points, and there is no relevant analysis. In order to analyze the influences of different rectification grouting points on deformation rectification effect of tunnels, a model for lateral grouting is established on the basis of indoor model tests, and the influences of rectification grouting points on a shield tunnel are analyzed. Based on the established model, several working conditions of single-point grouting mode and multi-point grouting mode at the side are simulated, and the unit horizontal axial force, additional earth pressure, diameter change and deflection deformation data of the tunnel under different working conditions are read and analyzed. The smaller the net distance between the grouting point and the tunnel, the greater the maximum horizontal earth pressure generated by grouting at the tunnel side, but the smaller the influence range of the additional earth pressure of grouting. When the rectification range is small, it is recommended to adopt single-point grouting. Under the same grouting quantity, uniform grouting at multiple grouting points is beneficial to the uniform distribution of the additional earth pressure of the shield tunnel. When the rectification range is large, it is recommended to adopt multi-point simultaneous grouting mode.