Abstract:In order to investigate the changes of surface settlement caused by shield construction in small curvature radius tunnel, an analytical calculation model of surface settlement caused by shield construction in small curvature radius tunnel was established by using Mindlin solution, and the reasonableness of the settlement prediction model established was verified by comparing and analyzing with field monitoring and existing Mindlin analytical calculation model based on the shield tunnel project of Nanchang Metro Line 1. The results of this study show that the additional thrust of the shield, the uneven friction of the shield shell, and the ground deformation of the ground loss are analyzed in turn. The results show that the analytical calculation model of ground settlement caused by shield construction in small curvature radius tunnels can be effectively used for the prediction of ground settlement in actual tunnelling projects, and the prediction accuracy is improved. During the shield excavation process, the cross-sectional ground settlement trough is "V" shaped and approximately normally distributed, and the ground settlement is more influenced by the stratum loss generated by the construction. With the increase of uneven distribution of thrust and friction force on both sides of the shield path, the offset of the center of the ground settlement trough increases, and the ground settlement is nonlinearly related to the ground loss. The results of the study can provide theoretical guidance and reference for similar proposed and under-construction shield tunnel projects.