Objective Shield construction in small-radius curves easily induces adverse conditions such as segment misalignment and damage, degraded assembly quality, and horizontal axis deviation. Therefore, it is necessary to study analytical methods for displacements, such as deviation and floating during the shield construction of small-radius curve tunnels to identify the patterns of segment displacement.

Method The causes of displacement scenarios such as segment stress and deformation induced by shield thrust and segment floating induced by grouting pressure during construction are analyzed. Based on a modified longitudinal equivalent shear stiffness model and the Winkler elastic foundation beam theory, an analytical method for segment displacement of small-radius curve shield tunnels is proposed using a modified equivalent stiffness model. The algorithm's rationality and engineering applicability are validated relying on the shield tunnel project in Nanchang Metro Line 3 Qingshanhu West Station–Shangshagou Station section, and influence laws of shield thrust and grouting load on segment displacement in curve sections are analyzed further.

Result & Conclusion For segments deviation and floating, the solution results of the displacement analytical method for small radius curve shield tunnel segments fit well with the on-site monitoring results. This indicates that the analytical method possesses good engineering applicability and can be effectively applied to solve displacement calculation problems such as segment misalignment and uplift during shield tunneling in small-radius curve tunnels.