Long-term horizontal displacement induced by shield tunneling in consolidating soft ground

• Investigate how consolidating state affects shield tunneling-induced horizontal displacement. • Simulate the magnitude and distribution of long-term horizontal displacement numerically. • Compare the differences in long-term horizontal displacement between normally-consolidated and consolidating cases. • Propose an empirical method to estimate long-term horizontal displacement in consolidating soft ground. Shield tunneling often gives rise to excessive long-term horizontal displacement in consolidating soft ground, posing risks to the safety of adjacent structures. This study investigates the characteristics of long-term horizontal displacement induced by shield tunneling in consolidating soft ground, with the aim of providing practical guidance for optimizing ground treatment strategies. Firstly, a three-dimensional numerical model, validated by a case history in Shanghai, is employed to analyze the horizontal displacement of the soft ground. Comparisons are conducted between the horizontal displacements in normally-consolidated and consolidating cases. Subsequently, the influence of the consolidating state on the horizontal displacement is investigated by numerical analyses. The simulation results indicate that the short-term horizontal displacements follow a similar trend and comparable magnitude in both normally-consolidated and consolidating soft soil. However, the long-term horizontal displacements display a quite different pattern. The maximum discrepancy between normally-consolidated and consolidating cases is observed at the ground surface, where the long-term horizontal displacements of the two cases orient toward entirely opposite directions. The discrepancy at the ground surface increases as the degree of consolidation or the tunnel depth decreases, while it is relatively insensitive to the thickness of the newly filled layer. Finally, an empirical estimation method is proposed to predict the long-term horizontal displacement at the ground surface for shield tunneling in consolidating soft ground.