Analysis of segment uplift during shield tunnel construction considering stratum seepage effects

Segment uplift is a common phenomenon during shield tunnelling. To investigate the underlying mechanism and influencing factors under groundwater seepage, this study examines a tunnel section of the Dalian Metro. A three-dimensional grout–segment–soil interaction model was developed based on actual geological conditions, incorporating synchronous grouting and soil permeability. The model was validated against field measurements, and a systematic numerical investigation was conducted to assess the effects of standard operating conditions and various parameters on segment uplift. Results indicate that pore water pressure increases during shield advancement and synchronous grouting, with the greatest influence observed at the invert and the least at the crown. Uplift magnitude increases progressively from the crown to the invert. Most uplift occurs within Rings 0–5 behind the shield tail, after which deformation stabilises. Synchronous grouting accounts for the majority of total uplift, particularly during the injection phase, while groundwater seepage contributes approximately 18.21%. Greater tunnel burial depth, higher grouting pressure, and longer initial setting point distance all lead to increased uplift magnitudes. Based on the normalised analysis, an empirical expression was established to describe segment uplift as a function of tunnel burial depth, grouting pressure, and the initial setting point location.