Tunnel segment uplift model of earth pressure balance shield in soft soils during subway tunnel construction

Segment uplift is a frequent problem during the construction of shield tunnels. This article presents a full-scale field test to study the influence factors of segment uplift, such as chamber pressure, advance rate, vertical component force of total thrust and grouting pressure and grout composition. This paper proposes a tunnel segment uplift calculation model of earth pressure balance shield based on a series of in situ tests in the typical soft soil stratum in China. The test results show that grouting pressure and grout composition have significant impacts on the segment uplift. However, the influences of chamber pressure, advance rate and total thrust are insignificant for the uplift. The analysis data based on the calculation model correspond well with the monitoring data in the shield tunnelling construction. By comparison, the deviation rate ranges from -19% to +15%.