关键词: 盾构隧道; 软土地层; 施工沉降; 注浆加固; 数值模拟;

Abstract: Construction of shield tunnel in urban soft soil stratum can easily result in ground surface settlement, so the analysis and control of settlement is particularly important for protection of buildings around the tunnel.Aiming at a shield tunnel project of subway in Wuhan soft soil area, some typical soft soil geological sections are selected to analyze the settlement law of shield construction under different soft soil distribution based on the combination of monitoring data and numerical simulation.The range of grouting reinforcement in deep and thick soft ground section is also analyzed.The results show that the spatial distribution of soft soil has a great influence on ground surface settlement during shield construction, and the settlement increases with the increase of proportion of soft soil in the tunnel section, thus reducing the intersection of the tunnel section and soft soil can effectively reduce the settlement of ground surface.In addition, grouting reinforcement in the deep and thick soft soil region can significantly restrain the ground settlement, but with the increase of grouting scope, the improvement effect gradually decreases.The ground settlement can be well controlled when the grouting range is in 3 m around the tunnel.

Key words: shield tunnel; soft soil stratum; construction settlement; grouting reinforcement; numerical simulation;