武汉软土地区盾构施工地面沉降与注浆加固研究

Research on settlement of ground surface and grouting reinforcement of shield construction in soft soil region of Wuhan

城市软土地层中盾构施工极易引起地面沉降,沉降的分析与控制对于保护隧道周边建筑物尤为重要。依托武汉软土地区地铁3号线某盾构隧道工程,选择典型软土地质断面,将现场监测数据与数值模拟相结合,研究了不同软土地质分布下盾构施工沉降规律,并对软土深厚区段注浆加固范围进行分析。结果表明:软土空间分布对盾构施工地面沉降影响较大,且沉降量随着隧道断面软土比例的增大而增大,减小隧道断面与软土相交能有效降低地面沉降;对于软土深厚区段洞内注浆加固能显著改善地面沉降,但随着注浆的范围增大,改善效果逐渐减小,注浆范围达到隧道以外3 m就能较好地控制地面沉降。

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.