浅覆越河盾构隧道施工期管片上浮力学特性研究

Research on Mechanical Properties of Segments Floating in the Construction of Shield Tunnel Through River Shallow Overburden Strata

盾构隧道穿越跨河段浅覆土地层时,在施工阶段管片上浮问题不容忽视。以土压平衡盾构穿越深圳地铁7号线大沙河段为工程依托,采用三维数值模拟与现场监测数据分析,对脱离盾构的管片衬砌结构在注浆压力作用下所发生的上浮现象进行计算研究。通过分析盾构掘进过程中管片上浮对地表沉降、管片变形量及受力的变化特征,获得管片上浮对地表及衬砌结构的影响规律;对现场监控量测数据进行分析,进一步证实了数值模拟的合理性。

When the shield tunnel passes through river shallow overburden strata, segments floating problem can’t be ignored during the construction process. Based on the project of shield tunneling underneath Dasha River of Shenzhen Metro Line 7, the three-dimensional numerical simulation and field monitoring data were adopted to analyze the phenomenon of floating that segments jumps out from shield tail under grouting pressure. By analyzing the change features of ground settlement, segments floating values and stress in the shield segments floating, the influence rules of surface and lining segments were obtained. The field monitoring data were analyzed and compared with simulation results to further prove that the laws are reasonable.