跨江泥水盾构掘进过程中的沿江路段地表变形特征

Surface deformation characteristics cross the river during slurry shield tunneling

为研究盾构隧道施工对地表变形的影响,以某过江盾构隧道沿江大道段的施工为背景,通过对现场监测数据以及施工过程的分析得出地表变形规律及其成因,结合三维有限元模拟该段盾构施工,并与实测值进行对比,根据分析结果以及工程实践提出盾构施工地表变形控制措施。研究结果表明:施工过程中泥水压力对地表沉降影响显著;实际盾构掘进过程中引起的地表横向变形分布表现为隆起变形,且与传统Peck沉降曲线存在区别,纵向地表变形整体表现为先沉降后隆起的趋势,在掘进过程中应调整泥水压力控制地表变形;隧道有限元模型模拟结果与监测数据趋势一致,在有针对性的工程措施保证地表变形值总体可控。

Based on a real project of cross river shield tunnel,the influence of shield driving on ground deformation had been studied,by combing the analysis of field monitoring and three-dimensional finite element simulation.The results show that:the longitudinal settlement is greatly affected by the slurry pressure fluctuation during shield driving.The lateral deformation of ground surface caused by shield driving is different from the one obtained from traditional Peck settlement curve.Longitudinal deformation of ground shows the trend of settlement first and then uplift,and the slurry pressure should be adjusted to control the ground deformation in the process of tunneling.The simulation result is in accord with the field monitoring data,which indicates that the settlement could be under control if some related measurements are adopted.