软流塑地层盾构隧道近接下穿运营线路的变形影响及控制技术

Deformation Influence and Control Technology of Shield Tunnels in Soft Flow Plastic Strata Passing through Operating Lines at Close Range

以南京地铁某区间盾构近接下穿运营隧道工程为依托,采用理论分析、模型试验、数值计算与现场监测等方法,研究软流塑地层中运营隧道在新建盾构隧道掘进全过程的变形特点。结果表明:左线盾构掘进完成后,运营隧道变形曲线为“V”形,右线盾构掘进完成后,运营隧道变形曲线由“V”形变为“W”形;数值计算与现场监测的沉降规律基本一致,最大沉降值分别为-4.36、-3.47 mm;洞内钢环+微扰动注浆联合加固措施,能够有效控制软流塑地层中盾构下穿引起的运营隧道沉降变形。

Based on the shield tunnel project in a section of Nanjing Metro passing through an operating tunnel at close range,the deformation characteristics of the operating tunnel in soft flow plastic strata during the whole process of newlybuilt shield tunneling are studied by theoretical analysis,model test,numerical calculation and field monitoring.The results show that after the completion of the left line shield tunneling,the deformation curve of the operating tunnel is in a"V"shape,while after the completion of the right line shield tunneling,the deformation curve of the operating tunnel changes from a"V"shape to a"W"shape.The settlement law of numerical calculation is basically consistent with that of field monitoring,and the maximum settlement values are−4.36,−3.47 mm respectively.The combined reinforcement measures of steel ring in the tunnel and micro-disturbance grouting can effectively control the settlement deformation of the operating tunnel caused by the shield tunneling through in soft flow plastic strata.