基础设施 2025年 第卷 第24期

DOI: 10.7672 / sgjs2025240009

浅覆土盾构小净距上穿对既有区间隧道的影响及控制措施研究

周毅

作者简介:

周毅,高级工程师,E⁃mail: 1509600720@ qq. com

作者单位:

上海隧道工程有限公司,上海 200032

基金项目:

∗河南省科技攻关项目(242102321025)

摘要:

郑州新建地铁 8 号线区间隧道上跨已运营地铁 2 号线区间隧道,最小上穿净距 1.45m,2 号线上浮风险极大。为保证地铁 2 号线运营安全,在 2 条线路重叠区域采取抗拔桩+盖板+MJS 注浆加固的保护性控制措施,并开展了盾构上穿施工诱发 2 号线区间隧道变形的现场监测和三维有限元数值模拟。研究结果表明,盾构小净距上穿施工使得既有区间隧道上浮量超过变形限值;采取抗拔桩+盖板+MJS 注浆加固综合性控制措施后,既有隧道最大上浮量约 3mm,满足既有隧道变形控制要求。既有区间隧道的上浮大致呈等腰梯形形态;既有隧道与新建隧道相交位置处的上浮量随左、右线盾构掘进施工的变化规律具有明显对应性;盾构机在一侧掘进时引起的上浮量大,在另一侧掘进时引起的上浮量小,但同一线路上两交点的最终上浮量大致相同。当既有区间隧道邻近地下建筑物时,受其约束作用,邻近地下建筑物一侧线路的隧道上浮量要小于未邻近线路的上浮量。

English:

The newly constructed Metro Line 8 in Zhengzhou crosses over the operational Metro Line2 running tunnel,with the minimum clearance of 1.45m, posing a significant risk to Metro Line 2. Inorder to ensure the operational safety of Metro Line 2, protective control measures of anti⁃pull pilescombined with cover plates and MJS grouting reinforcement are taken in overlapping areas of the twolines. Additionally, in⁃site monitoring and three⁃dimensional FEM numerical simulation are conducted toassess the potential deformation of Metro Line 2 running tunnel induced by the shield tunnelingconstruction of Metro Line 8. The research results show that the shield tunneling construction with smallclearance causes the existing tunnel to exceed the deformation limit; However, after implementingcomprehensive control measures of anti⁃pull piles combined with cover plates and MJS groutingreinforcement, the maximum uplift of the existing tunnel is approximately 3mm, meeting the deformationcontrol requirements. The uplift of the existing tunnel generally takes on a trapezoidal shape; The upliftat the intersection of the existing and new tunnels corresponds significantly to the variations in shieldtunneling construction on the left and right lines. The uplift caused by shield tunneling on one side isgreater than on the other side, but the final uplift at the two intersection points on the same line is roughlythe same. When the existing tunnel is adjacent to underground buildings, the uplift on the side of thetunnel adjacent to the building is smaller than that on the side not adjacent to buildings due to the constraint effect of the nearby structures.