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投稿时间：2021-10-10 修订日期：2022-03-18
投稿时间：2021-10-10 修订日期：2022-03-18
中文摘要: 相比直线线路盾构施工，新建曲线盾构下穿施工引起既有隧道沉降规律更为复杂，且相关研究较少。基于两阶段分析法研究新建曲线地铁盾构隧道下穿施工引起的既有隧道沉降。第1阶段，结合镜像法、修正Loganathan法和Mindlin解，考虑曲线盾构转弯过程中的转弯超挖间隙和弯道内外侧不平衡施工参数的影响，计算新建曲线盾构施工引起土体竖向位移的3维解；第2阶段，将土体竖向位移视为位移荷载，施加在既有隧道上，基于Pasternak地基理论和Timoshenko梁理论，构建能够同时考虑土体剪切效应和既有隧道剪切效应的既有隧道沉降控制方程，运用有限差分法对方程降阶并求解。最后，与工程实例对比验证理论和控制方程的正确性，并对影响既有隧道沉降的关键参数进行分析。结果表明：新建曲线地铁盾构隧道下穿施工引起的既有隧道沉降槽曲线具有非对称性，最大沉降位置位于弯道内侧1～2 m处，与未考虑曲线影响的计算结果相差较大。减小掘进路线的转弯半径R0会增加既有隧道沉降，弯道内侧沉降增速大于弯道外侧，一般要求R0不小于300 m；当R0大于600 m时，可视作直线隧道下穿。增大刀盘直径D′会增加既有隧道沉降，沉降增加速度也随D′的增大而增大，但增大D′对沉降槽曲线的偏移程度影响较小。增大新建隧道与既有隧道竖向间距Zc会减少既有隧道沉降。
Abstract:Compared with the shield construction on straight lines, the settlement of existing tunnel caused by undercrossing construction of a curved metro shield tunnel is more complex and less studied. The settlement of the existing tunnel was analyzed using a two-stage analysis method. In the first stage, considering the effects of the over-excavation gap and the unbalanced construction parameters during the undercrossing, a three-dimensional solution of the tunnel-induced free ground settlement caused by the construction of a new curved shield was established using the mirror image method, modified Loganathan method and Mindlin solution. In the second stage, the tunnel-induced free ground settlement was considered as the displacement load imposed on the existing tunnel, and based on the Pasternak foundation and Timoshenko beam theory, a governing equation that can consider both soil and tunnel shear effects was established, and the finite difference method was used to reduce the order of the equation and solve it. The effectiveness of the governing equation was verified by engineering monitoring data, and the key parameters affecting the settlement of existing tunnels were analyzed. The results showed that the settlement groove of existing tunnels caused by the undercrossing construction of the new curved shield tunnel was asymmetrically distributed, and the maximum settlement position was located at 1～2 m inside the curve, which was different from the calculation results without considering the influence of the curve. The settlement of existing tunnels increased with the decrease of the radius of shield curve R0, and the settlement growth rate inside the curve was greater than that outside the curve, the general requirement was not less than 300 m. When R0 was greater than 600 m, it could be regarded as a straight tunnel. The settlement of existing tunnels also increased with the increase of the shield blade diameters D′, and the variational trend was presented obviously, but the impact on the settlement groove was small. The settlement of existing tunnels decreased with the increase of the vertical distance between the new tunnel and the existing tunnel Zc.
文章编号：202101018 中图分类号：TU43 文献标志码：
基金项目:国家自然科学基金项目（52068004）；广西自然科学基金项目（2018GXNSFAA050063）；广西重点研发计划项目（AB19245018）
作者简介:第一作者：江杰(1979-),男,研究员,博士.研究方向:隧道工程.E-mail:jie_jiang001@126.com
引用文本：
江杰,龙逸航,欧孝夺,邢轩伟,张探.新建曲线地铁盾构隧道下穿施工引起的既有隧道沉降分析[J].工程科学与技术,2023,55(1):313-324.
JIANG Jie,LONG Yihang,OU Xiaoduo,XING Xuanwei,ZHANG Tan.Analysis of Existing Tunnel Settlement Caused by Undercrossing Construction of Curved Metro Shield Tunnel[J].Advanced Engineering Sciences,2023,55(1):313-324.
引用文本：
江杰,龙逸航,欧孝夺,邢轩伟,张探.新建曲线地铁盾构隧道下穿施工引起的既有隧道沉降分析[J].工程科学与技术,2023,55(1):313-324.
JIANG Jie,LONG Yihang,OU Xiaoduo,XING Xuanwei,ZHANG Tan.Analysis of Existing Tunnel Settlement Caused by Undercrossing Construction of Curved Metro Shield Tunnel[J].Advanced Engineering Sciences,2023,55(1):313-324.