For the characteristics of allowing constructing tunnels in adverse geological conditions including difficult ground conditions as well as tunnels in vulnerable urban areas, tunnel boring machine (TBM) has well-established tunnel construction method recently.^1,2 When a tunnel is being excavated, the following two steps in the shield machine are conducted alternatively: the tunneling of the TBM by all jacks in the thrust system applying active forces on the rear segments that simultaneously carries out the excavation of the soil and rock at tunneling face by the rotating cutter-head, and the installation of a segment ring of the shield lining system with simultaneous void grouting at the tail while the machine stops working.³ Therefore, the design of the thrust system is playing an important role in building a high-quality tunnel with great seal performance.⁴

中文翻译：

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混合地层下基于几何级数的隧道掘进机非等距推力系统布置优化

针对隧道掘进机（TBM）可在恶劣地质条件下（包括困难的地面条件）以及在脆弱的城市地区隧道施工的特点，近年来，隧道掘进机（TBM）形成了成熟的隧道施工方法。^1,2隧道开挖时，盾构机交替进行以下两个步骤： 推力系统中的所有千斤顶对 TBM 进行掘进，对后段施加主动力，同时进行土方开挖通过旋转刀盘对掘进面进行岩石和盾构衬砌系统的节片环安装，并在机器停止工作时在尾部同时进行空隙注浆。³因此，推力系统的设计对于建设具有良好密封性能的高质量隧道起着重要作用。⁴