先隧后站工法中盾构管片分阶段拆除施工技术改进优化

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中图分类号：TQ178；TU713 文献标志码：A文章编号：1001-5922（2025）12-0245-04

Improvement and optimization of construction technology for phased demolition of shield segment in tunnel first and station later construction method

WU Ruoyu （Foshan Airport Construction and Development Co.，Ltd.，Foshan 528ooo，Guangdong Chian）

Abstract：In viewof the complex working conditions of the intersection betweenthe foundation pit and the section of Foshan Metro Line 3in thecomprehensive transportation hub projectofFoshan Stationof Guangzhan high-speed railway，he construction methodof“tunnel first and station later”is adopted.In the original scheme，the shield segment of the interference section needs to be removed in advance to setupthe internal support when the foundation pit is excavated tothe tunnelarea.However，thedemolition operationleads to the sudden change of the axial deformationofthe tunneloutsidethe pit，and exposes the defects ofthelagof the support timeliness and the discontinuity of the structure.Therefore，the optimization scheme is proposed：the thicknessof theunderground continuous wallof the retaining structure is increased from1m to1.2 m;an internalsupport is added when excavating to the topof the segment;the segments inthe pit wereremoved instages （half-rings wereremoved at the waistline and supports were erected，andthe remaining parts were removed at the botom of the pit）.The comparative analysis shows that the optimization scheme significantly suppresses the sudden change of the axial deformation of the tunneloutside the pit under the key working conditions，and the peak displacement decreases by15%～25%，which effectively improves the stability of the foundation pit and the safety of the adjacent subway.

Key words：tunnel-firstand station-later;optimizationof deep foundation pit support;tunnel deformation control

随着城市地下空间开发的不断深入与轨道交通网络的日益密集，邻近既有隧道（特别是地铁隧道）进行深基坑开挖的工程挑战日益凸显。（剩余5215字）