大曲率弧形隧道基坑坑中坑施工结构影响分析

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中图分类号：TU753 文献标志码：A 文章编号：1672-1098（2025）06-0076-11

Abstract： Objective In recent years，the acceleration of urbanization has driven the demand for underground transportation infrastructure， with the construction of large-curvature irregular deep excavations and nested pits attracting increasing attention due to their impact on surrounding environments and main stability. Methods Based on the Huimin Avenue renovation project in Nanjing，the deformation paterns of excavation and its effects on the surrounding environment was investigated by using finite element numerical simulations to address issues such as basal heave，retaining structure deformation，and surface settlement during excavation.Results It was found as folow.During the excavation of the main foundation pit and the pit-in-pit，the horizontal displacement of the north-side diaphragm wall and the ground settement behind it increased significantly，whereas the south side experienced lesser effects.The maximum horizontal displacement of the diaphragm wall was closely correlated with excavation depth， exhibiting a distribution pattern characterized by smaler displacements at both ends and larger displacements in the middle. As the excavation progressed deeper，the deformation inthe "bulging section" became more pronounced.Further excavation of the pit-in-pit also exacerbated the displacement trend of the retaining piles on the north-side.To mitigate deformation， the two control measures of inclined piles and soil reinforcement were compared，with the results indicating that the inclined pile scheme offered limited effectiveness in controllng retaining pile deformation，but the soil reinforcement using triple-axis deep mixing piles significantly reduced displacement of the northern diaphragm walland surface settlement， while also mitigating the outward displacement trend of retaining piles. Conclusion This study provides scientific guidance and technical support for similar projects.Through optimized designs and reasonable reinforcement，efficient control of complex underground engineering will be achieved while ensuring construction safety and environmental protection.

Key words： tunnel construction; pit deformation; finite element analysis; large curvature; pit-in-pit; diaphragm wall

伴随着国内经济的快速发展城市化率不断提高，城市地下空间不断被开发利用。（剩余9914字）