端头井基坑施工对紧邻地铁车站的影响和对策  

The Influence of the Excavation Construction of Working Shaft on Adjacent Metro Station and Countermeasures

作　　者：陆可伟 陆风娟 唐嘉程 

机构地区：[1]江苏先行建设有限公司,江苏 常州 [2]南京理工大学机械工程学院,江苏 南京

出　　处：《土木工程》2023年第3期244-257,共14页Hans Journal of Civil Engineering

摘　　要：地铁端头井基坑开挖深度超过25 m,属于超深基坑。软土地区超深基坑施工必然发生围护墙水平挠曲变形和坑底土层回弹,这将导致周边土体较大的扰动,进而导致紧邻的既有地铁车站结构的变形和应力重分配。本文就常州六号线某车站端头井施工对紧邻既有地铁一号线车站结构的影响,采用有限元软件Midas/GTS-NX进行了计算分析,结果表明,施工导致的底板竖向位移超出地铁维护部门的位移控制标准。如果采取坑内地基加固和打设抗拔桩措施,位移可以减小到标准允许值范围内。在三维数值模拟中,粘性土和水泥土采用修正莫尔–库仑模型(MMC模型),粉土和砂土采用莫尔–库仑模型(MC模型),计算结果可与实测结果较好地吻合。Working shaft of metro station needs to dig more than 25 m deep and the excavation is classified as super-deep one. Super-deep excavation in soft soil always leads to deflection of retaining wall and rebound deformation of soil below final excavation line, which will bring disturbance to surrounding soil of the working shaft, and further leads to the deformation and stress re-distribution of the structure of existing metro station adjacent to the working shaft. In this paper, finite element software Midas/GTS-NX is used to calculate and analyze the influence of the excavation construction of working shaft of a station of Line No. 6 Metro Station in Changzhou on the structure of adjacent existing Line No. 1 Metro Station. The results show that the vertical displacement of bottom slab caused by the construction exceeds the displacement control standard of the subway maintenance department. The displacement can be reduced to the standard allowable value if the measures such as introducing ground improvement and adding uplift pile are taken. In the 3D numerical simulation, the Modified Mohr-Coulomb model (MMC model) is adopted for cohesive soil and cement mixed soil, and Mohr-Coulomb model (MC model) for incohesive soil, and the calculation agrees well with the site measurement.

关 键 词：端头井 基坑 既有地铁车站 数值模拟 修正莫尔–库仑模型 

分 类 号：TU7[建筑科学—建筑技术科学]