摘要
市政隧道深基坑开挖工程是市政建设的重要工程课题之一,开展深基坑支护结构的力学分析及优化设计研究具有重要的工程应用价值。依托南通啬园路隧道深基坑开挖工程,采用数值仿真技术对该市政隧道深基坑的变形规律进行研究。利用MIDAS GTS软件建立结构的三维有限元模型,模拟基坑开挖过程,获得支护结构位移和周围地层沉降位移等基坑变形数据以及钢支撑轴力特性,确认支护结构的安全性和稳定性。鉴于项目工期紧、施工工序复杂等施工难题,提出免去钢支撑斜撑并抬高第一道钢管支撑标高以加快工程进度的优化施工方案。通过对比有无斜撑的2种方案下支护结构的位移和应力,验证优化施工方案的有效性和可行性。根据数值分析,确定第一道钢管支撑的合理标高。所提出的优化施工方案可加快工期并降低工程造价,为同类深基坑开挖工程提供参考。
Deep foundation excavation of municipal tunnel is one of the important subjects of municipal construction,and it is of great value to carry out mechanical analysis and optimization design of support structure of deep foundation pit.Based on the deep excavation pit of Seyuan Road Tunnel in Nantong,the deformation law of this deep foundation was studied by numerical simulation.A three-dimensional finite element model of the structure was established by using MIDAS GTS to simulate the excavation process of the foundation pit,and obtain the deformation characteristics and mechanical property of foundation pit such as the displacement of the support structure,the settlement displacement of surrounding strata and axial force of steel supporting.The safety and stability of the support structure were further analyzed.In view of the construction problems such as tight construction period and complicated construction process,an optimized construction scheme was proposed,in which the diagonal brace was removed and the elevation of the first steel pipe supporting was raised in order to speed up the project.By comparing the displacement and stress of the support structure with or without diagonal brace,the feasibility and effectiveness of the optimized construction scheme are verified.The reasonable elevation of the first steel pipe support is determined by numerical analysis.The proposed optimized construction scheme can accelerate the construction period,reduce the cost,and provide theoretical reference for the excavation of similar deep foundation pits.
作者
柴磊
孙亚星
CHAI Lei;SUN Yaxing(Zhengzhou Engineering Co.,Ltd.of China Railway Seventh Group,Zhengzhou 450052,China)
出处
《现代交通技术》
2021年第5期18-26,共9页
Modern Transportation Technology
关键词
深基坑
支护体系
优化
有限元
位移
deep foundation pit
support system
optimization
finite element
displacement
