摘要
针对洛阳龙门地铁站深大基坑CFG桩复合地基承载特性及优化设计问题,利用有限元软件MIDAS-GTS NX建立CFG桩复合地基三维模型,分析地基沉降变形、桩身轴力、桩侧摩阻力的变化规律以及桩长、桩间距、褥垫层厚度对地基沉降和桩土应力比的影响,确定CFG桩复合地基最优设计。结果表明:CFG桩复合地基沉降最大值为18.5 mm,较天然地基沉降减小43.9%;轴力最大值位于桩长3.2 m处,与中性点位置一致;确定CFG桩复合地基最优方案为:CFG桩桩长不小于5.5 m且桩端深入持力层0.5 m,纵横桩间距为2.5 m,碎石褥垫层厚度为0.3 m。优选方案数值模拟变化规律与现场监测数据和理论计算结果基本一致,可为同类工程的设计施工提供参考。
Aiming at the bearing characteristics and optimal design of the CFG pile composite foundation for the deep and large foundation pit of Luoyang Longmen Metro Station,the finite element software MIDAS-GTS NX is used to establish the 3D model of the CFG pile composite foundation.The variation law of foundation settlement deformation,pile axial force,pile side friction resistance,and the influence of pile length,pile spacing,and cushion thickness on foundation settlement and pile-soil stress ratio are analyzed,and the optimal design of CFG pile composite foundation is determined.The research results show that the maximum settlement of CFG pile composite foundation is 18.5 mm,which is 43.9% lower than that of natural foundation.The maximum axial force is located at the pile length of 3.2 m,which is consistent with the position of the neutral point The optimal scheme to determine the CFG pile composite foundation is as follows:the length of the CFG piles is not less than 5.5 m,the pile end is 0.5 m deep into the bearing layer,the vertical and horizontal pile spacing is 2.5 m,and the thickness of the gravel cushion is 0.3 m.The numerical simulation variation law of the optimal scheme is in good agreement with the on-site monitoring data and theoretical calculation results,and achieves ideal results.
作者
袁英奇
李经宇
罗明国
吴潇
于英霞
李文杰
YUAN Ying-qi;LI Jing-yu;LUO Ming-guo;WU Xiao;YU Ying-xia;LI Wen-jie(The 1st Engineering Ltd.,of China Railway 11th Bureau Group,Xiangyang 441104,China;School of Civil Engineering,Henan University of Science&Technology,Luoyang 471000,China)
出处
《河南城建学院学报》
CAS
2022年第6期1-7,共7页
Journal of Henan University of Urban Construction
基金
国家自然科学基金项目(U1604135)
中铁十一局集团重点科研课题(18-AⅡ-02)。
关键词
深大基坑
CFG桩复合地基
承载力
优化设计
deep and large foundation pit
CFG pile composite foundation
bearing capacity
settlement
optimization design
