框筒结构高层建筑CFG桩复合地基基底反力及变形特征

Base reaction and deformation characteristics of CFG pile composite foundation for high-rise building with framed-tube structure

  • 摘要: 采用有限压缩层地基上中厚板等参元共同作用分析程序,对CFG桩复合地基分区不均匀布桩模型进行数值计算,并与均匀天然地基模型和CFG桩复合地基均匀布桩模型进行对比分析.研究发现,采用强化核心筒区布桩、相对弱化外框架柱区布桩的不均匀布桩优化模型,核心筒最大沉降和筏板相对挠曲均明显小于均匀布桩模型,对控制核心筒部位的绝对沉降量和筏板相对挠曲效果明显.不均匀布桩模型的基底反力分布与均匀布桩模型具有明显区别,和复合土层模量分布相关性明显:核心筒周边外扩1倍板厚范围内基底反力最高,分布较为均匀,基本呈线性分布;核心筒荷载有效传递范围为核心筒周边外扩2.5倍板厚区域,核心筒周边外扩1倍板厚至2.5倍板厚区域基底反力逐步衰减;核心筒周边外扩2.5倍板厚范围以外的外框柱区域基底反力最低,分布较为均匀,基本呈线性分布;基底反力总体呈盆形分布.

     

    Abstract: The base reaction of CFG pile composite foundation with non-uniform pile arrangement was numerically calculated by applying interaction analysis software that can consider the isoparametric elements of medium plates on a limited compressible foundation, and it was compared with that of uniform natural foundation and CFG pile composite foundation with uniform pile arrangement. The results show that if the piles are placed more densely at the core tube area than the external frame column area, the maximum settlement and the raft3s relative deflection are obviously smaller than those of the uniform pile arrangement. The base reaction distribution of non-uniform pile arrangement is quite different from that of uniform pile arrangement and it correlates well to the modulus of the composite earth layer:the base reaction is the largest and distributes evenly, nearly a linear distribution, within the extent of 1 time the slab thickness surrounding the core tube area; the effective transfer range of load is 2.5 times the slab thickness, and the base reaction gradually decreases within the extent from 1 time to 2.5 times the slab thickness surrounding the core tube area; the base reaction reaches minimum outside 2.5 times the slab thickness and distributes uniformly, almost following a linear distribution. On the whole, the base reaction shows a basin-shaped distribution.

     

/

返回文章
返回