不同布桩形式群桩基础模型试验研究

变刚度调平设计是2008版《建筑桩基技术规范》的重要修订内容,群桩基础变桩长、变桩距是变刚度调平设计手段之一。为了减小等刚度布桩群桩基础的差异沉降及调整桩顶反力分布,通过4组改变桩长、桩距、桩数的模型试验,对等刚度和变刚度布桩的应力位移场进行研究。结果表明：等刚度布桩中各基桩桩顶反力不均匀,差异沉降较大。变刚度布桩能调整群桩整体场刚度效应,减小差异沉降,促使桩顶反力均匀及更好地发挥地基土的承载力。

Model test of pile group for different arrangement piles

For pile group,varying pile length and diameter is one method of optimized design of pile foundation stiffness to reduce differential settlement,which is an important revised syllabus of Technical Code for Building Pile Foundations.In order to reduce differential settlement and optimize reacting force above pile of equal stiffness pile group,four sets model tests varying pile length,diameter and number have been done to study site stiffness effect which vary stiffness or not.The result indicates that each foundation pile has unequal reacting force above pile and big differential settlement in equal stiffness pile group,but varying stiffness arrangement piles can adjust whole pile group stiffness effect,reduce differential settlement,improve the uniformity of reacting force above pile and increase bearing capacity of soil foundation better.