竖向受荷长短桩基础的侧端阻力分析方法

运用幂函数有限项级数的表达式表示群桩中单桩的桩侧摩阻力分布函数,并基于弹性理论中的变形协调关系、桩体物理方程和力的平衡关系,推导了长短桩群桩基础中联系桩顶荷载和桩顶位移之间的刚度矩阵。利用该矩阵可以分析长短桩桩基础中桩侧摩阻力和桩端阻力的分布情况。对于不同桩长的群桩基础的侧阻力、端阻力与Poulos方法、Chow混合方法和有限元分析结果进行了比较,证明该方法是可行的,精度也满足要求。

ANALYSIS METHOD OF SIDE RESISTANCE AND END RESISTANCE IN LONG-SHORT PILE GROUP SUBJECTED TO VERTICAL LOADING

Expression comprising finite series of power function is applied to characterize shear force allocation along pile shaft.Based on displacement compatibility relation,pile body stress and strain equation and force equilibrium relationship in elasticity mechanics,the stiffness matrix which relates pile top force to pile top displacement is deduced.With the above stiffness matrix,the pile shear force along pile shaft and the pile tip stress allocation in long-short pile group can be analyzed.It does not involve the discretization of the soil or piles.The method follows the same analysis process and the content of stiffness matrix is just related to the number of piles for long-short pile group.Comparison with the results of Poulos's method,Chow's hybrid method and finite element method shows that the analysis method in paper is feasible and accurate.