本文从桩基的结构特点出发,阐述了桩和桩基作为空间结构在三维力系作用下的性态及分析方法。利用主解系数等方法导出了桩轴向、横向及扭转刚度系数的通用算法并用于桩基作为空间结构的矩阵分析。文中提出了以容许位移原理为基础的设计原则和土阻抗函数的线性化方案,以保证安全及便利计算。 Based on the structural characteristics of the pile foundation, this paper expounds the behavior of the pile and pile foundation as a spatial structure under the three-dimensional force system and analysis method. The general algorithm for the axial, lateral and torsional stiffness coefficients of the pile is derived using the principal solution coefficients and other methods and used for the matrix analysis of the pile foundation as a spatial structure. In this paper, the design principle based on the principle of allowable displacement and the linearization scheme of the soil impedance function are proposed to ensure safety and facilitate calculation.