（宁波市建筑设计研究院  315012）
【提要】  分析了目前常见的两种计算基坑支撑刚度方法的差异、优缺点和适用范围。通过建模，用弹性支点法分别计算分析了单道支撑和两道支撑条件下，支撑刚度变化对支撑轴力及支护桩桩身内力的影响。计算结果表明：对于单层支撑系统，随着支撑刚度的增大，支护桩的最大弯矩和剪力稍有增加，而支撑轴力的增大幅度比较明显，且当支撑刚度增大到临界值后轴力趋于稳定；对于双层支撑系统，增加支撑刚度对支撑轴力起到增大
的作用，但对支护桩内力的影响却各不相同。
【关键词】  基坑  支撑刚度  支护桩  内力
Calculating Methods for Stiffness of Bracing Structure and Their Influence on Internal Force of Retaining Piles/Xu Yang, He Libo, Xu Guoping, Wu Zhehua(Ningbo Architectural Design & Research Institute,Ningbo 315012,China)
Abstract:The difference of two calculating methods for stiffness of bracing structure are compared. The model for analyzing stiffness of bracing structure influence upo
n internal force of retaining pile is established, and some useful conclusions are obtained. The force of bracing structure becomes bigger with the increasing of its stiffness. For monolayer and twodouble bracing structure, the change of moment of retaining piles is different with the increasing of stiffness of bracing structure.
Keywords:foundation pit; stiffness; bracing structure; retaining piles; internal force