[提要]  采用能量变分原理与多重子结构技术相结合的方法，建立了考虑上部结构与箱基、地基土共同工作的箱基内力空间分析模型。特别提出了上部结构为框架一剪力墙体系时箱基内力的实用算法。在空间内力分析的基础上，建立了箱形基础造价优化的数学模型，并采用子空间组合可行方向法求优。所提出的优化方法应用于工程实例，取得了明显的经济效益。
[关键词]  箱形基础 最优设计 相互作用  钢筋混凝土结构 变分法

By combining variational method with multi-level substructure technique,a spatial analysis model is established to calculate the internal forces of box foundation considering its interaction with superstructure and soil. Especially,a practical algorithm is worked out for analyzing box foundation with superstructure of frame-shear walls.Based on spatial analysis,a mathematical model is derived to minimize the price of box foundation.By applying the optimization method presented to the numerical example, the structural cost of box foundation is apparently reduced.
Keywords:  box foundation; optimum design; reinforced  concrete structure; variational  method