箱形基础在上下部共同作用下整体受力的极限分析

提出箱形基础在上下部共同作用下整体受力极限分析方法,并与实际工程实测结果对照验证其合理性与可靠性。将上部结构与箱基、地基视为整体,借助于上下部同步进入极限状态的虚功率方程,从极限分析的角度对箱基在上下部共同作用下的整体受力进行求解。根据十字机动破坏模型和双抛物线基反力破坏模式,求出相应箱基整体受力上限解。箱基整体进入极限受弯状态时,视上部结构为框架体系,计算上部结构抗弯刚度对箱基整体受力解约束效应分析。选取两个具有较完整实测结果的箱形基础工程按以上方法进行极限分析,并与实测对比。结果显示,与现行“箱筏基规范”考虑上部效应法相比,该极限分析方法计算结果更接近实测。同时,上下部共同作用整体受力极限分析方法更易于手算和电算编程,并可用于各种基反力模式。

Limit analysis of box foundation and its interaction with superstructure

By integrally considering the interaction effects of superstructure and foundation,a limit analysis of box foundation is conducted,using the principle of virtual work together with a cruciform flexible damage model and a dual parabola foundation pressure model.From the analysis,a set of design formulas are proposed.In order to verify the validity of the proposed formulas,limit analysis of two realistic box foundations is carried out.Comparing with the actual measurements,the proposed formulas are proved to be rational and reliable.The limit analysis of the box foundation involves an simple calculations,and can be employed with several damage models.