条形基础地基极限承载力的改进径向移动算法研究

The research of ultimate bearing capacity for strip foundation with improved radial moving optimization

基于极限分析法,在将地基划分成刚塑性三角形块的基础上,综合考虑地下水位和非饱和土基质吸力的影响,利用内外虚功率相等原理建立极限承载力的求解方程,从而将条形基础地基极限承载力问题等价为一个边界待定的泛函极值问题。在将径向移动算法的数据结构进行改进之后用于对地基滑移线的搜索与相应极限承载力的计算,并在此基础上研究地基土层参数、基质吸力与地下水位对地基极限承载力的耦合影响。结果表明,改进的径向移动算法能快速准确而稳定地搜索滑移线并求解地基极限承载力;各地基参数变化会对地基极限承载力产生不同的耦合影响。

On the basis of limit analysis method and the division of the foundation into rigid-plastic triangular blocks and considering the effect of the groundwater level and matric suction for unsaturated soil, the solve equation was established using the same virtual power inside and outside. Then the ultimate bearing capacity of strip foundation was equivalent to a functional extreme value problem with unknow boundary. After improved the data structure, the radial movement optimization was used to search the foundation slip line and calculate the corresponding ultimate bearing capacity. On this basis, the relationship among the ultimate bearing capacity of the foundation and parameters of the foundation soil, matric suction, groundwater level could be further studied. The results show that the improved radial movement optimization can quickly and accurately search the slip line and solve the ultimate bearing capacity of the foundation. The foundation parameters show different influences with the ultimate bearing capacity.