基于极限分析法的桩周土体承载力探讨

考虑复合桩基极限状态时承台下土体可能破坏的特点,将土体的塑性变形分为竖直向的整体滑动和水平向的绕桩流动。根据极限分析法上限定理,分析上述因素对条形承台复合桩基的极限承载力的贡献,给出圆桩时地基土极限承载力的上限理论解。算例分析表明桩在复合桩基中的另一种不可忽视的贡献,无论只是把它当作安全储备还是考虑到设计中,都是合理和有必要的。

Discussion on ultimate bearing capacity of soils around piles based on limit analysis

Based on the possible destructive features of soils under strip composite pile foundations in the ultimate state,plastic deformation is divided into vertical whole sliding and horizontal sliding around pile.According to upper limit theorem and analyzing the contribution of above factors to the ultimate resistance of strip composite pile foundation,the upper theoretical solution for the ultimate resistance to the soil under caps of circular piles is put forth.Analysis on the example shows that in composite pile foundation piles have another unneglectable contribution,which can be considered as safety allowance in design,it is reasonable and necessary.