Progressive failure is common in many natural clays of strain-softening behavior and may affect the bearing capacity of foundations placed on such soils. The progressive failure might be insignificant for small structures where the mobilized strains are generally uniform within the failed soil mass. This places a demerit to the applications of knowledge obtained from physical model tests to prototype. The study aims to understand and quantify this scale effect on bearing capacity of shallow foundations on strain-softening clays, with a numerical investigation using a large deformation finite element analysis. The progressive failure is numerically replicated and the controlling parameters for the bearing capacity have been discussed. A correction factor is introduced which is inversely proportional to the foundation size normalized by the proposed characteristic length. An empirical relationship of the correction factor and the normalized foundation size has been obtained via the numerical data, which may improve the design of shallow foundations on strain-softening clays.

渐进破坏在许多应变软化的天然粘土中很常见，并且可能会影响放置在此类土壤上的地基的承载力。对于小结构来说，渐进式破坏可能是微不足道的，在这种结构中，动员的应变在破坏的土壤中通常是均匀的。这不利于从物理模型测试到原型获得的知识的应用。该研究旨在通过大变形有限元分析进行数值研究，以了解并量化这种尺度效应对应变软化粘土上浅层基础承载力的影响。数值模拟了渐进式破坏，并讨论了承载力的控制参数。引入校正因子，该校正因子与通过建议的特征长度归一化的基础尺寸成反比。通过数值数据得到修正系数与规范化地基尺寸的经验关系，可以改善应变软化粘土上浅层地基的设计。