土层相对位置对桶形基础承载力的影响

为了研究双土层情况下土层相对位置不同时桶形基础地基土在单一荷载作用下的极限承载力,采用南水土体本构模型进行ABAQUS有限元建模。在分析过程中,首先采用位移控制法,通过计算地基的p-s曲线确定相应的地基极限承载力,然后以单一加载情况下的地基极限承载力为基准进行归一化,最后提出土层相对位置修正系数的概念,从而获得土层相对位置不同时的地基极限承载力表达式。分析结果表明:土层由单一黏土层向单一淤泥层变化的过程中,竖向承载力、水平承载力和力矩承载力都逐渐减小,且减小幅度最大的是竖向承载力,其次是水平承载力,最后是力矩承载力;当土层相对位置比分别达到0.33,0.25和0.2时,竖向承载力、水平承载力、力矩承载力依次趋于稳定。

Effects of soil relative position on bucket foundation bearing capacity

To study the single loading ultimate bearing capacity of the bucket foundation in different depth of double soil, the NHRI model was used in ABAQUS finite element modelling. Firstly,movement controlling method was used, and the relative ultimate bearing capacity of foundation confirmed by calculating the p-s curve. Secondly,the ultimate bearing capacity of foundation was normalized by the single loading. Finally, the correction factor of the relative position was put forward, and the expression of the ultimate bearing capacity of foundation in different depth obtained.The result shows that as the soil becomes deeper and deeper from soil to clayer, vertical,horizontal,moment bearing capacity directions decrease,respectively, and the vertical bearing capacity direction loading decreases the most followed by loadings in horizontal bearing capacity direction and moment bearing capacity direction. What's more, when the soil relative position ratios reach 0.33, 0.25 and 0.2, the loadings in vertical,horizontal and moment bearing capacity directions become stable.