圆形及矩形基础非均质地基极限承载力数值分析

摘要

我国经济发达地区广泛分布有软弱黏性土地基，近年大量超高、超大建筑和高速铁路等设施的快速建设对这类复杂地基极限承载力及破坏机理的认识提出更高的要求。采用有限差分方法建立三维数值分析模型，分析强度随深度线性增大的黏性土非均质地基在矩形基础和圆形基础情况下的地基极限承载力和破坏模式。结果表明：黏性土强度不均匀系数越大，地基承载力系数越大；基底粗糙度通过影响土体发生破坏的位置影响地基承载力系数；矩形基础和圆形基础的基础形状系数随着土体强度不均匀系数的增大而减小；数值计算得到的长宽比为10的矩形基础情况下的地基承载力系数与条形基础情况下的地基承载力系数相等。%Soft cohesive soil foundations are widely distributed in developed regions in our country. In recent years, as a large number of ultra-high, over-limit buildings and facilities such as high-speed railway are under rapid construction, a deeper understanding of the ultimate bearing capacity and failure mechanism of this kind of foundation is required. Three-dimensional numerical analysis model is established with finite difference method to analyze the ultimate bearing capacity and failure mechanism of cohesive non-homogeneous foundation under rectangular and circular footings. Analysis results show that with the increase of the uneven coefficient of the strength of cohesive soil, the ultimate bearing capacity increases. The roughness of base affects the bearing capacity coefficient. Shape factors of rectangular and circular footings decrease when the uneven coefficient of the strength of cohesive soil increases. The bearing capacity of the rectangular footing with numerically calculated length/width ratio of 10 equals that of rectangular footing.