中文摘要：

根据路堤荷载下复合地基的变形特征,将柔性基础下复合地基分解为填土、垫层、复合地基、下卧层土体4部分。将4者作为一个共同作用的系统,假设桩土界面之间存在相对滑移且同一水平面上地基土沉降不同,考虑系统4部分交界面上的应力与变形协调,通过对典型单元体的分析,推导了表征柔性基础下复合地基性状的桩土应力比和沉降变形的求解公式。最后将工程实测结果和本文方法分析的结果进行对比,二者基本一致,说明本文方法能较好反映柔性基础下复合地基的工作性状。

英文摘要：

Based on the deformation characteristics of composite ground under the flexible foundation,the composite ground is divided into four parts,including fill,cushion,composite foundation,and underlying layer.Through the analysis of a typical element,a simplified analytical model,which considers the above four parts as an interactive system,allows for the relative movement between piles and soils and assumes different settlements of foundation soil at the same level plane,is presented.And then according to the compatibility of stress and deformation on the interfaces between these four components,the formulas on settlement and stress ratio of pile-soil,which is used to characterize the behaviors of the composite ground,are derived.Finally,it is demonstrated that the results from this solution are in accordance with the measured ones of a project.So the proposed method can reflect the working behaviors of composite ground under the flexible foundation favorably.