中文摘要：

柔性基础下复合地基已广泛应用于公路和铁路路堤、水利土石坝、尾矿坝及各类堆场等工程领域,但其理论尚落后于工程实践。结合解析法研究现状分析,对所推导的柔性基础下复合地基沉降的简化解析解给予介绍,并通过工程实例对该解析解的可靠性进行验证。然后,基于该解析解和标准算例,对系统8个影响因素与等沉面高度、中性点位置、向上和向下的刺入变形及桩和土的沉降等内在联系作了分析。结果表明：系统8个因素对各沉降特性指标都有不程度的影响,必须重视对系统上、下部共同作用的深入研究。

英文摘要：

The theory lags far behind the engineering practice,though the composite ground under flexible foundation has been widely applied to several engineering fields,such as embankments of highway and railway,dams,tailing dams,stack yards.Combined with the present situation analysis of analytical method,the settlement characteristics of the composite ground under flexible foundation was summarized firstly.Then,a simplified analytical solution was presented briefly.The fellowing verification by an engineering case indicates that the solution can more accurately reflect the working behavior of the composite ground under a flexible foundation.And then,on a basis of a standard example,the relationships among eight influence factors and the height of the equal settlement plane,the depth of the neutral point,the stab deformation,the settlement of pile and soil etc.were studied through the solution.It can be concluded that the factors of the four components of the system can all affect the settlement characteristics more or less.It is necessary to pay more attention to the composite ground under flexible foundation based on super-sub structure interaction.