中文摘要：

采用传递函数法和单元体相结合的方法研究路堤荷载下桩土复合地基的性状。首先，通过对土中的位移分布做适当的假设，推导得出了桩土复合地基性状的弹性解析解；然后，采用该方法分析了路堤刚度、桩土刚度比和桩长对桩土应力比的影响，以及路堤刚度对桩土相对位移和负摩阻力的影响，得到的规律与已有的认识较为统一；最后，用该方法对一高速公路搅拌桩复合地基桩土应力进行计算分析。结果表明：计算值和实测值吻合较好，该方法有较大的实用价值。

英文摘要：

The load-transmission function method （LFM） coupled in the unit cell concept was used to study the behavior of pile-soil composite ground under embankment load. The analytic solution of pile-soil composite ground was obtained when the displacement distribution of soil was properly assumed. The influences of embankment stiffness, pile-soil stiffness ratio, column length on pile-soil stress ratio were analyzed by the solution. The influences of embankment stiffness on the relative displacement between column and soil, and the induced negative friction were also studied by the solution. Rules got by the solution unified with presented viewpoint. Finally, pile-soil stress of mixing pile composite ground of a freeway was calculated by the solution. Results show that calculated values agree well with field test values.