中文摘要：

桩-网复合地基是近年常用的一种地基加固措施,桩土应力比则是复合地基研究中一个很重要的参数。通过对某客运专线试验段的桩土应力现场测试,得到了路堤下桩-网复合地基桩土应力及桩土应力比的变化规律和复合地基工作机理。现场测试结果表明：路堤下复合地基桩土应力比要比刚性基础下小很多,而且需要在桩、网垫层和桩间土的相互作用下,逐渐达到稳定;拉膜效应和土拱效应在桩-网复合地基工作时起到非常重要作用,网垫层能够有效提高复合地基桩土应力比。

英文摘要：

The pile-net composite foundation was commonly used as a kind of ground reinforcement measures in recent years, and the pile-soil stress ratio is a very important parameter in the research of the composite foundation. Through the field measurements of the pile-soil stress ratio of the composite ground of a passenger traffic line, the law of the pile-soil stress ratio＇ s variation and the work mechanism of the pile-net composite foundation under embankment are obtained. The measured results show that： 1 ） the measured pile-soil stress ratio is much more less than that under rigid foundation, and the ratio achieves stable gradually by the pile-net-soil interaction; 2）the effect of soil arch and the effect of tension membrane play extremely important role in the pile-net composite foundation ; 3）the geogrid can enhance pile-soil stress ratio of the compound foundation effectively.