中文摘要：

桩-网复合地基同时具备竖向增强和水平向增强两种加固形式的优点，由桩、网、土三者共同协调作用，有效分担路堤荷载，是一种作用机理复杂的地基加固方法。通过对某客运专线红粘土桩-网复合地基试验段进行的现场测试试验，对复合地基的基底土压力、土工格栅变形、孔隙水压力以及桩土沉降量等方面的测试，得出红粘土复合地基需要在桩、网、桩间土通过一个反复的作用过程才能达到稳定状态等结论，将有助于深入研究桩-网复合地基加固机理，并为进一步完善桩-网复合地基设计方法提供依据。

英文摘要：

The pile-net composite foundation, combining the advantages of vertical reinforcement and the horizontal reinforcement simultaneously, in which the pile-net-soil coordinates together affects and shares the embankment load effectively, is a reinforcement method that has complex mechaism. Through in-situ test of the red clay foundation of the railway line for passenger traffic line reinforced by pile-net composite foundation, some tests including the earth pressure of the base of the foundation, the deformation of the geogrid, the porewater pressure as well as the settling of the pile and the soil are made. Though the results of the test, the paper obtains the result that the pile-net composite foundation of red clay need an iterative process to get balance. The result will be helpful to the further research of reinforce mechanism of the pile-net composite foundation, and provide the basis for perfecting the design method of the pile-net composite foundation in future.