A Study Of Properties Of The CFG Pile-Net Composite Foundation Under High Fill Embankment

The construction of high-speed rail is thriving in China. With the advantages of shorter construction period, smaller settlement deformation and quicker convergence, the CFG pile-net composite foundation is widely applied in the rail building, and achieves the goal of design. But this technique was rarely used in the soft soil under high fill (more than20m high) embankment in the roadbed engineering of railway, if we want to apply this technique under high fill embankment, we should reconsider the questions as the stability of the composite foundation and embankment, and the settlement etc.This thesis analyzes the theory and design method of pile-net composite foundation in the roadbed engineering of railway. Based on the project of the high fill embankment on YunGui railway, a series of geotechnical centrifugal model tests are conducted, and by these tests, the properties of the CFG pile-net foundation and the mattress layer, the embankment settlement and deformation, the failure of the composite foundation are observed. We also research the character of external force of piles in different positions in roadbed. In the end, some advices for construction and design optimization are proposed.