Field experiment and numerical analysis of bearing features of CFG pile composite foundation of expressway

A field experiment had been conducted on the bearing capacity of a CFG-pile composite foundation for the sand-filled embankment for a certain expressway. The finite difference method could be adopted to build the mathematical model and to conduct a numerical calculation of the pile-soil stress of the composite foundation and the sedimentation of the earth mass. The results show that: When the distance between tested piles in the static load experiment is 1.5 m, the pile-soil stress ratio is 5.58, which is significantly higher than 2.26 (actual monitored value when the embankment is under load) and 2.72 (the calculated value). Therefore, determining the bearing capacity of a CFG-pile composite foundation for a road embankment under load using the static load experiment is inappropriate. The results of field measurement could be used as a basis for the design parameters of CFG-pile composite foundations for highway soft foundation in Poyang Lake region.