The foundation of a large LNG tank area is formed by dredger fill，which is soft and liquefied seriously.According to the geological conditions and preliminary tests，we propose a variety of treatment schemes such as dynamic drainage consolidation method and local interpenetration or full lap cement mixing piles and carry out a large number of field tests.The results show that the vibratory tube sinking gravel pile can effectively improve the strength of soil between piles and eliminate the liquefaction of sandy soil within the pile length.The improved Billam method based on the effective tamping energy can better estimate the effective reinforcement depth of the gravel pile composite foundation by dynamic compaction.The dynamic drainage consolidation method is suitable for processing sandy dredger fill，whereas the foundation stiffness after treatment is far lower than that of the cement mixing pile scheme.For areas with thick soft dredger fill，the dynamic drainage consolidation method and interpenetrating cement mixing short pile scheme，and full lap cement mixing long pile scheme can greatly improve the strength of the composite foundation，which can be used in different areas according to the thickness of soft soil.For the foundation of large single buildings in the dredger filling area，it is feasible to adopt the idea of a combination of multiple schemes for zonal treatment，which is helpful to save engineering costs.