Abstract: The program of gravel piles with vibroflotation is used to handle the liquefaction of large-thickness saturated sand foundation. In this program, the pile effect of different types of vibrator is discussed, the different pore-forming auxiliary ways and pile filler methods are tested, frequently asked questions in construction, such as "holding hole",vibrator fallen,virtual height etc., are analysed and the preventive measures are suggested in order to discuss on the construction process, improve construction efficiency, reduce security risks, provide some reference for the similar engineering.