Abstract: The soil properties are affected by the compaction effect of Prestressed High Concrete (PHC) pipe pile installations. The case history of a PHC pipe pile installations for a power plant project in the alluvial plains of Yellow River is presented in this paper. The compaction effect of the PHC pipe piles are studied by comparing both the insitu and laboratory tests before and after the pile installations. The results indicate that the compaction effect increase with the reduction of pile spacing; the compaction effect reduces with the increase of the clay content in soils. The compaction effect is more obvious in silty and sandy soils than that of in clayey soils. If applied appropriately, the PHC pipe pile can be used to increase the shear strength of the surrounding soils and eliminate the liquefaction potential. The liquefaction degree can be reduced but this reduction is getting less effective with the increase of pile spacing.

Key words: PHC pipe piles, Compaction Effect, Liquefaction Potential