Abstract: The installation compactive effects of the impacting Installed closed end, pre-casted reinforced concrete pipe piles in a steel factory in Guangdong are studied throughout a field testing program. The compaction effect after the installation of the closed-end pipe pile is studied by measuring the Standard Penetration Testing (SPT) blow counts at different distances from the pile. The results indicate that an obvious compactive effect can be found in sandy soil layers and the compactive effect in the cohesive soil layer is not significant. In the same soil layer, the compactive effect decreases with the increase of distance away from the installed pile. Along the pile, the compactive effect in the adjacent soil increases with depth first and then decreases with the depth. Further, time effect of an increase major influence zone from 0 ~ 3d (d: diameter) initial to 0-4d with time can be found in the comapctive effect. The secondary influence zone is existed between 4d and 8d. No compactive effect can be found in distance beyond 8d. The above study results can be used in avoiding the adverse compactive effect of pile installed in thick sand by arranging the optimized pile spacing and utilizing the axial capacity potential.

Key words: Impacting Installed Piles, Compactive Effect, Insitu Tests, Field Tests