Tension tests on smooth and rough model piles in dry sand

In order to delineate the significant variables affecting the ultimate uplift shaft resistance of a pile in dry sand, a testing program comprising 64 pullout tests was conducted on open- and closed-ended rough and smooth model piles of two sizes (41 and 61 mm outside diameter). The model piles were installed in medium dense and dense sand to an embedded depth of 0.8 m using two methods of pile placement, static jacking and driving. A rigid steel box measuring 1.1 × 1.1 × 1.3 m was used as a sand container. The results obtained from this study indicated that pile placement method, initial sand condition, pile surface roughness, and pile end type are all significant variables (given in descending order) affecting the ultimate uplift shaft resistance of a single pile in dry sand. Overall, the closed-ended piles showed a 24% increase in shaft resistance compared with the open-ended piles and the average unit shaft resistance of the driven model pile was 1.33 times that of the jacked model pile in the dense sa...