Centrifuge tests on axially loaded tapered piles with different cross-sections under compressive and tensile loading

The compressive behavior of tapered piles, particularly those with circular cross-sections, has been investigated during the last few decades. However, the tensile behavior of such piles has been rarely studied in the literature. In this paper, 12 static axial tests, comprising six compressive and six tensile tests, were performed on instrumented piles with uniform and tapered cross-sections using a geotechnical centrifuge. Three of the piles had correspondingly circular, square, and X-shaped uniform cross-sections along their length, while the other three were non-uniform (tapered), all of which had the same length and volume. The results are presented in three main forms: variation of load versus pile head displacement, distribution of axial force along the pile length, and distribution of unit shaft resistance along the pile length. Behavior of the tapered piles is compared with that of the uniform cross-section piles. The results confirm the superiority of tapered piles over uniform cross-section piles in terms of load-bearing capacity and construction costs under both tensile and compressive loading.