Estimation of Settlement of Soils around Tapered and Non-tapered Piles in Multi-layered Soils

Abstract

The result of a comprehensive study on the estimation of deformation of soils around tapered and nontapered piles in multi-layered soil is presented in this study. These results show the pile-soil interaction when tapered and non-tapered piles were driven through layers of inter-bedded sandy clay soil. The investigation was carried out to study the influence of tapering on the behavior of the soils around the 20 mm diameter and 200 mm long modeled circular piles, driven through specially conditioned layered sandy clay soil in a specially designed multi-purpose testing device (laboratory), and modeled reinforced concrete instrumental test piles of diameters 200mm, 250mm in a corresponding fairly modeled field condition at a construction site. The piles were subjected to axial compressive load on incremental basis till failure. The effects of the pile tapered on its side response to axial compressive loads were examined. The distribution and stress pattern around the two configurations of piles were also examined. The results of the study confirmed the efficiency of tapered piles over cylindrical piles of straight-sided (uniform section) of the same material and under the same loading conditions considered in this study. From settlement analysis and shaft resistance consideration, the shaft resistance of non-tapered cylindrical piles was about 42% less than that of the tapered piles. It is concluded that, for structural and material optimization, the tapered piles offer a larger (better) resistance than the cylindrical non-tapered piles.