ABSTRACT
Many approaches and techniques are used to evaluate pile axial capacity ranging from static methods to dynamic methods, which are based on either the results of pile driving or numerical simulations, which require reliable constitutive models representing the real soil behaviour and the interaction between the pile and soil. In this paper, using PLAXIS software and different constitutive soil models including Mohr-Coulomb, Hardening Soil and Hypoplastic with Intergranular Strain models, the behaviour of concrete piles driven into saturated dense and loose sand deposits under a hammer blow is evaluated. The main objective of this study is to assess the influence of different factors including frequency of loading and Hypoplastic soil model parameters on the recorded velocity and pile head displacement. In addition, the concept of one-dimensional wave propagation induced by pile driving is discussed. It is indicated that using the Intergranular Strain concept, defined in Hypoplastic soil model, small strain behaviour of soil around the pile during driving can directly be captured. The results of this study reveals that considering the Hypoplastic model, incorporating the Intergranular Strain concept, can accumulate much less strains than the corresponding predictions excluding the Intergranular Strain, and hence predict the pile performance during driving more realistically.
