CHD pile performance: part II - numerical modelling

A set of simple finite-element modelling procedures that can be used to estimate the load-settlement behaviour of continuous helical displacement (CHD) piles in sand is presented. The approach makes use of a stress-and strain-dependent non-linear soil model that can be parameterised using basic soil data that can be determined through routine site investigation. The procedures are validated against a database of physical model tests (reported in a companion paper), where they are shown to be suitable for estimating the load-settlement behaviour of CHD piles within the serviceability range. In this way they are complementary to the analytical method reported in the companion paper for estimating the ultimate capacity of a CHD pile. In this paper, the finite-element method and analytical model are applied to four historical load tests on CHD piles conducted at three different sand sites. The modelling is further validated and used to discuss potential savings in pile material and therefore cost due to additional confidence in performance determination at both ultimate and serviceability limit states.