Development of a practical engineering tool for axially loaded piles calculation

Abstract

Abstract The assessment of the head load-displacement response of a pile under axial loading is the key aspect for analysing the pile behaviour under such type of loading. Therefore, an adequate modelling of the soil-pile interface makes it possible for numerical investigations to give a relevant prediction of the pile response. The commonly used approaches for displacement analysis either consider that the soil resistance can be simulated by a series of discrete springs, or that the soil is a continuum. However, the use of either approaches presents some drawbacks related to the disregard of the rheological aspect of the problem, or to the need of time-consuming numerical techniques. This paper presents a practical 1D approach, based on the finite element method, for soil-pile interface modelling. This approach is coupled with a simplified flow rule, used to simulate the interface response, based on the analogy between the behaviour of the soil-pile interface and the interface of a direct shear test. The response of a theoretical pile using the developed approach is compared to results of a load-transfer analysis and results of a 3D analysis using the commercial finite difference software (FLAC3D). The results allow to estimate the change in pile shaft resistance induced by normal stress variations along the pile.