Practical macro‐element for vertical and batter pile groups

Abstract

This paper presents a novel macro-element for vertical and batter pile groups. The numerical scheme is based on de-coupled, single pile response. Each pile consists of two separate load-displacement formulations (axial and transverse) that take a displacement increment as input and return a diagonal tangent stiffness value. The effect of rotation is implicitly incorporated in the transverse load-displacement formulation. The presented macro-element does not require pre-defined failure surfaces or other parameters, and is therefore not restricted to a specific foundation configuration, soil profile or soil type. The macro-element may be calibrated using any type of non-linear pile-soil model.The developed macro-element is validated using rigorous numerical models for a variety of configurations.

Nonlinear earthquake response of integral abutment bridges on vertical and batter piles: A practical approach

“…These methods aim to capture the essence of SSI while also being straight‐forward to understand, implement and apply. This paper supplements the research conducted by Cemalovic et al 20,21 . by demonstrating the developed solutions.…”

“…A detailed description of the plastic modulus evolution for both transverse and axial response in the different loading stages, as well as the calibration procedures and its parameters, is provided by Cemalovic et al 20 . For convenience, the presented algorithms only show selected parts of the total numerical scheme.…”

“…The macro‐element formulation also neglects pile‐soil‐pile interaction, which may decrease the accuracy of the macro‐element when the piles are closely spaced. The limited set of analyses presented by Cemalovic et al 20 . showed that the macro‐element performed well for pile spacing's down to $$3 d_p$$, but the analyses were limited to soft soil where it is expected that pile‐soil‐pile interaction is relatively low 55,56 .…”

“…The model was verified against large‐scale model tests 19 . More recently, Cemalovic et al 20 . developed a nonlinear macro‐element for vertical and batter pile groups that considers the inelastic behavior of both pile and soil.…”

“…by demonstrating the developed solutions. More precisely, it involves the implementation of (1) the macro‐element 20 within a time domain solution and (2) the linear impedance matrix 21 within a modal domain solution. Subsequently, these solutions are utilized to perform a set of incremental dynamic analyses (IDA) of an IAB where the effect of linear and nonlinear SSI, batter angle and pile spacing is evaluated.…”