Non-linear analysis of partly buried piles of circular section
Priscila Feitosa de Sá Ferreira1; Bernardo Horowitz1
1 Universidade Federal de Pernambuco
doi:10.20906/CPS/CILAMCE2017-0133
Resumo
The present work consists of an analysis of partly buried piles of circular section under lateral loads by three different analysis models, which consider both the material nonlinearity (MNL) and geometric nonlinearity (GNL). These models, called Levels of Approximation (LoA), are organized in increasing order of precision. In LoA I, a commercial three-dimensional structure analysis program is used (SAP 2000). In this model, the soil is represented discreetly through a series of springs with an elastic and linear behavior. MNL is approximately treated by a coefficient, applied to the gross moment of inertia, which simulates the decrease of the stiffness due to cracking. GNL is internally handled by the program through the iterative process P-delta. In LoA II, a program developed by the authors is used, which considers the non-linearities and the interaction soil-structure by the equation of the beam on elastic foundation. This equation is solved numerically, with the application of the Finite Differences Method. The MNL, in this model, is considered through moment-curvature diagrams. The GNL and the soil-structure interaction (Winkler Model) are considered directly in the equation. Finally, LoA III uses a commercial finite element program of non-linear analysis of bridges (FB-MultiPier). In this program, the MNL is treated by the integration of stress-strain curves and the GNL is modeled using P-delta moments. Consideration of the soil-structure interaction in this model is done through p-y curves models. To compare results, these three models were applied to the same example, which considers a partly-buried pile in sand. The results obtained by the three methods were very satisfactory and were shown to be coherent with each other, in line with the expected for each degree of refinement of the analysis.
Palavras-chave: Piles; Material nonlinearity; Geometric nonlinearity; Soil-structure interaction; Finite Differences Method