Nonlocal FEM modeling of piles as beam elements embedded within 3D continuum

Abstract

Finite element analysis of piled rafts and other foundation systems, in which concrete columns/piles are used to strengthen weak subsoil, is a commonly accepted tool in modern geotechnical engineering. It enables one to analyze all important aspects of soil–structure interaction (SSI), including nonlinear stress–strain constitutive relations for soils, strong displacement discontinuity between rigid inclusions (piles/barettes/columns) and subsoil, but also coupling soil deformation with groundwater flow. In practice, the number of designed inclusions is usually large. Therefore, the standard approach in which the subsoil, and rigid inclusion as well, are discretized using continuum finite elements, may yield huge computational models, which are not acceptable from the practical point of view. To remedy this serious drawback a nonlocal method of modeling rigid inclusions as beam elements embedded within the 3D continuum is proposed and verified. Moreover, it removes another pathological mesh dependency effect when modeling beam–shell connection.