NONLINEAR FINITE-ELEMENT ANALYSIS OF REINFORCED-CONCRETE 4-PILE CAPS

An investigation to study the behaviour of reinforced concrete four-pile caps by three-dimensional nonlinear finite element analysis is presented. Four-pile caps having different reinforcement layouts were considered. Eight-noded isoparametric brick elements with incompatible modes and two-noded three-dimensional truss elements were used to model the concrete and steel, respectively, of the pile caps. The steel elements were assumed to lie on the edges of the brick elements. The smeared cracking model was employed for modelling cracks during the analysis. The nonlinear components, such as multiaxial compressive behaviour of concrete, including strain softening, cracking of concrete and yielding of steel reinforcement, were considered. The load deflection characteristics, the strains in the reinforcement, the crack patterns and the ultimate loads are presented herein. Some of the theoretical results are compared with those obtained from experiments carried out on reinforced concrete pile cap specimens.