Finite element simulation of pile behaviour under thermo-mechanical loading in integral abutment bridges

To study the behaviour of piles in integral abutment bridges, under seasonal and daily thermal loading, a three-dimensional, nonlinear finite element model was constructed for a bridge. The model was parametrically run for five different bridge lengths that varied from 122 to 549 m. A sinusoidal model was used to represent the daily and seasonal temperature variations. The results showed that maximum lateral displacement of the piles occurs during the winter when the thermal contraction and the dead and live loads on the bridge produce displacements in the same direction. Maximum stress occurred in the pile furthest from the centre of the bridge and was found to be in the flange of the pile immediately below the concrete abutment. Plastic deformation was observed in all of the piles for all bridge lengths. The lateral displacement and maximum plastic deformation in piles increased as the length of the bridge increased. A linear relationship was found between the length of the bridge and the lateral displacements for both seasonal and daily temperature variations.