Rigidity of abutments in integral abutment bridges

Abstract

In this article, we present the results from a numerical and an experimental analysis of the Scotch Road integral abutment bridge located in Trenton, New Jersey. A three-dimensional, non-linear finite element (FE) model of the bridge has been developed to study the effect of thermal loading on pile–soil interaction. The abutment, pile and soil were modelled using solid elements. Material non-linearity is accounted for both, the piles and the soil. The bridge substructure was fully instrumented. An analysis of the pile-soil system was performed using the finite difference software LPILE. Field data were used to verify the results obtained from the FE and finite difference (FD) analyses. We found that the integral abutments are not behaving rigidly as was assumed and a plastic hinge is formed at the connection between the piles and the abutment at a lateral displacement of 0.06 m which is greater than the maximum displacement of 0.023 m that the bridge can experience as a result of a maximum expected temperature change of±26.7°C during the life time of the bridge. Therefore, the 0.6 m embedment of the piles inside the integral abutment is adequate for maintaining their fixity inside the abutment.