Numerical Study of the Asynchronous Excitation Effect of Boumerdes’ Earthquake on a Bridge Behavior

This work shows the numerical analysis of asynchronous excitation effects on a bridge response due to the Boumerdes earthquake, employing the finite element approach in modeling and the Newmark method for dynamic response analysis. The influence of the temporal delay of excitation between the supports on the reaction of the structure is investigated, and how these differences can change structural behaviour during seismic occurrences is studied. The dynamic displacements, normal and shear forces, and bending moments are estimated by comprehensive simulations. The obtained results reveal that, due to the non-uniformity in the earthquake excitation, there are changes in qualitative and quantitative aspects of the dynamic displacements of the bridges. This will subsequently subject the bridges to increasing displacements, hence harming their structural safety and integrity. The analysis further shows that, due to non-uniform seismic forces, the distribution of normal and shear efforts, combined with bending moments, generates large concentrations of stresses that were underestimated in uniform loading conditions. From these data, it can stress the necessity of non-uniform distribution of seismic loading during bridge design or evaluation. It provides essential insight for the engineers and designers who will execute the improvement in the seismic resistance of bridge constructions in earthquake areas.