Numerical study of the asynchronous excitation effect of Boumerdes’ earthquake on a bridge behavior

This paper represents the numerical analysis of asynchronous excitation effects on a bridge response due to the Boumerdes earthquake, using the finite element method in modeling, and the Newmark method for dynamic response analysis. The influence of the time delay of excitation between the supports on the response of structure is investigated and study how these variations can affect structural behaviour during seismic events. The dynamic displacements, normal, and shear forces and bending moments are computed through detailed simulations. The obtained results show that due to the non-uniformity in the earthquake excitation, changes in qualitative and quantitative features of dynamic displacements of the bridges. This will consequently subject the bridges to increased displacements hence compromising their structural safety and integrity. In fact, the analysis also underlines that, due to non-uniform seismic forces, the distribution of normal and shear efforts, along with bending moments, gives important concentrations of stresses that were underestimated under uniform loading conditions. From these observations, one underlines the importance of non-uniform distribution of seismic loading during bridge design or evaluation. It provides useful data to the engineers and designers who will implement the improvement in the seismic resistance of bridge structures in earthquake areas.