On practical performance of a technique for more efficient dynamic analysis in view of real seismic analysis of bridge structures

Abstract

Time history analysis is a broadly accepted versatile approach, for real seismic analyses. In the most general case, time history analysis is based, on time integration, for which, the computational cost might be intolerable. For reducing the computational cost, a technique is recently proposed, based on replacing the digitized excitations, with excitations, digitized, at larger steps. After several successful implementations, of the technique, arriving at a deeper insight, into the practical performance, is the objective, here. Attention is paid to the significant role of bridges, at major earthquakes, and, a multi-span concrete bridge, designed according to the existing codes, and later upgraded laterally, by nonlinear steel shear keys, is selected. By carrying out time integration analyses, against earthquakes in consistence with the design codes, it is demonstrated that: (a) implementation of the technique can be well effective in reducing the computational costs of real seismic analyses, (b) when the nonlinearities are not severe, the effect of nonlinearity on the performance is trivial, (c) the assumptions, essential, in order to implement the technique, can be simplified, for seismic analyses.