Affiliations: [a] Department of Civil Engineering, Ecole Nationale Polytechnique, Algiers, Algeria
| [b] Department of Civil Engineering, University of Djelfa, Djelfa, Algeria
Correspondence:
[*]
Corresponding author. Nassira Belkheiri, Department of Civil Engineering, Ecole Nationale Polytechnique,10
Avenue des Frères Oudek, Hassen Badi, BP. 182, 16200, El Harrach, Algiers, Algeria.
E-mail: [email protected].
Abstract: The stochastic responses of highway bridges to spatial variation of ground motions (SVGM) are analysed in this paper. A model of spatially varying ground motions is used to investigate the relative importance of the incoherency effect, the wave passage effect and the site effects on the stochastic dynamic response of an asymmetrical R.C box girder highway bridge with variable inertia. In this study, the incoherency effect is investigated using two widely used models while the wave-passage effect is incorporated using various wave velocities. Then, the random vibration theory is applied to study the effect of the non-uniform seismic excitations on the bridge structure. The bridge response is evaluated in terms of the mean values of the maximum displacements and the bending moments. Analyses of both stationary and transient response are performed. The results show that the stochastic dynamic responses related to site effects are mostly much greater than those calculated using uniform, delayed and incoherent seismic excitation assumptions. As a result, analytical models used for the stochastic dynamic analysis of long span highway bridges should take into account all the SVGM components, particularly the site-response effects.
Keywords: Stochastic, highway bridge, 3-D FEM, random vibration, incoherency, wave-passage effect, site effect
