Published online on January 2014.
D. Bruno, F. Greco, P. Lonetti
Abstract: The aim of the paper is to provide numerical evaluations of the static and dynamic behavior of long span cable stayed bridges. In particular, investigations are presented to evaluate, in the framework of a dynamic analysis, the behavior of cable stayed bridges when subjected to the action of moving loads. In addition, the nonlinear static behavior is analyzed with the purpose to evaluate the influence of the geometrically nonlinear effects on the instability phenomena affecting the bridge structure. In both cases, the basic formulation is developed by using a finite element approach, in which a refined schematization is adopted to analyze the interaction behavior between cable system, girder and pylons. The proposed model takes into account geometrical nonlinearities of girder, pylons and of the cable system, for which local vibrations of the stays are also considered. Sensitivity analyses are proposed in terms of dynamic impact factors, emphasizing the effects produced by the external mass of the moving system and the influence of both "A" and "H" shaped tower typologies on the dynamic bridge behavior. Parametric results, developed in the framework of nonlinear static analysis, are also presented to evaluate the effects produced by instability effect of the axial compression in the girder on the maximum load-carrying capacity of the bridge.
International Journal of Bridge Engineering, Vol. 1, No. 1, 2013: pp. 3-27
Abstract: The strongly nonlinear phenomenon of rain-wind induced vibrations of stay cables is discussed, focusing on issues related to their exciting mechanisms, the cable response characteristics and the adequate modeling. Numerical results obtained are compared to wind-tunnel test data as well as to full scale measurements on cable-stayed bridges.
International Journal of Bridge Engineering, Vol. 1, No. 1, 2013: pp. 29-36
M. Tazarv, M. Saiid Saiidi
Abstract: Residual drift under moderate and strong earthquakes has received attention because of its effect on the post-earthquake serviceability of bridges. Even though seismic codes ensure life safety for bridges, their serviceability and safety may be compromised due to large residual displacements after a severe earthquake. In this paper, a robust analytical modeling method was developed to estimate both peak and residual displacements of reinforced concrete (RC) bridge columns with high accuracy. The calculated responses showed close correlation with those measured in shake table testing of a full-scale RC bridge column. In an analytical investigation, reinforcing shape memory alloy (SMA) was used instead of conventional reinforcing steel to mitigate residual displacements. Results of cyclic and dynamic analyses of the SMA-reinforced version of the full-scale column showed that residual drifts of the SMA-reinforced concrete bridge column were significantly smaller than the calculated residual drift in the conventional RC column.
International Journal of Bridge Engineering, Vol. 1, No. 1, 2013: pp. 37-50
Abstract: The phenomenon of twisting appears in bending beams as a special case of the lateral-torsional buckling of a beam. In this paper, we will study the influence of the prestressing on the stability (twisting stability) of a simply supported beam. The case of the prestressing by rectilinear tendons is studied and numerical applications are presented.
International Journal of Bridge Engineering, Vol. 1, No. 1, 2013: pp. 51-65
M. Petronijević, D. Ladjinović, A. Rašeta
Abstract: Eighteen types of idealized four span bridges are investigated in this paper in order to determine the effects of soil-structure-interaction (SSI) on the regular dynamic behaviour of bridges. The simplified dynamic analyses in the transverse direction are performed for fixed-based structures and for structures where the soil-structure interaction is taken into account. Three different types of soil, representing soil classes B, C and D, in accordance with EC8-1, are considered. Different criteria for regular dynamic behaviour of bridges are applied and influence of the SSI on the regularity of bridges is discussed.
International Journal of Bridge Engineering, Vol. 1, No. 1, 2013: pp. 67-80