Dynamic response of long span cable stayed bridges under traffic loadings

Vehicle-bridge interaction has become an important issue for the dynamic response of the bridges especially after the achievement of long spans by cable bridges during the last two decades. In this study, the effects of vehicle speed and variations in the speed, which is one of the important parameters of vehicle-bridge interaction, on the response of bridge is analysed. Tatara bridge which is the second largest cable bridge in the world, is considered by 3-D finite element model. Four sets of traffic load combinations are applied for three different vehicle speed values and analyses are conducted for the evaluation of speed induced dynamic response of the bridge. The largest internal forces in the bridge are generally observed from low speeds. On the other hand, larger responses begin to occur in the mid-span after the vehicles leaves the mid-span of the bridge for higher speeds.