Author(s)

L. Frýba

Abstract

Vertical accelerations of bridges - a new limit state L. FGba Institute of Theoretical and Applied Mechanics, Academy of Sciences of the Czech Republic, Czech Republic Abstract The high speed trains intensively excite the railway bridges and destabilize the ballast in some cases. Therefore, a simple theoretical model of a bridge was set up and yields the deflections, bending moments and vertical accelerations. The paper shows the effect of the train speed, span of bridges, their weights and damping on the vertical accelerations of bridges. Both concrete and steel bridges of spans 5 to 50 m, three types of trains, ICE 2, Eurostar (TGV) and Talgo AV2, at speeds 5 to 500 km/h were investigated. The highest dynamic effects appear at resonance. 1 Motivation A long sequence of axle forces, which are in almost regular distances, offers a simple load model of new types of high speed trains. A resonant vibration of bridges occurs in some cases and results in the destabilization of ballast on bridges

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