Complete modified notch functions for a welded detail of a trough bridge

Among the most frequent tasks occurring in railway bridge construction, there is the replacement of old structures of length up to 25 m. To reduce the own weight, old bridges are usually erected without a ballast bed. On the contrary, today railway bridges are provided with a ballast bed with a standard depth of 55 cm. As in most cases neither the top of rail can be raised nor the bottom line of the structure can be lowered, the depth of the construction itself must be kept as low as possible. An appropriate (though special‐purpose and expensive) solution is given by a trough bridge with 120 mm‐deep heavy a steel plate as road deck. This plate is connected by fillet and single‐level broad welds to the web plates. The present article deals with the fatigue verification of these welded details based on a modified formulation of notch stresses.