Effects of Impact Loads from Train Wheel Passing Rail Joints on Fatigue at Deck System of Steel Box Girder

Abstract

Impact loads from train wheels passing rail joints tend to cause fatigue cracks in steel bridges near the rail joints. In order to evaluate the effects of impact load on the fatigue of the deck system of a steel box girder, we carried out stress measurements on steel girders on an existing bridge. The results showed that the impact loads at rail joints generate two types of high frequency natural mode vibrations of around 40 Hz, and around 350 Hz. It was also shown that these vibrations lead to an increase in the range and cycle of stress at the welded joints of the deck system.