Dynamic Performance Analysis Of Steel Orthotropic Bridge Deck In High Speed Railway Under Moving Loads

Orthotropic steel truss bridge deck has currently become one of the widely used structure form for high-speed railway with large-span steel bridge because of its light weight, low building height, high strength, continuous structure, easy construction and installation, ballasted railway line can be used, etc. However, due to the smaller surface quality of orthotropic bridge deck, it is easy to produce large vibration under the action of moving loads by train, thus causing many adverse effects on the bridge deck system.This paper established a space finite element model of orthotropic steel bridge deck, which analyzed the dynamic response of structure under moving load from three areas, stress, dynamic displacement and vibration acceleration in detail. And then it carried out the fatigue and degradation state research of its weak parts. Finally, for condition factors affecting the stress performance of the bridge deck, we changed relevant parameters, conducted quantitative analysis of the impact of various factors on force behavior and put forward optimization tips for orthotropic deck design.The research results show that, in orthotropic bridge deck, the stress is larger at bridge deck located just below the track and the welding place of deck and U rib. Dynamic response of the orbit is significantly greater than the deck. Different speeds and Single-double line both have impact on the dynamic response of bridge deck. When U rib deteriorated, bridge deck stress increases significantly, unable to meet the requirement of normal train running. Increasing the thickness of bridge deck under rail, increasing the width of U rib, and reducing the space of diaphragm plates all can effectively improve force status of the deck. And the measure of increasing bridge panel thickness is relatively more feasible.