The Researches on Adaptability of Existed Large Span Railway Steel Bridges Under Heavy Haul Freight Train in China

摘要

Taken the typical structural type with a span falling into L≥64m as the research object,rnbased on the consideration of the influence from different coefficient of check carrying capacity andrndynamic coefficient on existing large-span steel railway bridge as well as the new fatigue train withrnheavy axle load train, 27t heavy axle load train adaptive analysis of bearing capacity and fatigue lifernare studied. Strengthen methods are discussed for the structure or members which are locallyrnunsuitable for the heavy train. Research shows that it is feasible for the existing large-span steelrnrailway bridges to carry 27t heavy train, while members with influence line less than 6m can’trnsatisfy the needs, which should be locally strengthened. The load effect caused by heavy train isrnalmost equal to the design load effect，which will decrease the safety margin of the structure andrnlong-term operation would lead to degradation in structural behavior and decrease in fatigue life.