Research on Static and Fatigue Properties of New Structure of Section Steel-UHPC Lightweight Composite Deck with Open Rib
To solve the problems of fatigue cracking and pavement damage in orthotropic steel decks(OSD),the author's research team successfully developed a steel-ultra-high-performance concrete(UHPC)lightweight composite bridge deck system in 2010,which has been widely applied to steel bridges in China.Because the UHPC layer significantly improves the local stiffness of the steel deck,the OSD can be further optimized to simplify construction and reduce costs.Therefore,a hot-rolled section steel-UHPC lightweight composite deck with an open rib(HSD)is proposed in this paper and applied to the girder of a long-span arch bridge for the first time,and different deck schemes and finite element calculations based on a real bridge are compared.On this basis,a negative bending moment strip static test of the HSD was carried out,the crack development of the UHPC was observed,the crack width was calculated,the fatigue resistance performance of the HSD was calculated and analyzed,and a negative bending moment strip fatigue test was carried out for the important connection welds between the longitudinal and transverse ribs in the HSD.The research results show that UHPC in the negative moment area shows good flexural tensile toughness,and the tensile strength is 1.4 times that of the real bridge;HSD connects the longitudinal ribs and the diaphragm in a novel way;by placing all the necessary connecting welds in the low-stress area and non-welding hot-rolled section steel in the high-stress area,the fatigue resistance of the bridge deck is improved.HSD contains 10 key fatigue details,and the calculated fatigue stress amplitude of each fatigue detail is below the constant amplitude fatigue limit;fatigue failure of the connecting weld between longitudinal and transverse ribs in HSD occurred after 48.4 million equivalent loading times under the design fatigue stress amplitude;the fatigue strength meets the requirements of real bridge applications.In summary,the HSD exhibits good static and fatigue behavior,simple processing and manufacturing,low construction costs,and is a new competitive bridge deck scheme.
bridge engineeringsection steel-UHPC lightweight composite deckstrip model teststatic and fatigue performanceorthotropic steel deck