Mechanical characteristics of decks for double-deck steel truss girder was studied taking the Shanghai Minpu Bridge as the engineering background

which has the longest span of double-decks cable-stayed bridge until now.The finite element model of the bridge with fine beam and shell elements was discussed in details.The axile force in web members between decks and the stress distribution of the decks were investigated.Fine finite element model of decks with U-rib between the longitudinal and the cross beams was established to analyze the stress distribution of decks and U-rib

under action of vehicles load.Results show that the transversal stress of the bridge deck is larger than the longitudinal stress at both decks.The nonuniformity of the transversal stress distribution is much more significant than that of the longitudinal stress distribution on the decks.The location of the wheel load has little effect on the peak transversal and longitudinal stresses of orthotropic deck.The transversal stress plays an important role in the stress distribution

with the peak stress located at the intersection of the U-ribs and the top deck.