Study Of A Viaduct Reconstruction Project Mechanical Properties Of Steel Box Girder

Box beam is widely used in transportation construction because of its great stiffiiess and larger capacity bounds.Compared with concrete box beam,steel box beam has many advantages.It can decrease self-weight, get greater net height under the bridge and can shorten construction period. So it is often used in city bridges,large span bridges and many others with special requirements for construction cycle. Continuous steel box girders are widely used in the city's BRT project.This paper takes the (40 +55 +40)m continuous steel box girder bridge as an example, and makes a systematic study on the stress of this bridge. The main results obtained are as follows :1, Using finite element method, the space model for the bridge has been set up .Stress state of the steel box girder under eight load cases, the location of the maximum tensile and compressive stress and local stress concentration have been studied.2, The stress state of the steel box girder and the reaction force of bearings under the extreme partial loads have been studied.The results show that this structure has sufficient capacity to anti-overturning.3, The shear lag problem of the upper flange of the main beam has been studied and the distribution of shear lag has been given.4, The effects inverted T-stiffening rib on the roof has brought to the shear lag has been studied and a conclusion has been made: a single stiffening rib whose thickness at 2～3mm can improve the effect of the shear lag.5, The impact steel fiber concrete has brought to the shear lag of the orthotropic steel bridge panel has been analysised ,and some valuable conclusions have been obtained. The production of this article has supplied a theoretical basis for one viaduct ,and it also provides references for other steel box beam bridges.