The-design Research On Light-weight Arch Structure Of Reinforced Concrete Upper Bearing Arch Bridge

As China is mountainous, reinforced concrete upper bearing arch bridges are widely usedhere. The upper bearing bridge has very big dead weight which make the construction processmore difficult and also has gradually become a important factor that restrict the bridge get a longspan. So it is really necessary to take some research to reduce its big self-weight. Up to now, theresearchers of domestic and overseas have made much work to lighten the arch but the upperarch structure. So taking some arch bridges have been built as reference, and the WanxianChangjiang Bridge as project cases, this paper launchs research work on methods of lighteningthe upper arch structures of reinforced concrete upper bearing arch bridges. The main contents ofthis paper include the following.(1) The continuous beam. To analyze that how the continuous beam works on the bridge, weredesigned the beam with a continuous box beam which has5cells. The results shows that thecontinuous beam affect the arch bridge significantly and especially to its dynamic performance.For example, it is helpful to lower the axial force and bending moment of the beam when thearch bridge is in the three-plus earthquake. But it is adverse to lateral moment of the beam.(2) Form of the upper arch structure. It shows that the steel-concrete composite structurecan save35.4%of the dead weight of the upper arch structure. Accordingly the axial force andbending moment of the arch feet are reduced by16.4%and16.7%. Incremental launchingmethod is applied to simplify the the construction process, and also shorten the constructionperiod.(3) RPC upper arch structure. RPC200is adopted to redesighn the upper arch structure. As aresult, the dead weight can be reduced by34.3%. And if a RPC arch is adopted the whole deadweight of the bridge can be reduced by38.6%, accordingly the axial force and bending momentof the arch feet can be reduced by43%and21%.