Superstructural Design And Research Of Ramp Bridge With Protrudent Diaphragm

With the development of transportation, the Interchange and viaduct hadbeen widely used. To achieve traffic steering function, and the intersectionbetween the main line connecting the difference in elevation, which need tobe designed to ramp bridge. Meanwhile influenced by topography, feature,underground pipelines and other factors in the city, in order to satisfy theplan and clear height of road,which need to be set protrudent diaphragmacross the road in the key nodes.In this paper, the design theory of calculation of ramp bridge withprotrudent diaphragm was simply introduced, and analysis the main factorsaffecting the force of superstructure, combined with Huizhou Jin Kai AvenueRamp A4x30m continuous prestressed concrete box girder, the main researchcontents are:(1) The bending and torsion coupling effects are more complex forprotrudent diaphragm，analysis of internal force distribution studies girderunder self-weight and the temperature load cases.(2) the constraints bearing arrangement of different effects on thedistribution of internal forces and the PSC girder longitudinalcross-sectional design, as well as changes in reaction force supporting roleunder load conditions.(3) According to the current seismic design codes, comparativelongitudinal fixed bearing to get the reaction force.By Midas Civil finite element analysis software to calculate summarizesthese bridges overhanging beams due to the presence of longitudinal girderinternal force distribution, cross-sectional design, bearing reaction forceeffects:(1) Due to the presence of large overhanging beams, so that the main beamat large negative moment beams reduced by about10%, about double the torquevalue increases, the shear value no major changes. (2) due to the interaction with the large longitudinal girder beams in theoverall temperature conditions will have a greater level of support reactionforce, as well as the basis for the lower part of the pier from the adverseeffects.(3) the recommendations provided in the outer longitudinal extension fixedbearing beams at protrudent diaphragm,and pay attention to the seismic designof the substructure.Can provide some reference to the above conclusions for the future in asimilar ramp bridge design and construction.