Study On Cable Tension Optimization And Reasonable Design States Of Extradosed Cable-stayed Bridge

With continuous development of up-to-date bridge technology and new material, manynew bridge types have been built at the present stage. The extradosed cable-stayed bridge hasbeen considered as a new type of structure in recent twenty years, whose mechaniccharacteristic lies between continuous rigid frame bridges and cable-stayed bridges. Becauseof the predominant structural behavior, excellences of beautiful sculpt and favorableeconomic index, the extradosed cable-stayed bridge has been widely and rapidly applied inmany areas all over the world, especially in the East Asian region. Therefore, it is necessary tocarry out the research of structure and mechanical characteristics of extradosed cable-stayedbridge.On the basis of the summarize of this kind of bridge design data all around, the cabletension optimization, mechanical behavior and design practice of the extradosed cable-stayedbridge are analyzed by finite element software. The Paper tries to introduce the principles andspecific methods of cable tensions optimization and what rational completion status is andhow to get close to it which based on researching the relative optimized theory and methodsprofoundly for the extradosed cable-stayed bridge and historical origins and development ofcurrent situation. The dissertation proposes a synthesis method on the basis of influencematrix to determine the rational cable forces of cable-stayed bridge. That is, using rigidsupport continuous beam method, influence matrix of main beam stress by changing cableforces and prestress tendons in the main beam, inner force balance equation of main beam iscreated on the basis of inner force balance of main beam and the rational cable forces ofcompletion status is obtained, as well as the reasonable initial cable tension can be gotten byiteration method. Analyze about mechanical characteristics between pier-girder rigidconnection and pier-girder hinged connection structures, different cable-distance, differenttower-height extradosed cable-stayed bridges, concludes that compared to pier-girder rigidconnection, pier-girder hinged connection structures get more reasonable force environmentduring the using stage only in case of dense cable. It is adjustable of initial cable tensionunder various kinds of different cable-distance structures in order to achieve a “relativelyrational completion status”.This Paper provide a reference for the design concepts and optimization methods ofextradosed cable-stayed bridge.