Three Dimensional Mechanical Characteristics Simulation Analysis Of Double Towers And Single Central Cable Plane Pre-concrete Cable Bridge

Double towers , single central cable plane and prestressed concrete cable-stayed bridge with its beautiful appearance, the advantages of broad visions is often designed in large pan bridge areas. Because the overall torsional stiffness of the bridge is low, the design is different from the double cable plane cable-stayed bridge. Also there are some arguments that whether building the auxiliary piers. This paper bases on the design of Pinghai Bridge.According to the professional drawings, two integral finite element models,which include auxiliary piers and not, are builded on Midas Civil,large-sacle FEM sotfwaer. Assistance to the analysis in this simulation,some conclusions are obtained,as follows:(1) A combination of the minimum bending-energy method and the stress- balance method is used to set the reasonable cable tensile force of Pinghai Bridge. The results show that it is an efficial method to obtain a groud of ideal and equality cable forces in finished state. By the way of forward-backward analysis and otimizing the cable tensile force,it is able to get the ideal cable tension in construction. With the comparative analysis of the cable tensile force in finished state and constructing state, while the structure has auxiliary piers or hasn't, it can be knowed that in the static force condition, the overall force of main bridge with auxiliary pier is slightly better than the structure without auxiliary pier. Both of which can meet the specifications by taking relevant measures.(2) By analyzing and comparing the live-load effect on structure stiffness and cable stress range,it can find out the difficences between the structure without or with auxiliary pier,Considered the whole structural life, this type of single central cable plane cable-stayed bridge is necessary for building the auxiliary piers.(3)With the analysis of the inherent vibration, seismic and wind stability,it can abain this bridge mechanical characteristics and the key component of design.Compare with the data of the structure while it has auxiliary piers or not, it can be knowed that the structure is still in a safe state without the auxiliary pier.(4) With the analysis of the ship crash on bridge while it has auxiliary piers or not,it is clear that some components are important.Also, it can be knowed that the whole bridge without auxiliary piers is still safe when crashed by ship.By the analysis above, it can get more comprehensive understanding about these bridges'static, dynamic characteristics . Also the calculation method of large bridges can be mastered.