Analysis Of The Cable And Tower Of Long-span Suspension Bridges

With the development of long-span suspension bridges, analysis of the cable is more and more precise. The tangent point change of cable and saddle in construction is even considered sometimes. But so far, all of the analysis are still based on the assumption that the cable cannot be bended or compressed. There is no doubt that all of steel wires are tied before boom mounted. The cable is suppleness because of the long span. However, the cable flexural rigidity is real existent. In order to figure out the cable flexural rigidity influence on the suspension bridge, a finite element model of a large span suspension bridge-Jiangyin Bridge is establish in this paper. Compared to numerical simulation results of four different cable models, the following conclusions are with the span increasing and sag ratio reducing, the influence of cable flexural rigidity is significant, and the differences of nodes displacement will reach more than ten centimeters in construction analyzing, which will bring some trouble to the construction. And the difference of the maximum section edge normal stress may reach 15%, which may have an adverse impact on the bridge. Therefore, considering the cable flexural rigidity is necessary on the process of fully and correctly reflecting the actual static performance of the main cable, and then ensuring accurate and safety analysis of long-span suspension bridges.With the span of suspension bridges increasing, the height of towers rising, box girders thin-walled, and high strength materials widely applied, calculating and analyzing towers, as another important component of the suspension bridge and making smaller safety factor in design, has been concerned by more and more scholars. Based on the tower of Jiangyin bridge, two different models-single tower fiber model without regard to the impact between the cable and the top of tower and the entire bridge fiber model, are established by self program MockCool, and then made elastic stability analysis and large displacement elastoplastic analysis after considering the geometric and material nonlinearity. The result shows that in terms of the two models, although the elastic instability problems of both models belong to the second type stability. Due to the different boundary conditions, elastic buckling modes not only make some change, but ultimate bearing capacities also vary greatly.Hope that the conclusion can provide some references for the design and research of the same type of bridge in future.