Optimizing Analysis Of Auxiliary Piers On Beipan River Bridge

As the rapid development of modern computer technology and the continuing development of the theory of FEM(Finite Element Method), many problems lying in elastic mechanics, elastic mechanics and structural mechanics are solved perfectly. At the same time, with the ceaseless innovation of modern material science and the rapid development of construction technology, the span of the cable-stayed bridges refreshes the records over and over again. Now the construction of cable-stayed bridges is coming into a hot period. The long-span cable-stayed bridges and the extra long-span cable-stayed bridges even appear.The research subject of this thesis is the Beipan River Bridge. It is located at the Bijie to Duge period (along Yunnan-Guizhou border) of Hangzhou-Ruili Expressway. The starting chainage of the main bridge is K218+903.406, the ending K220+224.806. The main bridge of Beipan River bridge is a two-tower cable-stayed bridge supported by double planes with steel truss beams. The main span is (80+88+88+720+88+88+80)m; while the side span is supported by two auxiliary piers and one transitional pier. It is1232m, belonging to a long-span cable-stayed bridge. The main span is located above the branches of Beipan River Bridge along Yunnan-Guizhou border. The maximum distance between the river and the bridge is265.5m.The geological survey of the area where the bridge is located shows that the Beipan River Bridge situates at the karst area with many grikes and karst carves. Therefore, decreasing the number of piers reduces the negative influence of the geological environment.The main span of Beipan River Bridge is720m, the side span256m. The ratio of them is0.355. It is a bridge with a relatively small side span. In the original design, two auxiliary piers are set to support the side span of one side. Auxiliary piers help to decrease the stress amplitude of the stays, enhance the rigidity of the main span and alleviate the counter force at the joint points of each end. However, the auxiliary piers within Guizhou boundary reach64.2m and84.1m. The construction of such heights requires high technology and long-term construction. Besides, the geological environment where the bridge situates is unfit to build many piers. Therefore, the construction unit and the building unit entrust us to optimize the number of piers, hoping that our optimizing analysis will be able to provide guidance on the general construction of the program, as well as save the price and time of the whole project. This thesis calculates the original design by using two auxiliary piers with FEM MIDAS Civil2011. At the same time, a reasonable position is chosen to optimize two auxiliary piers into one auxiliary pier. Besides, the cancellation of auxiliary piers is also calculated. The economic efficiencies of different designs are compared. The conclusion of this thesis provides not only scientific guidance for the construction of the Beipan River Bridge, but also advice and reference for the future construction of the bridges of the same type.