Study On Plan Selection For Long-span Cable Stayed Bridge

Since the cable-stayed bridge has developed into the most popular bridge type for long-span bridges.The mixture of shapes and form of cable stayed bridges are the most-demanding architects also a whole public.Engineers encountered them technically disputing and innovative.Cable-stayed bridges are more economical for the bridge that the spans up to about 1000 m.Because of these special characteristics that make me decide to choose this kind of bridge to take in to this study.In this research we have to study selective on plan of the long span cable stayed bridge according to it economics characteristic with the parameter of the cable stayed compositions such as the tower height(H),the cable spacing(S),and the depth of girder(h).It was concerning according to the two kinds of internal force that are the maximum bending moment along the girder and the maximum bending moment at the bottom of tower.By changing the value of those three components of the cable stayed bridge respectively,we get 24 kinds of cable stayed bridge to analyze and discuss.These 24 bridges will work on numerical analysis by using Midas Civil software for modelling bridge according to parametric factors with three kinds of loads like dead load,vehicle live load and wind load.Then after,it wills determine the internal force and the mechanical behavior of the cable stayed bridge by verify with the two critical point sections whether it satisfy or not.Those two sections are the girder section and the bottom tower section.The girder section will verify by using pre-stress concrete method and the bottom tower section will verifier by using reinforce concrete with UCFyber software according to maximum bending moment a long girder and the maximum bending moment at the bottom of tower respectively.The result shows that only 15 kinds of bridge that satisfy to the girder section strength and only 14 kinds of bridge that reach to the bottom tower strength requirement.Found data of all graph result will continuously use to analysis and discuss in order to select the most significant bridge according to the economic condition.The discussion of the cost of this long span cable stayed bridge is concerning about the tower height and the depth of the girder that are used much among of concrete.Finally,we can select the most significant one is the bridge that has the shortest tower height,the longest cable spacing,and the smallest depth of the girder among all kinds of cable stayed bridge that satisfy to the section strength requirement.