TRIAL DESIGN OF COMPOSITE ARCH BRIDGE WITH STEEL TRUSS WEBS AND SRC FLANGES

Focusing on the key problem which obstructs the span increase of RC arch bridges, based on the composite structure with steel truss webs and stiffened skeleton construction method, a new composite structure with steel truss webs and SRC (Steel Reinforced Concrete) flanges is proposed. Taking Wanxian Yangtze River Bridge, the longest span (420m) RC arch bridge in the world 'using stiffened skeleton construction method, as the prototype, a trial design of composite arch bridge with steel truss webs and SRC flanges is conducted. The result shows that the trial design can satisfy the requirements. The structural behavior of the innovative arch bridge is similar to that of the original concrete arch bridge, but the self-weight is reduced about 25%. The application of the composite structure in long-span arch bridges could produce considerable weight saving and facilitate construction methods. It seems feasible for practical application.