Exploration of large-span steel box-concrete composite continuous rigid frame bridges

摘要

Based on the existent study of prestressed concrete (PC) continuous rigid frame bridges and steelconcretecomposite bridges, a new type of steel box-concrete composite continuous rigid framebridge (SBCB) constructed by cantilever means is proposed in this paper. Analysis of an exemplary245m-span bridge design justifies the feasibility and reasonability of SBCB which can fully makeuse of the respective material advantages of steel and concrete and effectively decrease the mainbeam self weight, enabling relatively smaller substructure sizes but much larger spanning ability. Inaddition, SBCB is basically robust against the usual defects of harmful excessive deflection due toconcrete cracking and creeping. With the same quantity of overall steel use, SBCB can save 75% ofthe concrete quantity compared to the traditional PC continuous rigid frame bridge.