Analysis on whole-span deck replacement plan for large-span network arch bridge

Abstract

An integral beam and shell mixed finite element(FE) model was established and solved utilizing ANSYS platform in order to research the whole-span deck replacement for large-span network arch bridge based on the 420m main span of Qilu Yellow River Bridge at Jinan, China. Renewable concrete deck was adopted in this large-span network arch bridge with composite girder, considering the easy fail of the concrete deck caused by direct vehicle load during the operation. Several typical whole-span deck replacement plans were put forward according to the properties of composite box girder, and the corresponding mechanical behaviors of the bridge structure were studied by the FE program. The results of different removal sequences in whole span were compared with the stress of the bridge under completion state. And a changing law of the stress variation in the longitudinal direction was also obtained during the dismantling process of each condition. The analysis results demonstrate that all the whole-span replacement work plans discussed in this paper are feasible. However, the structural responses show a significantly difference under different operating conditions, the asymmetric whole-span deck replacement method affects the mechanics performance of the main bridge more obviously and adversely. And replacing the whole-span deck from both end supports to the mid-span is the optimum scheme for Qilu Yellow River Bridge.