The Design And Research Of The Vertical Rotation From Above To Below Method For The Large Span Arch Bridge

The key problem in the construction of long span arch bridge of RC structure (LSABRC) is the constructive technology. The construction of arch flame is applied in the present projects. However, with the development of the Non-bracket Construction Technology (NBCT), the application range of arch bridge is extended while its competitive strength is also enhanced comparing to other methods utilized in long range bridge building.In the resent years, several sorts of NBCT in arch bridges are implemented, such as cable erection cantilever construction,stiff skeleton, rotation construction.Among which rotation construction is applied in the bridge construction with higher frequency by its unique advantages. Meanwhile, with its technique become more and more perfect, the bridge construction in china has obtained considerable economic and social profit.In the domestic constructions, the method is only applied in three forms: the horizontal rotation, the vertical rotation, the vertical and horizontal rotation. On the basis of consulting vertical rotation utilized abroad, a new method named "The Vertical Rotation from above to below" is adopted in construction of main arch ring of LSABRC, which is a creation in Chinese bridge construction.This paper is written on the background of the Zhenzhu Bridge on the road from Wuchuan to Pengshui. With the basic theory of finite element analysis and relevant literatures published domestically and abroad, numerical analysis on flat member FEA model is implemented in the rotation construction of the Zhenzhu Bridge. The details are specified as followed:Firstly, the outline of the rotation construction is summarized. The pouring and rotation of the arch rib is simulated by the FEA model. The stretching opportunity and the stress of the cable, temporary cable, tie bar are optimizing computed to make the internal force of the arch rib meeting requirement. There is no doubt that the stability of the arch rib during the construction process is dependable with the analysis of the FEA.Secondly, the vital detailing, such as the hinge for the vertical rotation ,the frame of arch foot, stretching bed, are exhaustively analyzed in order to ensure their adequate rank of safety.Finally, as the rotation from above to below hasn't been applied in any of the practical projects in china and no experience can be consulted, Construction Monitoring and Control is the vital issue. In this paper, according to the features of the given bridge and numerical FEA analysis, the key points of the construction control are specified and constructive scheme is proposed, which can provide indemnification to ensure the successful constructive procedure.