The Construction Technology Of CFST Rib Of Frame Tied Arch Bridges

The construction process of Concrete Filled Steel Tube (CFST) arch rib is complicated, and it is also key process of CFST tied arch bridge construction. Based on the construction of Lanzhou Yanyan Yellow River Bridge, the construction schemes of rib erection by overhang and concrete pumping of a three-span continuous frame tied arch bridge are introduced.Firstly, the development and basic theory of CFST arch bridge are introduced briefly. Considering the fact of the Yellow River Bridge, the construction schemes of hanging segmentally by long span and great tonnage cable crane, fixing by inclined cable, once pouring to the arch top symmetrically along the whole rib, are adapted.The structure of cable crane and cable system are designed, the fabrication and detection methods are introduced in detail. The reasonable and workable rib machining and hanging techniques rules are established and the quality of steel rib is guaranteed. The fixing tower and fixing cable are calculated and each parameter is confirmed. The hanging techniques of steel rib are explained concretely, the pre-raise value of each rib subsection is computed and rib profile adjustment method is discussed too.The ingredient proportion of concrete poured by pump is determined, according to the capacity of the pressure pump the appropriate pumps are chosen and a suit of pressure pouring techniques is established. By numerical analysis the pouring sequence is from side span to middle span, from lower tube to upside tube, and the concrete in each steel tube is poured just once.The success of the rib construction of the Yellow River Bridge is helpful to the further developing of CFST tied arch bridge and the instituting of involved specifications.