Key Problems Research On Horizontal Swing Construction Of Continuous Beam Bridge

With the rapid development of road and rail infrastructure in recent years, the density of the road network is significantly increased, which commonly leads to the flyover crossing between the new built bridge and the old roads and railways. The adoption of horizontal swing construction for the continuous beam bridge seems more rational in order to reduce the influence to the down traffic caused by bridge construction, especially the impact on railways. The segments generally are casted on the scaffold before horizontal swing construction, therefore the reasonable segment length and scaffold demolition sequence which are studied less at home and abroad may cause some influence on the structure, the construction safety, the monitoring and so on.Therefore, the relevant research has been carried out on the scientific and technological project of Shanxi communications department (Key technology research on horizontal swing construction of long-span continuous box-girder bridge for super DWT) and a real case of the Weizi overpass project in Shanxi Changping expressway, including following work.①The influence on the internal force caused by variant length of segment is analyzed ,and so do with the effects of shrinkage and creep of concrete , prestressed effect, the relationship between and segment length.②The displacement and stress of the beam has been got with different friction, different constraint caused by the formwork. The influence on the effective stress is discussed with the variable friction coefficients and constraint,and the measures to reduce friction coefficients between the girder and the scaffold are proposed.③The variance process of internal force of the scaffold is discussed in detail when construction, meanwhile the different sequences of the scaffold removal in one time or several times which affect construction monitoring are also covered.Based on the calculation of different sequences,the displacement and stress of the beam, the internal force of the scaffold are got ,and the advantages and disadvantages are compared among the different sequences, finally a optimal removal sequence is proposed and successfully applied in the actual project.④The key points and considerations have been proposed through the Weizi overpass monitoring and analysis.