The Process Monitoring Method Analysis On Cantilever Construction Of Prestressed Concrete Continous Girder Bridge In High Elevation Region

With the development of the bridge design and calculating theories and construction technology, especially the prestressing technique progress, long-span prestressed concrete continuous rigid-frame bridge has been widely used, due to mechanics reasonability, smooth and comfortable, streamlined appearance and convenient construction. In the prestressed concrete continuous rigid-frame bridge cantilever construction stage, the deflection happened on the bridge is not adjustable. In order to ensure the bridge linear and mechanical behavior meeting the design requirements, as well as the safety in symmetrical cantilever construction stage, It is necessary to do the construction monitor control works.In this paper, with the Bai Ma bridge as engineering background, which located on sichuan-tibet plateau, according to the behavior and construction characteristics, the reasonable construction monitoring schemes and the comprehensive monitoring system are establiished. Combining with the theoretical analysis and engineering practice, the "Self Adaptive Control" theory in the application of construction monitoring is discussed. By finite element analysis of the bridge, the sensitivity for various factors are calculated in the process of cantilever construction, for the basis of the process parameters adjustment.According to the plateau climate characteristics, based on the temperature filed theory and its solving method, as well as the measurea temperature data to Bai Ma bridge, a concrete temperature field is given by radiation theory and experience, and with the Bridge standard for the temperature curve compared. Through calculation and analysis of the effects of sunshine, the actual local temperatual effect on the stage of construction and operation of bridge structure on stress and deformation are determined to provide the reasonable cantilever construction control data, and offer a reference for the design and construction of similar bridges in sichuan-bibet plateau in the future.