Study On Construction Control For Prestressed Concrete Continuous Rigid Frame Bridge With Wide Box Girder

In the recent years, the Prestressed Concrete Continuouss Rigid (PCCR) brigde had been widely applied all over the world with larger and lager spans. On the expressway the PCCR bridge with the single-box wide cross sections for the double driveway breadths had appeared, for those structurs with wide box girders the construction control usually is conducted with the plane rod Finite Element Method(FEM) analytic software which gives stress results quite different from those of the testing procedure, because the plane rod FEM model could hardly simulate the actual three-dimensionally mechanically behaving bridge. Aiming at such a problem, the paper apllies multiple analytical methods on single-box wide cross section PCCR Bridge K442+665 on Dali-Baoshan expressway in Yunnan province, to get the calculated results for comparison with the tested data in research. The main contents are as follows:1,Based on the existent elastic analysis, some holomorphic analysis, including the box girder shear hysteresis effect analysis and the local stress analysis at the large-tonnage prestressing anchor spots, is introduced in the research of the PCCR bridge with wide box girders.2,The plane rod-model analysis of the construction procedure of the PCCR wide-box-girder bridge is conducted to get the results of structural deformation and stresses.3,The three-dimensional FEM analysis, including the local stress analysis at the large-tonnage prestressing anchor spots and the maximum cantilever stress analysis during the construction course, is done for the construction procedure of the PCCR wide-box-girder bridge to get the structural spacial stresses and deformation. The longitudinal-prestress and the the shear-hysteresis-effect influencing extent on the girder-section uneven stress distribution and the variation of the section stresses along the bridge longitudinal axis are respectively studied to put forward the concept of averaging the prestress over the wide-box-girder section.4,The process control on the construction of the PCCR wide-box-girder bridge is summarized to study the influencing factors on the mechanical behavior of the actual structure.5,Some advice is offered on the design, construction and control of the future PCCR wide-box-girder bridges.