Stress Analysis Of Partial PC Box Girder Bridge Under The Action Of Prestress

With the gradual increase of the width of the box girder, continuous beams and continuous rigid frame bridge which using cantilever construction method,the beam element theory is not applicable in stages at the first several construction stages (short cantilever construction status), gradually attracted attention in bridge industry.In short cantilever state, the difference between the stress calculated with beam element theory and the actual stress distribution in the structure, how to simulate prestressed steel properly and other issues need to be researched. Therefore, this article studyed local stress caused by prestresse for bridges under short cantilever state and carried out an in-depth research,hoping hopes to further improve the design theory and method for PC box girder bridges, as well as and providing references to construction.In this paper, the design and analysis theory PC box girder bridge system were discussed, and summarized and contrasted studies show that the state of the construction boom in the use of short beam element analysis is inaccurate, but also caused a bridge or in the process of post-operation cracking problems.Proposed a method based on solid finite element numerical simulation method to achieve the Stress Analysis of Partial PC Box Girder Bridge Under the Action of Prestress". In this paper, the main points of different modeling methods were clearly explained, which can provide guidance for the engineering and construction.By using two different node coupling ways between prestressed reinforced concrete elements and prestressed steel elements, established ANSYS solid finite element analysis model.At the same time,Midas-civil elementary beam element model was established.Based on comparison of the data, the results show that the use of elementary beam elements can not be analyzed accurately reflect the section stress distribution.Due to the larger cross-sectional width, the same cross-sectional stress distribution is not uniform along the height direction.To further correction of deficiencies beam model, use equivalent load and effective flange width theories for sectional amendment.Results show that this theory can’t be used in analyzing stress stress level of structure.Besides, the web longitudinal normal stress agrees well with solid element analysis.To further verify the reliability of solid finite element data, the Flower Bridge monitoring data were compared. Studies have shown that the use of finite element simulation (Partialcoupled) solid elements can simulate the stress distribution ccurately.Studies have shown that using "elementary beam element theory" to inalyze the local stress caused by prestressing load will cause errors which should be taken seriously.