The Effect Analysis Of Prestressing Tendon’s More Or Less Tension On PC Continuous Box Girder Bridge’s Stress And Linear

This paper mainly aim at the problem of the more or less tension during the cantileverconstruction of the PC continuous beam bridge, based on the designing theory of prestressedbox girder,establish the analytic overall moder of the three tendons’ impact on box girder bythe method of numerical simulation, discussing the influence of more less tension to the mainbeams’ stress and deformation,which further discussing the prestressed continuous box girderbridge design and construction-related issues.In particularly mainly include the following fouraspects:(1) It is reviewed the basic theory of the development of prestressed concrete structuresand three-way PC continuous box girder bridge design, design and construction features, etc.by reading the relevant literature.(2) Combined with the practical engineering examples, establish a three-dimensional solidelements finite element analysis model through MIDAS-FEA software, respectively analysisthe longitudinal, the horizontal and the vertical prestressing’s effect to the box girder’s stressand the principal stress on the whole.(3) Based on the designing theory of the PC continuous box girder bridge, analysis theeffect of the longitudinal, the horizontal and the vertical tendons’ more or less tension to themain beam. The results showed that:The longitudinal prestressing tendons will make animpact on the main beam’s linear and stress, and the cantilever tendons and the closuredtendons’ effect is different, also the horizontal tendons and the vertical tendons’ tendons willhave a positive effect on the top and the belly plate and their effect is basically identical.(4) Combined with the background bridge, to further exploring the longitudinal, thehorizontal and the vertical tendons design issues related:①The local finite element analysis model is established to understand the distribution oflongitudinal beam local stress under anchor web, and optimized the prestressed steel beam onthe background bridge across to the medium and long term deflection as control index.②Based on the theory of plane frame method and finite element numerical analysismethod, explore the effect of the horizontal tendons on the structure internal force, followedbased on the finite element model of solid elements to explore the relationship of thehorizontal tendon’s different tensioning sequence to the roof’s transverse stress. ③Based on the elastic half plane’s theory, and with the help of the single web analyticsolution of stress under vertical force, set up the multiple root under the force of the verticalstress analytic expression, analysis the influence of the web’s stress by the numericalsimulation method and the two results are in good agreement; followed based on the finiteelement model of solid elements to explore the relationship of different transverse tendon’stensioning sequence to the roof’s transverse stress.