The Test Section Of The Wuhan-guangzhou Passenger Line 32m Simply Supported Beam Creep Testing And Prediction

For the prestressed concrete bridges, the deformations of the structure caused by creep should not be neglected. The influences must be considered during the design and construction. Nowadays, ballastless track has been widely used in the passenger dedicated line, however, the enhancement of train's running speed needs a higher request to the track regularity and it is very difficult to ensure the smoothness of the track because the height of the track can be adjusted little without ballast. Therefore, it is necessary to research the creep of concrete bridge and control the latter deformation to ensure the safety of passenger dedicated line.With the "Test and Research of Typical Section Deformation Monitoring to the Underline Engineering of WuHan-GuangZhou Passenger Dedecatied Line" as background, the paper did the job as following:(1) Firstly, it connected the research information of creep concrete home and abroad, analysised the mechanism and essence, discussed the main factors that affects creep of concrete and several measures of calculate.(2) Secondly, this paper expatiated the impacted factures, mechanism; calculate theory of concrete creep in detail, then desired a test of creep with the Liu JieZhang Bridge in Yueyang City. The test took two kinds of observation method including precise leveling and static leveling to get the developmental rule using the analysis of result. And after checking out each other we can test the effectiveness of elements.(3) Thirdly, the paper established integrated model and simulated various construction stage by applying finite element software to the simply supported beam of Liu Jiezhang Bridge, and calculated the deflection change of beams from different stage which caused by creep according to the pattern of Chinese Standard, CEB-FIP and Japanese Standard. Through comparison between the field measurement level and theoretical calculation level, it analyzed the difference and cause in the various results of calculation pattern, ensured the reasonable pattern of finite element and predicted the later deformation. And finally determined the pattern of CEB-FIP standard is reasonable for calculating and forecasted the deflection change in 30 years.(4) With the software it discussed the long-term deformation affect on the beam from shrinkage and creep and analysis the factor such as relative humidity, concrete strength grade and prestress loss. And finally, it suppose the measure of controlling the later deformation by means adjusting the loading age of concrete and the applied time of secondary deadline in desire and construction.