Simply Supported Continuous Beam Bridge Structure Conversion Mechanics Analysis And Research On Construction Technology

The thesis is to study the changes of internal force of simply supported to continuous beam bridge in the process of construction, mainly discussed from several aspects as follows:Firstly, in the process of construction, the simply supported beam with installation of precast beam and the continuous beams formed by the simply supported continuous beams had deformation and internal force of changes. After analysis, the simply supported continuous beams had smaller displacement in the middle of the span, and more uniform distribution of bending moment than the simply supported beam;Secondly,after the precast beam installation is complete, continuous wet end joint section of tension and transverse girder pouring connection sequence were discussed and defined for different construction stages and then to phase analysis. The conclusion is that, first continuous wet end joint section of casting tensioning construction was more conducive to the system, s stress and deformation than the first transverse girder casting insulation connection;Thirdly, the tensioning sequence of continuous wet joint section different, it was discussed from three aspects:turn tension, symmetrical tension and interval tension, and defined for different construction stages before simulation analysis. It was concluded that, the interval tension was more instructive to the stress of system and long-term use of a pridge;Shrinkage and creep of concrete had been changing for a long time from the precast beam to being a bridge, but the rate of shrinkage and creep of concrete gradually decreased, and then the shrinkage and creep since stored beams to a bridge within three years was discussed.Fourthly, the beam storage period time was divided into 30 days,60 days,90 days, and analyzed the effects of concrete shrinkage and creep on the simply supported beam in the three periods. Through software simulation analysis, combined with the construction process and the construction budget, it was concluded that the 30 days of beam storage period time was better.At last, analysis into the bridge within 1 year,2 years,3 years after the influences of concrete shrinkage and creep on the bridge. The results showed that, the effects of the concrete shrinkage and creep on the bridge within 1 year was slightly larger, while smaller within 2 years and 3 years, so that the rate of shrinkage and creep of concrete was falling.