Long-Term Deformation Analysis And Control For Prestressed Concrete Continuous Rigid Frame Bridge With The Consideration Of Time-Dependent Effect

With the continuous development of our country’s transportation, the continuous rigid frame bridge is widely used due to its strong span ability, convenient construction and comfortable travel. However, mid-span’s long-term deformation of the existing continuous rigid frame bridge has become a common concern, which not only brings much trouble for driving, but also crazes or damages the structures, and even greatly impacts the normal operation and safety of the bridge.This thesis was based on the project of Jialing River2nd Bridge in Peng’an. By taking the concrete time-dependent effect into account, the measures to control the mid-span long-term deformation combined with theory and actual situation, through establishing the Midas/Civil finite element model to analyze the long-term deformation of continuous rigid frame bridge. The main research contents are as follows:(1) Based on the analysis of relevant information, the author expounded the structural characteristics, development situation and current issue of continuous rigid frame bridge, and put forward the concept of time-dependent effect according to the causes of those issues. Then the author introduced the characteristics of the time-varying factors.(2) The author presented the calculation theory and analysis method of creep effect and pre-stress tendon losses, and also developed the research on the related parameters. Besides, then the author introduced the long-term deformation of continuous rigid frame bridge influenced by each time-dependent effect.(3) Based on the construction plan and actual situation of the background project of Jialing River2nd Bridge in Peng’an, the author proposed several closure schemes, and compared those schemes through analyzing the deformation and stress state in finished bridge state.(4) The author made a comparison between the calculated results at the initial period and the time when the bridge has been completed and used10years, and developed the research toward the long-term deformation and stress of the bridge from time-dependent effect.(5) Combined with the calculated results and the analysis conclusion in this thesis, suggestions about reduce the influence of time-dependent effect and control the long-term deformation of continuous rigid frame bridge were put forward from the three aspects of design, construction and maintenance.The conclusion of this thesis can provide some useful and theoretical guidance for the construction of background project. At the same time also can provide a reference for the same type bridge in the future and the related field.