Analysis Of Structure Simulation For Long-span Prestressed Concrete Continuous Rigid-frame Bridge

Prestressed concrete continuous rigid frame bridges has caused the extensive concern in the large span beam bridge because of its characteristics such as large span ability, flat driving and reasonable structure material. This article first reviewed continuous rigid frame bridges'development history, construction technology, Structural Characteristics and development trends, also described the analysis method and significance of continuous rigid frame bridge's construction control.Concrete continuous rigid frame system is a complex space loaded system, usually uses the finite element analysis. This article established a reasonable finite element analysis and calculation model, used the plane member finite element program, to make structural simulation of Taihe Gan river grand bridge. By simulation and analysis of prestressed concrete continuous rigid frame bridges' construction process, calculating the structural stress, deformation and formwork's height control during construction, a complete set of theoretical data can be provided to correct monitor the construction and ensure the implementation of bridge monitoring.Earthquake is a very serious disaster and very important to take aseismic measures for special structure. This paper calculated and analyzed specifically structure aseismic behavior of Taihe Gan river grand bridge, used subspace iteration method to do dynamic eigenvalue analysis and response spectrum vibration analysis. The results indicate that the structure system is stable.Present one major disease of some big span prestressed concrete continuous rigid frame bridges (especially the main span is more than 150 meters) is down deflection of girder's midspan. In order to prolong the bridge's service life, it analyzed the reason of the bridge midspan's long-term down deflection problems, proposed the design concepts of " dead load zero moment and zero deflection", changing beam height to control midspan's deflection and introducing externally cable at midspan of main span to reduce live load during operation and concrete late systolic creep deflection. Big span continuous rigid frame bridges often use cantilever cast method, the bridge alignment is affected by many uncertain factors during the construction process, such as the design calculating model, the physical and mechanical properties of material, the construction precision, the construction load, the air temperature etc. it has always differences between the ideal state and the actual state. During the construction through the field monitoring and control of some indicators, such as the main pier displacement (verticality) and settlement of pier and abutment, the girder's stress and alignment, the stress strain and construction temperature of prestressed concrete structure, the monitoring results indicate that the stress and displacement during the construction process were always in safe controllable condition, the construction control reached expected requirement.