Large Span Prestressed Concrete Continuous Rigid Frame Bridge Construction Simulation Analysis

The prestressed concrete continuous rigid frame bridge has been widely used in long-span bridges with its predominance of high strength, crisp linear, handy construction and long-span ability. To avoiding interruption of navigation and construction of expensive river stent, the most commonly used construction method of long-span prestressed concrete continuous rigid frame bridge is symmetric cantilever casting method. In the construction process, bridge structure was impacted by many factors such as concrete shrinkage and creep, differences between design parameters and actual value, construction error, inaccuracy of measurement, temperature shift, and so on. Thus, the symmetric cantilever casting method would inevitably lead to very complex change of internal force and displacement to bridge structure. To ensure the construction quality and safe, to ensure the main beam linear and displacement change of completed bridge complying with design requirement, to making the virtual condition of continuous rigid frame bridge consistent with the design status as far as possible, bridge construction control is indispensible.Based on analysis and summaries of both foreign and domestic long-span prestressed concrete continuous rigid frame bridge development and construction control technology, this article introduces the characteristics of prestressed continuous rigid frame bridge and construction methods. Taking a continuous rigid frame bridge example for engineering background, researches the linear control and stress control of its cantilever casting process. Using bridge finite element software Midas/civil, simulates and analyzes the every stage cantilever casting process of whole bridge. In the simulation and analysis many factors have been considered such as the shrinkage and creep of concrete, the prestressing loss of fixture etc. The pressure and the change of deflection of every construction stage are obtained. Then the sensibility of design parameter of the bridge is analyzed. Through changing the value of main parameter, researching the influence degree the parameter error impacts on the deflection and pressure of prestressed concrete continuous rigid frame bridge, the main parameters of construction control are discerned.