In Continual Rigid Frame Bridge Span Down-warping Prevention And Control

In recent years, continuous rigid frame and structures have been rapid developments in technology, but most in operation under excessive deflection of main girder of long span continuous rigid frame bridge, affects the stability of vehicle operation or even a crack of, affect the security of the bridge. As a result of continuous rigid frame bridge that exists across the middle and lower deflection and cracking main reasons of selection of design parameters and construction elevation control.Design is the precursor of bridge engineering, bridge design determines the overall performance of bridge engineering. Engineering design of large bridge failures and shortcomings will make a huge loss of such losses in the subsequent detailed design phase and construction phase and the operational phase is irreparable. These errors are caused by factors are:(1) gravity, (2) material characteristics of bridge.Dead load for large span bridges structure loads more than 80%, persistently high proportion of dead load leading to sustained growth, across the middle and lower flexible box girder cracks continued to increase. Shrinkage and creep of high strength concrete, inadequate understanding on the mechanisms of creep and shrinkage of high strength concrete, and also appears under the incompatible theoretical calculation of torsion. Determines the size weight and material effect on the deflection value problems are some of the design parameters. This article mainly on predecessors on the basis of research, analysis and summary beam curved forms, thin-walled high Pier, wall thickness, height-span ratio, span ratio and other factors effect on bridge of rigid-frame.Construction control is the last time bridge engineering performance checks, complexity of the construction process of large-span continuous steel box girder, material mechanical performance, loads, mechanical models are sometimes modified. Analysis and calculation of field monitoring and simulation to ensure bridge line meets the design requirements. Factors affecting the bridge line monitoring for box beam deflection. This article in a comprehensive domestic and foreign large-span continuous steel box girder on the basis of monitoring technology for bridge upper structure, combining G65 high speed Chang family River bridge construction monitoring instance expand research.(1) In the predecessors on the basis of research, analysis and summary Master beam curve style, height-span ratio, span ratio and other factors effect on bridge of rigid-frame.(2) Combination of analysis and calculation on analysis and calculation of forward and back, using MIDAS/CIVIL special analysis software, analysis of established monitoring model, give the deflection, stress analysis and calculation of results.(3) Of the hanging blue and cantilever bracket deflection, stress analysis and calculation of 0# block, so that further analysis of box beam deflection, and verify that the construction of security.(4) Summarizes the least squares method in the bridge construction control application, the especially big bridge controls the elevation adjustment and the forecast to Chang family river, proposes the box Liang linear control main conclusion.(5) Pair of future continual rigid frame box beam bridge construction will put forward certain proposals.