Research On Construction Control Technology On Long-span Prestressed Concrete Continuous Rigid Frame Bridge During Short Tower Cable-stayed System Modification

Continuous rigid frame bridge in bridge construction is more and more widely,in 80s and 90s the national construction of a large number of continuous rigid frame bridge,due to the limitation of the design and construction process of the bridge,after these more than 20 years of operation,widespread cross deflection and web cracking phenomenon,a serious threat to the safety of the bridge structure and traffic safety.In order to prevent the further deterioration of structural diseases,it is usually adopted to paste carbon fiber cloth,thickening web plates,and sticking strip steel plates on the web.After the measures such as sticking carbon fiber cloth,thickening web plate and sticking steel strip on the web of Dongming the Yellow River bridge,the phenomenon of mid to lower deflection and cracking of web plate has not been greatly improved.In order to ensure the safety of the structure and avoid the loss of property of the major personnel,the bridge is reformed with a short tower cable-stayed bridge.In this paper,the bridge reconstruction project of Dongming the Yellow River highway as the basis,through access to a large number of documents and examples of engineering projects,calculated by the combination of theory and field monitoring means,carry out analysis and test research,summarize some conclusions and rules to provide reference for the same type of bridge.In this paper,using the finite element software Midas Civil simulation analysis,the Dongming the Yellow River highway bridge,the bridge structure,the linear analysis in various stages of construction stress and cable force,study the changes of shape,stress and cable force etc.,and apply it to the bridge construction site monitoring,deformation prediction of follow-up the construction phase structure,which is always in a safe state in the cable tensioning process structure.Finally,the stress characteristics of each cable tension stage structure are studied in this paper,and the control indexes are analyzed synthetically,and the final tension force is determined.Through the analysis of the Dongming the Yellow River highway reconstruction project construction monitoring results summary,indicate that this control method has been used in the project,the bridge line is improved,the stress is always in a reasonable range,the structure is always in a safe state,construction control work is very successful,provides a good reference for similar bridge reconstruction project.