Construction Controlling Analysis And Study On Closure Technology Of A Speed Railway PC Continuous Girder Bridge

Infrastructure construction of the bridge has entered the unprecedented high tide period along with rapid development of our country high-speed railway. PC continuous beam occupies the important position with advantage of span arrangement. But linear uncoordinated and irregular structure internal force etc are especially outstanding, which often appears in kind of bridge construction process. Thus stimulated domestic bridge technicians carry out a comprehensive research and practice of bridge construction control and set up a variety of control theories and methods. A whole process of tracking monitoring is implement to verify each other to reduce the interference caused by different kinds of uncertain factors in construction. Construction control, meanwhile, has became one kind of the important means to evaluate PC continuous beam bridge quality and safety.In this paper, a PC continuous beam bridge of one high-speed railway from Dandong to Zhuanghe, Dalian is taken as engineering background, construction control and closure technology of bridge upper structure are analyzed and studied in depth based on design and construction technology etc, specific content as follows:(1) According to the mechanical characteristics of the structure, deformation and stress of main girder cross section are timely tracking collected, and adaptive control method is used to identify the parameters and make optimizing adjustment, thus the influence of the error on prediction in the construction of beam section could be eliminated. Through the theoretical calculation results and the actual data comparative analysis, it can offer important reference for this type of construction study.(2) The factors influencing the closed period of construction are analyzed in this paper, and it also summarizes the concrete material properties, pouring concrete temperature in closure stage, and rigid support embedded method etc.(3) Closure phase is one of the important link of the whole bridge construction. In this paper, to reduce the error, it is analyzed with the aid of the finite element analysis software simulation to obtain that different closure turns have great influence on bridge vertical deformation and internal force variation. This paper compares and analyzes the vertical displacement and internal force in closure phase, the second constant load phase, shrinkage and creep a thousand days phase in three closure turn respectively. More reasonable closure turn is chose from the analysis result, and it also proves the correctness of closure turn in the design. It is simulated and analyzed with more5days,10days,15days curing time respectively for the last cantilever stage. The result shows that different curing time have different influence on closure precision. (4) Not only formwork elevation in the cantilever stage construction influence the closure precision but also temperature and cantilever length do. Through large quality of data analysis, it shows that the deflection decreases with the atmosphere temperature rise, whereas the atmosphere drop, the deflection increased.At the same time, the cantilever length influences the deflection’s variety range.In this paper, the research results show that, through effective monitoring control method and calculation analysis method, bridge linear and section stress control on this bridge are taken successfully. The target of closure precision improvement is obtained, which based on the results of closure turn’s element model analysis and cantilever stage’s continuous monitoring. It lays a solid foundation for the later construction and could regarded as a effective reference for this kind of bridge.