Study On Construction Control Of Taishizhuang(48+80+48)m Prestressed Concrete Continuous Girder Bridge

The cradle cantilever construction method is widely used for prestressed concrete continuous girder bridge. During cantilever construction, the alignment and internal force of continuous girder structure are continuously changed. The comprehensive influence or error of the dead weight of continuous girder segment, tension of prestressed steel strand, cradle load, concrete shrinkage creep, temperature change, displacement measurement, etc. may cause that, during construction, the structure of a continuous girder bridge presents a difference between the theoretical alignment and internal force condition and actual condition. With reasonable model of mechanical calculation, the prestressed concrete continuous girder bridge is accurately and theoretically calculated and analyzed, and, the real-time alignment and stress are controlled and monitored during construction so as to control the alignment and stress status of bridge during construction, timely find possible anomaly in the process of construction, analyze the possible cause(s) of anomaly, and eliminate potential quality and safety risk(s) during construction. And, ensure that, after the girders are joined as bridge, the alignment and internal force may meet the requirements of design specifications by giving appropriate elevation of vertical formwork of cantilever segment at different stages.This article analyzes the purposes and significances as well as flow method and main scope of construction control based on the collection and summary of relevant data of prestressed concrete continuous girder bridge construction control at home and abroad. And, with Taishizhuang Bridge on Zhangjiakou-Tangshan Railway as engineering background, it explores various factors having influence on the alignment and stress on Taishizhuang Bridge. The construction process of the whole bridge is analyzed and the alignment and stress of this bridge are controlled and monitored during construction by establishing an FE simulation and calculation model of Taishizhuang Bridge using Midas/civil FEA software. The site monitoring data shows that the alignment and stress during construction and those of the finished bridge may meet the design requirements and fulfill the expected purposes of control and monitoring.