Study On Key Techniques Of Prestressed Concrete Bridge Construction In The Cold Area And Marine Environment

In the cold area and marine environment,poor nature conditions,such as complicated geological conditions,big changes of the tidal,deep water and rapid flows,high waves and strong winds,the erosion and thawing effect of seawater and the corrosion effect of underground water and soil layers,bring huge challengs to the construction of prestressed concrete bridges.This thesis studied key construction techniques of prestressed concrete bridge.The Qinglong River Bridge and the No.2 Nachao River Bridge were taken as research objects.(1)Study on the construction technology of large-scale steel trestles in the marine environment:Considering the characteristics of the Qinglong River Bridge and the No.2 Nachao River Bridge and the natural environment of the bridge site,the necessity of using large-scale steel trestles and the construction difficulties were analyzed.The corresponding solution methods and engineering application effects were summarized,and some suggestions of the further research on the steel trestles construction technology of the future cross-sea bridge were put forward.(2)Study on the construction technology of super-long bored pile in the cold area and marine environment:Considering the characteristics of the No.2 Nachao River Bridge and the natural environment of the bridge site,the necessity of using bored piles and the construction difficulties were analyzed.The corresponding solution methods and engineering application effects were summarized,and some suggestions on the further research on the bored pile construction technology of the future cross-sea bridge were put forward.(3)Study on the construction technology of larg-volume bearing platform with steel boxed cofferdam in the cold area and marine environment:Considering the characteristics of the No.2 Nachao River Bridge and the natural environment of the bridge site,the necessity of using bearing platforms with steel boxed cofferdam and the construction difficulties were analyzed.The corresponding solution methods and engineering application effects were summarized,and some suggestions on the further research on the bearing platform with steel boxed cofferdam construction technology of the future cross-sea bridge were put forward.(4)Study on the construction technology of blast cofferdam:Considering the characteristics of the No.2 Nachao River Bridge and the natural environment of the bridge site,the necessity of using blast cofferdam and the construction difficulties were analyzed.The corresponding solution methods and engineering application effects were summarized,and some suggestions on the further research on the blast cofferdam construction technology were put forward.This thesis summarized the key technology in the cold area and marine environment systematically and formed the construction technology with regional characteristics.Theresults of this thesis guided the construction of the Qinglong River Bridge and the No.2 Nachao River Bridge.This thesis can provide technical supports and references for the construction of similar bridges in the marine environment and serves as a supplement to the construction technologies of bridges in the marine environment in China.