Research And Practice On Construction Monitoring Of Prefabricated Continuous Beam Bridge

The prefabricated cantilever assembly technology is a green bridge construction technology,and the short-line prefabrication process design is a relatively new type of bridge segment prefabrication process.In recent years,many parts of assembled continuous beam bridges or continuous rigid-frame bridges in China have advocated the use of the short-line method for prefabrication,but at the same time,what has to be dealt with is that the short-line method prefabrication process has more advantages than the traditional long-line method.High technical and precision requirements.The main research contents are:(1)The theories and calculation methods related to the construction technology and construction control of the short-line precast cantilever assembly are summarized and analyzed: the content and method of the construction control,the simulation analysis method of the construction process,the line shape calculation method of the short-line precast cantilever assembly bridge,and the overall coordinates And local coordinate conversion calculation methods.(2)Combined with a bridge engineering example of the Fourth Ring Road Project in Zhengzhou City,the specific construction technology of prefabrication and assembly of segment beams is introduced,and the alignment calculation of the prefabrication and assembly process is performed.The mechanism of segment prefabrication error control and different adjustment schemes when linear deviations are generated during assembly are analyzed.(3)The finite element analysis software Midas Civil 2019 was used to model an assembled continuous beam bridge in Zhengzhou,and the entire prefabricated segment assembly process was simulated and analyzed,and the assembly line shape of the assembled continuous beam bridge under different construction conditions was concluded And the change of stress in corresponding positions of different sections of the main beam.Practice in the actual construction of the bridge in Zhengzhou City.Real-time monitoring of the line shape and stress of the important construction stages in the process of assembling the segment box girder,and analyze the relevant data change rules to find out the cause of the deviation and subsequent changes.trend.Comparing the measured line shape and stress data with the results of finite element analysis,it is found that there is still a certain difference between the two,but the error has always remained within the allowable range of the code,which proves that the segment beam frame construction process is safe and reasonable.