Maintenance Construction Survey And Surveying Data Management System Of Nanjing Yangtze River Bridge

Nanjing Yangtze river bridge repair and renovation project is the completely maintained for the first time since Nanjing Yangtze river bridge was completed,Maintenance and reinforcement of main bridge is the main task in the project,the core of reform is demolition of old bridge and installation of orthotropicplate.Construction survey work is the key factor to determine the alignment of bridge after maintenance and renovation.Because of the special historical position and significance of Nanjing Yangtze River Bridge,the alignment of the main bridge of Nanjing Yangtze River Bridge must be restored to the alignment when the bridge is completed and opened to traffic after maintenance and transformation,it puts high requirements for measurement methods,measurement accuracy,measurement data processing methods and effective guidance of field construction in the construction process.This paper starts from the content and significance of bridge construction survey,according to the principles and difficulties of surveying the maintenance and reconstruction construction process of the main bridge of Nanjing Yangtze River Bridge.The error sources in installation and construction of steel main girder are analyzed,some measures to reduce errors are also put forward.In view of the errors caused by the surveying work in the installation and construction of main bridge,the preparatory work of pre-construction survey is amply introduced,including leveling network retest and leveling point encryption which focus on the deflection and deformation measurement of steel truss girder,elevation measurement of support system and attitude control measurement of main bridge installation.As the Nanjing Yangtze River Bridge is the bridge of highway and railway,the lower railway line is still in operation during the construction process which brings a serious test to the measurement work in the process of installation of steel main girder.Moreover,the installation and construction of steel girders have the characteristics of tight time,heavy tasks and high requirements,the traditional measurement method and data processing process cannot ensure the quality and quantity of construction.It isnecessary to adopt high-precision surveying means,scientific surveying data processing methods,efficient surveying data processing and transmission methods,and reasonable construction procedures to ensure the completion of the maintenance and renovation project of Nanjing Yangtze River Bridge.In this paper,a Web management system of measurement data is developed around the measurement work during the installation of steel girder.The functions of reading,adjustment,transmission,sharing,management and storage of field raw data are realized in the system.In the system,the original data output from the measuring instrument can be adjusted and processed.At the same time,it is possible to compare and analyze the measured data under multiple working conditions and observe their changing trends.Above advantages greatly reduce the workload of data processing for surveying staff;The system realizes data online synchronization function.The processed measurement data can be submitted to the designer in real time,The designer corrects the measurement results according to the bridge professional software,the revised values are fed back to the surveyors to guide the construction work on site,which greatly improves the efficiency of the whole construction operation.Other project managers can log on to the system to check the current installation progress,measurement data and installation data.According to the data in the system,the site construction quality is checked.The system has practical value in this project.The design of the survey data Web management system and the construction survey results of Nanjing Yangtze River Bridge are analyzed and evaluated.In terms of data processing accuracy and data transmission efficiency,the system conforms to the construction specifications for the maintenance and reinforcement of the main bridge of Nanjing Yangtze River Bridge.With the support of the system,the installation and construction of the main steel girder of the main bridge are completed on time.After the completion of the installation of the main steel girder of the main bridge,the alignment and internal force of the bridge deck meet the design requirements,and the maintenance and reinforcement of the main bridge of Nanjing Yangtze River Bridge are successfully completed.