Error Analysis In The Construction Monitoring Of Cable-stayed Bridges

Due to the specificity of the cable-stayed bridge, there are several systemtransformations during the construction process. Therefore, it is particularly importantto monitor the process of construction. Construction monitoring is to monitor theforce, deformation and stability during the construction of the bridge, so that thestructure is in the best state during the construction and the finished bridge statecomply with requirements of the design and code.In this paper, taking the main bridge of Wenfeng Avenue-separation ofBeijing-Hong Kong-Macao Expressway as engineering background, the constructionmonitoring implementation of single tower double cable plane partial cable-stayedbridge is analyzed, as well as the error analysis of measurement.At first, the mechanical behavior of the structure is simulated using the softwareMIDAS Civil to get the internal force, stress and displacement under differentconditions. And the cable force influence matrix is built to get the second tensionforce of cables after calculation, which bases the theoretical foundation for cable forceadjustment in later stages. Sensitivity analysis is done of such structural parameters assupport stiffness, beam deadweight, cable tension forces and so on.Then, according to the measurements of stress, bridge floor vertical alignmentand cable forces during the construction process, the error is analyzed and the realdata is obtained, which comply with the theoretical calculation and code.The shrinkage strain and creep strain are calculated by the method recommendedby the code JTG D62-2004, and the temperature strain is got by the data measured inthe construction site. And the elastic strain is obtained using the formula of strain, aswell as the curves of control sections’ stress in different conditions. Also the verticaldeformation of the beam is analyzed using station check, especially during the twoprocesses of cable tensioning. The cable forces are calculated by frequency method inthe construction control, and the error is simply analyzed as well as the solution.The construction control of cable-stayed bridge is a complicated process whosemeasuring error is influenced by various factors. This paper only discusses partialcable-stayed bridge, and there are many problems to be explored further. Structure control is a process of long period, which includes not only the safety in constructionbut also the monitoring and control of the finished bridge state in the long run.