Study On Construction Monitoring Technology For Large-Span PC Continuous Box-Girder Bridge With Corrugated Steel Webs Based On Grey System Theory

Because of its unique advantages, Large-span PC continuous Box-girder Bridge with corrugated steel webs, which is constructed by cantilever casting method, has gained continuous development and promotion in China. In order to ensure the quality and safety of construction, monitoring and control during construction is very important. Construction monitoring and control consists of two parts. Problems can be found through monitoring and data can be provided for control. Construction control can ensure construction quality and safety.For large-span bridge which is constructed by cantilever casting method, adaptive control should be the optimal control strategy. Along with the construction process, parameter identification is applied to modify the theoretical calculation model, on the other hand, subsequent construction phase is controlled based on the feedback of construction error. The adaptive control system is formed based on these two processes.Least square method is applied in the parameter identification and grey system theory is applied in the prediction of error. The actual value of model parameter is identified based on the principle of least squares residuals and the error between the calculation of model and measurement results is reduced. Grey system method can build models with a small amount of data. According to the error data during construction, the error of the subsequent segment can be forecasted by grey system model and the formwork erection elevation can be adjusted.