Construction Control Technologies And Application For Long-Span Bridges

With the rapid development of China's traffic, more and more long-span bridges are needed to span wide rivers and straits. More long-span, more difficult in construction. The bridge construction control is an essential measure and step to ensure that the quality and safety are obtained during bridge construction, also to ensure that the final structural state is in agreement with what the designer requires.Because of the complicated construction procedure of the long-span bridges, the bridges will be affected by many certain or uncertain parameters. The actual construction state of the bridges might deviate from the state of theoretical design. Therefore, the bridge construction control emphasizes the problem-finding out and error-adjusting in time, and state-predicting for following construction, so as to guarantee the construction system under control all the time.Firstly, this thesis introduces briefly the construction control technologies and systems for long-span bridges. Then an approach identifying the said influential parameters using Back Propagation (BP) neural network is put forward. The method is operated based on construction measuring and its feedback is used to conduct the construction. Thirdly, the Kalman'filtering method and the Gray System theory are applied to forecast the potential structural deformation based on the research of the influential parameters in structural geometric deformation. Finally, the principle of strain measurement is described. Combined with engineering application and case study, several primary factors are analyzed based on theoretical computation and in-situ measuring with the vibrating wire sensor in a PC continuous girder bridge.Both theoretical and experimental study results show that the methods presented in this thesis would be useful to bridge construction control.