Research On The Construction Camber Of Prestressed Concrete Continuous Beam Of Long Span Bridge

With the development of science and technology and traffic enterprise, the prestressed concrete continuous bridge has been growing up rapidly in recent 20 years with it's unique predominance of handy construction, economical cost, reasonable internal force and comfortable traveling. It almost has become the first selective bridge style When the main span is in the range from 100m to 300m. But the theories and experience in it are not very perfect because of it' s short appearance. In modern bridge building, the the construction controlling technique is a warranty of safe and quality of the bridge in the construction process. This paper introduced the importance of the camber of the longer span bridge in the construction.In recent years, Artificial Neural Network(ANN) has become a striking research topic in china and abroad. It is generally believed that development in this field will bring significant outcomes and great promise for application. ANN is one of the efficient information processing'method in studying the sophisticated systems. It need not mathematical model, but can deal with non-liner fuzzy problems. It is often used in predicting, classification and so on. Inrecent years, ANN has been used in engineering fields. Back Propagation neural Network(BPN) is one of the most widely used network, The practice algorithm is similar to deta rule. With long period developing, BPN has been improving.The No. 4 bridge of Xiangfan bridge over-crossing Hanriver is a specially long span river bridge on freeway by tieing freeway form HanShi to Xiangjing. The main span is 70+5*120+70m. It is a prestressed concrete continuous beam bridge. The bridge has builded by balanced cantileverconstruction technique. The beam camber of construction is a controlling index of construction quality control.It is nonlinear, and now is not mature forecasting method. Relying on The No. 4 bridge of Xiangfan bridge over-crossing Hanriver bridge, in this paper a ANN is applied to the parameter of the long span bridge in the construction beam. A model with some parameters is used to forecasting the beam camber in the construction. Based on the differences between the design value and the survey of the bridge deck elevation in constructing the pre-stressed and so on working condition, the model parameters are identified by ANN, and the beam camber of different sections are given. The results demonstrated that the ANN is efficient and the theoretical results fit well with that of forecasting the beam camber in construction.In this thesis, aim to the beam axis shape be exactitude for design, the internal force of the beam be appeased by design request, the concept of modem cybernetics is applied, At the same time, the effecting parameter has collected. The paper build the ANN model in predicting the beam camber an construction and discuss indetail the extraction of inputting nodes information when quoting the fundamental principle of ANN model and introducing research process of the improved BNN. According to them, ANN is applied in the construction control of prestressed concrete continuous bridge. It is successful for used in the No. 4 bridge of Xiangfan bridge over-crossing Hanriver brideg. To predict the construction camber of by ANN method is useful and effective. On the bridge construction control technique, attempted a new method.