Study On Cantilever Casting Construction Of Prestressed Concrete Continous Girder Bridges

Because of the structure stress performance good, deformation small, the expansion joint to be few slightly, the driving smooth and comfortable, the modelling succinct and artistic, the maintenance resilience is small, earthquake resistance ability strong and so on,the prestressed concrete continuous bridge becomes one of richest competitive power main bridges. In the great span prestressed concrete continuous bridges which already completed in our country, the majority were constructed by the cantilever concreting. This is because we have the mature experience on the cantilever concreting, and the cantilever casting prestressed concrete continuous bridge as a kind of bridges taking the non-support construction are advantageous to be constructed at the navigation rivers, the remote mountain canyon and the urban grade separation.Regard to cantilever casting continuous bridge, the stress control and deformation control are especially important. With the rapid development of the high-speed railroad, the request on bridges'curve mode and deformation become stricter and the bridges'curve mode and deformation become the most important factors of construction control to be considered. This article carries on the simulation analysis with the aid of the finite element software on the cantilever casting bridge. In this thesis, I analysissed the stress an deformation of the bridge of each construction stage.however I have already analysissed the influence of the load, the temperature and the creep and shrinkage of concrete to the construction camber. At the same time,I simply elaborated the fundamental theory and method of the stress and deformation measuring, the correlation testing and the closure of the cantilever casting construction continuous bridge. Through the analysis, it's easy to draw a conclusion that the pre-stress and the dead load are the main factors which affects the bridge'vertical deformation and the other factors are secondary. However, the factors which affect shifting bearing'pre-displacement are successively creep of concrete,tempreture,shrinkage of concrete,prestress and dead load in the order of variation of beam'longitudinal displacement from big to small.According to the cantilever casting construction continuous bridges' construction characteristic, This thesis emphasize and summarize the related basic theory and some main points of construction.And this will be beneficial for us to carry on construction control and get a good result.