Stability Analysis Of Prestressed Concrete Continuous Rigid Frame Bridges With High Piers And Large Span

Many continuous rigid frame bridges have been built in recent years. This type of bridge is developing towards the high pier and long span. So the stability problem is becoming more and more prominent day after day. Sometimes, it is the controlling factor to the whole structure. Maybe the structures will partial or whole lose steadily, if technology is not good treated. In order to guarantee its safety handling. Studying stability of prestressed concrete continuous rigid frame bridges in the construction becomes very important.Based on the Niujiaoping Bridge, this thesis focuses on the stability of the continuous rigid bridge with high Piers during the construction of cantilever. The main work is summarized as follows:(1) The stability analysis of main pier: the pier has been completed, and the beam is not built. This thesis use the software ANSYS to build up the element analysis model. Reinforcing steel bars in the pier was simulated in different ways and the influence to self stability was compared, therefore, an approach simple and meeting calculation precision was obtained to simulate reinforcing steel bars, which can refer to constructing stability analysis and the calculation as this type. Further more, this thesis carries out the eigenvalue stability analysis to the pier with the wind-load effect.(2)The double nonlinear stability analysis of the largest cantilever construction: take geometrical nonlinear and material nonlinear into account, this thesis considered four possible load situations aiming at the load: construction load, construction weight error, wind load, the normal and abnormal working of hanging basket. The double nonlinear stability analysis of the largest cantilever construction is processed.Through the analysis we find that: only considering the vertical reinforcing steel bars in the stability analysis of construction phase and operation phase can meet the calculation precision, and the modeling can be simple as well. Furthermore, this thesis also gets the coefficient of reference loads, The results can make evaluation to the stability of the largest cantilever construction and can also provide reference to the practice engineering.