Application And Research Of Partially Prestressed Concrete Beams In Long Span & Two Tower Cable-stayed Bridge

The increasing span and more lighter structure of cable-stayed bridge makes the structural performance more complex. Therefore, further optimization of the forced performance of the cable-stayed bridge is particularly necessary. It is very important to perfect the design theory of concrete cable-stayed bridge and ensure the rational design of such bridges that how to used the partially prestressed concrete beams which have more rational forced performance in a cable-stayed bridge. This paper takes Guizhou Six Red River Bridge as the engineering background, established full-bridge MIDAS space finite element model and analyzed the different stress of the bridge(PPC and PC) in different situation, study the application of PPC beam in cable-stayed bridge which have large-span and two tower. The main work is as follows:(1) This paper introduce the research status at home and abroad about the cable-stayed bridge and partially prestressed concrete; Discourse the design method and theory of the cable-stayed bridge and partially prestressed concrete while read a lot of domestic and international design theories and standards; The paper also introduces the calculation method and theory of crack width of the prestressed concrete.(2) The paper use MIDAS and BDCMS established two PC bridge finite element model which based on the actual project situation and two PPC bridge finite element model which is the optimization of the bridge. Then check the two model in accordance with the relevant standard in order to discuss the reasonableness of the structure for a more comprehensive evaluation. According to the same result of MIDAS and BDCMS, proved the reliability of the models.(3) The model with PC beam and the model with PPC beam has carried on the calculation and comparative analysis (including prestressed configuration, overall forced characteristics and stress conditions); Calculate the crack width of the PPC beam while it sustain twice of the normal automobile load whose value has ruled by relevant standard, ensure the feasibility and rationality of the PPC beam applied to the cable-stayed bridge.This paper demonstrate the PPC beam applied to the cable-stayed bridge is rational and safe, get some useful conclusions about cable-stayed bridge design which can guide the prestress design of the cable-stayed bridge.