The Calculation And Research On Prestressed Loss Of Long Span Rigid-continuous Composite Beam Bridge

With the rapid development of technology and communication, the long span prestressed concrete bridge is used widely for its advantage. In modern prestressed concrete structure, the prestressed loss will affect the structure crack resistance and deflection. So, to calculate the prestressed loss correctly is the important subject in prestressed concrete domain. Since the emergence of prestressed concrete, people always study and analyze the prestressed loss and have achieved a lot of results. Because the influential factors of prestressed loss is amount, and the influential factors interact each other, to calculate the various prestressed loss accurately is complicated. The prestressed loss value is more than or less than calculated value, which will bring about little effect to the structure strength, but will affect the structure performances(e.g. deformation, camber, cracking load) .In the service load, to estimate the loss value higher and lower is adverse. At present, how to calculate accurately and to meet the project requirement, to bring forward calculation methods that is easy and contented the project accuracy standard, is an important work to popularize the prestressed concrete technique.So, in the process of designing the long span concrete bridge, the estimation to prestressed loss should be sufficient. According to the actual construction situation, the prestressing tendon can be distributed properly. Only to do this, the value of prestressed force is designed suitable, the capability that the prestressed concrete structure bears weight, security and dependability, economy and service life of the structure can be convinced.hi this paper, the prestressed loss in the prestressed concrete structure will completely be analyzed in the theory. This paper combines with the progress of construction and design in the Xingjiang Yili He bridge, uses Midas/civil to model and calculate the structure. The theory results are used to analyze the experimental results of prestressed friction loss. By the friction loss experiment, the reasonable friction and deviation coefficient can be acquired; the regular pattern of prestressed friction loss can be discovered. And then this paper combines Xinjiang Yili He bridge temperature field, simulates the temperature load by Midas/civil and acquires the prestressed loss variation datum. The conclusions may provide reliable datum for structure construction control and guarantee the quality of construction. At the same time, the conclusions have guide significance for designing and constructing long span prestressed concrete bridges.