Simulation Analysis Of Concrete Box Beam Prestressed Defect Effect

Through the research on bridge structure of the defects of prestressed concrete box beam, provide a theoretical foundation for the importance of prestressed bridge construction, at the same time provide the theoretical reference for evaluate the impact of prestressed defect. It has important theoretical and practical significance as well as a wide range of applicable values and market prospects. In this paper, aiming at the defects of prestress of prestressed concrete box beam has made the following researches:At the beginning of the research, it studies the characteristics and development of prestressed concrete box beam, then puts forward some defects in the process of development, and the causes of the defects were analyzed. Consequently, we can draw a conclusion that the defects of prestressed contribute to bridge deflection and crack problem. Therefore, research on what are defective prestressed concrete, why this prestressed defects occur, how to control the defects and how to simulate analysis of prestressed defects become the research direction of this paper.And then, one of the prestressed defect that prestressed uneven is introduced. The concept of the uneven degree of prestress is defined, and proposed to use the uneven degree in tendon or in a section to evaluate the uneven degree of prestress. The use of the data shows that the distribution of the effective prestress of the prestressed strand have severe non-uniformity. This lead us to pay more attention to the effective prestress uniformity. However the prestressed uneven degree in tendon or in a section is not the only way to evaluate the uneven degree of prestress. This paper proposed that the average value of each single strand of effective prestress and the average deviation from the average distance of the number of the strand of effective prestress can reflect the uneven degree of the effective prestress of the strand more efficiently.In terms of prestress loss, due to the lack of research on the relationship between the loss of prestress and the stress in a section, for the first time this paper write from the angle of stress. Along the paper finite element model is established, model calculation value and measured data is compared with, a cross section of the construction stage is stress analysised, and the relationship between the prestress loss and the stress of the section is calculated, and propose to use the residual rate to evaluate the size of the loss of prestress.Then this paper introduces the prestressed refinement construction technology. This technology is currently the best method to effectively control the defects of the prestressed construction during the construction process, which is of great significance. The main contents are: prestressed refinement construction technology, including anchorage and installed in place quality control, beam process of steel bundle carding, prestressed tension construction and effective prestress detection control and intelligent system.