The Method Of Adding And Substracting And It's Application Of Unbonded Prestressing Polygonal Beam

As a novel structure style, unbonded prestressed concrete structure have been widely applied in china, and prossess capacious prospect. Although the relative research has been carried out and obtained some achievements. Engineering practice provides a series of problems in prestressed concrete science to experimental engineering continually. One of the problems that should be solved above all is how to decide the real and effective pretressed steel equivalent load. Because the natcre aren't be grasped and understood exactly, there aren't a complete and exact method on computing and determining prestressed steel equivalent load.This situation will obstract further application of prestressed concrete structure. The work of this paper tries to develop the research on the subject.Based on relevant engineer backgrounds, deeply analyzing the nature and characteristis of unbonded prestressed concrete structure, conceiving comprehensively some practical designing methods of prestressed concrete, this paper considers that a computational method of equivalent load should be established which has exact concept and be thought comprehensively and be used conviently and practically and rapidly. From the point of view to solve prestressed steel equivalent load, this paper comprehensively and systematically discusses the basic concept of dding and substracting constraints method and practical value. Using adding and substracting constraints method to decide prestressed steel equivalent load, it can provides the real affecting orientation and magnitude, and set up a complete and exact concept of equivalent load in human beings'brain. Other methods havn't the excellence.At first, this paper uses adding and substracting constraints method in unbonded prestressed concrete polygonal beam, then second uses nomal formulas existed in practical computational manual to compute equivalent load. Finally, the two computational results and its effect on prestressed steel effective prestressed stress be analyzed and compared.Because of the polytrope of architectural style and unbonded prestressed concrete structure used widely day after day, the designing and applicatiion of unbonded prestressed concrete polygonal beam often be centered.Because of unperfectio of computational method on prestressed steel equivalent load, the application of unbonded prestressed concrete polygonal beam is limited and architectural schemes cann't be adopted. To solve this problem, this paper uses adding and substracting constraints method to analyze and compute unbonded prestressed concrete polygonal beam qualitatively. This paper also comprehensively and systematically discusses the problem of controlling crack in con-structure phase and using phase, which let people unworry about the polygonal beam cracking in luring point.Based on architectural style and requirement in use , unbonded prestressed concrete polygonal beam can be used completely in practically engineering.On performing the effect of prestressed steel, polygonal beam has more dominance in application than straight line beam.In the last part of paper, some suggests about later analyzing work of adding and substracting constraints method are refereed.