Research On Bridge Analysis Method Based On Coordination Relationship Of External Cables And Concrete

Compared with traditional prestressing, external prestressing system has its own merits. That is why this kind of structure has been widely used and constantly innovated all over the world in recent years. Foreign experts conducted lots of experiments and theory analysis, and discussed carrying capacity limit of the external prestressed concrete beam in order to study the structure behavior of the external prestressed concrete beam. While many formulas are established on the basis of the experiment results, and the issue on stress limit of prestressed reinforcing steel bar was not researched based on the dynamics performance of the structure, so usually there were some limits in the conclusions. This paper gives a systematical research on the calculative principles and methods of the stress increment, prestress loss and carrying capacity, which is on the basis of the analysis of domestic and foreign experiments and data, design criterion and relevant literatures. The researches conducted are as the following:Firstly, it simply discusses the structure form and mechanics characteristic of external restressed concrete bridge, comprehensively analyzes kinds of calculation theories under terminal carrying capacity, and discusses their advantages and disadvantages individually.Then, before analyzing the terminal carrying capacity, it is required to make sure the stress increment first. There is no relation between displacement of the prestressed cable and the concrete section under loads, the stress changes could be acquired from the transform coordination term of the whole beam. This paper is based on the steel and concrete co-relation theory, respectively discusses the calculation on the prestressed cable protraction value under the terminal loads of simple supported beam and constant beam, therefore has proposed the simple formula for stress increment calculation.After that, it makes further research on some problems related to the prestressed loss calculation of external prestressed concrete bridge, and points...