Study On Mechanical Behavior And Cable Force Of Segment Construction External Prestressing Bridge

In recent years, bridge workers at home and abroad have done a lot of experiments and theoretical analysis on external pressing structure, and explored the flexural behavior and stress increment of the bending properties, but there is large difference among research results. And therefore it needs to be further explored. At the same time, as the construction of precast segmental building method has unparalleled advantages compared with integral construction method, the construction of precast segments in vitro prestressed bridge has generally recognized by the engineering sector, and been widely used in practical engineering. As a result, this paper studies on precast segments assembled in vitro prestressed bridge.(1) About the construction on the section of the stress increment on the external pressing bridge, the vitro cable stress produced in the steering due to friction arising from the role of stress will be re-allocated. This paper recalculated the re-allocation of the vitro cable stress, based on the pre-stressed loss caused by friction, no claim of stress and deformation of the same principle, and then puts forward the calculating method of vitro tension. It analyzed the relationship between the increment under limit state and the deformation of the overall structure.(2)In the construction of precast segments in vitro prestressed bridge, on one hand, the deformation in vitro cable and the cable force will not change with the main beam cross-section which should be coordinated in disguise but related to the overall structure and deformation; on the other hand, the segments in the indirect method to the seam direction can only withstand stress, once it is subjected to tension, it will be out of work. Both made vitro analysis of precast segments of prestressed bridge become more complex. This essay has given an overall review on the concrete finite element model (separate model, the modular model, the overall model), the choice model which apply a wide range and high accuracy of the separation model to simulate a section of the vitro construction of prestressed concrete beam joints mechanical properties of the element model.(3)A finite element model has been established, which can analyze the flexural resistance of a reinforced concrete structure and vitro prestressed concrete structure in the whole process of bending performance. The models considered the physics of non-linear, non-linear of geometric structure, the correct choice of the joint unit of cable and stress the role of friction in the re-allocation of calculation. (4) The model has been developed on the basis of non-linear finite element program. The programs can be used to analyze the whole procedure of ordinary reinforced concrete, bonded in vitro without bond, and the allocation of ordinary steel in the vitro prestress into a bridge after loading. It is able to make accurate analysis and calculation on the effect of external pre-stressing segmental construction between the role of vitro construction and the section of the bridge structure because of the friction. It verifies the finite element model and the preparation of the procedures presented in this paper by comparing the test results and procedures for calculating.(5)The writer takes the construction of a prestressed bridge as the study object, using self procedures on the value to study the impact of the coefficient of friction in the in vitro cable to block the slip, in vitro cable to block the cable force on both sides of the margin and the structure Linear response to load and segmental construction joints cracking load. Combining the reference information on the testing results and the analysis of this research,this thesis put forward suggestions on vitro prestressed bridge design.