Bending Behavior Analysis Of Prestressed Continuous Steel Beams Under Sagging Moment

Prestressed continuous steel beam is an important structure of prestressing steel structure,because of its advantages,such as high bearing capacity,high stiffness,good stability,low material consumption and large elastic working zone,it has been widely used in the field of bridge engineering practice,research on it has important theoretical significance and practical value.Through static load test,theoretical calculation and finite element simulation,the bending behavior of the prestressed continuous steel beam under sagging moment is analyzed.According to the research data of flexural behavior of prestressing steel structures at home and abroad,Static load tests were carried out on existing models of common continuous steel beam and prestressing continuous steel beam,which without considering deck pavement,to comparative analysis the regularities of mechanical properties of continuous steel beam under sagging moment before and after prestressing.The research results are as follows:(1)After introducing prestress into the structure,the flexural performance of the structure is improved,the moment of the structure under load is reduced,and the flexural capacity of the structure are improved.(2)Based on the different stress states of models,the theoretical analysis is carried out,comprehensive moment of the structure is deduced by equivalent load method,which produced by prestressing.The calculation process of prestressing statically indeterminate structures is summarized,to quantitative analysis of flexural behavior in the of prestressed continuous steel beam under sagging moment.(3)Finite element numerical model is established,which can simulate the stress development process from elastic to plastic,to analyze the influence of prestressing on the bending capacity of ordinary continuous steel beams and prestressed continuous steel beams under sagging moment,to discuss the influence factors of bending behavior of prestressing continuous steel beams under sagging moment and stress increment of prestressed reinforcement,and the formula for calculating stress increment of prestressed reinforcement based on the deflection is established.