体外预应力加固预应力增量的计算

The Stress Incremental Computing on Externally Prestressed Reinforcement

体外预应力加固技术是现如今最有效的加固既有预应力混凝土桥梁的方法,可大幅提高原桥刚度及承载能力并克服其他加固方法中难以克服的二次受力问题。利用结构变形前后的几何关系,提出了在车道荷载作用下三折线布筋形式的体外预应力应力增量计算公式,计算公式的物理意义明确,并可分别计算不同荷载及不同布筋形式下的体外预应力应力增量。通过一座预应力混凝土简支T梁的加固设计实例,计算了体外预应力在车道荷载作用下的应力增量及施工阶段、使用阶段梁的上下缘混凝土应力,为简支梁的体外预应力加固工程提供了理论技术支持。

External prestressing reinforcement technology is nowadays the most effective method of strengthening existing prestressed concrete bridge,it can significantly improve the rigidity and load carrying capacity of the original bridge and overcome other strengthening methods are difficult to overcome the force of the secondary issues. By using the geometric relationship of structure before and after deformation,this paper puts forward the form of external prestressing stress increment calculation formula of three line under the lane load distributed,the physical meaning of calculation formula is clear,and can be calculated separately under different load and different distributed form of external prestressing stress increment. In this paper,through the instance of reinforcement design on prestressed concrete simply supported T beam,and can calculates the stress increment of externally prestressed under lane load and the concrete stress of the edge of the beam on construction stage and using stage,providing a good technical support for externally prestressed reinforcement engineering of simply supported beam.