预应力混凝土结构总变形计算统一方法

Unified method of calculating total deflection in prestressed concrete structures

论述了对预应力筋及预应力效应的认识,认为可以将预应力筋的工作分成两个阶段:第一阶段是由张拉到预应力筋有效预应力pe的建立,这一阶段视预应力筋为能动的作用者,将预应力引起的等效荷载作为外荷载来对待(可作为恒载来对待);第二阶段是当预应力过程结束后,预应力筋抗拉强度设计值fpy中高于有效预应力pe的富裕部分(fpy-pe)又像普通钢筋一样被动地提供抗力。在此基础上,建立了与普通混凝土结构变形计算相协调的预应力混凝土结构总变形计算统一方法。从理论体系上实现了与作者建立的承载力计算方法的统一。

The role and effect of prestressed steel can be described at two different stages as detailed below:at stage one,they rage from stretching prestressed steel to its stress down to effective prestress(σ pe )after prestress losses and prestressed steel is positive and equivalent loads steel are regarded as external loads(or dead loads);at the second stage,prestressed steel is only a kind of material,which resists passively external loads just as an ordinary steel,and its stress is the term (f py -σ pe )of the design strength of steel (f py )and effective prestress.From all mentioned above,a unified method of calculating deflection in prestressed concrete structures is established,which is in agreement with the calculation of deflection of reinforced concrete structures,and the ultimate load-carrying capacity for-mula as well.