Abstract: The Prestressed concrete bending member must be filfulled in both limit state and normal limit state requirements.This paper briefly describes the cable zone plot with its advantage as well as shortcoming using the usual ideal of working stress theory. The author proposes the improved and revised correction on Magnel's diagram in order to determine the rationable cable zone. Illustrative example is also added in the paper.

摘要： 预应力受弯构件必须满足承载能力极限状态和正常使用极限状态的各项要求。本文简要述评了惯用的利用容许应力法概念绘制的索界图的优缺点,提出了应用改良的麦尼耳图确定合理索界的方法。文后附有算例。