预应力混凝土超静定结构中的次弯矩

The secondary moment in redundant structure of prestressed concrete

针对现有预应力混凝土正截面承载力计算方法中对次弯矩的考虑 ,文章阐述了在特殊布筋形式及高次超静定的井式梁结构中 ,次弯矩的形状、大小、正负均不同于一般连续梁和框架结构 ,次弯矩不再是对支座有利对跨中不利 ,次弯矩图在支座间也可能不是直线 。

There is some limitations in consideration of the secondary moment in the design method of normal section bearing capacity of prestressed concrete according to the current Code. This paper clarifies that the shape,quantity,positive and negative sign of the second moment are different from common continuous beam and frame structure in prestressed concrete structure having special arrangement of prestressed bars and in cross beam system of multiple redundancy. The secondary moment is not always advantageous to supports while disadvantageous to middle point span. The secondary moment of cross beam may not be a linear distribution between two supports.