后张预应力混凝土结构中预应力约束损失的计算分析

Calculation Analysis for Prestress Loss due to Structural Constraint in Post-Tensioned Concrete Structures

在后张预应力混凝土结构中,所施加的预应力可能因受关联构件约束而发生损失,现行相关设计规范和结构设计均不考虑该现象,这将导致低估结构的预应力总损失,或高估结构的实际抗裂性能。本文对这一普遍存在的工程现象进行了分析,给出了计算框架梁预应力结构约束损失的方法与实例,并提出了相关设计建议。

In post-tensioned concrete structures, the prestress loss may be caused by constraint of connected members, which is not considered in the present codes and in the relative designs, and this perhaps leads to underestimate the total prestress loss, or overrate the anti-crack capability of the designed structure. In this paper, the kind of prestress loss existed widely in engineering is analyzed firstly, then the related method and the calculation example for the multi-span frame are given to further confirm the results, at last some design suggestions are proposed.