(中国建筑科学研究院建筑结构研究所， 北京 100013)

［摘要］通过构建无粘结预应力混凝土受弯构件极限状态下的几何分析模型，补充预应力配筋极限伸长量与构件极限挠度的协调关系，推导了适用性较好的无粘结预应力筋极限应力σpu的解析算法。根据19根试件的弯曲破坏试验数据，对σpu的解析计算值与相应实测值进行了比较，验证了两者的一致性。为便于读者理解与应用，分析说明了所述算法中的关键参数。相对目前结构设计普遍采用近似经验方法确定σpu，所提出的算法可供无粘结预应力混凝土结构的规范修订、配筋设计、软件更新与课题研究参考。

［关键词］混凝土受弯构件； 无粘结预应力筋； 极限拉应力； 几何分析模型； 协调变形条件； 极限挠度； 解析算法

中图分类号：TU378-1文献标识码：A文章编号：1002-848X(2019)03-0061-05

Analytical algorithm for ultimate stress of unbonded prestressed tendons in concrete flexural members

Pan Li

（Institute of Building Structures, China Academy of Building Research, Beijing 100013, China）

Abstract:Based on the established geometric analysis model of unbonded prestressed concrete members in ultimate flexural state, the coordinated relationship between the ultimate elongation of the prestressing tendons and the ultimate deflection of the members was supplemented, and the analytical algorithm of the ultimate stress σpu of unbonded prestressing tendons with better applicability was deduced. Based on the flexural failure test data of 19 specimens, the analytical calculation value of σpu was compared with the corresponding measured value and the consistency of the two values was verified. In order to facilitate the reader′s understanding and application, the key parameters of the algorithm were analyzed and explained. Compared with the approximate empirical method commonly used in structural design to determine σpu, the proposed analytical algorithm could provide reference for the revision of code, reinforcement design, software updating and subject research of unbonded prestressed concrete structures.

Keywords:concrete flexural member; unbonded prestressed tendon; ultimate tensile stress; geometrical analysis model; coordinated deformation condition; ultimate deflection; analytical algorithm

作者简介：潘立,硕士，教授级高级工程师，一级注册结构工程师，Email: Panlicabr@163.com。