混凝土桥梁抗弯承载能力的退化分析  

Analysis of Flexual Bearing Capability Deterioration in Concrete Bridges

作　　者：许树壮[1,2] 

机构地区：[1]同济大学土木工程学院,上海200092 [2]上海市政工程设计研究总院(集团)有限公司,上海200092

出　　处：《沈阳建筑大学学报（自然科学版）》2014年第6期961-970,共10页Journal of Shenyang Jianzhu University：Natural Science

基　　金：国家自然科学基金项目(51378383);西部交通建设科技项目(200631822302-01)

摘　　要：目的研究钢筋锈蚀对混凝土桥梁抗弯承载能力的影响,实现混凝土桥梁抗弯承载能力的时变分析,为混凝土桥梁的全寿命分析与设计奠定基础.方法在实桥设计分析中,将锈蚀率作为基本变量进行混凝土桥梁的抗弯承载能力的时变退化分析,分析过程考虑了普钢钢筋强度、预应力钢筋强度、钢筋与混凝土之间的粘结强度等随锈蚀率的特性变化,从而进一步分析不同锈蚀率、不同位置钢筋锈蚀工况下混凝土桥梁的时变抗弯承载能力.结果分析结果表明,对于预应力混凝土桥梁,预应力钢筋的锈蚀会引起桥梁承载能力的大幅下降,当预应力钢筋锈蚀率为4.2%时,算例T梁桥的抗弯承载能力下降高达16%.结论预应力混凝土桥梁中预应力钢筋的耐久性尤为重要,尤其是最外层预应力钢筋,必须采取措施避免预应力钢筋出现锈蚀情况,确保桥梁结构的安全性能.This paper aims to analyze the flexural bearing capability deterioration induced by the reinforcement corrosion in concrete bridges,w hich is the base of life cycle analysis and design for concrete bridges. The corrosion rate w as considered as a basic variable,and the strength deterioration of pre-stressed reinforcement,the bond-slip relationship betw een concrete and reinforcement w ere involved for analysis of time variable bending capacity under different corrosion rates and reinforcement corrosion at different positions. Results show that the capability declined significantly because of the corrosion of pre-stressed reinforcements. When the pre-stressed reinforcement corrosion rate is 4. 2%,the flexural bearing capability of a T-beam bridge decreases 16%. Conclusion is that the durability of the pre-stressing reinforcements,especially,the outlayer reinforcements,isparticularly important for concrete bridges. Some measures must be taken to avoid the pre-stressing reinforcement corrosion for security of bridge structures.

关 键 词：混凝土桥梁 抗弯承载能力 锈蚀率 退化 

分 类 号：TU375.1[建筑科学—结构工程] U448.35[建筑科学—桥梁与隧道工程]