摘要
针对受火时间、不同保护层厚度等多种工况进行了三侧整跨受火时钢筋混凝土简支梁桥的火灾高温反应分析.引入弦切角收敛标准,建立荷载因子非线性计算方法,分析了等荷载和变荷载条件下荷载因子的变化规律,研究了火灾高温下钢筋混凝土简支梁的跨中截面极限弯矩时变效应状况,将其计算结果与有限元方法做了比较.研究表明:荷载因子能明确反映出在外部荷载相等条件下,极限弯矩随时间的变化规律,以及外部荷载提供给此结构的有效度;钢筋混凝土简支梁桥极限弯矩随火灾时间的延伸近似呈二折线下降,随保护层厚度的增加呈线性递增关系;控制火灾时间,提高混凝土保护层厚度,可有效阻止结构火伤程度,因此,该方法可行.
It is our aim to analyze the mechanical performance on variation protective thickness and fire time ot multiple load cases for reinforcement concrete Simply supported beam exposed to three sides and full span fire. Tangential angle is adopted, and load factor method proposed for calculating the ultimate hearing moment for reinforced concrete simply supported beam. The variation law is analyzed under multi-load case, and the ultimate moment on mid-span section for simply supported beam of reinforcement concrete. The results indicate that load factor can reflect the variation law of ultimate bearing moment under condition of equal load value. Ultimate bearing moment approximately decrease as the relation of two broken lines, but increase linearly with the increase of concrete protective layer thickness. The control of fire time and increment of concrete protective thickness is effective in prevening the degree of fire damage. Therefore, the computation method is feasible.
出处
《西安建筑科技大学学报（自然科学版）》
CSCD
北大核心
2008年第3期317-322,共6页
Journal of Xi'an University of Architecture & Technology(Natural Science Edition)
基金
国家交通部西部交通建设科技项目(200531881215)
关键词
桥梁工程
钢筋混凝土简支梁
荷载因子
极限弯矩
计算方法
bridge engineering
simply supported beam .for reinforcement concrete
load factor
ultimate bearing moment
calculation method
