【摘要】 基于一维Fick第二定律,采用Dura Crete规范中钢筋锈蚀初始时刻的概率预测模型,并基于概率统计的钢筋直径预测模型,计算不同龄期下RC结构中钢筋的锈蚀深度。基于修正斜压场理论并以锈蚀深度为单变量,对不同龄期下受压区锈胀开裂混凝土峰值应力进行计算;根据锈蚀深度对钢筋本构和Mander约束混凝土本构模型中相关参数进行了修正。于地震易损性模型中引入时间参数,建立含时间参数的RC结构地震易损性模型。最后,基于上述材料力学性能退化模型,采用基于力的纤维塑性铰模型,建立三层RC平面框架结构数值模型,并结合本文所提出的时变地震易损性模型,给出了三层平面RC框架0、5、10和15年龄期的易损性曲线和曲面。所提研究方法可用于既有RC框架结构生命周期内的抗震性能及损失预测分析。更多还原

【Abstract】 Based on a one-dimensional Fick’s second law and the probability prediction model of initial corrosion time in Dura Crete Code,the remaining reinforcement diameters were calculated by the Statistical formula. Considering the cracking and spalling in the compressed concrete of compression zone caused by reinforcement corrosion,the modified compression-field( MCF) was used to predict the peak value of compressive strength by the function of the single-factor time-dependent remaining reinforcement diameters. Concerning parameters of the material constitutive models of corroded reinforcement and Mander confine concrete were also modified by the remaining reinforcement diameters. At the same time,the time-dependent fragility model was developed for corroding reinforced concrete( RC) frame designed according to the Chinese Code with a merger between a probabilistic model for chloride-induced corrosion and fragility model for undamaged RC frames. Finally,with the forced-based fiber plastic hinge model,the software Seismo Struct was employed to build the numerical model of the three-floor plane frame. Based on the material degradation models presented above,the time-dependent fragility curves and surfaces of three-floor RC frame in four ages( i. e.,non-corroded( t = 0),5,10 and 15 years),corresponding to different performance levels,were depicted by the incremental dynamic analysis( IDA)method. This method may be employed to predict service-life and life-cycle cost analysis of RC frame structures更多还原