锈蚀钢筋混凝土结构加固抗震性能研究

Seismic Performance Analysis of Strengthened Corroded-Reinforced Concrete Structure

钢筋锈蚀降低了钢筋混凝土结构的承载力,因此对钢筋锈蚀的结构进行加固及加固效果评价至关重要。本文以钢筋混凝土门式框架为研究对象,利用低周推覆,研究锈蚀对结构承载力影响及评价粘贴钢板加固后的效果;最后通过地震易损性分析,计算加固后结构的倒塌概率,建立易损性曲线及曲面。低周推覆结果表明锈蚀降低结构的承载力,随着锈蚀程度增加,承载力逐渐下降;粘贴钢板提高锈蚀结构的承载力,加固钢板厚度选择取决于锈蚀程度。地震易损性分析结果显示,当主震-余震序列强度大于一定的值时,结构倒塌概率随加固钢板厚度的增加而降低。同时易损性曲面的建立为加固方案优化设计提供指导。

Corroded steel bars lead to the reduction of capacity of reinforced concrete structures. Therefore,it is meaningful to strengthen the corroded structure and evaluate the effectiveness of reinforcement. In this work,a reinforced concrete frame is used to evaluate its performance after corrosion and reinforcement through cyclic pushover. Then seismic fragility is used to calculate the probability of collapse of the corroded structure after reinforcement,and fragility curves and surface are created. The findings show that corrosion decreases the capacity of the investigated structure. With increased corrosion,the capacity decreases more. Steel plate reinforcement is effective to increase the capacity of a structure. And the thickness of plate is determined by the severity of corrosion.Seismic fragility results imply that with increased thickness of steel plate,the probability of collapse decreases if the intensity of mainshock and aftershock sequence is larger than a threshold value. Seismic fragility surface is benefit for guiding the optimum design of reinforcement.