再生混凝土框架结构地震作用下随机损伤与评估分析

Random damage and evaluation analysis of recycled aggregate concrete frame structure under seismic load

通过对缩尺比例为1∶4的3层再生混凝土框架结构模型双向输入模拟振动台试验结果的分析,研究了该结构频率、阻尼以及层间位移角的变化情况。结果表明:该再生混凝土框架结构具有良好的抗震性能。综合考虑再生混凝土框架结构X、Y向不同频率、阻尼比、刚度、结构振型以及不同的结构形式与自振频率的测试方法,提出了相应的再生混凝土框架整体结构损伤模型;基于该损伤模型对该再生混凝土框架结构破坏等级的分析,结合现行相关规范要求,建立了再生混凝土框架结构破坏等级划分;拟合了再生混凝土框架结构损伤指标的计算式。研究结果表明:提出的损伤模型与试验现象基本吻合,能够用于再生混凝土框架结构震后损伤与定量评估分析。

According to the bidirectional shaking table-simulation tests on a 1 ∶ 4 scaled model of three-story frame model with recycled aggregate concrete( RAC),variation of the frequency,damping and inter-story drift of the model was analyzed. The results indicate that the RAC frame structure has good seismic resistance capacity. The damage model of the overall RAC structures was proposed with synthetically considering frequency,damping ratio,stiffness,modal number in X and Y directions of the structures. Meanwhile,the type of structures and measurement method of natural frequency were also taken into account in the model. The damage level of RAC structures was analyzed with the damage model. Meanwhile,considering the result and existing codes,five synthetical damage level standards for RAC structures were established. Finally,a quick calculation formula for the RAC structural damage indicators was fitted in order for the application of practical engineering. The results show that the damage results based on the proposed model are consistent with the experimental phenomena,which can be applied to the analysis of the earthquake damage and quantitative assessment for actual RAC structures.