Prediction of Residual Flexural Capacity of Reinforced Concrete Beams After Fire
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摘要: 为了研究火灾后RC梁的抗弯性能,考虑钢筋/混凝土界面黏结退化和混凝土高温爆裂特征,构建了RC梁的高温数值分析模型,并通过火灾试验验证数值分析模型的有效性。利用验证的数值分析模型建立由受火时间、爆裂深度、爆裂面积比与抗弯承载力组成的数值分析样本库,提出了火灾后RC梁的残余抗弯承载力的多元回归预测和SVM预测模型,并采用新工况样本数据进行验证。结果表明,两种预测方法的决定系数均大于0.9;与数值模拟结果相比,SVM预测的相对误差较小,在0.05%~4.05%之间,表明利用SVM预测火灾后RC梁残余抗弯承载力是可行的,且精度较高。Abstract: In order to study the bending performance of reinforced concrete (RC) beams after fire, a high temperature numerical analysis model of RC beams was established considering the bond degradation between rebar and concrete and the characteristics of concrete spalling, and the validity of the numerical analysis model was verified by fire test. Based on the verified numerical analysis model, a numerical analysis sample library consisting of fire exposure time, spalling depth, spalling area ratio and flexural capacity was established. The multiple regression prediction method and SVM prediction model of residual flexural capacity of RC beams after fire were proposed. The new working condition sample data were used for verification. The results showed that the coefficient of determination of the two prediction methods were greater than 0.9. Compared with the numerical simulation results, the relative error of SVM prediction was small, ranging from 0.05% to 4.05%, which indicated that it should be feasible and accurate to predict the residual flexural capacity of RC beams after fire by SVM.
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Key words:
- fire /
- bond performance /
- concrete spalling /
- RC beam /
- flexural capacity /
- prediction
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