锈蚀RC柱的概率抗剪承载力模型与校准分析

Probabilistic Shear Strength Model and Its Calibration for Corroded RC Columns

为了克服传统确定性抗剪承载力模型无法合理考虑随机性所存在的不足,综合考虑力学机制和多种随机性,研究建立了锈蚀钢筋混凝土(RC)柱抗剪承载力分析的概率模型,并据此提出了可以校准传统确定性模型的概率方法。首先依据桁架-拱模型的剪力传递机制,综合考虑锈蚀对纵筋和箍筋的截面积、箍筋有效屈服强度、混凝土有效抗剪截面积的影响,建立了锈蚀RC柱的确定性抗剪承载力模型;然后综合考虑模型假定、试验数据和材料参数等方面所存在的随机性,建立了抗剪承载力分析的概率模型;最后基于概率模型的置信区间,提出了传统确定性抗剪承载力模型的概率校准方法。分析表明,该模型可以描述抗剪承载力的概率特性,并评估传统确定性抗剪承载力模型的预测精度。

In order to overcome the disadvantage of traditional deterministic shear strength models which cannot reasonably consider uncertainties,a probabilistic shear strength model and corresponding probabilistic calibration method for corroded reinforced concrete(RC)columns were established by taking into consideration both mechanical mechanism and uncertainties.Firstly,the deterministic shear strength model of corroded RC column was established based on the shear transfer mechanism of truss-arch model by considering the influences of corrosion on cross-sectional area and mechanical properties of steel bar as well as effective shear area of concrete.Then the probabilistic shear strength model was established by considering the uncertainties from model assumption,experimental data and material parameters.Finally,the probabilistic calibration method for the traditional deterministic shear strength models was proposed based on the confidence internals of probabilistic model.Analysis shows that the model can represent the probabilistic characteristics of shear strength and calibrate the prediction accuracy of traditional deterministic shear strength models.