ABSTRACT

A probabilistic classification criterion was proposed to classify likely failure modes of reinforced concrete (RC) columns under seismic loading conditions. The accuracy and applicability of available flexure and shear strength models were scrutinized first to calculate the ratio of shear demand to shear strength (m). Then the probabilistic distribution characteristics of m, shear aspect ratio (λ), and transverse reinforcement ratio (ρ_sv) were examined to determine the probability of RC columns failing in different failure modes. Subsequently, a probabilistic classification criterion for likely failure modes of RC columns was suggested by considering the coupling effects of m, λ and ρ_sv. Finally, the classification accuracy of the proposed classification criterion was corroborated by comparing with existing classification criteria. Results reveal that the classification accuracy of the proposed probabilistic criterion is about 20% higher than those of existing classification criteria for RC columns failing in flexure, flexure-shear, and shear critical modes. The failure modes of RC columns progressively change from ductile flexure failure to flexure-shear, and then shear critical failure mode with the increase of m, and the decrease of λ and ρ_sv.

摘要

提出了一种概率分类标准，用于对地震荷载条件下钢筋混凝土 (RC) 柱的可能失效模式进行分类。首先仔细检查可用弯曲和剪切强度模型的准确性和适用性，以计算剪切需求与剪切强度 ( m )的比率。然后检查m、剪切纵横比 ( λ ) 和横向钢筋比 ( ρ _sv )的概率分布特征，以确定 RC 柱在不同破坏模式下发生破坏的概率。随后，通过考虑m、λ和ρ _sv。最后，通过与现有分类标准的比较，证实了所提出的分类标准的分类准确性。结果表明，对于在弯曲、弯曲-剪切和剪切临界模式下失效的 RC 柱，所提出的概率准则的分类精度比现有分类准则高约 20%。随着m的增大， λ和ρ _sv的减小，RC柱的破坏模式由延性弯曲破坏逐渐转变为弯剪破坏，再转变为剪切临界破坏模式。