Abstract The studies on the seismic fragility evaluation of semi-rigid (SR) steel moment frames are meager in the existing literature. The purpose of the present numerical study is to investigate the seismic fragility of SR frames subjected to near-field earthquakes. Specific characteristics of the fragility curves for near-field earthquakes are highlighted by comparing them with those for far-field earthquakes. A ten-story SR frame is analyzed subjected to four sets of earthquakes considering the moderate degree of semi-rigidity. The four sets of earthquakes, namely, far-field, near-field with high directivity, low directivity, and fling-step consist of ensembles of ten real ground motion records in each ensemble. The fragility plots are developed by considering a number of damage measures, namely, the maximum inter-story drift ratio, maximum base shear, maximum roof drift angle, maximum top-story acceleration with the peak ground acceleration (PGA) as an intensity measure. Threshold values for different damage states are decided based on the engineering judgment. For the near-field earthquake with directivity effect, the frequency repercussions on the fragility curves are investigated by varying the peak ground velocity (PGV) to PGA ratio with high ( > 160 cm/s-g), and low (

中文翻译：

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近场地震作用下半刚性框架的地震脆性评价

摘要 现有文献对半刚性（SR）钢框架抗震脆性评价的研究很少。本数值研究的目的是研究 SR 框架在近场地震作用下的地震脆性。通过与远场地震脆性曲线的比较，突出了近场地震脆性曲线的具体特征。考虑到中等程度的半刚性，分析了 10 层 SR 框架在四组地震下的作用。远场、高指向性近场、低指向性和跳步四组地震由每个系综中十个真实地震动记录的系综组成。脆弱性图是通过考虑许多损坏措施而开发的，即最大层间漂移比，最大基础剪切、最大屋顶漂移角、最大顶层加速度，以峰值地面加速度 (PGA) 作为强度度量。不同损伤状态的阈值是根据工程判断确定的。对于具有方向性效应的近场地震，通过改变峰值地速 (PGV) 与 PGA 的比值，高 ( > 160 cm/sg) 和低 ( > 160 cm/sg) 来研究频率对脆性曲线的影响。