Earthquake-induced pulse-like ground motions are often observed in near-source conditions due to forward-directivity. Recent worldwide earthquakes have emphasised the severe damage potential of such pulse-like ground motions. This paper introduces a framework to quantify the impact of directivity-induced pulse-like ground motions on the direct economic losses of building portfolios. To this aim, a simulation-based probabilistic risk modelling framework is implemented for various synthetic building portfolios located either in the fault-parallel or fault-normal orientations with respect to a case-study strike–slip fault. Three low-to-mid-rise building typologies representative of distinct vulnerability classes in the Mediterranean region are considered: non-ductile moment-resisting reinforced concrete (RC) frames with masonry infills, mainly designed to only sustain gravity loads (i.e. pre-code frames); moment-resisting RC infilled frames designed considering seismic provisions for high ductility capacity (i.e. special-code frames); special-code steel moment-resisting frames. Monte Carlo-based probabilistic seismic hazard analysis is first performed, considering the relevant modifications to account for the pulse-occurrence probability and the resulting spectral amplification. Hazard curves for sites/buildings located at different distances from the fault are obtained, discussing the spatial distribution of the hazard amplification. A set of pulse-like ground motions and a set of one-to-one spectrally-equivalent ordinary records are used to perform non-linear dynamic analysis and derive fragility relationships for each considered building typology. A vulnerability model is finally built by combining the derived fragility relationships with a (building-level) damage-to-loss model. The results are presented in terms of intensity-based and expected annual loss for synthetic portfolios of different sizes and distribution of building types. It is shown that, for particularly short-period structures (e.g. infilled RC frames), the influence of near-source directivity can be reasonably neglected in the fragility derivation while kept in place in the hazard component. Overall, near-source directivity effects are significant when estimating losses of individual buildings or small portfolios located very close to a fault. Nevertheless, the impact of pulse-like ground motions on losses for larger portfolios can be considered minimal and can be neglected in most of the practical large-scale seismic risk assessment applications.

由于前向性，经常在近源条件下观察到地震诱发的脉冲状地震动。最近的世界范围的地震都强调了这种脉冲状地震动的严重破坏潜力。本文介绍了一个框架，可以量化由方向性引起的脉冲状地面运动对建筑资产组合的直接经济损失的影响。为此，针对案例研究的走滑断层，在断层平行或断层法向方向上，针对各种合成建筑组合，实施了基于模拟的概率风险建模框架。考虑了三种代表地中海地区不同脆弱性类别的中低层建筑类型：带有砖石填充物的非延性抗弯钢筋混凝土（RC）框架，主要设计成仅承受重力载荷（即预编码框架）；抗震RC填充框架设计考虑了高延展能力的抗震规定（即特殊代码框架）；特殊代码钢制抗力矩框架。首先进行基于蒙特卡洛的概率地震危险性分析，考虑相关修改以考虑脉冲发生概率和结果频谱放大。获得与断层距离不同的站点/建筑物的危险曲线，讨论了危险放大的空间分布。一组类似脉冲的地面运动和一组一对一的频谱等效普通记录用于执行非线性动态分析，并为每种考虑的建筑物类型得出脆弱性关系。最终，通过将派生的脆弱性关系与（建筑物级别的）损损模型相结合，构建了漏洞模型。结果以强度为基础，并针对不同规模和建筑物类型分布的合成资产组合按预期的年度损失来表示。结果表明，对于特别短周期的结构（例如，填充的RC框架），在易碎性推导中将近源方向性的影响忽略不计，而将其保留在危险组件中即可。总体而言，当估算位于断层附近的单个建筑物或小型投资组合的损失时，近源方向性影响非常明显。不过，