Historically, the seismic performance of structures with conditions of structural irregularity has been poor in strong earthquakes when compared to those of regular structures. In particular, structural irregularities associated to torsion, soft stories, weak stories and flexible diaphragms have been highlighted among the most dangerous ones. In this paper, the author documents the seismic performance of irregular structures based upon a universe of 2458 damaged structures surveyed in Mexico City during the September 19, 2017 earthquake which underwent from moderate damage to collapse. The discussion is oriented with regard to code design requirements for irregularities set up in the seismic code of Mexico City since 1987 and special design considerations established since then and slightly modified in the 2004 code, the ruling code at the time the 2017 earthquake struck. Based upon this updated information, it is confirmed that the procedure established since 1987 is useful to reduce the severity of damage in irregular structures projected according to them. In addition, some recommendations are done to improve the definitions of regularity and strong irregularities available in Mexican seismic codes in general.

从历史上看，与常规结构相比，具有结构不规则条件的结构在强地震中的抗震性能一直很差。特别是，与扭力相关的结构不规则，软故事，薄弱故事和柔性膜片在最危险的事件中得到了强调。在本文中，作者记录了不规则结构的抗震性能，该结构基于2017年9月19日地震（从中等程度的损坏到坍塌）在墨西哥城进行的2458个受损结构的调查。讨论的重点是针对自1987年以来在墨西哥城的地震法规中制定的不规则性的法规设计要求，以及自那时以来确立并在2004法规中稍作修改的特殊设计注意事项，2017年地震发生时的法规。基于此更新的信息，可以确认，自1987年以来建立的程序可用于降低根据其投影的不规则结构的损坏严重程度。此外，还提出了一些建议，以改善总体上墨西哥地震法规中有关规则性和强不规则性的定义。