مدلسازی توزیع خرابی پیش رونده لرزه ای در ساختمانهای 3 طبقه بتن مسلح متقارن و نامتقارن

نویسندگان

1 پژوهشگاه بین المللی زلزله شناسی و مهندسی زلزلهپژوهشگاه بین المللی زلزله شناسی و مهندسی زلزله

2 پژوهشگاه بین المللی زلزله شناسی و مهندسی زلزله

چکیده

دراین مقاله خرابی پیش رونده به صورت سه بعدی در ساختمانهای 3 طبقه بتن مسلح متقارن و نامتقارن با خروج از مرکزیتهای جرمی مختلف تحت بار زلزله مدل می شود. بدین نحو که توزیع و گسترش شکست از اولین عضو سازه تا شکست کلیه اعضای ساختمانها با مقایسه و ارزیابی نتایج بدست آمده از تحلیلهای تاریخچه زمانی بررسی می شود. نتایج حاصله حاکی از آن است که توزیع نامتقارن جرم در ساختمانهای پیچشی منجر به تخریب موضعی بیشتر شده که این امر خود سبب تشدید تخریب پیش رونده می گردد. ارزیابی نتایج نشان میدهد که تمرکز شکست بیشتر در مکانی است که تمرکز جرم بیشتری وجود داشته باشد و همچنین توزیع شکست نه در ارتفاع سازه به صورت عمودی بلکه به صورت افقی در طبقات ساختمان رخ می دهد. با افزایش خروج از مرکزیت نه تنها رخداد شروع شکست به سمت لبه نرم سازه نزدیکتر می شود بلکه احتمال رخداد شروع خرابی از ستونها نیز افزایش می یابد. بعلاوه توزیع خرابی مستقل از شتاب نگاشت است و با افزایش خروج از مرکزیت تغییر می کند به گونه ای که می توان سناریوی شکست را در سازه های متقارن و نامتقارن مشابه پیش بینی کرد.

کلیدواژه‌ها


عنوان مقاله [English]

Modeling of Seismic Progressive Collapse Distribution in 3 Story Symmetric and Asymmetric Reinforced Concrete Buildings

نویسندگان [English]

  • somayyeh karimiyan 1
  • aboreza sarvghad moghadam 2
1
2
چکیده [English]

This paper models the 3D progressive collapse of a 3 story reinforced concrete symmetric/asymmetric building with different levels of mass eccentricity under earthquake loads. We investigate collapse propagation, from the first element to the entire of the buildings, through comparing the results obtained via evaluation of the nonlinear time history analyses. Our analyses signify that mass irregular distributions result in further local damages and consequently are led to a larger progressive collapse in torsional buildings. We found that collapse is tend to be concentrated in the positions with a high level of mass concentration and the collapse distributions are horizontal through the stories, but not vertical through the height of the building. When the value of mass eccentricity is increased, collapse initiation points tend to transfer to the flexible edges and the probability that the collapse is initiated from the columns is increased, too. Besides, the spread of the collapse is independent of the earthquake records and vary according to the level of mass eccentricity in structures. This gives the ability to predict collapse scenarios in similar symmetric/asymmetric buildings.

کلیدواژه‌ها [English]

  • collapse distribution
  • Progressive collapse
  • Time history analysis
  • mass eccentricity
  • Reinforced concrete ordinary moment resisting frame
  • symmetric and asymmetric building
 
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