بررسی شکنندگی ‌‌لرزه‌ای قاب‌های بتنی مسلح با دیوارهای پر ‌کننده تحت اثر زلزله اصلی و ‌پس‌‌لرزه

نوع مقاله : مقاله پژوهشی

نویسندگان

1 *دانشیار، دانشکده مهندسی عمران، دانشگاه تبریز، ایران، تبریز،

2 دانشکده عمران، دانشگاه تبریز

چکیده

هدف این مقاله ارزیابی شکنندگی لرزه‌ای و ظرفیت باقی‌مانده‌ی قاب‌های بتنی مسلحبا دیوارهای پر‌ کننده بنایی تحت توالی زلزله اصلی و پس‌لرزه در حوزه دور و نزدیک است. در تحلیل دینامیکی افزایشی استاندارد (IDA)، فقط اثر زلزله اصلی در تحلیل‌ها در نظر گرفته می‌شود، در حالی ‌که در این مقاله از روش تحلیل دینامیکی افزایشی دوبل (D-IDA)، برای در نظر گرفتن اثرات پس‌لرزه استفاده شده است. اساس روش تحلیل دینامیکی افزایشی دوبل ترکیب زلزله‌ی اصلی در شدت‌های مختلف با مجموعه‌ای از پس‌لرزه‌ها است که در دامنه‌ی ماکزیمم شتاب زمین مقیاس شده‌اند. در این مطالعه 20 رکورد نزدیک و20 رکورد دور انتخاب شده است. در هر تحلیل از یک رکورد برای زلزله اصلی و پس‌لرزه استفاده شده است. منحنی‌های شکنندگی قاب سالم و آسیب دیده با استفاده از مدل‌سازی فایبر در نرم‌افزار اپنسیس، برای زلزله‌های حوزه نزدیک و دور تهیه شده است. همچنین با استفاده از نتایج به دست آمده از تحلیل دینامیکی افزایشی منحنی ظرفیت قاب‌ها تعریف و پاسخ قاب با دیوار پر‌ کننده و تنها در شدت‌های مختلف زلزله اصلی مقایسه شده است. با توجه به نتایج به دست آمده برای قاب با دیوار پر کننده مشاهده می‌شود، شکنندگی لرزه‌ای قاب بتن مسلح تحت اثر زلزله اصلی و پس‌لرزه به شدت کاهش می‌یابد. با مشاهده منحنی‌های شکنندگی می‌توان گفت زمانی که در قاب تنها فروپاشی 100 درصد اتفاق می‌افتد، احتمال فروپاشی قاب با دیوار پر‌ کننده در همان شدت PGA (ماکزیمم شتاب زمین) برای زلزله دور و نزدیک، کاهش چمشگیری پیدا می‌کند که بیانگر نقش موثر دیوارهای پر ‌کننده در افزایش مقاومت جانبی است.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Evaluation of Seismic fragility of infilled frames subject to mainshock/aftershock sequences

نویسندگان [English]

  • Saman Yaghmaei Sabegh 1
  • Sevda Nassjyan 2
2 Department of Civil Engineering, University of Tabriz
چکیده [English]

The purpose of this paper is to assess the seismic fragility and residual capacity of the reinforced concrete frame (RC) with masonry infills subject to mainshock/aftershock sequences in the far- and near-fields. In conventional incremental dynamic analysis (IDA), only the effect of the main shock is considered in the analysis, while the double incremental dynamic analysis (D-IDA) method which is used in this paper, considers the aftershock effects. Double incremental dynamic analysis approach is used, based on the combination of the mainshock(MS) at different intensities with a set of aftershocks (AS) scaled in amplitude with respect to peak ground. In this study, 20 near-field records and 20 far-field records were selected. In each analysis, a same record has been used for the main shock and after shock. The fragility curves of the intact and pre-damaged frames have been prepared for the records using fiber modeling in OpenSees software. Also, based on the results obtained from the incremental dynamic analysis, the frame residual capacity diagrams are defined and the infilled frame response is compared with the bare frame at different intensities of the main shock. According to the results obtained for infilled, the seismic fragility of the reinforced concrete frame is reduced due to the mainshock and aftershock. Also, the damages and losses economic of the structure under moderate earthquakes are reduced. According to the fragility curves, when only 100% collapse occurs in the bare frame, the probability of the frame collapsing with the infill wall at the same intensity as PGA (maximum ground acceleration) for near- and far-field earthquakes records is significantly reduced.

کلیدواژه‌ها [English]

  • Incremental Dynamic Analysis
  • Fragility Curves
  • far-field and near-field earthquakes
  • Masonry Infilled Frames
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