کنترل ضوابط محدودیت تغییر مکان جهت بهبود رفتار لرز های ساز هها

نوع مقاله : مقاله پژوهشی

نویسندگان

1 پژوهشگاه بین المللی زلزله شناسی و مهندسی زلزله، تهران، ایران

2 تهران- شهرری- خ سلمان فارسی- مجتمع سلمان فارسی- ورودی D- واحد یک

چکیده

امروزه روش معمول در طراحی ساختمان‌‌ به این صورت است که طراحی آن بر اساس بار‌های وارد و ضوابط نیرویی موجود در آیین‌نامه انجام می‌شود، سپس تغییر مکان طبقات سازه با مقادیر مجاز مقایسه می‌گردد و در صورت نیاز قسمت‌هایی از سازه تقویت می‌شود تا این ضوابط در همه طبقات برآورده شود. تا‌کنون ملاک خاصی برای یافتن مناسب‌ترین اعضایی که با تقویت آنها، این ضوابط به بهترین شکل ارضا شوند وجود ندارد و بنابر‌این به هنگام طراحی سازه روش‌های مختلفی برای ارضای ضوابط کنترل تغییر مکان به‌کار می‌رود که مطالعات گذشته نشان داده است اگرچه برخی از این روش‌ها منجر به ارضای ضوابط آیین‌نامه‌ می‌شود اما عملکرد لرزه ای سازه را با چالش مواجه نموده است. در این تحقیق راهکاری برای ارضای منطقی ضوابط کنترل تغییرمکان ارائه و در چند سازه فولادی قاب خمشی ویژه لاغر نشان داده شده است که راهکار ارائه شده نسبت به روش‌های موجود، به سازه با رفتار لرزه ای بهتر منجر می‌شود. برای مقایسه رفتار لرزه ای سازه‌های مورد مطالعه از تحلیل تاریخچه زمانی غیر‌خطی استفاده شد که ملاک مقایسه نیز شاخص خرابی و زمان دوام در نظر گرفته شده است.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

A Proposed Method to Satisfy Code Drift Criteria to Achieve Building with Higher Seismic Performance

نویسندگان [English]

  • M. Mohammadi 1
  • Sepehr Gholami 2
1 International Institute of Earthquake Engineering and Seismology, Tehran, Iran
چکیده [English]

The first step in designing structures is choosing sufficient elements for the applied loads, including dead, live, wind and earthquake ones. Then, drifts of all stories are compared with allowable values and if required some structural elements are so resized to satisfy the drift criteria. The process of resizing is normally carried out by trial and error and relied mostly on engineering judgment. In other words, there are many approaches for satisfying the drift criteria, which some of them may lead to structures with poor seismic behavior. Moreover, based on Iranian Standard 2800, the designer is allowed to use analytical period of vibration in drift controlling process, instead on one calculated by the code proposed formula.
In this study, a method is proposed to find the best elements for resizing and subsequently satisfying the drift controlling criteria. Furthermore, it is shown that applying the analytical period of vibration leads to structures with better seismic behavior. For the purposes, Endurance Time method is applied in which nonlinear behavior of slender special moment resisting frame steel structures and their damage indices are considered.

کلیدواژه‌ها [English]

  • Drift
  • steel structure
  • Special moment resisting frame
  • damage index
  • Endurance time
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