تاثیر تراز کمربند سخت کننده بر عملکرد ساختمانهای بلند فولادی تحت زلزله های نزدیک گسل

نوع مقاله : مقاله پژوهشی

نویسندگان

دانشکده فنی و مهندسی، دانشگاه خوارزمی، تهران، ایران

چکیده

در این پژوهش با استفاده از روش تحلیل دینامیکی غیر خطی تاریخچه زمانی ، تحت یک گروه هفت گانه از رکوردهای سه مولفه ای حوزه نزدیک و یک رکورد حوزه دور، پارامترهای پاسخ لرزه ای ساختمان های بلند با سازه مقاوم ترکیبی قاب محیطی مهاربندی شده و کمربند سخت کننده بررسی شده است. یک مدل سه بعدی با ساختار قاب محیطی مهاربندی شده، همراه با سه مدل دیگر که دارای آرایش‌های گوناگونی از قرارگیری کمربند سخت‌کننده در ارتفاع سازه هستند، بر اساس ضوابط لرزه‌ای موجود در ویرایش چهارم آیین‌نامه ۲۸۰۰ و نیز مبحث دهم مقررات ملی ساختمان (طرح و اجرای ساختمانهای فولادی) طراحی و با یکدیگر مقایسه شده اند. بر پایه تحلیل رفتار دینامیکی واقعی سازه، رکوردها در حالت میدان آزاد اعمال شده اند. از آنجایی که پاسخ دینامیکی سازه ها رکورد به رکورد با یکدیگر متفاوت است، برای توجیه چگونگی رفتار مدل‌های مطالعاتی، طیف پاسخ سرعت متناظر با هر رکورد آنها رسم شده است. همچنین به منظور تبیین اثرات مودهای بالاتر نیز طیف‌های پاسخ سرعت، در محدوده طیفی متناظر با پریود سازه‌های مطالعاتی بررسی شده است. ارزیابی نتایج این پژوهش حاکی از آن است که وجود کمربند سخت کننده سبب افزایش قابل توجه سختی سازه و کاهش دریفت و لنگر پای سازه می‌شود. هم‌چنین بیشترین تقاضای دریفت برای مدل بدون کمربند سخت کننده و مدل با کمربند سخت کننده میانی، در حدود 0/83 تا 0/9 تراز نرمال شده و برای مدل‌هایی که کمربند سخت کننده در تراز بالای سازه قرار دارد، در 0/5 تا 0/8 تراز نرمال شده اتفاق می‌افتد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

The Effect of Belt Truss Level on the Performance of Steel High-Rise Buildings Subject to Near Field earthquake

نویسندگان [English]

  • M. Abdi Moghadam
  • A. Meshkat-Dini
Faculty of Engineering, Kharazmi University, Tehran, Iran
چکیده [English]

In this study based on conducting several non-linear dynamic time history analyses subjected to the both types of near and far field three components earthquake records, the seismic response parameters of inelastic behavior of tall buildings with belt truss frameworks have been investigated. A three-dimensional basic outrigger braced tube model as well as three other resistant skeletons which contain different configurations of belt trusses in height, have been designed according to the Iranian seismic code 2800 (4th edition) and Iranian national building code (steel structures-division 10). The dynamic response parameters of all studied structures have been assessed under influence of free field three components earthquake records. Because the overall dynamic response of the studied structures would change subjected to record by record separately, the corresponding response velocity spectra of each of the selected records were notified numerically. Furthermore, in order to denote the effects of higher modes, the aforementioned response velocity spectra were evaluated corresponding to the natural period of the studied structures. Having accurate evaluation of the analytical results indicate that the existence of belt truss causes a significant increase in structural stiffness and mitigates drift and base bending moment. Also the highest drift demand obtained for the model without belt truss and the model with belt truss located at 0.5H, occurs relatively in 0.83 to 0.9 of normalized height. This demand parameter calculated for the model with the top belt truss occurs in 0.5 to 0.8 of normalized height.

کلیدواژه‌ها [English]

  • Tall Building
  • Steel Skeleton
  • Braced Tube
  • Belt Truss
  • Velocity Response Spectra
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