طراحی بر اساس جابجایی مستقیم در قاب های بتن آرمه همراه جداساز لرزه ای

نوع مقاله : علمی - پژوهشی

نویسندگان

1 دانشجوی کارشناسی ارشد مهندسی زلزله، واحد علوم و تحقیقات، دانشگاه آزاد اسلامی، تهران، ایران

2 استادیار دانشکده عمران، واحد علوم و تحقیقات، دانشگاه آزاد اسلامی، تهران، ایران

چکیده

از دیر باز برای کاهش خسارت های ناشی از زلزله راه کار های متفاوتی بیان شده است، از جمله افزایش شکل پذیری و کاهش جرم سازه. روش های نوین بر اساس جدا کردن سازه از پی بوده تا نیروی برش پایه ی سازه کاهش یابد .به عبارت دیگر جداسازی لرزه ای یک روش نوین برای طراحی ساختمان ها در برابر زلزله است که مبنای آن کاهش نیروهای وارد به سازه دراثر زمین لرزه، به جای افزایش ظرفیت سازه برای تحمل بارهای جانبی می باشد. در این مقاله قرار دادن جداساز لاستیکی با هسته سربی در رفتار سازه های بتن آرمه تحت اثر زلزله های حوزه دور مورد بررسی قرار گرفته شده است. از این رو برای جداساز های لاستیکی با هسته سربی در دو نمونه سازه های بتنی3 و 5 طبقه، دو میرایی 10 و 15 درصد در نظر گرفته شده است. سازه های دارای جداساز و سازه های پایه ثابت در نرم افزارOpensees مدل گردیده و تحت اثر زلزله های دور، تحلیل تاریخچه زمانی روی آن ها انجام گرفته شده است. در نهایت نتایج تحلیل های تاریخچه زمانی برای طراحی به روش نیرویی و جابجایی مستقیم، قرار داده شده که شامل، ماکزیمم دریفت طبقات، ماکزیمم برش پایه و پریود سازه ها می باشد. نتایج بدست آمده از تحلیل های تاریخچه زمانی، نشان داده با افزایش زمان تناوب، برش پایه ها و ماکزیمم دریفت در ساختمان های های دارای جداساز طراحی شده به روش جابجایی مستقیم بیشتر از ساختمان های طراحی شده به روش نیرویی هستند. ساختمان های های دارای جداساز طراحی شده به روش جابحایی مستقیم دارای مقاطع با ظرفیت کمتری نسبت به ساختمان های طراحی شده به روش نیرویی هستند.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Direct Displacement Based Design of RC Frame With Based Isolation

نویسندگان [English]

  • emad azimi 1
  • Pasha Javadi 2
  • masoud nekooei 2
1 Master Student of Earthquake Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
2 Assistant Professor, Department of Civil Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
چکیده [English]

From long time ago, various solutions have been proposed to reduce earthquake damages, including increasing ductility and reducing structural mass. New methods are based on separating the structure from the foundation, to reduce the shear force of the base of the structure. In other words, seismic isolation is a new method for designing buildings against earthquakes, which is based on reducing the forces entering the structure due to earthquakes, instead of increasing the capacity of the structure to withstand lateral loads. This paper is a focused on the study of the effect of the placement of rubber separators with lead cores in the behavior of reinforced concrete structures under the influence of remote earthquakes. Therefore, for rubber separators with lead core in two samples of concrete structures of 3 and 5 floors, a double damping of 10 and 15% has been considered. Separating structures and fixed base structures were modeled in “Opensees” software. Afterwards, under the influence of distant earthquakes, a time history analysis was performed on them. Finally, the results of time history analysis for designs by force and direct displacement method are exposed, which include, maximum drift of floors, maximum shear of base and period of structures. Results obtained from the analysis of time history show that with the increase of the rotation time, the shear of the bases and the maximum drift in the buildings with isolators designed by direct displacement method are more than the buildings designed by force method. Buildings with separators designed by direct displacement method have sections with less capacity than buildings designed by force method.

کلیدواژه‌ها [English]

  • "؛ Base Isolation"؛
  • ؛ "؛ Lead Rubber Base Isolation"؛ Design Based on Direct Displacement"؛ Design Based on Force"؛
  • "؛ Time History Analysis"؛ Time History Analysis
 
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