مهندسی سازه و ساخت

مهندسی سازه و ساخت

بررسی استفاده از راهکارهای بهبود دهنده رفتار لرزه‌ای قاب های بتنی دارای درز سرد

نوع مقاله : علمی - پژوهشی

نویسندگان
1 دانشجوی دکتری سازه، دانشکده مهندسی عمران، دانشگاه صنعتی شاهرود، شاهرود، ایران
2 دانشیار دانشکده عمران، دانشگاه صنعتی شاهرود، شاهرود، ایران
3 استادیار دانشکده عمران، دانشگاه صنعتی شاهرود، شاهرود، ایران
چکیده
در این پژوهش به بررسی تأثیر درز سرد و استفاده از راهکارهای مختلف جهت بهبود و کاهش تأثیر درز سرد در قاب بتن مسلح پرداخته‌شده است. برای این منظور بعد از صحت‌سنجی یک اتصال تیر به ستون بتنی دارای درز سرد در نرم‌افزار آباکوس، 20 مدل از یک قاب بتنی یک دهانه و یک طبقه، در حالات مختلف در نرم‌افزار آباکوس مدل‌سازی شد. سه نوع تقویت‌کننده درز سرد شامل کلید برشی، میلگرد اضافی و قوطی در محل درز سرد با ابعاد و هندسه‌های مختلف ایجاد شد. تمامی نمونه‌های تحت بارگذاری سیکلی قرار گرفت و نمودار پوش هیسترزیس، بیشترین ظرفیت باربری و فاکتور افت مقاومت از نمونه‌ها استخراج و مقایسه گردید. نتایج به‌دست‌آمده از این پژوهش نشان داد که با ایجاد درز سرد، بیشترین ظرفیت برابری تا مقدار 15 درصد کاهش خواهد یافت. همچنین با استفاده از سه راهکار پیشنهادی، استفاده از قوطی، کلید برشی و میلگردهای اضافی در محل درز سرد می‌توان ظرفیت بیشترین ظرفیت باربری و نمودار پوش سازه را بهبود بخشید که در این میان بیشترین تأثیر مربوط به استفاده از قوطی و کمترین تأثیر مربوط به استفاده از میلگرد اضافی بود. در نمونه‌ها دارای قوطی با افزایش مقطع و ضخامت قوطی ظرفیت باربری نسبت به نمونه درز سرد و در برخی موارد نسبت به نمونه بدون درز سرد نیز افزایش یافت. در نمونه‌های دارای کلید برشی با افزایش سطح مقطع و کاهش طول کلید برشی ظرفیت باربری نسبت به نمونه دارای درز سرد افزایش یافت. در نمونه‌های دارای میلگرد اضافی افزایش ظرفیت باربری نسبت به نمونه دارای درز سرد اندک بود و این افزایش با افزایش قطر میلگردها، بهبود یافت
کلیدواژه‌ها

موضوعات


عنوان مقاله English

Numerical investigation of seismic improvement solutions of cold joints in concrete moment frames

نویسندگان English

amir atashi 1
Vahid Reza kalatjari 2
Ebrahim Zamani beydokhti 3
1 PhD candidate, Department of civil engineering, Shahrood University of Technology, Shahrood, Iran
2 Associate Professor, Department of Civil Engineering. Shahrood University of Technology, Shahrood, Iran
3 Assistant Professor, Department of Civil Engineering. Shahrood University of Technology, Shahrood, Iran
چکیده English

In this research, the effect of cold joint and the use of different solutions to improve and reduce the effect of cold joint in reinforced concrete frame have been investigated. For this purpose, after validating a concrete beam-to-column connection with a cold joint in Abaqus software, 20 models of a one-span, one-story concrete frame were modeled in Abaqus software in different situations. Three types of cold joint reinforcement including shear key, additional rebar and steel box in the cold joint location with different dimensions and geometries were created. All the models were subjected to cyclic loading, and hysteresis envelope diagram, maximum load capacity and resistance loss factor were extracted from the models and compared. The results obtained from this research showed that by creating a cold joint, the maximum load carrying capacity will decrease by 15%. Also, by using the three proposed solutions, the use of boxes, shear keys, and additional rebars at the cold joint location, it is possible to improve the capacity of the maximum load-carrying capacity, among which the greatest impact is related to the use of cans and the least impact is It was to use additional rebar. In models with boxes, with increased cross-section and web thickness, the bearing capacity increased compared to the cold joint model and in some cases compared to the model without cold joint. In the models with shear key, the bearing capacity increased compared to the model with cold joint by increasing the cross-sectional area and decreasing the length of the shear key. In the models with additional rebars, the increase in load capacity compared to the models with cold joints was small, and this increase was improved by increasing the diameter of the rebars.

کلیدواژه‌ها English

Cold joint
concrete moment frame
shear key
Additional rebar
Seismic behavior
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  • تاریخ دریافت 13 خرداد 1403
  • تاریخ بازنگری 10 مرداد 1403
  • تاریخ پذیرش 02 مهر 1403