Modares Civil Engineering journal
مهندسی عمران مدرس
MCEJ
Engineering & Technology
http://mcej.modares.ac.ir
1
admin
2476-6763
10.22034
fa
jalali
1397
9
1
gregorian
2018
12
1
18
6
online
1
fulltext
fa
رفتار لرزه ای تیر همبند فولادی تعویض پذیر در دیوار برشی بتنی مسلح
Seismic Behavior of Replaceable Steel Coupling Beam in Reinforced Concreat Shear Wall
استفاده از تیرهای همبند فولادی در دیوارهای برشی بتن مسلح به علت عملکرد لرزه ای و انعطاف پذیری بهتر و همچنین اجرای راحت تر و ابعاد کوچکتر آن نسبت به تیرهای بتنی رو به گسترش می باشد. جهت اجتناب از خرابی ماندگار اتصال تیر فولادی به دیوار بتنی، می توان از تیر فولادی دارای المان تعویض پذیر استفاده نمود. در این مقاله یک تیر همبند فولادی طراحی شده بر اساس استاندارد 2800 و مبحث دهم مقررات ملی ساختمان طراحی و ساخته شده است. همچنین المان تعویض پذیر و بخش های کناری آن بر اساس ضوابط تیر پیوند مبحث دهم مقررات ملی ساختمان طراحی و ساخته شده است. مجموعه دو دیوار طرفین تیر و تیرهمبند تعویض پذیر با مقیاس 1 به 3 ساخته شده و با تاریخچه جابجایی چرخه ای بر اساس تغییر شکل نسبی طبقات مورد آزمایش قرار گرفته است. با توجه به نتایج بدست آمده، رفتار غیر خطی تیر همبند به المان تعویض پذیر محدود شده است اما با توجه به مقاطع استفاده شده و نیروهای موجود در تیرها، رابطه استفاده شده از مبحث دهم جهت طراحی تیرهای کناری نیاز به اصلاح دارد. همچنین بر اساس سختی محاسباتی و سختی اندازه گیری شده سیستم و بر مینای طول مهاری تیر فولادی در دیوار بتن مسلح، روشی برای محاسبه سختی واقعی این مجموعه برای طراحی سازه ها و محاسبه جابجایی طبقات پیشنهاد شده است.
Reinforced concrete shear walls are frequently used as lateral load resisting systems because of their ductile response and very good energy dissipation. When openings in RC shear walls are used due to architectural requirements, coupling beams are forming to connect two adjacent walls. The behavior of coupled shear walls is governed by coupling beams and they are the most vulnerable parts of coupled shear wall systems and were seriously damaged due to severe past earthquakes. To avoid construction difficulties and huge size of the RC coupling beams and better seismic performance an ductility, steel coupling beams in reinforced concrete shear walls have been mostly used during last years. Steel coupling beams connections to concrete shear walls are vulnerable and it is practically difficult and economically waste to repair damaged coupling beams, which would cause the building life cycle cost increasing. Therefore, it is necessary to transform traditional design approach to a design method in which some important parts would be replaceable rather than repairable. In this paper a building with special shear walls with steel coupling beams as lateral force resisting system is designed based on Iranian Standard 2800 and Iranian National Building Code. One of the 5th to 8th floor steel coupling beams section considered as fuse element and side beams and stiffeners of I-shaped beams designed based on eccentrically braced frames link beam criteria of Iranian National Building Code (part 10). Experimental specimen containing two RC shear walls that connected to each other with designed replaceable steel coupling beam in 1 to 3 scale is constructed and assembled in strong floor lab. For providing one degree of freedom movement of load wall four TBI Motion Company TRH65VE linear supports used. Cyclic displacement history of experiment calculated based on story drift and amplitudes of loading determined using Iranian Standard 2800 limit for story drift. Based on experimental results side beams remained in the border of elastic range and inelastic behavior of system concentrated in fuse element so the goal of system is satisfied. The side beam section is stronger and different with that was obtained from link beam criteria of Iranian National Building Code (part 10) because of available steel sheet size and since the side beam force is almost equal to elastic capacity of beam, the criteria for designing side beams is modified. Total system stiffness and fuse beam stiffness that obtained from experiment are fewer than analytical stiffness of system and fuse beam. Stiffness degradation of system occurs due to partially fixed performance of steel coupling beam connection to RC shear wall and micro cracks of wall in the connection zone. Different between real and analytical stiffness of system is very important and it is necessary to repeat the building design with modified stiffness and recalculate story drifts and distributed forces in structural elements. In this paper modifying method of stiffness is developed with moving fixed end point of steel coupling beam and increase of beam length. Effective fixed point of beam is defined by adding a portion of embedment length of steel beam in RC shear wall to both steel coupling beam ends.
دیوار برشی بتن مسلح,تیر همبند فولادی,المان تعویض پذیر,محل تکیه گاه موثر,
RC shear wall,Steel coupling beam,Fuse element,Effective fixed point,
131
141
http://mcej.modares.ac.ir/browse.php?a_code=A-16-39633-190&slc_lang=fa&sid=16
davood
Zarei
داود
زارعی
1003194753284600120086
1003194753284600120086
No
Tarbiat Modares university
دانشگاه تربت مدرس
Abbas Ali
Tasnimi
عباسعلی
تسنیمی
1003194753284600120087
1003194753284600120087
Yes
Tarbiat Modares University
دانشگاه تربیت مدرس