مهندسی سازه و ساخت

مهندسی سازه و ساخت

بررسی پاسخ لرزه‌ای سازه‌های بتن‌آرمه تحت تحلیل‌های پوش‌آور با در نظر گرفتن اثر مودهای ارتعاشی بالا برپایه ضوابط استاندارد 2800 ایران

نوع مقاله : علمی - پژوهشی

نویسندگان
1 دانشجوی کارشناسی ارشد، دانشکده فنی و مهندسی، دانشگاه رازی، کرمانشاه، ایران
2 دانشیار، دانشکده فنی و مهندسی، دانشگاه رازی، کرمانشاه، ایران
3 دانشجوی دکتری تخصصی، دانشکده فنی و مهندسی، دانشگاه رازی، کرمانشاه، ایران
چکیده
در روش سنتی پوش‌آور که تاکنون مورد توجه آیین‌نامه های طراحی لرزه‌ای بوده، صرفا اثر مود ارتعاشی اول سازه در نظر گرفته می‌شود. آیین‌نامه‌های لرزه‌ای برای صرفنظر از اثر مودهای بالاتر در تحلیل پوش‌آور، ضوابط خاصی را ارائه کرده‌اند که در این میان، استاندارد 2800 ایران ضوابط سختگیرانه‌تری دارد. بر این اساس چنانچه اثر مودهای ارتعاشی بالاتر بر سازه حاکم بود، بجای تحلیل پوش‌آور بایستی از تحلیل دینامیکی غیرارتجاعی تاریخچه زمانی استفاده شود. این درحالیست که براساس آیین‌نامه‌هایی همچون ASCE 41-23، FEMA356 و نشریه 360 بهسازی ایران، در صورت موثر بودن مودهای ارتعاشی بالاتر، می‌توانیم از تحلیل استاتیکی غیرارتجاعی استفاده کنیم اما باید یک تحلیل دینامیکی طیفی نیز انجام شود. برای ارزیابی ضوابط آیین‌نامه‌های طراحی در این مورد یادشده، 3 ساختمان قاب خمشی بتن آرمه ویژه با تعداد طبقات 15، 18 و 21 انتخاب شدند. تحلیل‌های استاتیکی معادل، دینامیکی طیفی، استاتیکی غیرارتجاعی و دینامیکی غیرارتجاعی تحت 6 زوج شتابنگاشت و 3 الگوی بار جانبی، توسط نرم‌افزار‌های ETABS و SeismoStruct انجام شد. از پاسخ تغییرمکانی سازه‌ها برای مقایسه، بررسی و ارزیابی ضوابط آیین‌نامه‌ها استفاده و مشاهده شد که نتایج الگوی بار جانبی مود اول، تشابه بهتری نسبت به سایر الگوهای بارجانبی مورد بررسی در این مقاله با نتایج تحلیل‌های دینامیکی غیرخطی دارند. ضوابط سختگیرانه استاندارد 2800 در بحث مودهای بالاتر، قابل توجیه است. کمترین اختلاف میان پاسخ‌ها در حدود 1 درصد بوده که توسط الگوی بار مود اول ایجاد و بیشترین اختلاف میان پاسخ‌ها، 154 درصد بوده که توسط الگوی بار مثلثی ایجاد شد.
کلیدواژه‌ها

موضوعات


عنوان مقاله English

Investigating the seismic response of RC structures under pushover analysis considering the effect of high vibration modes based on Iran's 2800 code

نویسندگان English

Dana Darvishi 1
Reza Aghayari 2
Nima Shahbazi 3
1 M.Sc. Student, Civil Engineering, Department, Razi University, Kermanshah, Iran
2 Associate professor, Civil Engineering, Department, Razi University, Kermanshah, Iran
3 Ph.D. Candidate, Civil Engineering Department, Razi University, Kermanshah, Iran
چکیده English

In the traditional pushover method, which is the focus of seismic design regulations, only the first mode of the structure is considered. Seismic regulations have provided special criteria to solve the issue of the effect of higher modes, among which, Iran's 2800 standard has considered stricter criteria. According to this regulation, if the effect of higher modes prevailed on the structure, we cannot use pushover analysis and inelastic dynamic time history analysis should be used. This is despite the fact that regulations such as ASCE41-23, FEMA356 and Iran's 360 Rehabilitation publication have stated that if the effect of higher modes prevailed on the structure, we can use inelastic static analysis, but a spectrum dynamic analysis must also be performed. In this article, in order to examine the rules of regulations in the discussion of higher modes, three irregular buildings (15 to 21 floors) with a special RC-Moment resisting frame system were selected and modeled by ETABS program. Linear static and spectral dynamic analyzes were performed. After the design, the structures were inelastically modeled in the SeismoStruct program and inelastic dynamic analysis was performed under six pairs of records. Inelastic static analysis (Pushover) was also performed under three lateral load patterns of the first mode, triangular and spectral. The structural displacement responses were extracted and used to check the criteria. The first mode lateral load pattern, in estimating the maximum ratio of inter-story displacement of structures, has better accuracy than other and is closer to the results of inelastic dynamic analysis, although there are differences However, it is concluded that the criteria of standard 2800 are justified in the discussion of pushover analysis and the effect of higher modes, and it is better to use inelastic dynamic analysis if the effect of higher modes dominates the structure.

کلیدواژه‌ها English

Pushover analysis
Standard 2800
Higher modes
Inelastic dynamic analysis
Reinforced concrete moment-resisting frame
1.         Ferraioli M and Lavino A. (2020). Irregularity effects of masonry infills on nonlinear seismic behaviour of RC buildings. Mathematical Problems in Engineering.2020(1):4086320.
2.         Abass HA and Jarallah HK. (2021). Comparative Study of the Seismic Assessment According to ATC-40, FEMA-356 and FEMA-440 for Existing Hospital Building Located at Baghdad City. no June.
3.         moradiyan m, pachideh G and moshtagh A. (2022). Study of seismic behavior and development of fragility curves of divergent braced frames under successive earthquakes. Journal of Structural and Construction Engineering.8(Special Issue 4):156-75.
4.         Kheyroddin A, Gholhaki M and Pachideh G. (2019). Seismic Evaluation of Reinforced Concrete Moment Frames Retrofitted with Steel Braces Using IDA and Pushover Methods in the Near-Fault Field. Journal of Rehabilitation in Civil Engineering.7(1):159-73.
5.         Bektaş N and Kegyes-Brassai O. (2022). Conventional RVS methods for seismic risk assessment for estimating the current situation of existing buildings: A state-of-the-art review. Sustainability.14(5):2583.
6.         Zameeruddin M and Sangle KK. (2021). Performance-based seismic assessment of reinforced concrete moment resisting frame. Journal of King Saud University-Engineering Sciences.33(3):153-65.
7.         Horrison MS, V DS and P MSKKR. (2023). Review on Pushover Analysis Procedures. International Journal of Advanced Research in Science, Communication and Technology.514-521.
8.         Kuria KK and Kegyes-Brassai OK. (2023). Pushover Analysis in Seismic Engineering: A Detailed Chronology and Review of Techniques for Structural Assessment. Applied Sciences.14(1):151.
9.         Bektaş N and Kegyes-Brassai O, (2022.) A comparative study of rapid visual screening methods to detailed seismic assessment of a reinforced concrete residential building. In:  Proceedings of the 3rd European Conference on Earthquake Engineering & Seismology, Bucharest, Romania; 2022.
10.       Lima C, Martinelli E and Faella C. (2017). Simplified nonlinear static procedures for seismic assessment of masonry infilled RC structures. Ingegneria Sismica.34(3-4):139-50.
11.       Aşıkoğlu A, Vasconcelos G and Lourenço PB. (2021). Overview on the nonlinear static procedures and performance-based approach on modern unreinforced masonry buildings with structural irregularity. Buildings.11(4):147.
12.       Kuria KK and Kegyes-Brassai OK. (2023). Nonlinear static analysis for seismic evaluation of existing RC Hospital Building. Applied Sciences.13(21):11626.
13.       Worku AM and Hsiao P-C. (2022). An improved first-mode-based pushover analytical procedure for assessing seismic performance of special moment resisting frame building structures. Engineering Structures.252:113587.
14.       Jalilkhani M, Ghasemi SH and Danesh M. (2020). A multi-mode adaptive pushover analysis procedure for estimating the seismic demands of RC moment-resisting frames. Engineering Structures.213:110528.
15.       Rahmani AY, Badaoui M, Bourahla N and Bento R. (2022). Extension of the improved upper-bound pushover analysis for seismic assessment of steel moment resisting frames with setbacks. Bulletin of Earthquake Engineering.20(13):7609-40.
16.       Habibi A, Izadpanah M and Namdar Y. (2022). A new modal lateral load pattern for improving pushover analysis to estimate nonlinear responses of structures. Australian Journal of Structural Engineering.23(4):289-302.
17.       Rooshenas A, (2020.) Comparing pushover methods for irregular high-rise structures, partially infilled with masonry panels. In:  Structures; 2020: Elsevier.
18.       Daei A and Poursha M, (2021.) On the accuracy of enhanced pushover procedures for seismic performance evaluation of code-conforming RC moment-resisting frame buildings subjected to pulse-like and non-pulse-like excitations. In:  Structures; 2021: Elsevier.
19.       Seismic Evaluation and Retrofit of Existing Buildings, (2023). ASCE41-23.
20.       Seismic Evaluation and Retrofit of Existing Buildings (2017). ASCE41-17.
21.       Seismic Evaluation and Retrofit of Existing Buildings (2006). ASCE41-06.
22.       Seismic Evaluation and Retrofit of Existing Buildings (2013). ASCE41-13.
23.       Prestandard and Commentary for the Seismic Rehabilitation of Buildings (2000). FEMA 356.
24.       Instruction for Seismic Rehabilitation of Existing Buildings, (2014). Code 360.
25.       Instruction for Seismic Rehabilitation of Existing Buildings, (2007). Code 360.
26.       SeismoStruct. (2021). p. A computer program for static and dynamic analysis for framed structures.
27.       Scott MH and Fenves GL. (2006). Plastic hinge integration methods for force-based beam–column elements. Journal of Structural Engineering.132(2):244-52.
28.       Mander JB, Priestley MJ and Park R. (1988). Theoretical stress-strain model for confined concrete. Journal of structural engineering.114(8):1804-26.
29.       Menegotto M, (1973.) Method of analysis for cyclically loaded RC plane frames including changes in geometry and non-elastic behavior of elements under combined normal force and bending. In:  Proc of IABSE symposium on resistance and ultimate deformability of structures acted on by well defined repeated loads; 1973.
30.       Pinho R and Elnashai A. (2000). Dynamic collapse testing of a full-scale four storey RC frame. ISET Journal of earthquake Technology.37(4):143-63.
31.       Gerami M, Mashayekhi A and Siahpolo N. (2016). Assessment of higher modes effects in the steel moment resistinng frames under the far and near sault earthquakes using the DAP method Asian journal of CIVIL ENGINEERING (BHRC).17(8):1111-30.

  • تاریخ دریافت 24 خرداد 1403
  • تاریخ بازنگری 19 مهر 1403
  • تاریخ پذیرش 18 آبان 1403