بررسی موقعیت قرارگیری سازه تکدرجه آزاد غیرالاستیک با شکلپذیری ثابت در برابر نگاشت‌های حوزه نزدیک

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشکده مهندسی عمران، دانشگاه صنعتی نوشیروانی بابل، ایران

2 دانشگاه صنعتی نوشیروانی بابل

چکیده

ویژگی‌های منحصربه‌فرد و آثار مخرب رکوردهای حوزه نزدیک گسل و ارائه‌ی راهکارهای مهندسی جهت پیشگیری از خساراتشان مورد توجه بسیاری از پژوهشگران می ­باشد؛ مسأله‌ی موقعیت قرارگیری سازه‌ها در برابر این رکوردها به دلیل کمبود داده ­ها کمتر مورد توجه قرار گرفته است. از این رو، در این پژوهش تمرکز بر روی تأثیر موقعیت قرارگیری سازه در میزان خسارت‌هایی است که در هنگام زلزله به آن اعمال می­ شود. به منظور بررسی در این زمینه نیازمند رکوردهای زلزله می ­باشیم که به دلیل کمبود داده های شتاب°نگاری دستگاهی، می ­توان با استفاده از تکنیک­ هایی جنبش نیرومند زمین را شبیه­ سازی کرد. با استفاده از پارامترهای گسلش به ­دست آمده برای زلزله-ی کوجائیلی ترکیه 1999، 273 شتاب­نگاشت زلزله با توجه به مختصات مکانی مختلف به وسیله ­ی تابع گرین نظری تولید شد. به منظور ارزیابی عملکرد لرزه­ای سازه ­ها از نرم ­افزار OpenSEES و 9828 تحلیل دینامیکی تاریخچه زمانی استفاده شد. سازه­ های بررسی شده، تک‌درجه آزاد غیرالاستیک با شکل‌پذیری ثابت می‌باشد که رکوردها با توجه به موقعیت قرارگیری سازه نسبت به گسل اعمال گردید و با به­ دست آوردن پاسخ ­ها، طیف­ های مربوطه به صورت کانتورهای رنگی ترسیم شد. نتایج نشان داد موقعیت پاسخ‌های بیشینه در حالت غیرالاستیک تقریباً مشابه حالت الاستیک می‌باشد. لذا به وسیله‌ی یک تحلیل الاستیک که ساده‌تر است می‌توان موقعیت‌های بحرانی‌تر را مشخص کرد؛ ایستگاه‌هایی که در پریودهای پایین مقدار بیشینه را نشان دادند دامنه‌ی بیشتر، و ایستگاه‌هایی که در پریودهای بالا مقدار بیشینه را نشان دادند پریود پالس بیشتری دارند. همچنین در تعیین موقعیت خرابی شدیدتر هر دو عامل فاصله و زاویه‌ای که سازه مورد نظر از خط گسل می‌گیرد، تأثیرگذار می‌باشند.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Influence of Inelastic Constant-Ductility SDOF Location versus Near-Fault Records

نویسندگان [English]

  • Shakiba Monfaredi 1
  • Hamed Hamidi 2
  • Horr Khosravi 1
1 Graduate Student, Faculty of Civil Engineering, Babol Noshirvani University of Technology, Iran
2 Faculty of Civil Engineering/Assistant Professor
چکیده [English]

The unique features and destructive effects of near-fault records are of high interest to many researchers; the issue of the location of structures against these records has received less attention due to the lack of data. Therefore, in this study, the focus is on the effect of the location of the structure vs. causative fault on the amount of damage. To this end, we need enough near-fault records, which can be simulated using the synthetic generation technique due to the lack of real data. Using the fault parameters obtained for the 1999-Kocaeli earthquake, 273 earthquake records were generated by different location coordinates using the theoretical-based Green's function. To evaluate the seismic performance of the structures, OpenSEES software was used to carry out 9828 dynamic time-history analyses. The studied structures are SDOF with constant ductility. The records were applied according to the position of the structure against the causative fault and the relevant spectra were drawn as colored contours. The results showed that the location of the maximum responses in the inelastic state is almost the same as in the elastic state, so the critical location can be determined by a simpler elastic analysis; Stations that showed a maximum value at low periods have a larger amplitude, and stations that showed a maximum value at high periods have a higher pulse period. Both the distance and the angle of the SDOF location are influential in determining the location of the more severe failure.

کلیدواژه‌ها [English]

  • SDOF
  • location of the structure
  • near-fault
  • constant ductility
  • Bi-linear steel material
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