نویسندگان
1 دانشکده مهندسی عمران دانشگاه علم و صنعت ایران
2 دانشگاه کایست، کره جنوبی
چکیده
در مقاله حاضر بعد از صحت سنجی یک مدل عددی با نتایج آزمایشات سانتریفیوژ انجام گرفته بر روی یک تونل متـرو، اثـر سـازه زیرزمینی بر حداکثر شتاب سطح زمین در دو حالت رفتارخطی و غیرخطی خاک مورد مقایسه قرار گرفته است. نتایج نشان می دهد در محـدوده فرکانس طبیعی سیستم، مدل غیرخطی، کوچک نمایی PGA در اثر حضور سازه نسبت به میدان آزاد را نشان می دهد؛ در حالیکه در مدل خطـی عکس این روند مشاهده می شود. در محدوده فرکانسهای خارج از فرکانس های طبیعی سیستم، ضریب بزرگنمایی در مـدل خطـی و غیرخطـی نزدیک به یکدیگر بوده و هر دو مدل در فرکانس های پایین، بزرگ نمایی و در فرکانس های بالا، کوچک نمایی PGA نسبت به میـدان آزاد را نشـان می دهند.
کلیدواژه‌ها
عنوان مقاله [English]
Effect of Underground Structure on PGA at Ground Surface Considering Linear and Nonlinear Behaviour for the Soil
نویسندگان [English]
- M. Hassan Baziar 1
- M. Rabeti Moghadam 1
چکیده [English]
In this paper, a numerical model was first verified against dynamic centrifuge tests results performed on an
underground subway tunnel and then, the effect of underground structure on peak ground acceleration (PGA) at the ground
surface investigated considering linear and nonlinear behavior for the soil. The results show that in the range of natural
frequency of the system, nonlinear model shows deamplification of PGA with respected to the freefield. Whereas, linear model
shows opposite trend. Out of the range of natural frequency of the system, linear and nonlinear models predict same results and for both model, underground tunnel resulted in amplification of low frequencies and deamplification of high frequencies with
respected to the freefield.
کلیدواژه‌ها [English]
- Underground structure
- freefield
- Peak Ground Acceleration (PGA)
- linear and nonlinear behavior of soil
- parametric study
- FLAC 2D software
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