بررسی اندرکنش پی‌های سطحی و گسلش شیب‌لغز با استفاده از مدل‌سازی سانتریفیوژ

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشکده مهندسی عمران، پردیس دانشکده های فنی، دانشگاه تهران، تهران، ایران

2 دانشکده مهندسی عمران، دانشگاه صنعتی نوشیروانی بابل، بابل، ایران

چکیده

جابه‌جایی ناشی از گسل‏ها می‏تواند سازه‏های موجود در امتداد محل بیرون‏زدگی آنها را تحت تأثیر قرار دهد و سطوح مختلف آسیب را در ساختمان‌ها ایجاد کند. در این زمینه، اندرکنش انواع مختلف پی اعم از سطحی، مدفون و شمعی، در مواجهه با این پدیده مورد مطالعه قرار گرفته‌اند. در این تحقیق، به‌منظور بررسی تأثیر موقعیت قرارگیری پی و نوع مکانیسم گسل بر روی اندرکنش گسل شیب‏لغز و پی‏های سطحی، تعدادی آزمایش سانتریفیوژ با لحاظ نمودن اثر سینماتیکی پی، انجام شده است. تغییر موقعیت پی از روی فرودیواره به فرادیواره، در برخورد با گسلش معکوس، موجب افزایش دوران و جابه‌جایی پی گردید و مکانیسم اندرکنش آن با گسیختگی گسل، دست‏خوش تغییر شد. ضمن حفظ موقعیت یکسان برای قرارگیری پی نسبت به بیرون‏زدگی گسیختگی گسل در شرایط میدان آزاد، با تغییر مکانیسم گسلش از معکوس به نرمال، مشخص شد که در گسلش نرمال، پی و روسازه سریع‏تر دچار آسیب می‏شوند. نتایج نشان می‌دهند که علاوه بر موقعیت پی، میزان جابه‌جایی گسل نیز در نوع مکانیسم خرابی پی تأثیر قابل‌توجهی دارد. همچنین، با توجه به نقش روسازه در سطح خرابی وارده به روسازه و پی، مدل‌سازی روسازه تأثیر قابل‌توجهی بر روی مکانیسم‌های اندرکنشی پی و گسلش نداشته است.

کلیدواژه‌ها


عنوان مقاله [English]

Investigation on the Interaction of Shallow Foundations and Dip-Slip Faulting Using Centrifuge Modeling

نویسندگان [English]

  • Vahid Sadra 1
  • Abbas Ghalandarzadeh 1
  • Mehdi Ashtiani 2
1 School of Civil Engineering, College of Engineering, University of Tehran, Tehran, Iran
2 Faculty of Civil Engineering, Babol Noshirvani University of Technology, Babol, Iran
چکیده [English]

Fault displacement can affect structures along their outcropping on the ground surface and cause varying levels of damage to buildings. In this regard, the interaction of different types of foundations, including shallow, buried and pile ones, in the interaction with this phenomenon have been studied. In this study, a series of centrifuge tests have been conducted considering the kinematic effect of the foundation in order to investigate the effect of foundation location and type of fault mechanism on the interaction of dip-slip faults and shallow foundations. The dip-slip fault rupture at a dip angle of 75° propagates in a moderately dense sand layer and interplays with the shallow foundation. A summary of conclusions is as follows:
- For the reverse fault, the formation of tension cracks on the ground surface is due to the soil moisture and the apparent cohesion of the wet sand. Also, the fault-zone width is greater in wet sand than dry sand due to the formation of tension cracks. Therefore, these cracks should be considered in specifying the width of the set-back zones.
- For the reverse fault, changing the position of the foundation from the foot wall to the hanging wall increased the rotation and displacement of the foundation, and the interaction mechanism was changed. The behavior of foundation and the development of rupture mechanisms are fully dependent on the location of the foundation relative to the fault rupture and the magnitude of the fault offset.
- The formation of a graben due to normal faulting is one of the results of this study.
- By changing the fault mechanism from reverse to normal, it was found that the foundation and superstructure are damaged at smaller fault-induced dislocation. In a normal fault, the foundation will experience rotation for small amounts of the fault displacement because of the nature of stress in normal faulting and the weakness of the soil in tension.
- The superstructure did not have a significant effect on the interaction mechanisms of the foundation and the fault, but it certainly had an effect on the foundation rotation.

کلیدواژه‌ها [English]

  • Centrifuge Modeling
  • Dip-Slip Faulting
  • Shallow Foundation
  • Kinematic Effect
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