بررسی تأثیر ابعاد پدستال بتنی بر کاهش آسیب ‏پذیری پی‏ های مجاور مستقر بر ماسه اشباع بابلسر با مدل‌سازی فیزیکی

نوع مقاله: مقاله پژوهشی

نویسندگان

1 دانشجوی دکتری، گروه عمران، دانشگاه آزاد اسلامی، واحد نجف‌آباد

2 دانشیار، پژوهشکده مهندسی ژئوتکنیک، پژوهشگاه بین‌المللی زلزله‌شناسی و مهندسی زلزله، تهران

3 استادیار، گروه مهندسی عمران، واحد نجف آباد، دانشگاه آزاد اسلامی، نجف آباد، ایران

چکیده

دو پی در کنار هم، اغلب دارای رفتاری متفاوت از پی تک هستند. امروزه، با توجه به کمبود زمین و افزایش جمعیت، مخصوصاً در نوار ساحلی دریای خزر، احداث ساختمان‌ها در مجاورت هم، بدون در نظر گرفتن اثر متقابل پی‏ها، در حال افزایش است. این موضوع، زمانی دارای حساسیت بیشتری است که دو ساختمان هم‌جوار به‌صورت غیرهمزمان و با دو سربار متفاوت، بارگذاری شوند. به‌عبارت دیگر، ابتدا پی سبک یا قدیمی ساخته، و سپس پی سنگین در مجاورت پی سبک احداث می‌گردد. این موضوع، در مورد بنادر، که کانتینرها با شرایط نابرابر در کنار هم دپو می‌گردند، نیز صادق است. در این مطالعه، با استفاده از آزمایش مدل‌سازی کوچک‌مقیاس g1، به بررسی تأثیرات ابعاد پدستال‏های بتنی غیرمسلح بر بهسازی خاک ماسه‌ای سست اشباع، هنگامی‌که پدستال‏ها در خاک زیر پی سنگین یا جدید قرار می‌گیرند، بر پارامترهایی نظیر ظرفیت باربری پی سنگین، نشست و چرخش پی سبک، ناشی از هم‌جواری پی سنگین، پرداخته خواهد شد. نتایج این تحقیق حاکی از آن است که در یک قطر ثابت پدستال (D=5 cm)، با افزایش عمق (L) پدستال‏ها از 15 به 25 سانتی‌متر، به‌عنوان عامل بهسازی کننده خاک زیر پی جدید، میزان نشست و چرخش پی قدیمی ناشی از هم‌جواری پی سنگین در نرخ S/B=0 به­ترتیب 18 و 38 درصد کاهش می‌یابد. 

کلیدواژه‌ها


عنوان مقاله [English]

Evaluating the Effect of Concrete Pedestal on Reducing the Vulnerability of Adjacent Footings on Babolsar Saturated Sand Using Physical Model Tests

نویسندگان [English]

  • Siavash Salamatpoor 1
  • Yaser Jafarian 2
  • Alborz Hajiannia 3
1 Ph.D. Candidate, Department of Civil Engineering, Islamic Azad University, Najafabad Branch, I. R. Iran.
2 Associate Professor, Geotechnical Engineering Research Center, International Institute of Earthquake Engineering and Seismology, Tehran, I. R. Iran.
3 Department of Civil Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran.
چکیده [English]

Two adjacent footings behave often differently from a single footing. Nowadays, with the scarcity of suitable land for construction purposes and population growth in the coastal zone of Caspian Sea, construction without considering the interference of the footings is increasing. This issue has been further complicated due to the unequal and non-simultaneous loading of the adjacent footings. In other words, initially, the light or old footing has been constructed, and then the heavy or new footing will be constructed adjacent to the old footing. This is also true in ports where containers are stacked side by side. In this study, the influence of unreinforced concrete pedestals on improvement of saturated loose sandy soil is investigated through modeling the small-scale 1g tests. The main focus was on the load bearing capacity, settlement and tilt of the light footing nearby the heavy footing, when the pedestals are placed beneath the heavy footing. Results of this study illustrated that with fixed diameter pedestals (D=5 cm), increasing the pedestal length (L) from 15 to 25 cm, as refining factor of the soil underneath the heavy footing, led to 18 and 38 percent decrease in settlement and tilt of the light footing nearby the heavy one, respectively, when the S/B ratio was zero.

کلیدواژه‌ها [English]

  • Sand stabilization
  • Concrete pedestal
  • Bearing capacity
  • Settlement
  • Physical modeling
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