مطالعه عددی تغییر شکل‌های گودبرداری عمیق به روش ساخت از بالا ایرانی (مطالعه موردی پارکینگ نیایش)

نوع مقاله : مقاله پژوهشی

نویسندگان

1 گروه مهندسی عمران، دانشکده فنی و مهندسی، دانشگاه خوارزمی تهران، ایران

2 گروه مهندسی عمران، دانشگاه خوارزمی، تهران، ایران

چکیده

یکی از روش‌های نوین پایدارسازی گودهای عمیق، استفاده از روش ساخت از بالا است. در این روش ضمن کاهش زمان اجرا و کنترل تغییرشکل دیواره گود، شرایط لازم برای احداث سازه در فضاهای محدود و پرتردد شهری فراهم می‌شود. در این مقاله، روش نوین ساخت از بالا ایرانی معرفی شده است. به منظور ارزیابی این روش، تغییرشکل‌های افقی و قائم حاصل از روش ساخت از بالا ایرانی، با روش ساخت از بالا دیوار دیافراگمی و روش میخکوبی مقایسه می‌شود. روش ساخت از بالا دیوار دیافراگمی با ضخامت دیوار 0.45 متر، روش ساخت از بالا ایرانی با دو ضخامت متفاوت دیوار 0.45 و 0.65 متر و‌ روش میخکوبی در ترکیب با دیوار 0.45 متر، با استفاده از نرم‌افزار المان محدودMIDAS GTS NX  مورد مطالعه عددی قرار گرفته است. به عنوان مطالعه موردی پروژه پارکینگ طبقاتی نیایش در تهران با عمق گود 29 متر انتخاب شده است. نتایج حاصل از این تحقیق نشان می‌دهد که روش ساخت از بالا ایرانی در مقایسه با روش ساخت از بالا دیوار دیافراگمی 20 الی 25 درصد، تغییرشکل افقی کمتری دارد. روش میخکوبی سه تا چهار برابر، تغییرشکل بیشتری نسبت به هر دو نوع روش ساخت از بالا دارد و با افزایش عمق گود تفاوت آن‌ها بیشتر می‌شود. ضخامت بیشتر دیوار در روش ساخت از بالا ایرانی تأثیر ناچیزی بر روی تغییرشکل‌ها دارد و اثر آن را می‌توان نادیده گرفت. همچنین در روش ساخت از بالا ایرانی 10 الی 15 درصد نشست سطح زمین کمتر از روش ساخت از بالا دیوار دیافراگمی است. روش نوین بیان شده نشان می‌دهد که ساخت دیوار دیافراگم به صورت چندمرحله‌ای، می‌تواند کاهش تغییرشکل‌ها را در پی داشته باشد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Numerical Study of Deep Excavation Deformations by Iranian Top-Down Method (Case Study: Niayesh Parking)

نویسندگان [English]

  • Parham Tirzan 1
  • Ali Ghanbari 2
1 Department of Civil Engineering, Faculty of Engineering, Kharazmi University of Tehran, Iran
2 Department of Civil Engineering, University of Kharazmi, Tehran, Iran
چکیده [English]

One of the novel methods for stabilization of deep excavations is the use of top-down method. In this method, while reducing the execution time and controlling the deformation of the excavation wall, the necessary conditions for constructing structures in limited spaces or crowded urban areas are provided. In this paper, the Iranian top-down method is introduced. In order to evaluate this method, horizontal and vertical deformation of Iranian top-down is compared with diaphragm wall top-down method and nailing method. Diaphragm wall top-down with a wall thickness of 0.45 m, Iranian top - dawn with two different wall thicknesses of 0.45 and 0.65 m and  Nailed pile wall method with 0.45m thick wall, is studied numerically by using the finite element software MIDAS GTS NX. Niayesh parking lot in Tehran with a depth of 29 m is select for the case study. The results of this research show that Iranian top-down has a 20 - 25 percent lower horizontal deformation than the diaphragm wall top-down. Nailing method has three to four times more deformation compared to both types of top-downs and their difference increases by increasing the depth of excavation. The greater thickness of the wall in Iranian top-down has a negligible impact on the deformations and the effect can be ignored. Also, in Iranian top-down the ground surface settlement is 10 - 15 percent less than diaphragm wall top-down. The new method mentioned here shows that the construction of the diaphragm wall in a few steps can lead to reduction of deformations.

کلیدواژه‌ها [English]

  • Deep Excavation
  • Diaphragm wall top-down method
  • Iranian top-down method
  • Ground Settlement
  • Deformation of the pit wall
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