مدلسازی کامل سه بعدی حفر تونل و نصب پوشش با تاکید بر حفاری مرحله‌ای، مقایسه تحلیل سه بعدی با دوبعدی

نوع مقاله : مقاله پژوهشی

نویسندگان

گروه عمران، دانشکده فنی، دانشگاه زنجان، زنجان، ایران

چکیده

در این مقاله به مدل‌سازی سه‌بعدی و کامل تونل با در نظرگرفتن حفاری و نصب پوشش به صورت گام به گام پرداخته می‌شود. مدل‌سازی کامل سه‌بعدی تونل با روش اجزا محدود می‌تواند تا حد بسیار مطلوبی نشان‌دهنده رفتار طولی و عرضی زمین در مقابل پیشرفت مراحل حفر و نصب پوشش باشد. با مقایسه نشست طولی بدست آمده از تحلیل عددی با روابط تجربی ارائه شده، تطابق خوبی بین نتایج مشاهده شد. همچنین دیده شد که اثر شرط مرزی ابتدای مدل تا 5 برابر قطر تونل وجود دارد و از این طول به بعد نشست به حالت پایدار و بیشینه خود می‌رسد. با افزایش عمق تونل نشست سطحی زمین در قبل از سینه کار کمتر و بعد از سینه کار بیشتر می‌گردد. مطابق با دیگر نتایج بدست آمده، پروفیل‌های طولی نشست حاصل از عمق‌های مختلف تونل، در محل سینه کار یکدیگر را قطع می‌کنند، یعنی نشست سطحی زمین در محل سینه کار برای تونل‌های با عمق مختلف یکسان می‌شود. در بخش دیگر این مقاله پروفیل عرضی بدست آمده از تحلیل دوبعدی با پروفیل متناظرش از تحلیل سه‌بعدی مقایسه می‌گردد، با تطابق سطح زیر نمودار این دو پروفیل، می‌توان به پارامتر درصد آزاد سازی تنش که یکی از پارامترهای کلیدی در تحلیل‌های دوبعدی است، رسید.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Full 3D Modeling of Tunnel Excavation and Lining with Emphasis on Sequence Excavation,Comparison of 3D and 2D Analysis

نویسندگان [English]

  • A. Lakirouhani
  • S. Jolfaei
Department Civil Engineering, University of Zanjan, Zanjan, Iran
چکیده [English]

In this paper 3D and full tunnel modeling with considering step by step excavation and installation of lining, will be discussed. Full 3D modeling of tunnel by finite element method (FEM) can be ideally represents the behavior of longitudinal and transverse ground settlement by progress of excavation and installation of lining. Results of numerical analysis showed good agreement with empirical formulations for longitudinal settlement. It is also seen that the effect of boundary condition of the model, there are up to five times the diameter of the tunnel and then reaches its maximum and steady-state condition. With increasing the tunnel depth, ground surface settlement decreases before the tunnel face and increases after the tunnel face. Also according to the results, settlement longitudinal curves of different depths intersect in the tunnel face, which means ground surface settlements in the tunnel face are the same for different depths. In the other section of the paper transverse settlement curve obtained by 2D analysis compared with the corresponding trough from 3D analysis, by comparing these two profiles area, can be reached to the stress release factor, that is one of the key parameters in the 2D analysis.

کلیدواژه‌ها [English]

  • 3D Analysis of Tunnel
  • Longitudinal Settlement Trough
  • Stress Release Factor
  • 2D Analysis
  • Sequence Excavation
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