تحلیل تراوش در شرایط افزایش ظرفیت مخزن با بالا بردن تراز سرریز (مطالعه موردی: سد خاکی کمال صالح)

نوع مقاله : مقاله پژوهشی

نویسندگان

1 مهندسی عمران، ژئوتکنیک. دانشگاه اراک

2 عضو هیئت علمی گروه عمران- دانشکده فنی و مهندسی- دانشگاه اراک

3 معاونت طرح و توسعه شرکت سهامی آب منطقه‌ای مرکزی

چکیده

تراوش یکی از دلایل اصلی تهدید پایداری سدهای خاکی است که می‌­تواند سازه سد را تضعیف و سبب جوشش، شسته­ شدن مصالح درون بدنه یا پی سد و نهایتا تخریب آن گردد. در این تحقیق تحلیل تراوش سد خاکی کمال­ صالح با استفاده از نرم افزار Seep/W در سه شرایط تراوش پایدار، افت سریع و پایان ساخت برای وضعیت فعلی سد و همچنین برای افزایش تراز سرریز در شرایط تراوش دائمی انجام شد. تأثیر افزایش ارتفاع سرریز بر روی میزان تراوش از بدنه و پی سد، گرادیان هیدرولیکی و سطح فریاتیک بررسی گردید. به منظور بررسی رفتار سد در شرایط افزایش ظرفیت مخزن، تحلیل تراوش برای تراز فعلی سرریز و افزایش تراز در گام‌­های یک متری انجام شد. بر اساس نتایج نرم‌­افزار، سد در برابر تراوش برای تراز فعلی سرریز در هر سه شرایط پایدار بود و ضرایب اطمینان لازم را تأمین می­‌کرد. در شرایط افزایش تراز سرریز، مقدار تراوش و گرادیان هیدرولیکی خروجی افزایش و ضریب اطمینان در برابر جوشش کاهش ­یافت به طوری که با افزایش تراز سرریز سد به میزان 4 متر، مقدار تراوش عبوری از بدنه و پی سد 85 درصد و ضریب اطمینان در برابر جوشش4/5 درصد کاهش یافت اما در تمام این شرایط سد در برابر جوشش پایدار بود. در ارتفاع فعلی سرریز و در شرایط افزایش ارتفاع، تطابق مناسبی بین خط فریاتیک حاصل از روش­ تحلیلی منتخب و محاسباتی وجود داشت. بیشترین تطابق در پوسته بالادست و هسته و بیشترین اختلاف در محل برخورد خط فریاتیک با دامنه پایین ­دست سد دیده شد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Analysis of seepage in the conditions of increased reservoir capacity by raising the spillway level (Case study: Kamal-Saleh earth dam)

نویسندگان [English]

  • sanaz aalimohammadi piranshahi 1
  • Nazanin Shahkarami 2
  • Hosein Asadi 3
1 Arak university
2 Department of Civil, Faculty of Engineering, Arak University, Arak, Iran
3 Deputy of Planning and Development, Regional Water Company of Markazi, Arak, Iran
چکیده [English]

Seepage is one of the main threats to the stability of the earth dam, which can weaken the dam structure and cause piping, washing the earth dam materials inside the body or foundation and eventually its failure. In this study, seepage analysis of Kamal-Saleh earth dam was performed using Seep/W software under three conditions of steady-state, rapid drawdown and end of construction for the current dam as well as for increased spillway level in stable seepage condition. The effect of increasing the height of spillway on the seepage rate inside the body and foundation of the dam, hydraulic gradient and phreatic surface was investigated. To evaluate the dam behavior in the conditions of increasing reservoir capacity, seepage analysis was performed for the current level and increased levels of spillway by one-meter intervals. According to the software results, the dam was safe against seepage in the current spillway level in every three conditions and provided the required factors of safety. In the conditions of increased spillway level, the amounts of seepage and the hydraulic gradients increased and the factors of safety against boiling decreased in a way that by increasing the dam spillway level equal to 4 meters, the seepage through the dam body and foundation increased 85% and the safety factor against boiling decreased 4.5% but in all these conditions, the dam was safe against boiling. In the current and increased levels of the spillway, there are the appropriate similarity of phreatic lines produced by the selected analytical method and Seep/W.  The most similarity is seen in the upstream shell and core and the maximum difference is seen in the phreatic line intersection with the downstream slope of the dam.

کلیدواژه‌ها [English]

  • Seepage analysis
  • Kamal-Saleh earth dam
  • phreatic surface
  • storage capacity increase
  • seep/w
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