تاثیر پی چند لایه بر روی پارامترهای جریان نشت از زیر سدهای انحرافی

نوع مقاله : مقاله پژوهشی

نویسندگان

1 'گروه آب و خاک، انشکده کشاورزی، دانشگاه صنعتی شاهرود، شاهرود، ایران

2 گروه آب و خاک، دانشکده کشاورزی دانشگاه صنعتی شاهرود، شاهرود، ایران

3 گروه آب و خاک، دانشکده کشاورزی، دانشگاه صنعتی شاهرود، شاهرود، ایران

چکیده

در این تحقیق پارامترهای نشت در پی مطبق  دو لایه و سه لایه  یک سد انحرافی به صورت آزمایشگاهی بررسی شد. نتایج نشان داد که با افزایش هد بالادست مقدار دبی خروجی افزایش می­یابد. روند افزایش برای دانه­بندیd50= 0.6 mm   وd50= 1.2 mm  میلیمتر مشابه و محدوه تغییرات زیاد بوده اما برای دانه­بندیd50= 0.2 mm  میلیمتر محدوه تغییرات دبی کم است. برای پی­های دو لایه بهترین عملکرد در کنترل جوشش، آرایش  d50= 0.2 mmو d50=1.2 mm  و با هد بالادست 465 میلیمتر بود. همچنین آرایش d50= 0.6 mm  و d50= 0.2 mm  حداقل دبی نشت را بدون حضور پرده آب­بند در حدود 266/0میلی­لیتر بر ثانیه داشت. در حضور پرده آب­بند نیز بهترین عملکرد در کنترل دبی نشت آرایشd50= 0.6 mm, d50=0.2 mm   بود و دبی نشت در حدود 066/0 میلی­لیتر بر ثانیه به دست آمد. در کنترل گرادیان هیدرولیکی، در حالت بدون پرده آب­بند و با پرده آب­بند بهترین عملکرد به ترتیب مربوط به آرایشd50= 1.2 mm, d50= 0.6 mm  و d50= 0.6 mm, d50= 0.2 mm به ازای هد بالادست 410 میلیمتر در حدود 002/0 و 0011/0 بود. در آرایش سه لایه، آرایش­های d50= 0.2 mm,   d50= 0.6 mm, d50=1.2 mm و  d50=1.2 mm, d50= 0.6 mm, d50= 0.2 mm بهترین عملکرد را در کنترل پدیده جوشش داشتند به­طوری­که به ترتیب به ازای هد بالادست 490 میلیمتر و 480 میلیمتر اتفاق افتاد. بهترین آرایش به لحاظ کنترل دبی نشت بدون حضور پرده آب­بند و با پرده آب­بند آرایش d50= 0.2 mm, d50= 0.6 mm, d50=1.2 mm و d50= 0.2 mm, d50=1.2 mm, d50= 0.6 mm بود که مقدار دبی نشت به ترتیب در حدود 533/0 و 433/0 میلی­لیتر بر ثانیه به دست آمد. بررسی نتایج پی­ها نشان داد که استفاده از پی­های چند لایه می­تواند راهکاری موثر در کاهش گرادیان هیدرولیکی، کنترل پدیده جوشش و دبی نشت باشد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

The Effect of Multi-layer Foundation on Seepage Flow Parameters under the Diversion Dams

نویسندگان [English]

  • Mohsen Karimi Pouch 1
  • Khalil Azhdary 2
  • seyyed Hossein Hosseini 3
  • Roozbeh Moazenzadeh 3
  • hassan Goli 3
1 ِDepartment of Soil and Water,Faculty of Agriculture, Shahrood University of Technology, Shahrood, Iran
2 Department of Soil and Water,Faculty of Agriculture, Shahrood University of Technology, Shahrood, Iran
3 Department of Soil and Water and, Faculty of Agriculture, Shahrood University of technology, Shahrood, Iran.
چکیده [English]

 In this study seepage factors in two-layered and three-layered foundation of a diversion dam was investigated experimentally. Results showed by increasing the upstream head, outlet discharge increases. The trend of discharge increase was similar and the variations range was high for d50=0.6 mm and d50=1.25 mm, but the range of discharge variations was low for d50=0.24 mm. For two-layered foundations, the arrangement of D50=0.2 mm and D50=1.2 mm with 465mm upstream head was the best performance for piping control. Also the arrangement of D50=0.6 and D50=0.2 mm without cutoff had the least seepage discharge (about 0.266 mlit/s). In the presence of cutoff, the best performance for piping control was obtained for the arrangement of D50=0.6-0.2 mm and the seepage discharge was about 0.066 mlit/s. The arrangements of D50=1.2 mm, D50=0.6 mm without cutoff and D50=0.6 mm, D50=0.2 mm with cutoff had the best performance for hydraulic gradient control which were about 0.002 and 0.0011 for 410 mm upstream head, respectively. For three-layered foundation, the arrangements of D50=0.2 mm, D50=0.6 mm, D50= 1.2 mm and D50=1.2 mm, D50=0.6 mm, D50=0.2 mm showed the best performance for piping control so that piping was happened in 490 and 480mm upstream heads, respectively. The best arrangements in terms of  seepage discharge control, without and with cutoff were respectively (D50=0.2 mm, D50=0.6 mm, D50= 1.2 mm) and (D50=0.2 mm, D50=1.2 mm, D50=0.6 mm) with 410mm upstream head, in which the seepage discharges were obtained about 0.533 and 0.433 mlit/s, respectively. The results of this study showed that the multi-layered foundations could be considered as an effective alternative in reduction of outlet gradient and control of piping and seepage discharge.

کلیدواژه‌ها [English]

  • Hydraulic potential
  • Cut off
  • Two-layered and three-layered foundation
  • Seepage discharge
  • Hydraulic gradient
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