بررسی آزمایشگاهی تاثیر آبشکن، صفحات مستغرق و آبپایه بر عمق آبشستگی در اطراف گروه پایه‌ها

نوع مقاله : مقاله پژوهشی

نویسندگان

1 استادیار، گروه مهندسی عمران، دانشکده فنی و مهندسی، دانشگاه مراغه، مراغه، ایران

2 استاد، گروه مهندسی عمران، دانشکده فنی و مهندسی، دانشگاه مراغه

3 دانشجوی کارشناسی ارشد، مهندسی عمران -آب و سازه‌های هیدرولیکی-دانشگاه مراغه

4 گروه عمران، فنی و مهندسی، دانشگاه مراغه، مراغه، ایران

چکیده

در این تحقیق اثر ارتفاع صفحات مستغرق با آرایش شبه مثلثی و آبشکن­ها با ارتفاع ثابت و آبپایه در دو ارتفاع متمایز بر روی آبشستگی گروه پایه پل­ها مورد بررسی قرار گرفته است. در این تحقیق تعداد 29 آزمایش با شرایط آزمایشگاهی یکسان در یک کانال مستطیلی به طولm  13، عرضm  2/1 و عمق m  8/0، با شیب طولی صفر مورد بررسی قرار گرفته است. حداکثر مقدار افزایش عمق آبشستگی ناشی از نصب آبشکنها 1/89 درصد و با نصب صفحات مستغرق، حداکثر کاهش عمق آبشستگی، با ارتفاع D44/0 ( Dقطر پایه) برابر با 3/79درصد نسبت به شاهد می­باشد. نصب آبپایه با ارتفاع D نسبت به صفحات مستغرق با ارتفاع D44/0 عملکرد بهتری داشته است به طوری که در پایه اول در عدد فرود 25/0، مقدار کاهش عمق آبشستگی 88 درصد بدست آمد. بعد طولی آبشستگی با نصب آبشکن در عدد فرود 15/0 به میزان 7/72 درصد افزایش یافته است و نصب صفحات مستغرق و آبپایه بعد طولی را کاهش داده­اند به­طوری­که مقدار کاهش بعد طولی آبپایه با ارتفاع D در عدد فرود 25/0 برابر 2/54 می­باشد.

کلیدواژه‌ها


عنوان مقاله [English]

Laboratory Study of the Effect of Sill, Submerged Vanes and Groyne on Scour Depth around the Piers Group

نویسندگان [English]

  • Mahdi Majedi Asl 1
  • Rasoul Daneshfaraz 2
  • Naser Salehi 3
  • Ehsan Aminvash 4
1 Assistant Professor, Department of Civil Engineering, Faculty of Engineering, University of Maragheh, Maragheh, Iran.
2 Professor , Department of Civil Engineering, Faculty of Engineering, University of Maragheh, Iran.
3 M.Sc.Student. Water and hydraulic structhures, Univ. of Maragheh, Iran
4 Civil Engineering. University of Maragheh
چکیده [English]

In this research, the effect of submerged vanes height with quasi-triangular arrangement and groyne with fixed height and foundation at two different heights on the scour of the base group of stairs has been investigated. In this paper, 29 experiments with the same laboratory conditions have been studied in a rectangular canal with dimension of 13 m in length, 1.2 m in width, 0.8 m in depth and with zero longitudinal slope. The maximum increase of scour depth due to the installation of groyne is 89.1% and with the installation of submerged vanes, the maximum reduction of scour depth with a height of 0.44 D (D is pier diameter) is equal to 79.3% compared to the control. The performance of 1D-height groyne was better than the 0.44D-height submerged vanes, as in the first base at Froude number of 0.25, the amount of scour depth reduction was 88%. The longitudinal dimension of scouring has been increased 72.7% by installing a sill at Froude number of 0.15. The installation of submerged vanes and the abutment have reduced the longitudinal dimension, as the reduction amount of abutment longitudinal dimension with 1D-height at Froude number of 0.25 was equal to 54.2.

کلیدواژه‌ها [English]

  • 1- Scour
  • 2- Submerged vane
  • 3- eppi
  • 4- piers group
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