بررسی آزمایشگاهی کارایی طوق نامتقارن مشبک در کاهش آبشستگی موضعی پیرامون پایه پل با مقطع دایره‌ایی

نویسندگان

1 دانشجوی دکتری سازه های آبی، دانشکده مهندسی علوم آب، دانشگاه شهید چمران اهواز

2 2- دکترای عمران آب، استاد دانشکده مهندسی علوم آب، دانشگاه شهید چمران اهواز

10.22034/ws.2021.12188

چکیده

تحقیقات نشان می‌دهند، از مؤثرترین عوامل تخریب پل‌ها، آبشستگی موضعی در محل پایه‌ها است. یکی از روش‌های کاهش آبشستگی اطراف پایه‌ها، نصب طوقه بر روی آن است. طوقه‌ها بستر را در مقابل جریان‌های گردابی اطراف پایه محافظت می‌کنند. در این تحقیق ضمن بررسی تأثیر طوق بعنوان یک سازه کنترل فرسایش پیرامون پایه پل، تأثیر شکل طوق نیز بر عملکرد آن مورد بررسی قرار گرفت. از این رو، نمودارهای کاربردی در این زمینه استخراج و مشخص گردید، که ابعاد طوقه بر عملکرد آن تأثیر بسزایی دارد. نتایج نشان داد با افزایش ابعاد طوقه عملکرد آن بهبود می‌یابد. با مقایسه دو نوع طوقه، مشخص شد، طوقه با ابعاد بیضوی عملکرد بهتری در کاهش آبشستگی نسبت به طوقه با ابعاد بیضوی دارد. طوقه‌های با ابعاد بزرگتر بدلیل اینکه مانع حرکت رسوبات ناشی از فعالیت گرداب برخاستگی در پائین‌دست پایه می‌شوند، عملکرد بهتری از خود نشان دادند. از سوی دیگر با کاهش زبری در سطوح طوقه از 40 درصد به 15 درصد، میزان کاهش آبشستگی از 39 درصد به 58 درصد نسبت به پایه بدون طوق افزایش می‌یابد.

کلیدواژه‌ها


عنوان مقاله [English]

Experimental Investigation of Unsymmetrical Netted Collar Performance on Local Scour Reduction around Bridge Pier with Circle Section

نویسندگان [English]

  • Narges Raeisi 1
  • Mahdi Ghomeshi 2
1 phd of Science Student, Faculty of Water Sceinces Engineering, Shahid Chamran university of Ahvaz
2 Professor Faculty of Water Sceinces Engineering , Shahid Chamran university of Ahvaz.
چکیده [English]

Researches show that one of the most effective factors on bridge destruction is bridge pier scour. That one of the methods used to reduce of scour around bridge piers is installing collar. The collars protect the river bed against vortex flow in the vicinity of the piers. In this research, the role of collar as a control structure of bridge pier scour was investigated along with the effect of its shape. Therefore, dimensions of collar were investigated on bridge pier scour reduction and application diagrams proposed. Results show that increasing dimensions of collars will increase the efficiency of performance comparing of both collars indicated, that collar with dimensions have better performance in reducing scour than collar . Larger collar does prevent sediment movement due to lift vortex in downstream of bridge pier and for this reason. On the other hand, with decreasing roughness at the surfaces collar from 40% to 50%, the reduction of scour increases from 39% to 58%.

کلیدواژه‌ها [English]

  • Elliptically
  • Local scour
  • Pier
  • Rough area
  • Unsymmetrical Collar
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