بررسی عملکرد و راندمان کابل در کنترل آبشستگی موضعی پایه‌های پل مستطیلی گردگوشه

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشگاه محقق اردبیلی، اردبیل، ایران.

2 دانشگاه آزاد اسلامی واحد استهبان، استهبان، ایران.

3 دانشکده کشاورزی، دانشگاه صنعتی اصفهان، اصفهان، ایران

چکیده

در این مطالعه، عملکرد و راندمان کابل در کنترل آبشستگی موضعی در اطراف پایه پل مستطیلی گردگوشه با زاویه برخورد متفاوت جریان بررسی شده است. همچنین از ۳ نوع پایه، مستطیلی گردگوشه بدون کابل، مستطیلی گردگوشه با کابل ۱۰% قطر پایه و زاویه پیچش کابل ۱5 درجه (نوع دوم) و مستطیلی گردگوشه با کابل ۱۵% قطر پایه و زاویه پیچش کابل ۱2 درجه (نوع سوم) تحت زوایای جریان صفر، ۵، ۱۰ و ۱۵ درجه آزمایش شده است. هدف از این تحقیق، پیچیدن کابل به دور پایه و تغییر در زاویه برخورد جریان جهت کاستن شدت حرکت جریان رو به پایین آب می ­باشد که پس از برخورد به پایه، گردابه­ های نعل‌اسبی کاهش یابد و سپس میزان تأثیر آن بر کاهش عمق آبشستگی نهایی اندازه ­گیری شود. در این آزمایش­ ها تأثیر زوایای جریان بر روی پایه نیز بررسی شد و پایه‌ی تحت زاویه صفر درجه در جهت جریان با پایه ­های نوع دوم و سوم موازی جهت جریان مقایسه شد. افزایش زاویه برخورد جریان به پایه باعث عریض­ تر شدن پایه و در نهایت افزایش قدرت گرداب نعل‌اسبی شد. پایه­ های تحت زاویه 15درجه با جهت جریان بیشترین عمق آبشستگی را داشته و تأثیر کابل در کاهش عمق آبشستگی برای این زاویه برای پایه ­های نوع دوم و سوم برابر 10 و 22 درصد نسبت به پایه نوع اول می­ باشد. همچنین در حالت تغییر زاویه برخورد جریان پایه نوع دوم تحت زاویه 5، 10 و 15 درجه بیشترین مقدار را به ترتیب  3، 21 و 37 درصد افزایش عمق نسبت به زاویه صفر درجه دارند.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Investigation of the Cable Performance and Efficiency in Controlling Local Scour of Rectangular Bridge Piers

نویسندگان [English]

  • salim abbasi 1
  • Masoud Abam 2
  • Manuchehr Heidarpour 3
1 M.Sc. Graduated of Civil -Hydraulic Structures., Faculty of Eng., University of Mohaghegh Ardabili, Ardabil, Iran
2 M.Sc., Graduated of Hydraulic Structure., Faculty of Eng., Islamic Azad University of Estahban branch, Fars, Iran
3 Professor, Dept. of Water Engineering., Agricultural College., Isfahan University of Technology, Isfahan, Iran
چکیده [English]

In this study, the performance and efficiency of cable in control of local scour around the pier of the rectangular bridge have been investigated by changing the flow collision angle. In this study, three types of piers, namely, (1) round corner rectangular without cables; (2) round corner rectangular with cable with 10 % of pier diameter with a 15-degree twist angle of cable (second type pier); and (3) round corner rectangular with cable with 15 % of pier diameter with a 12-degree twist angle of cable (third type pier), were used with four different flow collision angles, including 0, 5, 10, and 15 degrees. The purpose of this study is to wrap the cable around the pier and changing the flow collision angle from the downstream flow water and then its effect for the reduction of the depth of the final scour measure. In this experimental study, the effect of flow angles on the pier was investigated, so that the first type pier under zero degrees angle was compared with the second and third types parallel to the flow direction. The maximum scour depth in experiments was achieved at the 15-degree angle with the flow direction, and the effect of the cable in reducing the scour depth in this angle for type-2 and type-3 piers was 10% and 22%, respectively. Also, for type-2 piers, in experiments under 5, 10, and 15-degree angles with the flow direction, the scour depth was increased by 3%, 21%, and 37%.

کلیدواژه‌ها [English]

  • Bridge pier
  • Collision angle
  • Local scour
  • Twist of cable
  • Vortex horseshoe
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