ارزیابی و مقایسه عملکرد شکاف و طوقه در کاهش آبشستگی در اطراف تکیه گاه های پل

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشکده عمران، دانشگاه آزاد اسلامی، واحد علوم و تحقیقات تهران

2 مدیر گروه عمران-علوم تحقیقات

3 گروه سازه های آبی، دانشکده کشاورزی، دانشگاه آزاد اسلامی واحد اهواز، ایران

چکیده

تخریب پل ناشی از پدیده آبشستگی موضعی در اطراف پایه ها یا تکیه گاه‌های آن یک پدیده رایج می‌باشد. به همین منظور می‌بایست با استفاده از روش‌هایی از تخریب این سازه‌ها جلوگیری کرد. از جمله ابزارهایی که بدین منظور می‌توان استفاده کرد، شکاف و طوقه می‌باشند. لذا در این پژوهش با انجام 49 آزمایش به بررسی و مقایسه عملکرد این دو ابزار با رویکردهای جدید در اطراف تکیه‌گاه‌های پل با استفاده از مدل آزمایشگاهی در شرایط جریان‌های مختلف خواهیم پرداخت. نتایج نشان می‌دهد که مؤثرترین مدل شکاف علیرغم اینکه می تواند ابعاد و عمق چاله آبشستگی را به میزان 61 درصد کاهش دهد، ولیکن قادر به تعویق انداختن زمان شروع پدیده آبشستگی و دور کردن چاله آبشستگی از اطراف تکیه گاه نمی‌باشد. در صورتی که در مؤثرترین طوقه و بیشترین عدد فرود، زمان رسیدن چاله آبشستگی به نقطه مبناء بعد از سپری شدن 120 دقیقه از شروع آزمایش می‌باشد. در این مدل طوقه، ماکزیمم ّبشستگی در نقطه مبناء و عمق چاله آبشستگی به نقطه دورتری از تکیه گاه منتقل شده و درصد کاهش عمق چاله آ بستر فرسایش پذیر به ترتیب 96 و 56 درصد می‌باشد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Evaluation and Comparison of the Slots and Collars Performance in Reducing Scouring around Bridge Abutments

نویسندگان [English]

  • mahdi osrush 1
  • seyed abbas hosseini 2
  • Amir abbas Kamanbedast 3
1 department of civil engineering, science and research branch, Islamic Azad university
2 Department of civil engineering, Science and research branch, Islamic azad University, Tehran , Iran
3 agricultural department, Islamic azad University, Ahvaz Branch
چکیده [English]

The bridge failure caused by the local scouring phenomenon around its piers or abutments is a common phenomenon. Therefore, some methods should be used to prevent the destruction of these structures. Slots and collars are among the tools that can be used for this purpose. Therefore, by conducting 49 tests in this research, we will examine and compare the performance of these two tools with new approaches around bridge abutments using an experimental model in different flow conditions. The results show that although the most effective slot model can reduce the dimensions and depth of scour hole by 61%, it cannot postpone the start of the scouring phenomenon and take the scour hole away from the abutment surroundings. However, for the most effective collar and highest Froude number, the scour hole reaches the base point after 120 minutes from the start of the test. In this collar model, the maximum depth of scour hole is shifted to a more distant point from the abutment, and the percentage of reduction in the depth of scour hole at the base point and erodible bed is 96% and 56%, respectively.

کلیدواژه‌ها [English]

  • bridge abutment
  • local scouring
  • Slot
  • collar
  • erodible bed
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