نوع مقاله : مقاله پژوهشی
نویسندگان
1 1-دانش‌آموخته کارشناسی ارشد سازه‌های آبی، دانشگاه فردوسی مشهد
2 2-استاد گروه سازه‌های آبی، دانشکده مهندسی علوم آب دانشگاه شهید چمران اهواز
3 3-استادیار،گروه سازه‌های آبی، دانشگاه فردوسی مشهد
4 دانش‌آموخته دکتری سازه‌های آبی، دانشگاه شهیدچمران اهواز
چکیده
کلیدواژه‌ها
عنوان مقاله [English]
نویسندگان [English]
Protecting the outer banks of rivers bend which are usually under severe toe erosion and reducing the area of Sedimentation in inner bank are among the major goals of rivers restoration. Such goals are achieved by many techniques that have been developed over the past decades. In this study in relation with sediment management an attempt has been made to experimentally investigate in a 90 degree mild bend the use of a new measure, namely trapezoidal vane shape (TVS) attached to the bank and compare the results with the common measure results, rectangular vane shape(RVS). Both TVS and RVS were attached to the outer bank where considerable toe scour was expected (at the angle of 70 ° from the beginning of the bend). Vanes were installed at angles of 23, 30, 40, 60 and 70 relative to Upstream external bank. The results showed that the scour hole was formed only around the nose of TVS when the vane installation angle relative to Upstream external bank was less than 40 degrees. The scour was extended up to the outer bank for the vane installation angles (relative to Upstream external bank) more than 40 degrees. For the RVS, the scour dimensions were extended up to the outer bank for all vane angles. The maximum scour hole for the RVS was more than, up to 65%, than for the TVS in all tests. Sediment which moved from the score hole was usually deposited downstream of the vane and created a point bar. This developed point bar for TVS was closer to the outer bank than RVS.
کلیدواژه‌ها [English]
)