الفهرس | Only 14 pages are availabe for public view |
Abstract Local scour around bridge piers is one of the main causes of bridge failure all over the world. Experimental and hydraulic models were carried out to investigate three types of scour reduction methods around a single pier, called slots, sacrificial piles and upstream curved face. These types of countermeasures were studied in this research alone and combination of them to achieve the minimum scour depth. The results revealed that slots, in general, have more influence in reducing scour depth than upstream curved face. The straight-slot acted better than other tested slots, with a reduction in the scour depths of about 31%. On the other hand, the upstream curved face and straight slot together appeared to be the most effective in reducing the scour around the bridge pier, with a 36% reduction in the scour depth downstream of the pier. When using sacrificial piles with upstream curved face and straight slot, the minimum scour amongst all the arrangement with a 53% reduction in the scour depth downstream of the pier was achieved. Then Statistical Package for the Social Sciences (SPSS) program was used to generate relations of different types of piers used in this research. The results showed values of Reynolds number Re and Reynolds pier number Rep cannot be neglected and have influence effects on the scour phenomenon. Empirical equations and charts were established to get relative scour depth as a function of both Froude number (Fr) only, Froude number (Fr) with Reynolds number (Re), and finally between relative scour depth and Froude number with Reynolds pier number (Rep). |