Effects of hooked-collar on the local scour around a lenticular bridge pier  

作　　者：Rashid Farooq Amir Hossein Azimi Muhammad Atiq Ur Rehman Tariq Afzal Ahmed 

机构地区：[1]Department of Civil Engineering,International Islamic University,Islamabad 44000,Pakistan [2]Department of Civil Engineering,Lakehead University,Thunder Bay,ON P7B 5E1,Canada [3]College of Engineering and Science,Victoria University,P.O.Box 14428,Melbourne,VIC 8001,Australia [4]Department of Civil Engineering,University of Engineering and Technology,Taxila 47080,Pakistan [5]James Watt School of Engineering,University of Glasgow,Glasgow G128QQ,United Kingdom

出　　处：《International Journal of Sediment Research》2023年第1期1-11,共11页国际泥沙研究（英文版）

基　　金：supported by the NSERC Discovery grant No.421785.

摘　　要：This paper presents the results of comprehensive laboratory experiments to investigate the effects of hooked-collar on the scour development around a vertical pier with a lenticular cross section.The flow around the pier was uniform,steady,and under the clear-water condition.The axial scour profiles for cases without and with a lenticular hooked-collar were measured and the effects of hooked-collar dimensions and elevation from the bed were examined.To compute the efficiency of hooked-collar for scour prevention,the results of local scour for a bridge pier without a collar and a bridge pier with a plain collar,without a hooked wall,were used as benchmark data sets.A wide range of hooked-collar geometries such as the ratio of collar width to the pier width,W_(c)/W_(p),ranging from 1.5 to 3.5,the ratio of hooked-collar wall height to the pier width,Hc/W_(p),ranging from 0.15 to 0.6,and the ratio of collar elevation to the pier width,E_(c)/W_(p),of
0.5,0,and 0.5 were tested.The experimental results indicated that the equilibrium scour depth decreased with the ratio of hooked-collar to the pier width whenW_(c) is twice the pier width,W_(p).For W_(c)/W_(p)>2,the scour depth was similar to the tests with an infinitely large pier width.In addition,the scour depth consistently reduced as the hooked-collar wall height,H_(c),to the pier width,W_(p),approached 0.3.The highest scour reduction efficiency was achieved when the hooked-collar being placed on the bed surface.Empirical models were developed for prediction of maximum scour depth near the lenticular bridge pier with a modified collar.The results showed that the volume of scour hole around a lenticular pier increased non-linearly with the maximum scour depth and it was independent of the hooked-collar geometry.

关 键 词：Local scour EROSION COLLAR Hooked-collar Lenticular pier Scour countermeasure Steady flow 

分 类 号：U442.32[建筑科学—桥梁与隧道工程]