环翼式桥墩最优挡板形状试验

Experimental research on optimal shape of the baffle of ring-wing bridge piers

为研究环翼式桥墩的最优挡板形状,基于桥墩局部冲刷机理,进行了不同流量和不同环翼式挡板形状下的环翼式桥墩局部防冲刷水工模型试验。在环翼式挡板延伸长度为45 mm、位置在水深的1/3处,研究了不同流量、不同挡板形状的桥墩最大冲刷深度、三维时均流速及纵向和垂向紊动强度。结果表明:与无挡板相比,挡板前端和尾端宽度都为45 mm时水流垂向流速减小程度最大;纵向、垂向紊动强度减小程度最大;最大冲刷深度可减小57.6%,防冲刷效果明显。

Based on the principle of local scour at bridge piers, a series of hydraulic model tests with different flow and different shapes of the baffle of ring-wing aiming to determine their optimal shape were performed. By doing so, the maximum scour depth of piers, the three-dimensional time average velocity, the lengthways, and the vertical turbulence intensity were studied considering the development lengths of the baffle of a ring-wing pier at 45 mm and the distance between baffle and riverbed at approximately 1/3 of the water depth. The results show that when compared with a scenario without baffles, the decreases of vertical flow velocities, the lengthways, and the vertical turbulence intensity are maximum. Additionally, the results show that the maximum scour depth could be reduced by 57.6% when both the front width and the tail width of baffle are 45mm.