冰盖下串列桥墩局部冲刷及水流特性研究OA

To elucidate the local scour characteristics and evolutionary patterns of bridge piers under ice cover,a series of flume tests were conducted to investigate the combined effects of ice,water,and sand interactions around piers under ice-covered conditions on local scouring.The dominant factors influencing scour morphology were thereby identified.The test results show that the scouring of the local scour hole of the pier under the rough ice cover condition was the most significant,followed by the smooth ice cover condition,indicating that the influence of ice cover roughness on the scouring depth and range should not be neglected.The Reynolds number of the water flow has a predominant effect on the local depth of the scour hole,and plays a dominant role in controlling the development of the scour hole.The scour hole was slightly larger in the longitudinal range than in the transverse range,resulting in an elliptical shape,indicating that the scour hole development in the transverse direction lags behind the development in the longitudinal direction.The low-frequency pulsations in instantaneous velocity time series originate from large-scale vortices,while the high-frequency pulsations are determined by small-scale vortices.