为探讨桥墩上设置开孔对墩后水流结构的影响,采用粒子图像测试技术(PIV)对矩形开孔桥墩墩后的水平面和立面流场进行了测量,并对墩后的水流结构进行了分析.结果表明:矩形开孔桥墩能够改变开孔位置所在水深处尾流的运动规律,贯穿方孔的高速水流与墩侧绕流以及墩后低速区水流形成强烈的剪切作用,抑制了大尺度旋涡的发展与运动,并且切断了墩后底部水流的上升运动轨迹;墩后瞬时流场存在周期性的运动规律,具有高度间歇特性.%The Particle Image Velocimetry(PIV) technique is applied to explore the flow structures behind a hollow bridge pier. Hydrodynamic characteristics of the flow field past the pier with a rectangular hollow slot are examined in both horizontal and vertical planes. The result shows that the motion of the wake flow at the height of the slot can be changed. The development and movement of large-scale vortex is restrained and the upward motion trajectory of the bottom flow behind the pier is cut off by the strong shear effect that is generated due to the interaction between the high-speed flow pass through the hole and the low-speed flow in the lateral and back region of the pier. Characteristics of periodicity and high intermittency exist in the instantaneous flow field behind the pier.
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