【摘要】 根据水工模型试验观测和大量试验数据及图象资料，应用流体力学原理对桥台及丁坝绕流的流场和旋涡体系进行了分析，阐明了桥台及丁坝冲刷的旋涡机理，发现并论证了决定冲刷的关键因素是天然河槽水力因素（弗汝德数Ｆｒ）和路堤及丁坝阻水因素（阻水面积Ａｚ或阻水长度ＬＤ）。根据本文和近年来国外发表的长历时平衡冲刷数据，应用图解和回归分析，建立了桥台及丁坝平衡冲刷深度公式。公式简明易用，并得到汛后工程实测资料验证。更多还原

【Abstract】 Based on the hydraulic experiments and fluid mechanics, the flow structure schemes around abutments and spur dikes are described and the vortex systems which lead to scour are studied. It shows that the crucial factors of scour are main hydraulic conditions of rivers and the hindrance for flow by embankments or spur dikes. According to the data of equilibrium scour experiments, the estimating equations for scour depth of abutments and spur dikes are established and applied. The equations are verified by measured data of practical engineerings.更多还原