中文摘要：

以现有半圆形桥台冲刷试验研究报道为基础，通过计算流体动力学（CFD）方法数值模拟冲刷发展过程中桥台周围复杂的三维流场及变化，依次确定河床切应力、泥沙运动状况和输沙率，基于计算区域边界的动态变化和相应的网格跟踪，通过连续的CFD模拟和河床泥沙输运计算，获得桥台周围冲刷坑的发展和最大冲刷坑形态。平衡冲刷状态下桥台周围水流速度场分布、河床切应力分布，以及冲刷坑形态等与试验研究结果的较好吻合，说明基于CFD模拟和泥沙运动理论的方法可用来研究桥台局部冲刷问题。

英文摘要：

Based on the local scour tests around semicircular bridge abutments, an approach for simulating complex three-dimensional flow field around bridge abutments due to local scouring was proposed. By using this method, the transient shear-stress on riverbed, sediment movement and sediment transport rate were determined, respectively. The evolution and shape of scoured riverbed with a dynamic change of computational boundaries were obtained by employing an adaptive mesh system for riverbed. The continuous CFD simulation and calculation on sediment transport is helpful to the prediction of the scour pit pattern and maximum depth around bridge abutment. The good agreement on development of scour pits between the present study and test results may validate the reasonableness of proposed CFD method.