Abstract: The situations of local erosion in riverbed around bridge piers have many project．Due to its complexit，studies on it have been condueted in a semi-empirical and semi—theoretical ways．Though the experimentation．we observe bridge’s local score and the movement of the water．By experimentation，we find that movement of the water is similitude between new type bridge pire and single bridge prie．When the distance of two bridges is closer，the upriver bridge will protect the downriver bridge．

Key words: bridge prie, local scour, experimental investigation：the maximum scour depth

摘要： 由异形桥墩引起的局部冲刷，因其成因较复杂，以前研究大都采用了半理论半经验的方法．笔者通过对异形 桥墩的单墩及组合试验，对其冲刷形态和冲刷坑深度进行系列研究和比较，结果发现，桥墩冲刷形态与原墩相近， 且当两墩距离较近时，上游桥墩对下游桥墩的冲刷有一定的保护作用．

关键词: 桥墩, 局部冲刷, 试验研究, 最大冲刷深度