Abstract: For further comprehension of the retrogressive erosion regulation in the landslide dam-leakage-period，an indoor flume experiment was formulated based on the Tangjiashan barrier lake. Combing with the test results，the longitudinal profile simulation was carried out. The conclusion was drawn that the initial scour morphology was in good compliance with the actual situations. The comparison analysis on the inflow and dam gradation influencing the scour velocity and accumulative erosion was also carried out. The conclusion was drawn that: retrogressive erosion velocity and accumulative erosion were positively correlated with the inflow，negatively correlated with the coarse content in dam; scour velocity decreased with time; the process of breach-forming was affected by inflow and dam gradation; the final accumulative erosions in various conditions differed a bit.

Key words: landslide dam, retrogressive erosion, longitudinal profile, scour velocity, accumulative erosion

摘要： 为了进一步认识堰塞湖泄流过程中的溯源冲刷规律，参考唐家山堰塞湖设计了室内水槽试验。结合试验结果进行纵剖面形态演变模拟，得到的冲刷初期形态与实际情况吻合较好。对比分析了入库流量和坝体级配对溯源冲刷速度和累计溯源冲刷量的影响。结果表明: 溯源冲刷速度和累计溯源冲刷量与入库流量正相关，与坝体粗沙含量反相关; 冲刷速度随着时间的推进而减小; 入库流量和坝体级配影响溃口形成的过程，总的累计溯源冲刷量在各种条件下相差不大。

关键词: 堰塞坝, 溯源冲刷, 纵剖面形态, 冲刷速度, 累计冲刷