泥石流排导槽槛后侵蚀实验研究

Experimental study of the erosion after debris flow drainage cannl ribs

通过排导槽室内实验,探究了泥石流重度分别为13、15、17、19 kN/m^3,坡度分别为7°、10°、12°、15°、17°,肋槛间距分别为40、50、60、70、80 cm的情况下排导槽肋槛后部冲刷坑的纵横剖面形态、最大冲刷深度及其变化规律.研究发现:排导槽槛后冲刷坑的深度随泥石流重度的增大而减少,随排导槽坡度的增加而增加,随肋槛间距的增大而增大,且冲刷坑深度随重度、沟床坡度、肋槛间距变化的关系分别为二项式关系、线性关系、对数关系.肋槛后部侵蚀坑纵剖面可分为槛后冲刷区、冲淤平衡区和槛前回淤区3个部分,侵蚀坑横剖面具有凹形横剖面、震荡型横剖面、平缓型横剖面3种形态.

In order to explore the law of debris flow deposition below the sills, a series of experiments were conducted. In the experiment, the bulk density of debris flow were 13, 15, 17, 19 kN/m^3, channel slope was 7 degrees, 10 degrees, 12 degrees, 15 degrees, 17 degrees, the threshold spacing were 40, 50, 60, 70, 80 cm. The results showed that the debris flow scour depth increased with the decrease in the density of debris flow, the increase in the trench slope, the increase in the distance between the ribs. The relationships between the scour depth and the bulk density, gully slope, rib spacing variation of threshold were of binomial, linear and logarithmic nature. The depth of rear vertical section erosion pit over-performed the middle on both sides, and the upstream was steeper than the downstream. The transverse section of the eroded pit has 3 forms： concave cross section, oscillating cross section and flat cross section.