动床条件下粘性泥石流沟道淤积实验研究

Experimental Study on Channel Deposition of Viscous Debris Flow over Erodible Beds

泥石流淤积是危害建筑物的主要方式之一。为了探讨动床条件下泥石流沟道淤积规律,开展了不同泥石流重度、不同沟床物质重度、不同沟道坡度以及不同泥石流总量共4组单次淤积实验和1组不同沟道坡度下的泥石流连续淤积实验。实验结果表明,单次淤积时,泥石流淤积厚度随着沟道坡度的增加而减小,随着泥石流重度的增大而增大,随泥石流总量的增大而增大,受沟床物质重度变化的影响较小;连续淤积时,随着沟道坡度的增加,第2次淤积相对于第1次淤积结果依次表现为完全淤积、冲淤交替以及完全冲刷,且冲刷始于沟道前缘,逐渐向后缘发展。在分析泥石流淤积厚度的影响因素基础上,通过回归分析建立了动床条件下粘性泥石流沟道淤积厚度的经验预测公式:H=0.005x+(1.63E-11)erc-0.003ln(sinθ)+0.22V-0.02。

Debris flow deposition is one of the main hazards for buildings. In order to explore the law of debris flow deposition over erodible beds, we carried out 4 groups single siltation experiment and 1 group successive siltation ex- periment. The single deposition experimental result shows that deposition thickness increases with the increase of channel slope debris, the increase of debris flow density and the increase of the total amount of debris flow. The bed material density has a small effect on the deposition thickness. By continuous sedimentation, along with the increase of channel slope,the second experiment in turn presented as complete cholestasis, half deposition and half erosion and scouring silting completely, and erosion began at the leading edge, gradually backward to edge of development. On the basis of analyzing of the factors of debris flow deposition thickness, this article established the prediction for- mula of viscous debris flow single siltation thickness through regression analysis ： H=0.005x＋（1.63E-11）erc-0.003ln（sinθ）＋0.22V-0.02.