颗粒粒径对泥石流形成影响的试验研究

Experimental Study on Particle Size Influence on Debris Flow Formation Type

为研究泥石流受土体颗粒粒径的影响,将细砂和中砂按不同质量比配置6组不同颗粒粒径的试验试样,进行泥石流室内模型试验.试验结果表明:颗粒粒径对泥石流的形成模式具有重要影响,随着细砂含量的增加,泥石流的形成模式从滑坡型破坏变为流滑型破坏.当细砂含量小于40%时,坡体分层块体下滑,发生滑坡型破坏;当细砂含量大于40%时,坡体整体快速下滑,发生流滑型破坏.分析中砂坡体泥石流形成过程中孔隙水压力变化规律,揭示了降雨作用下泥石流形成过程中水土作用关系.本文结果为泥石流研究提供理论参考价值.

Model test was carried out to study the influence of particle size on debris flow formation type . The fine sand and medium sand comprised 6 groups of different particle size test specimens in the ratio of differ-ent quality .The research manifested that particle size has great influence on debris flow formation type .With the increase of fine sand , the formation type of debris flow turned from sliding failure to fluidized flow failure .When fine sand content was lower than 40%, slope occured retrogressive sliding , sliding failure;when fine sand con-tent was more than 40%, the whole slope falled rapidly , fluidized flow failure .From the change regulation of pore water pressure in the process of sand slope debris flow , the interaction relationship between water and soil in the process of debris flow under rainfall was obtained .The results in this paper provide a theoretical reference value for the study on debris flow .