粘性泥石流残留层与泥深的关系分析  

Relationship Between Depth and Residual Layer of Viscous Debris Flow

作　　者：吴积善[1] 张军[1] 程尊兰[1] 游勇[1] 刁惠芳[1] 

机构地区：[1]中国科学院水利部成都山地灾害与环境研究所,四川成都610041

出　　处：《山地学报》2003年第4期487-492,共6页Mountain Research

基　　金：国家自然科学基金资助项目(49971012)~~

摘　　要：粘性泥石流泥深的观测数据过去大部分不包含残留层厚度,认为当后继粘性泥石流通过残留层时,残留层是不动的,泥深从残留层表面起算。本文通过大量的泥石流原型观测和简易模型试验表明,当后继泥石流通过时,残留层除底部很薄的一层不动外,都是运动的,并有三种运动形式,泥深应包含残留层。残留层的厚度一般为20～60cm,这样对过去不包含残留层厚度的泥深观测数据应进行更正,粘性泥石流流量和输沙率也需相应增加。Residual layer is left by viscous debris flow adhering to the channel, bank, or the surface of deposition fan, which plays an important role in changing flow depth, raising discharge, reducing resistance and silt and deposit However, it has escaped from researches for 20 years and left us some key problems, such as, whether the flow depth contains the residual layer Some authors point out that the subsequent flow is moving at high speed on the surface of the layer, keeping it unmoved, and the flow depth does not contain the layer (observations are those in Jiangjia Gully, Yunnan); others argue that the subsequent flow takes the underlayer moving forward together, and the depth actually contains the thickness of the layer (observations are those in Wudu, Gansu) Thickness of residual layer is about 020～060m on average, resulting in error of the same magnitude in depth calculation, which imposes direct influence on the calculation of velocity, discharge, and sediment yield Therefore it is urgent to answer that whether the flow depth contains the layer thicknessField observations of living debris flows in Jiangjia Gully, manmade debris flows in tiny tributary, and simulation experiments have shown that only a thin base part is left while the main moves together with the subsequent surges when they pass through on the precursory layer The layer moves in three manners: creep, wave, or base laminar flow through a extrusionupliftbase slip process; turbulence through collision, scattering and splash; intrusion into the above flow through dilution and convection The second manner, turbulence, is most frequent in natural debris flows In conclusion, flow depth does contain thickness of the residual layer, and observation data should take these in account Correspondingly, formulas for related calculations must reconfirmed by data after correction

关 键 词：粘性泥石流 残留层 泥深确定 

分 类 号：P642.23[天文地球—工程地质学]