佳禾沟泥石流堆积物的粒度与强度关系分析  

Analysis on Grain-size Characteristics and Shear Strength of the Deposit in Jiahe Gully

作　　者：苟万春 李泳[1,2] 王保亮[1,2,3] 刘道川 

机构地区：[1]中国科学院山地灾害与地表过程重点实验室 [2]中国科学院水利部成都山地灾害与环境研究所,成都610041 [3]中国科学院大学,北京100049

出　　处：《科学技术与工程》2015年第35期120-123,144,共5页Science Technology and Engineering

基　　金：国家自然科学基金项目(40771010)资助

摘　　要：佳禾沟位于云南省维西县中路乡佳禾村,历史上曾多次发生不同规模的泥石流,并造成了人员伤亡和财产损失。通过对沟道流域沿线不同位置取样,用泥石流颗粒标度分析法并结合强度实验,发现佳禾沟泥石流松散堆积物的颗分参数μ与P(D_2)之间存在线性关系,这说明μ影响了泥石流的启动;物源区中的细颗粒的迁移、上游泥石流部分物质的随机性停歇和沟道支沟和主沟陡坡物质的随机性补给导致了颗分参数(μ,D_c)的波浪式发展。黏聚力c与μ之间的关系为线性关系,c随着μ的增加而增加。这说明细颗粒的组成控制了黏聚力c的大小,因此推断黏聚力受到细颗粒之间的胶结作用和静电作用等因素的影响。内摩擦角φ与Dc之间的关系为负线性相关,而φ随着D_c的增加而变小,粗颗粒决定了φ的发展。因此,在相同条件下,较大的μ和较小的D_c组合的土体,其强度较大;这从定量的角度上验证了颗粒级配与土体强度的关系。以上结论是否适用于其他流域需进一步验证。此外,还应结合颗粒形状,土动力学,渗透理论分析泥石流发生机理。Jiahe gully is located in Weixi,Yunnan. Several different scale debris flows have happened here in history,which caused injuries,deaths and property loss. By sampling in different positions,then using scaling analysis and strength experiment,the grain size distribution parameter μ increases as P（ D2） increases with a linear way were found,which indicates that μ influences the debris flow startup. Fine-grained migration in provenance and debris flow material stochastic cease and random replenishment lead to the unordered variation of μ and Dc.Cohesive force c increases as μ augments,which manifests that the fine grains control c,so cementation and electrostatic interaction between fine grains determines c were deduced. The relationship between φ and Dcis linear,andφ becomes smaller with the increase of Dc,so it shows coarse grains control the φ. Consequently,in the same other conditions,the soil with the bigger μ and the smaller Dcowns higher shear strength. The conclusions above need more drainage basins to confirm and particle shape,soil dynamics and seepage theory shoul be combined to research.

关 键 词：泥石流 颗分参数 粒度分析 强度参数 

分 类 号：P642.23[天文地球—工程地质学]