沟道起动类泥石流松散堆积物起动分析  

Starting analysis of loose accumulation of gully-startup debris flow

作　　者：吴强[1] 徐林荣[1] 周凯[1] 刘志强[1] 

机构地区：[1]中南大学土木工程学院,湖南长沙410075

出　　处：《自然灾害学报》2015年第2期89-96,共8页Journal of Natural Disasters

基　　金：国家自然科学基金项目(41272376);铁路总公司专项项目(2011G017-C)

摘　　要：沟道松散堆积体的稳定性直接影响到泥石流暴发的概率与规模,其研究对泥石流灾害的预报和防治具有重要意义。同时考虑孔隙水压力和渗透水压力作用,确定了堆积体内潜水流浸润线高度,构建了沟道松散堆积体渗透破坏模型。结合案例计算,从松散堆积物、沟道地形、水动力方面分析了沟道松散堆积体中水土作用的变化,发现渗透系数、有效黏聚力、有效内摩擦角对松散堆积体的稳定性影响相对较大,天然密度、饱和密度的影响相对较小,沟道松散堆积体起动破坏形式按降雨的强度、历时及渗透系数分为整体失稳滑动破坏模式和逐级滑动破坏模式。The stability of gully loose accumulation directly affects the probability and scale of the debris flow,the research on the loose accumulation is important to the prediction and prevention work on debris flow. Taking pore water pressure and hydraulic seepage pressure into account simultaneously,the height of phreatic line in accumalation body was determined,then the model of gully loose accumulation seepage failure was established. In combination with an example,the soil-water interaction change of gully loose accumulation was analyzed from loose accumulation,gully terrain,and hydrodynamic condition. Results indicate that permeability coefficient,effective cohesion,and effective internal friction angle are relatively important to stability of loose accumulation,while natural density and saturated density are not relatively important. The startup failure patterns of loose accumutation can be divided into two types as whole accumulation slide and step-slide according to rainfall intensity,duration and permeability coefficient.

关 键 词：泥石流 松散堆积体 孔隙水压力 渗透水压力 影响因素 

分 类 号：P642.23[天文地球—工程地质学]