初始含水率对冰川泥石流的起动影响分析

发布时间：2018-06-22 04:34

本文选题：前期降雨量 + 初始含水率　；参考：《水土保持学报》2017年06期

【摘要】：通过开展不同初始含水率天然冰碛土的冰川泥石流起动试验,近似模拟不同前期降雨量下融水冲刷冰碛物形成泥石流的起动过程。结果表明:(1)研究区冰川泥石流起动类型为坍塌推移型;(2)初始含水率较低时渗流作用表现明显,渗流侵蚀将大量细颗粒运移,致使粒间孔隙增大至原孔隙率的2倍,土体骨架颗粒重新排列,颗粒间接触力降低,土体产生局部失稳变形,孔隙水压力呈"突降-突增-突降"趋势;(3)初始含水率较高时渗流与冲刷共同起主导作用,泥石流呈阵流爆发且与孔隙水压力峰值相对应;(4)含水率和孔隙水压力呈周期性变化,土体初始含水率与含水率达到峰值所需时间呈负相关关系;(5)基于试验现象及含水率和孔压的变化特征,将研究区泥石流起动过程划分为4个阶段,将其起动机理分为内渗流侵蚀、前缘骨架坍塌和径流冲刷起动。
[Abstract]:The starting process of debris flow caused by meltwater scouring under different early rainfall was simulated by starting test of glacial debris flow with different initial moisture content of natural moraine soil. The results are as follows: (1) the starting type of glacier debris flow in the study area is the type of collapse, (2) when the initial water content is low, the seepage effect is obvious, and the seepage erosion will move a large number of fine particles, resulting in the increase of intergranular porosity to 2 times of the original porosity. When the soil skeleton particles are rearranged, the contact force between particles decreases, the soil produces local unstable deformation, and the pore water pressure shows the trend of "sudden drop, sudden increase and sudden drop". (3) when the initial water content is high, seepage and scour play a leading role. Debris flow erupts in front and corresponds to the peak of pore water pressure. (4) Water content and pore water pressure change periodically. The initial moisture content of soil is negatively correlated with the time required to reach the peak value of water content. (5) based on the experimental phenomena and the variation characteristics of water content and pore pressure, the starting process of debris flow in the studied area is divided into four stages. The starting mechanism is divided into internal seepage erosion, leading skeleton collapse and runoff scouring start.
【作者单位】：新疆农业大学水利与土木工程学院;新疆维吾尔自治区交通规划勘察设计研究院;
【基金】：国家自然科学基金项目(41602331) 中国沙漠气象科学研究基金项目(Sqj2015015) 中国博士后基金项目(2016M602951XB) 新疆交通厅科技项目(2015-2017) 新疆农业大学研究生校级创新项目(XJAUGR2016-031)
【分类号】：P343.6;P642.23

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