降雨诱发黄土高填方支挡边坡失稳机理研究

发布时间：2018-03-14 10:53

本文选题：降雨入渗　切入点：黄土　出处：《工程地质学报》2017年04期 　论文类型：期刊论文

【摘要】：近些年,由于机场建设、公路铁路等地面交通网以及城镇化的建设在黄土丘陵地区开展越来越频繁,形成大量的黄土填方高陡边坡,虽然这些地区的年降雨量较小,但是降雨已经是诱发黄土滑坡的主要因素,通过对研究区黄土高填方边坡进行原位渗流实验和裂缝存在条件下暂态非饱和渗流以及饱和黄土力学特性进行分析的基础上,对降雨诱发黄土高填方支挡边坡失稳机理研究,研究表明:(1)3d后的原位渗流中实验试坑中心的最大入渗深度为1.30m,湿润锋最大深度位于入渗最大深度以下0.20m,但降雨条件下,裂缝的存在是黄土边坡发生浅层滑动的重要因素;(2)当围压小于300kPa时,饱和土体的轴向应变增长到20%左右时,达到稳定状态,在静力驱动剪应力大于稳态抗剪强度的条件下则会使高填方坡体的局部发生流滑破坏;(3)总体来说黄土高填方支挡边坡变形破坏的形成机制为:推移式蠕滑-支挡结构失效-累进性滑移剪断-牵引式溃滑。
[Abstract]:In recent years, the construction of airports, road and railway networks and urbanization has become more and more frequent in the loess hilly areas, forming a large number of loess fill high and steep slopes, although the annual rainfall in these areas is relatively small. But rainfall has already been the main factor to induce loess landslide. Based on the in-situ seepage experiment of loess high fill slope and the analysis of transient unsaturated seepage under the condition of cracks and the mechanical properties of saturated loess soil, rainfall is the main factor that induces loess landslide. The mechanism of instability of loess high fill retaining slope induced by rainfall is studied. The results show that the maximum infiltration depth in the center of experimental pit is 1.30m, the maximum depth of wetting front is 0.20m below the maximum depth of infiltration, but the maximum depth of wetting front lies below the maximum depth of infiltration, but the maximum depth of wetting front lies below the maximum depth of infiltration, but the maximum depth of wetting front is 0.20m under rainfall condition. The existence of cracks is an important factor for the shallow sliding of loess slope. When the confining pressure is less than 300kPa, the axial strain of saturated soil increases to about 20% and reaches a stable state. Under the condition that the static driving shear stress is greater than the steady shear strength, the local flow slip failure will occur in the high fill slope.) generally speaking, the deformation and failure mechanism of loess high fill retaining slope is as follows: the displacement creep and retaining mechanism. Structural failure-progressive slip-shear-traction collapse.
【作者单位】：地质灾害防治与地质环境保护国家重点实验室(成都理工大学);重庆市地质灾害防治中心;
【基金】：国家重点基础研究发展计划项目(2014CB744703)资助
【分类号】：P642.22

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