南江县浅层土质滑坡降雨入渗规律与成因机理

发布时间：2018-02-01 18:11

本文关键词： 浅层土质滑坡降雨入渗变形监测成因机理孔隙水压力　出处：《长江科学院院报》2017年08期 　论文类型：期刊论文

【摘要】：为揭示土质滑坡中降雨入渗规律和滑坡成因机理,通过对四川南江县100多个滑坡进行现场调查、统计,选取二潢坪滑坡深入剖析典型滑坡成因机理,对降雨量、GPS累积位移、土体孔隙水压力、土体含水率等综合因素分析后,采用有限元数值法对滑坡的降雨入渗过程进行模拟。结果表明:浅层土质滑坡中孔隙水压力及含水率变化有明显滞后现象,降雨初期以垂直坡面入渗为主,一段时间后则以坡向渗流为主;斜坡中前缘孔隙水压力变化比后缘对降雨更敏感,其原因为前缘黏性堆积体、侧壁陡崖及基岩面共同构成斜坡储水边界;因滑体结构的各向异性,降雨过程中土体中局部孔隙水压力及渗流力瞬时剧增,土体饱水使得软黏土层发生软化,最终导致斜坡整体失稳。
[Abstract]:In order to reveal the law of rainfall infiltration and the formation mechanism of landslide in soil landslide, through field investigation and statistics of more than 100 landslides in Nanjiang County, Sichuan Province, Erhuangping landslide is selected to deeply analyze the cause mechanism of typical landslide. After analyzing the accumulated displacement of GPS, pore water pressure, water content of soil mass and so on. The finite element numerical method is used to simulate the infiltration process of landslide. The results show that the variation of pore water pressure and water content in shallow soil landslide has obvious lag phenomenon, and the main infiltration is vertical slope in the early stage of rainfall. After a period of time, the main percolation is slope direction. The variation of pore water pressure in the middle front of the slope is more sensitive to rainfall than that of the back edge, which is caused by the front viscous accumulation, the side cliff and the bedrock surface forming the slope water storage boundary. Due to the anisotropy of the sliding body structure, the local pore water pressure and seepage force in the soil increase dramatically during rainfall, and the soft clay layer softens when the soil is saturated, which leads to the overall instability of the slope.
【作者单位】：成都理工大学地质灾害防治与地质环境保护国家重点实验室;中铁二院(成都)建设发展有限责任公司;
【基金】：四川省国土资源厅科学研究计划项目(KJ-2015-18))
【分类号】：P642.22
【正文快照】： 1研究背景国内外很多地区因降雨诱发的滑坡发生最为频繁,造成了巨大人员财产损失。笔者对南江县100多处滑坡进行现场调查,发现浅层土质滑坡形成的地形条件、汇水条件、物质组成、高程分布,以及破坏后的破体形态、成因机制都很相似,但有别于常见的均质陡倾斜坡。浅层土质滑坡与

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