延安地区黄土—基岩接触面滑坡模型试验研究

发布时间：2018-04-19 15:43

本文选题：延安地区 + 黄土-基岩接触面滑坡　；参考：《长安大学》2017年硕士论文

【摘要】：延安地区地质环境脆弱,地质灾害频发。尤其是黄土滑坡分布很广,对当地经济发展和人民生命财产威胁很大。延安市老滑坡复活中,以黄土-基岩接触面滑坡最为常见。这类滑坡的黄土基岩接触面倾角缓,一般小于10°,小于或近等于综合内摩擦角,理论上不应该发生滑动,但是却存在很多实例,例如二庄科滑坡、丁家沟滑坡、小砭沟滑坡、王家沟滑坡等。为了对该类滑坡有较全面的认识,本文以小砭沟滑坡为研究对象,对影响该类滑坡稳定性因素进行敏感性分析,并进行模型试验,探索其滑动原因及演化过程。取得以下成果:(1)通过均匀设计理论,在不考虑参数相关性的影响下,对影响黄土基岩接触面滑坡稳定性因素进行敏感性分析,采用逐步回归法进行回归分析,并用实例进行验证,最终得出内摩擦角、坡比、坡高为最敏感性因素。(2)利用量纲分析法对模型试验的相似准则进行了推导,以此为基础制作了降雨条件下的延安地区黄土-基岩接触面滑坡模型试验系统,获取了孔隙水压力、垂直方向土压力、水平方向土压力、位移等相关物理量间的关系。(3)通过模型试验得出降雨条件下的该类滑坡地质力学模式为蠕滑-拉裂,滑动过程如下:表层蠕滑→坡脚垮塌→后缘拉裂、中前部产生拉张裂缝→坡面泥流→整体滑移、裂缝扩展→前部受挤压隆起、坡体重心降低。
[Abstract]:The geological environment in Yan'an area is fragile and geological disasters occur frequently.Especially the loess landslide is widely distributed and threatens the development of local economy and people's life and property.The loess-bedrock interface landslide is the most common in the revival of the old landslide in Yan'an.The slope of the loess bedrock contact surface of this kind of landslide is gentle, generally less than 10 掳, less than or nearly equal to the comprehensive angle of internal friction. Theoretically, it should not slip, but there are many examples, such as Erzhuangke landslide, Dingjiagou landslide, Xiaobian gully landslide, etc.Wang Jiagou landslide.In order to have a comprehensive understanding of this kind of landslide, this paper takes Xiaobian Gou landslide as the research object, carries on the sensitivity analysis to the influence landslide stability factor, and carries on the model test, explores its sliding reason and the evolution process.The following results are obtained: 1) based on the uniform design theory and without considering the influence of parameter correlation, the factors affecting the stability of loess bedrock interface landslide are analyzed, and the stepwise regression method is used to carry out regression analysis.Finally, the internal friction angle, slope ratio and slope height are the most sensitive factors.Based on this, a model test system of loess-bedrock interface landslide in Yan'an area under rainfall condition is made, and pore water pressure, vertical earth pressure and horizontal earth pressure are obtained.The relationship between displacement and other related physical quantities. (3) through model test, it is concluded that the geomechanical model of this kind of landslide under rainfall condition is creep slide-tension crack, and the sliding process is as follows: the surface creeping slope foot collapses and the back edge of the slope collapses,In the middle and front part, the slippage of the mudflow on the slope is produced, the front part of the extension of the crack is extruded and the body weight of the slope is reduced.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P642.22

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