基于环剪试验的湟水河流域大型泥岩滑坡滑带剪切特征初探

发布时间：2018-05-06 09:12

本文选题：湟水河 + 泥岩滑坡　；参考：《工程地质学报》2017年01期

【摘要】：大型泥岩滑坡是青海湟水河流域最主要的地质灾害类型之一。为了揭示此类滑坡运动过程中的滑带土动态剪切特征,本文以湟水河流域两处典型泥岩滑坡滑带土为例,首先通过基本物理性质测试,判定该泥岩滑带土具有中膨胀性;然后利用环剪试验方法,得到了不同含水率的滑带土在不同剪切速率的环剪作用下的剪切特征曲线。结果显示:剪切过程表现出明显的应变软化特性,试样从峰值应力到残余应力有快速明显的应力降(降幅多介于30%~40%之间);试样的剪切速率和含水率与剪切强度呈反相关关系,残余应力对上述因素的响应小于峰值应力;剪切速率(含水率)变化条件相同时,含水率(剪切速率)越大,剪切应力和剪切强度的变化越大。上述结论为湟水河流域大型泥岩滑坡的成因机理分析和稳定性研究提供了参考。
[Abstract]:Large mudstone landslide is one of the most important geological hazards in Huangshui River Basin, Qinghai Province. In order to reveal the dynamic shear characteristics of the sliding zone soil in the course of the landslide movement, this paper takes two typical mudstone landslide slip zone soil as an example. Firstly, through the basic physical property test, it is determined that the mudstone slide zone soil is moderately expansive. Then the shear characteristic curve of sliding zone soil with different moisture content under different shear rate is obtained by using the annular shear test method. The results show that the shear process shows obvious strain-softening characteristics, the sample has a rapid and obvious stress drop from the peak stress to the residual stress (mostly between 30% and 40%), and the shear rate and moisture content of the sample are inversely correlated with the shear strength. The response of residual stress to the above factors is less than that of peak stress, and the larger the water content (shear rate) is, the greater the variation of shear stress and shear strength is when the change condition of shear rate (moisture content) is the same. These conclusions provide a reference for the genetic mechanism analysis and stability study of large mudstone landslides in Huangshui River Basin.
【作者单位】：中国地质环境监测院;中国地质科学院地质力学研究所;中国地质大学(北京);中国地质调查局;
【基金】：中国地质调查局地质调查项目(1212011220144) 国土资源部公益性行业基金项目(201411083-5)资助
【分类号】：P642.22

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