贾俊,张茂省,冯立,毕银强.流态破坏型黄土滑坡滑带土临界特征[J].西北地质,2019,52(2):136-147
流态破坏型黄土滑坡滑带土临界特征
Critical Characteristics of Slip Zone Soil in Loess Landslide with Flow Failure Pattern
投稿时间:2019-02-08  修订日期:2019-05-05
DOI:10.19751/j.cnki.61-1149/p.2019.02.014
中文关键词:  黄土滑坡;流态破坏;临界特征值;细微观结构;力学机制
英文关键词:loess landslide;flow failure;critical eigenvalue;meso-microscopic structures;mechanical mechanism
基金项目:国家重点研发计划项目(2018YFC1504700),自然资源部地质调查项目(DD20190714),地质灾害防治与地质环境保护国家重点实验室开放基金资助项目(SKLGP2015K007)
作者单位
贾俊 中国地质调查局西安地质调查中心/西北地质科技创新中心, 自然资源部黄土地质灾害重点实验室, 陕西 西安 710054;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, 四川 成都 610059 
张茂省 中国地质调查局西安地质调查中心/西北地质科技创新中心, 自然资源部黄土地质灾害重点实验室, 陕西 西安 710054 
冯立 中国地质调查局西安地质调查中心/西北地质科技创新中心, 自然资源部黄土地质灾害重点实验室, 陕西 西安 710054 
毕银强 中国地质调查局西安地质调查中心/西北地质科技创新中心, 自然资源部黄土地质灾害重点实验室, 陕西 西安 710054 
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中文摘要:
      泾阳南塬黄土滑坡运动形式具流态特征,以泾阳南塬西段L5致滑层黄土和东段L9致滑层黄土为研究对象,从非饱和黄土角度出发,开展了控制不同初始含水率的增湿常剪试验,在获取黄土增湿变形过程曲线的基础上,讨论了黄土流态破坏过程中的水土边界特征;并进一步从细微观角度揭示了黄土流态破坏前后的结构孔隙差异与含水率的关系,提出了黄土流态破坏临界条件和力学机制。研究表明,黄土具流态变形特征,其增湿变形曲线中存在发生流态破坏的临界含水率,提出了“自适应第一稳定场”和“被适应第二稳定场”的概念,微细观尺度下在临界点前后的土体孔隙突变结果揭示了该变形模式的合理性;流态变形的基本条件是与土体孔隙的分布及其颗粒大小相关的,非饱和高含水率状态下,含水率(吸应力)的微小改变可引起土体较大的应变增量;基于水力特征曲线模型闭型方程,提出了流态变形的力学机制,以期为流态破坏型黄土滑坡防控提供科学依据和理论基础。
英文摘要:
      The loess landslide movement in the southern tableland of Jingyang County has the characteristics of flow state. Taking L5 loess and L9 loess in the west section of Jingyang Southern Tableland as the research object, the humidifying constant shear test has been carried out from the angle of unsaturated loess, which controlled different initial moisture content. The characteristics of soil and water boundary in the process of loess flow failure have been discussed on the basis of the curve of loess humidification deformation process. The relationship between pore difference and moisture content before and after the failure of loess flow state has been further revealed from the microcosmic point of view. The critical condition and mechanical mechanism of loess flow failure has been put forward. The results show that the loess has the characteristics of fluid deformation, and there exists critical moisture content in its humidification deformation curve. The concepts of "adaptive first stable field" and "adapted second stable field" have been proposed for the first time. The results of soil pore mutation before and after the critical point reveal the rationality of the deformation model. In addition, the basic condition of flow deformation is related to the distribution of soil pore and particle size. Under the condition of unsaturated high-water content, the small change of water content (suction stress) can cause larger strain increment of soil. Based on the closed equation of hydraulic characteristic curve model, the mechanical mechanism of fluid deformation has been put forward in order to provide the scientific basis and theoretical basis for the prevention and control of fluid failure loess landslide.
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