黑方台黄土斜坡变形破坏机理研究

发布时间：2018-06-08 02:18

本文选题：黑方台 + 黄土滑坡　；参考：《水文地质工程地质》2017年01期

【摘要】：黑方台常年农业灌溉引起地下水位上升,在透水性差的粉质黏土层顶部形成了厚度不断增大的饱和黄土软弱带,导致斜坡蠕动变形诱发了大量的黄土滑坡,滑坡体在地下水的浸润作用下转化为黄土泥流向前运动。为对黄土斜坡的变形破坏机理进行分析研究,进行了8个围压下的固结不排水试验。试验结果表明:饱和黄土应力应变模式表现为强烈的应变软化剪缩型,并具有一定的稳态特性。300 k Pa围压以下,试样强度丧失,土体完全液化,其余围压下的试样产生部分液化,抵抗变形能力增加,土体应力状态可划分为完全液化区和部分液化区。斜坡的变形破坏特征因上覆黄土厚度不同而有所差异,通过插值计算,黄土层厚度大于临界黄土厚度(约20 m)时,斜坡产生突发性滑动变形破坏,反之斜坡产生缓慢变形的黄土泥流。研究结果证明了黑方台削方减载治理工程的科学性,并为滑坡的防治和治理提供了一定的理论依据。
[Abstract]:The annual agricultural irrigation in Heifangtai caused the rise of groundwater level, and formed the saturated loess soft zone with increasing thickness at the top of silty clay layer with poor permeability, which led to creep deformation of slope and induced a large number of loess landslides. The landslide is transformed into loess mudflow under the effect of groundwater infiltration. In order to analyze the deformation and failure mechanism of loess slope, 8 consolidation undrained tests under confining pressure were carried out. The experimental results show that the stress-strain model of saturated loess shows a strong strain softening shear shrinkage type, and has a certain steady-state characteristic below the confining pressure of .300kPa, the strength of the specimen is lost, and the soil is completely liquefied. The remaining specimens under confining pressure have partial liquefaction and increased resistance to deformation. The stress state of the soil can be divided into complete liquefaction zone and partial liquefaction zone. The deformation and failure characteristics of slopes vary with the thickness of overlying loess. Through interpolation calculation, when the loess thickness is larger than the critical loess thickness (about 20 m), the slope has sudden sliding deformation failure. On the contrary, the slope produces slowly deformed loess mudflow. The results of the study prove the scientific nature of the load reduction treatment project of the black square table cutting square and provide a certain theoretical basis for the prevention and treatment of the landslide.
【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;
【基金】：国家重点基础研究计划(973计划)资助项目(2014CB744703)
【分类号】：P642.22;P642.131

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