黑方台台塬斜坡演化特征研究

发布时间：2018-04-16 05:32

本文选题：黄土斜坡 + 坡体结构　；参考：《兰州大学》2017年硕士论文

【摘要】：研究以黑方台台塬斜坡为对象,结合现场地质条件、地质演化过程以及数值计算分析,开展黑方台台塬斜坡变形破坏的发育特征、空间分布特征以及斜坡演化特征等研究。研究主要结论如下:(1)常见的坡体结构类型为9类,各类型具有自身的结构和分布特征。(2)天然条件下接触面顺向型斜坡与反向型斜坡的变形破坏模式有所不同且顺向更易发生变形破坏;斜坡基岩稳定情况下,接触面顺向型斜坡的易发生剪出口为接触面的黄土接触面滑坡。岩土体和接触面性质弱化加速斜坡的变形破坏。接触面顺向型斜坡从基岩顶面(或卵石层顶面)剪出的可能性大,但当下部黄土层饱和时易从粉质粘土层顶面剪出。(3)滑坡包括纯黄土滑坡、黄土(基岩)接触面滑坡、黄土(粉质粘土)接触面滑坡、黄土—基岩切层滑坡和黄土—基岩顺层滑坡;台塬裂缝包括卸荷裂缝、牵引拉张裂缝和湿陷裂缝;崩塌包括黄土型崩塌和黄土—粉质粘土型崩塌。(4)斜坡变形破坏在空间分布上呈现群集性、选择性和取向性特征,滑坡、裂缝和崩塌特征明显。(5)纯黄土滑坡的形成机制为蠕滑—拉裂,黄土(基岩)接触面滑坡为滑移—拉裂和压制—蠕滑—拉裂—剪断,黄土(粉质粘土)接触面滑坡为压制—塑流—拉裂—剪断,黄土—基岩切层滑坡为蠕滑—拉裂,黄土—基岩顺层滑坡为滑移—拉裂;坡体结构从本质上控制了滑坡的演化过程。黄土型崩塌的演化模式为拉裂—倾倒和拉裂—滑移,黄土—粉质粘土型崩塌为拉裂—坠落。(6)斜坡演化呈现相似性、差异性、继承性、转化性、复活性、链生性等特征,野狐沟和磨石沟为典型实例。(7)研究区斜坡变形破坏的类型和位置选择、空间分布以及斜坡演化与坡体结构相关,野狐沟的实例分析有良好的反映。
[Abstract]:Taking the slope of Heifangtai tableland as an object, combining with the field geological conditions, geological evolution process and numerical calculation analysis, the development characteristics, spatial distribution characteristics and slope evolution characteristics of the slope deformation and failure in Heifangtai tableland are studied.The main conclusions of the study are as follows: (1) the common types of slope structure are 9 types.Each type has its own structure and distribution characteristics. (2) under natural conditions, the deformation and failure modes of forward and reverse slopes of contact surface are different, and the deformation and failure are more likely to occur in the direction of slope bedrock stability, and in the case of stability of slope bedrock, the deformation and failure modes of forward slope are different from those of reverse type slope.The loess contact surface landslide is easy to occur when the shear exit is the contact surface of the converse slope of the contact surface.The weakening of rock, soil and contact surface accelerates the deformation and failure of slopes.The possibility of cutting forward slope of contact surface from the top of bedrock (or pebble layer) is great, but when the lower loess layer is saturated, the slope is easy to be cut out from the top of silty clay layer. The landslide includes pure loess landslide and loess (bedrock) interface landslide.Loess (silty clay) interface landslide, loess bedrock shear layer landslide and loess bedrock bedding landslide, tableland fractures include unloading cracks, traction tension fractures and collapsible fractures;Collapse includes loess type collapse and loess-silty clay type collapse.The formation mechanism of pure loess landslide is creeping and pulling crack, loess (bedrock) contact surface landslide is slip-pull crack and compacting creeping slide pull crack shearing, the formation mechanism of pure loess landslide is obvious.The interface landslide of loess (silty clay) is pressure-plastic flow-tension-shearing, loess-bedrock shear landslide is creep-tension crack, loess-bedrock bedding landslide is slip-pull crack, and the structure of slope body controls the evolution of landslide in essence.The evolution patterns of loess type collapse are tensile crack, collapse and tension slip, loess clay type collapse is tension crack and fall. (6) the evolution of loess type collapse is similar, different, inherited, transformative, resurrection, chain nature, and so on, the evolution of loess and silty clay type collapse is similar, different, inheritance, transformation, resurrection, chain nature, and so on.The types and location of slope deformation and failure, spatial distribution and slope evolution are related to slope structure.
【学位授予单位】：兰州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU43

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