兰州大学机构库 >土木工程与力学学院
黑方台台塬斜坡演化特征研究
Alternative TitleStudy on Evolution Features about Loess Slope of Heifangtai
陈小军
Thesis Advisor刘高
2017-05-01
Degree Grantor兰州大学
Place of Conferral兰州
Degree Name硕士
Keyword黄土斜坡 坡体结构 变形破坏 育特征 空间分布特征 演化特征
Abstract

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。

Other Abstract

Development feature, spatial distribution feature and evolution feature of the deformation and failure about loess slope of Heifangtai which is treated as a study object are studied based on analysis of field geological condition, geological evolution process and numeral calculation. The main conclusions are as follows. (1) There are 9 types of slope structure in the study area, and each one has its own structure and distribution characteristics. (2) We know from the slope structure effect under the natural condition the deformation and failure modes of consequent-interface slopes are different from the ones of reverse-interface slopes, and the former slopes are more prone to deformation; Consequent -interface slope is likely to form a loess interface landslide under the condition of bedrock stability. We know from the effect under properties changing that changes accelerate the deformation and failure of slope. From the contrast between the two conditions, we can know consequent-interface slope is likely to be cut out from the top surface of bedrock (or pebble layer), but it is likely to be cut out from the top surface of silty clay layer when loess is saturation. (3) The types of loess landslide can be recognized as loess landslide, loess (bedrock) interface landslide, loess (silty clay) interface landslide, loess-rock incising landslide and loess-rock bedding landslide; The cracks in the plateau can be recognized as unloading crack, traction tension crack and collapse crack. Collapses can be recognized as loess collapse, loess-silty clay collapse. (4) Spatial distribution features of deformation and failure of slope show cluster, selectivity and orientation, the features of landslide, crack and collapse is typical. (5) The mechanism of loess landslide is creep sliding-tension cracking mode, loess (bedrock) interface landslide is sliding-tension cracking mode and sliding compression -tension cracking-shearing mode, loess (silty clay) interface landslide is sliding compression-plastic flow-tension cracking-shearing mode, loess-rock incising landslide is creep sliding-tension cracking mode, and loess-rock bedding landslide is sliding-tension cracking mode; The evolution mode of loess collapse is tension cracking-toppling and cracking tension-sliding, and loess-silty clay collapse is cracking tension-falling. (6) Slope evolution shows similarity, specificity, inheritance, transformation and geological hazard chains, Yehu valley and Moshi valley are two typical examples. (7) We can get the conclusion that type and position selection, spatial distribution and evolution of deformation and failure of slope in the study area are much association with slope structure, which is confirmed by an example about Yehu valley.

URL查看原文
Language中文
Document Type学位论文
Identifierhttps://ir.lzu.edu.cn/handle/262010/226361
Collection土木工程与力学学院
Recommended Citation
GB/T 7714
陈小军. 黑方台台塬斜坡演化特征研究[D]. 兰州. 兰州大学,2017.
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