砾石土边坡稳定性研究——以泥石流堆积砾石土为例
文献类型：学位论文
| 作者 | 朱颖彦
|
| 学位类别 | 博士 |
| 答辩日期 | 2006 |
| 授予单位 | 中国科学院水利部成都山地灾害与环境研究所 |
| 授予地点 | 成都 |
| 导师 | 崔鹏 |
| 关键词 | 泥石流 砾石土 边坡稳定性 |
| 其他题名 | Research on the Stability of Gravel Soil Slope，Based on Debris Flow Sediment |
| 学位专业 | 自然地理学 |
| 中文摘要 | 泥石流的起动现象大多涉及到松散堆积砾石土，也就是砾石土的稳定问题。滑坡向泥石流转化过程中，“土力类”泥石流将不可避免地涉及砾石土变形破坏的机理研究，而在探索不同滑坡起动的机制时，我们发现无论是室内模型实验还是野外定点观测，对泥石流堆积砾砾石土的应力应变特征与强度特性的认识不足，往往制约了研究的进一步的深入。然而，对于泥石流堆积砾石土的应力应变关系与抗剪强度特征，这方面的研究基本上还是空白。泥石流堆积砾石土边坡本质上一种混杂堆积，由于其组成物质、形成年代和沉积构造等方面的特点，与其他岩土边坡失稳有不同的表现。由于坡体内部物理力学参数的随机分布，泥石流堆积砾石土边坡运动常表现为断裂扩张、大变形，大量滑坡失稳是在渗流场作用下的固液耦合作用等等问题。对此，基于结构性网格进行离散的数值方法，如有限元法，已经表现出相当的困难。因此采用一种新的数值方法来模拟泥石流堆积砾石土边坡运动是极其有必要的。本文通过为常规试验、室内岩土测试、现场实验、数值模拟、理论分析，取得了以下创新成果：（1）首次系统地对砾石土的分类与工程地质特征、结构、物理力学性质和基本特点进行了阐述，对砾石土形成了较为全面的认识。在此基础上，较全面地对泥石流堆积砾石土的分类，泥石流堆积砾石土边坡的结构、构造等方面进行了分析与总结。（2）系统地研究了泥石流堆积砾石土的物理力学性质，分析直剪试验和三轴试验中固结排水、固结不排水、不固结不排水条件下含水量与土体强度的关系、土体密度与土体强度的关系，确定不固结不排水三轴剪的邓肯-张模型的参数，建立和验证泥石流堆积砾石土的应力应变关系和抗剪强度参数表达式，提出剪胀性是理解泥石流堆积砾石土的力学性质的关键，从而填补宽级配砾石土力学在这方面的空白。（3）利用室内实验数据与野外观测结果，采用非确定性与确定性相结合的数值模拟来研究边坡稳定性。利用自编的边坡滑面随机搜索VBA程序分析了泥石流堆积砾石土边坡的圆弧滑面、非圆弧滑面，实际滑面的稳定系数，进而提出了砾石土边坡随机失稳的机理；推导二维邓肯-张非线性弹性无网格伽辽金法的数学表达式，并进行了相应FORTRAN程序开发，实现泥石流堆积砾石土边坡大位移分析，从力学机理的角度为滑坡泥石流等地质灾害的预测预报和判别提供依据和方法。 |
| 英文摘要 | The research on the initiation of debris flow usually referred to loose deposited gravel soil, particularly to the stability of gravel soil. In the scientific investigation of debris flow initiation motivated from landslide, debris flow with type of “soil-mechanism” inevitably comes down to a research on the mechanism of slope failure. In the process of exploring different landslide phenomena by indoor model experiments as well as in situ observations, it achieved little in the past mostly due to deficient information regarding to stress-strain relation and strength of gravel soil, resulting in limited research advancement in the field of debris flow. It is established that the structure and the compositions of gravel soil substantially affect its behaviors such as strength and stress-strain relation. Furthermore, it is recognized that irreversibility, randomicity and chaos characterize slope movement, which is accounted for by probabilistic process. Unfortunately, the research on gravel soil related to aforesaid aspects has not yet been performed. By triaxial testing, in situ observations and experiments, numerical simulation and theory analysis, following scientific discoveries was made: (1) An extensive scientific investigation on gravel soil from debris flow involving with physical character, classification, structure and conformation were presented systematically. (2) A series of testings for soil strength of gravel soil by triaxial testing as well as direct shear testing were performed to evaluate the relationship between water content and soil strength. A mathematic expression was introduced to account for the behavior of gravel soil, which significantly contributes to the subject of soil mechanics. (3) A systematic exploration of the stability of gravel soil slope was implemented by a new mathematic model combining undetermined method and determined method. Using observation data from indoor experiment and in situ experiment, planar problem of landslide of debris flow sediment was modeled by two programs, Nonelinear Elasticity Meshless Garlekin (NEMG) and Slip Surface Stochastic Searching, which were developed with VBA and FORTRAN separately. (4)The mechanism of stochastic failure of gravel soil slope was investigated, which substantially provides an approach to prevent landslides, debris flows as well as others geological hazards. |
| 学科主题 | 自然地理学 |
| 语种 | 中文 |
| 公开日期 | 2010-10-22 |
| 分类号 | TU4;P64 |
| 源URL | [http://ir.imde.ac.cn/handle/131551/2286]  |
| 专题 | 成都山地灾害与环境研究所_成都山地所知识仓储（2009年以前） 成都山地灾害与环境研究所_山地灾害与地表过程重点实验室 |
| 推荐引用方式 GB/T 7714 | 朱颖彦. 砾石土边坡稳定性研究——以泥石流堆积砾石土为例[D]. 成都. 中国科学院水利部成都山地灾害与环境研究所. 2006. |
入库方式： OAI收割
来源：成都山地灾害与环境研究所
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。