| 题名 | 降雨滑坡启动的临界条件与变形预测研究 |
| 作者 | 李德心 |
| 学位类别 | 硕士 |
| 答辩日期 | 2011-05-19 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 何思明 |
| 关键词 | 降雨 滑坡启动 临界条件 前期降雨 变形预测 |
| 其他题名 | The Critical Starting Conditions and Deformation Prediction Study on Rainfall-triggered Shallow Landslide |
| 学位专业 | 岩土工程 |
| 中文摘要 | 滑坡是地质灾害的主要类型，具有分布范围广、发生频率高、损失严重等特点。降雨是滑坡发生的主要诱因，降雨诱发的滑坡占滑坡总数的90%以上，一般认为，雨水入渗时会引起边坡抗剪强度降低、土层重度增加、非饱和土土层吸力丧失和产生超静孔隙水压力，这些因素的综合作用会显著降低边坡的稳定性，导致滑坡灾害的发生。要减少降雨滑坡造成的财产损失和人员伤亡，对其进行预测预报是最为有效的减灾措施，而降雨滑坡的预测预报的关键在于确定降雨滑坡启动的临界雨量，因此，开展对降雨滑坡临界条件研究具有重要的科学意义和现实需求。 5.12汶川地震诱发了大规模的次生山地灾害，导致成灾环境剧变，具体表现为大量山体被震裂，为灾后降雨入渗提供了良好的通道，灾后3年来，大规模的降雨滑坡的发生印证了这一推断。都江堰是本次地震的极重灾区，它位于成都平原西北边缘，地处岷江出山口，为龙门山构造带的中南段，跨成都平原和龙门山地区两个不同自然地理区，属四川盆地中亚热带湿润气候区，平均年降雨量为1225.4mm。我们选取都江堰为研究区域，开展降雨滑坡启动的临界条件研究，探索震后降雨诱发区域滑坡启动的降雨临界值、前期有效降雨量以及对滑坡变形预测。论文首先将坡地水文模型与无限边坡稳定性模型耦合，建立降雨滑坡启动的临界降雨计算公式；其次是研究降雨时间过程对边坡地下水位的影响，揭示地下水位变化与边坡土体物理力学指标、降雨强度和渗流时间的定量关系，构建前期有效降雨量的预测模型；建立基于功能原理的边坡一维动力学模型，结合太沙基固结方程，研究滑坡运动过程中孔隙水压力的消散及其对滑坡动力过程的影响，揭示降雨滑坡从运动到静止的时空演化规律，构建降雨滑坡位移预测模型。将相关理论成果应用于示范区域都江堰的研究，建立了滑坡启动的临界降雨量与边坡坡度、汇水区面积、地层岩性的定量关系；前期有效降雨受边坡坡度、渗流时间、渗透系数等多种因素的影响；最后揭示了降雨滑坡运动速率、位移与降雨时过程的量化关系式。 |
| 英文摘要 | Landslide is the main type of geological hazards, It has the characteristics of wide distribution 、high frequency and serious losses. Rainfall is the main reason for landslide, Rainfall-induced landslides accounted for 90% of the total landslides, Generally, Infiltration will lower the shear strength of slope,Increasing the unit weight of soil,lossing the suction of unsaturated soils and generate excess pore water pressure. The combined effect of these factors will significantly reduce the stability of the slope and lead to the occurrence of landslides. In order to reduce property damage and human casualties, forecast is the most effective measures, the key is to determine the critical rainfall threshold for shallow landslide. Therefore, researching the critical rainfall threshold for shallow landslide has important scientific significance and practical needs. 5,12 wenchuan earthquake, which Induced a large-scale secondary mountain hazards, led to drastic changes in the environment, A large number of shattered mountains were specific performance, providing a good channels for the infiltration.3 years after the disaster, large scale rainfall landslides confirmed the inference . Dujiangyan is the very hardest disaster area. It is located in the northwest edge of the Chengdu Plain. It is located the exports of Minjiang River in the mountains .which is in the south section of Longmen Shan belt, acrossing two different geographical areas of Chengdu Plain and the Longmen Mountains region .it belongs to subtropical humid climate In Sichuan Basin .the average annual rainfall is 1225.4mm,We selected Dujiangyan for the study area to study the critical rainfall condition of landslide, exploring the critical rainfall threshold for regional shallow landslides,antecedent effective rainfall and the prediction of landslide deformation. Firstly, we combine the slope hydrological model with the infinite slope stability model to suggest the rainfall threshold for shallow landslide and establish the critical rainfall threshold formula.Secondly, we study the course of rainfall on the groundwater level, revealing the quantitative relationship between physical and mechanical properties of the soil and the groundwater level as well as the rainfall intensity and flow time .Constructing the antecedent effective rainfall prediction model. Finally we establish one-dimensional dynamic model based on the principle. Using Terzaghi consolidation equation, researching the dissipation of pore water pressure in the movement process of landslide and its influence on the dynamic processes. Revealing the space-time evolution law from movement to stationary of the landslide, and construct the displacement prediction model . We apply the relevant theory in the Dujiangyan area and establish the quantitative relationship among the critical rainfall threshold, slope gradient, catchment area and lithology. the antecedent effective rainfall is influenced by the slope gradient, flow time, permeability coefficient and many other factors. at last we reveal the quantitative relationship formula among the movement rate, displacement and the process of rainfall . |
| 语种 | 中文 |
| 公开日期 | 2013-01-23 |
| 内容类型 | 学位论文 |
| 源URL | [http://192.168.143.20:8080/handle/131551/4833]  |
| 专题 | 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 | 李德心. 降雨滑坡启动的临界条件与变形预测研究[D]. 北京. 中国科学院研究生院. 2011. |
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