数值模拟技术在九里滑坡应急处置中的应用研究

发布时间：2018-04-21 02:09

本文选题：地质灾害 + 应急处置　；参考：《中国地质大学(北京)》2017年硕士论文

【摘要】：突发地质灾害事件应急响应具有社会聚焦性和时间紧迫性,处置决策离不开科学高效的技术支撑,数值模拟技术具有成本低、效率高、且能够方便考虑多种不同工况等优势,本文开展了数值模拟技术在滑坡地质灾害应急处置中的专门研究,以期有助于提升科学防灾减灾能力,为地质灾害应急工作提供指导。本文通过文献分析、滑坡应急案例调研和九里滑坡灾情实证研究等三方面研究论证了数值模拟技术在滑坡地质灾害应急处置中的应用基础、应用过程和应用前景,本文的主要研究内容及成果如下:(1)通过综合分析大量前人研究成果,阐述数值模拟在常规状态地质灾害稳定性分析、滑坡机制分析和滑动过程推演中的应用状况,明确了应急处置基本工作内容和技术需求;(2)统计分析近六年重大滑坡地质灾害应急险情或灾情的典型案例,结合应急响应基本流程和工作内容,得出常规状态和应急情境下数值模拟技术条件的区别,明确应急数值模拟过程特点,提出应急数值模拟关键技术方法;(3)实证研究部分,以九里大型顺层岩质滑坡为例,在对滑坡变形破坏特征及周边工程地质条件现场调查和研究的基础上,通过地质分析手段获取区内滑坡体从缓慢变形到失稳破坏全过程的基本信息,提出滑坡演变地质模型,指出滑坡破坏模式为“强降雨-入渗-岩体软化-推拉”,属典型的蠕滑-拉裂型岩质滑坡;(4)结合非连续变形分析方法(DDA)模拟真实时间和便于分析岩土体单元非连续变形的特点,建立非连续变形分析数值模型,对滑坡体稳定性和滑动全过程进行数值模拟,结果表明,滑体滑动过程中最大水平位移约87m,峰值速度7m/s,滑距约38m,前缘堆积厚度53m,滑坡滑动过程持续时间70s左右,与应急调查结果相符;(5)对降雨弱化结构面强度参数影响滑坡滑距和速度进行敏感性分析,分析表明结构面内摩擦角φ对滑坡滑距和滑速影响显著,粘聚力c对滑坡位移和速度影响有限,模拟得到的滑坡最大滑移速度和后缘最大滑动距离与野外调查相符。同时依据模拟结果和滑坡现场调查情况对滑坡应急处置提出建议。
[Abstract]:The emergency response to sudden geological disasters has the characteristics of social focus and urgency of time, and the decision of disposal cannot be separated from scientific and efficient technical support. Numerical simulation technology has the advantages of low cost, high efficiency, and convenient consideration of various working conditions. In this paper, the special research on the numerical simulation technology in the emergency treatment of landslide geological hazards is carried out, which is expected to help to improve the scientific ability of disaster prevention and mitigation and to provide guidance for the emergency work of geological disasters. Through literature analysis, case study of landslide emergency and demonstration study of landslide disaster situation in Jiuli, this paper demonstrates the application foundation, application process and application prospect of numerical simulation technology in landslide geological disaster emergency treatment. The main contents and results of this paper are as follows: (1) by synthetically analyzing a large number of previous research results, the application of numerical simulation in the analysis of the stability of geological hazards in conventional state, the analysis of landslide mechanism and the deduction of sliding process are expounded. The basic working contents and technical requirements of emergency disposal are defined and the typical cases of major landslide geological disasters in the past six years are analyzed statistically, and combined with the basic flow and work content of emergency response, The differences between the technical conditions of numerical simulation in conventional state and emergency situation are obtained, the characteristics of numerical simulation process of emergency are defined, and the key technical method of emergency numerical simulation is put forward in the part of empirical research. Taking the large bedding rock landslide in Jiuli as an example, Based on the field investigation and study on the deformation and failure characteristics of landslide and the surrounding engineering geological conditions, the basic information of the whole process of landslide deformation from slow deformation to instability failure is obtained by means of geological analysis, and a geological model of landslide evolution is proposed. It is pointed out that the failure mode of landslide is "strong rainfall, infiltration, softening of rock mass and push-pull". It is a typical creep-tension type rock landslide, which combines the discontinuous deformation analysis method with DDA) to simulate the real time and facilitate the analysis of discontinuous deformation of rock and soil elements, and to establish a numerical model for discontinuous deformation analysis. Numerical simulation of landslide stability and the whole sliding process shows that the maximum horizontal displacement is about 87 m, the peak velocity is about 7 m / s, the slip distance is about 38 m, the thickness of the front edge is 53 m, and the duration of the slide process is about 70 s. In accordance with the results of emergency investigation, the sensitivity analysis on the influence of intensity parameters of rainfall weakening structural plane on landslide slip distance and velocity is carried out. The analysis shows that the friction angle 蠁 of structure plane has a significant effect on landslide slip distance and sliding speed. The cohesive force c has a limited effect on the displacement and velocity of the landslide. The maximum slip velocity and the maximum slip distance of the rear edge of the landslide obtained by the simulation are consistent with the field investigation. At the same time, based on the results of simulation and site investigation of landslide, some suggestions on landslide emergency disposal are put forward.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P642.22

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