雅鲁藏布江大古河段泥石流特征及工程影响研究

发布时间：2019-03-10 20:41

【摘要】：在我国西部,尤其是西藏地区深山峡谷区广泛发育,泥石流高频发育,人类工程活动或工程建设活动多处于稀少的中高海拔地区,并且由于西藏地区地形与质地条件复杂,极易诱发暴雨和冰融性泥石流,常对工程布置和交通运输产生重大影响。随着国家对西藏地区水利、水电、交通等工程建设的不断推进,泥石流对工程的制约日益突出,所以研究西藏地区的泥石流特征和对工程的影响十分的重要,通过本课题的研究,会对以后的西部建设起到十分重要的作用。大古、街需水电工程区位于西藏自治区桑日县境内的雅鲁藏布江中游河段上,这一区域属高原温带、寒温带气候,植被条件差,物理风化强烈,松散固体物质易于积累,发生泥石流的地形条件优越,工程区属于西藏典型的雨洪型泥石流,在地形地貌以及气象水文条件等具有很强的代表性。本文阐述了大古河段17条泥石流沟的基本特征和动力学特征,包括物源特征、沟道特征、堆积物特征、爆发频率特征、重度、流速和流量等等,通过研究发现,大古河段泥石流呈现物源量偏大、汇水面积较小、纵比降偏大以及细颗粒物质缺失的特点。在此基础上,依据大古河段的泥石流特征设计了三个物理模拟试验,分别是泥石流水下淤积试验、泥石流堵江试验、泥石流冲击力试验。试验的总体内容是分析影响试验的主要因素,通过改变这些因素的大小来测量对泥石流特性的影响,最终分析总结试验结论来建立数学模型,提出能适用于大古、街需水电工程区的泥石流数学模型,在泥石流的评估和防治起到重要的作用。结合现场调查与室内试验,分别提出泥石流的堵江、水下淤积以及冲击力对工程区的影响。根据对大古河段每条沟的性质、规模以及工程影响分析,结合具体坝址位置,最终确定了在街需水电工程对九锥沟进行冲击力治理措施,在大古水电工程对路垄沟进行淤积和冲击力治理措施。
[Abstract]:In the western part of China, especially in the deep valley area of Tibet, the development of debris flow is high frequency, the human engineering activities or engineering construction activities are mostly in the rare middle and high altitude areas, and because of the complex terrain and texture conditions in Tibet area, It is easy to induce rainstorm and ice melt debris flow, which often have a great influence on engineering arrangement and transportation. With the continuous advancement of water conservancy, hydropower, traffic and other projects in Tibet by the state, the constraints of debris flow on the project are becoming more and more prominent, so it is very important to study the characteristics of debris flow in Tibet and its impact on the project. Through the research of this subject, it will play a very important role in the construction of the west in the future. In ancient times, the Street need Hydropower Project area is located in the middle reaches of the Yarlung Zangbo River in Sangri County, Tibet Autonomous region. This area belongs to the plateau temperate zone, cold temperate climate, poor vegetation conditions, strong physical weathering, and easy accumulation of loose solids. The topography of debris flow is superior, and the engineering area belongs to the typical rainfall-flood debris flow in Tibet, which is very representative in topography, geomorphology, meteorological and hydrological conditions and so on. This paper describes the basic and dynamic characteristics of 17 debris flow gullies in the Dagu river section, including material source characteristics, channel characteristics, accumulation characteristics, burst frequency characteristics, severity, velocity and flow rate, etc. The debris flow in the Dagu reach is characterized by a large amount of materials, a smaller catchment area, a larger longitudinal ratio drop and a lack of fine particles. On this basis, according to the characteristics of debris flow in the Dagu reach, three physical simulation tests are designed, namely, underwater siltation test, river blockage test and impact force test of debris flow. The overall content of the test is to analyze the main factors that affect the test, to measure the impact of these factors on the characteristics of debris flow by changing the size of these factors. Finally, the conclusion of the test is analyzed and summarized to establish a mathematical model, and it is suggested that it can be applied to the Dagu. The mathematical model of debris flow plays an important role in the evaluation and prevention of debris flow. Combined with field investigation and laboratory test, the influence of debris flow blockage, underwater siltation and impact force on the engineering area is proposed. Based on the analysis of the nature, scale and engineering impact of each ditch in the Dagu reach, combined with the location of the concrete dam site, the measures for controlling the impact force of Jiuawangou in the street hydropower project are finally determined. In the great ancient hydropower project, silting and impingement measures were carried out on the ridges and furrows of the road.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：P642.23

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