尾矿坝渗透变形及稳定性研究

发布时间：2018-06-24 14:45

本文选题：尾矿坝 + 渗透变形　；参考：《长安大学》2014年硕士论文

【摘要】：尾矿坝坝体渗透变形是引起溃坝的主要原因，该问题一直被水利工程所重视。渗透变形初期常伴随发生局部塌陷、坝基及坝体渗水、水位异常、土体沉降等现象。随着渗透变形的继续发展，在岩土体中形成渗透通道或洞穴，将直接导致坝体稳定性迅速降低，甚至坝体失稳。因而，渗透变形的研究，不同工况下静力稳定性分析以及地震作用下动力稳定性分析是坝体工程安全预测、后期优化堆积的必要前提。本文以某尾矿坝为例，首先从渗透变形的必要条件和水力学角度分析了该坝体渗透变形的可能方式与路径，了解渗透变形产生的机理、条件，为渗透变形的防治提供资料。然后针对该坝出现的塌落坑和坝基渗水现象，应用不同的研究方法，诸如：现场调查、原位测试、连通试验、出水地段水质分析、坝体地下水位研究等，进行成果分析并得出渗透变形的特征、原因、方式及发展趋势。从而建立一套有效的渗透变形研究程序，，对类似实际工程问题提供参考。其次，鉴于渗流场的特征与渗透变形、坝体稳定性有着直接关系，本文运用Geo-studio软件的seep模块，对坝体的渗流场进行了模拟。基于模拟效果图，对坝体侵润线的特征、逸水点的位置、孔隙水压力特征等进行了分析。进而得出影响坝体渗流场的宏观因素：上下层渗透系数比、水面线起伏、干滩长度。为坝体的安全管理、稳定性控制起到关键作用。最后，本文运用Geo-studio软件的Slope模块及Slope/Quake耦合，对该坝体不同工况下坝体静力稳定性、动力稳定性进行了计算分析。由于渗流通道较小，且目前渗透变形仅为初期发展阶段，所以很难在模拟中考虑到渗透变形，本文仅以正常坝体为模拟对象进行分析。根据不同工况下稳定系数的比较，得出干滩长度、侵润线高低、相邻地层渗透系数的差异等对坝体稳定性的影响。通过对坝体地震作用下动力稳定性的模拟，分析了地震作用下坝体内部应力、应变、位移等的特征规律，分析了地震过程中坝体的稳定性变化特征。
[Abstract]:Seepage deformation of tailings dam is the main cause of dam break. In the early stage of seepage deformation, local collapse, seepage of dam foundation and dam body, abnormal water level and settlement of soil are often accompanied. With the continuous development of seepage deformation, the formation of seepage channels or caves in rock and soil will directly lead to the rapid decrease of dam stability and even the instability of dam body. Therefore, the study of seepage deformation, static stability analysis under different working conditions and dynamic stability analysis under seismic action are the necessary prerequisites for dam safety prediction and post-optimization accumulation. Taking a tailings dam as an example, this paper first analyzes the possible ways and paths of seepage deformation of the dam from the point of view of the necessary conditions and hydraulics of seepage deformation, understands the mechanism and conditions of seepage deformation, and provides data for the prevention and control of seepage deformation. Then, in view of the seepage phenomenon of the cave-pit and the foundation of the dam, different research methods are applied, such as field investigation, in-situ test, connection test, water quality analysis of the effluent section, research on the groundwater level of the dam body, etc. The results are analyzed and the characteristics, causes, methods and development trend of osmotic deformation are obtained. Thus a set of effective seepage deformation research program is established to provide reference for similar practical engineering problems. Secondly, in view of the direct relationship between seepage field and seepage deformation and stability of dam, the seepage field of dam is simulated by using seep module of Geo-studio software. Based on the simulation results, the characteristics of the embankment line, the location of the water escape point and the pore water pressure are analyzed. Then the macroscopic factors affecting seepage field of dam body are obtained: permeability coefficient ratio of upper and lower layers, fluctuation of water surface line and length of dry beach. Stability control plays a key role in the safety management of dam body. Finally, the slope module of Geo-studio software and Slope / quake coupling are used to calculate and analyze the static and dynamic stability of the dam under different working conditions. Because the seepage channel is small and the seepage deformation is only at the initial stage, it is difficult to consider the seepage deformation in the simulation. This paper only takes the normal dam body as the simulation object to analyze the seepage deformation. According to the comparison of stability coefficient under different working conditions, the influence of dry beach length, the height of embankment line and the difference of permeability coefficient of adjacent strata on the stability of dam body are obtained. Based on the simulation of the dynamic stability of the dam under earthquake, the characteristics of stress, strain and displacement in the dam under earthquake are analyzed, and the variation characteristics of the stability of the dam during the earthquake are analyzed.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV649;TV223.4

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