【作者】 李书娜；

【导师】 周科平；

【作者基本信息】 中南大学 ， 安全技术及工程， 2010， 硕士

【摘要】 随着国民经济的快速发展,人类社会对矿产资源的需求量激增。由于原矿品位较低,选矿过程中产生大量的尾砂。通过人工方法筑坝拦截山谷、傍山或平地而形成的尾砂储存场所即尾矿库。近年来事故频发。由于尾矿砂粒径较小,后期堆积坝采用库内尾砂堆筑而成,其稳定性差,在汛期极易发生溃坝事故。一旦溃决,库内堆存的尾砂与洪水一起下泄,形成人为泥石流体,具有流速高、冲击范围远的特点,这将对库区下游带来灭顶之灾。加之选矿厂排出的尾矿水中的含选矿药剂等有毒的化学成分及重金属离子,直接下泄将污染农田和村庄,并可能造成难以预估的环境破坏,因此尾矿坝溃坝事故在全球最危险的各项事故排名中列于第十八位。本文主要通过溃坝理论与数值分析计算,对溃坝过程及溃后尾砂与水的混合泥石流的流动状态进行了模拟与仿真。得出各个时间点时,计算区域上的水文分布图,从而为灾害的预警与防治提供了手段和依据。主要的研究内容包括：(1)建立了研究区域的DTM数字地表模型。先利用MapGIS中的自动矢量化工具,将扫描地图文件转化为电子格式的地形等高线之后,在3D-Mine中对错误和断点的等高线进行人工连线处理,最后将处理好的等高线模型赋高程值；(2)计算24小时各时程点的降雨量。根据《湖南省暴雨洪水差算手册》查出该地区的标准历时(10min,60min,6h,24h)的设计雨量,中间任意历时D的设计雨量HD,可由相邻2个标准历时(较短为S,较长为L)设计雨量Hs和HL的指数公式计算。(3)引入Flo-2d二维泥石流灾害模拟软件,在对研究区域暴雨量、溃坝、入流、出流、渗流、溃口发展模式等各项参数正确调查分析和设置基础之后,对该区域尾矿坝溃坝事故进行了24小时灾害发展情况模拟。模拟过程的实时动态展现了研究区域各处的流动速度及流体深度随时间变化情况,从而为尾矿库溃坝安全评价提供了一种定量的方法。(4)分析了距离尾矿坝坝脚下游约500米左右的一条规划中的厦蓉高速公路在完全溃坝情况下,路基淹水深度变化过程。从而为尾矿库的选址、高速公路的路线规划、尾矿坝溃坝下游灾害预警提供了依据。(5)提出了尾矿坝溃坝的防灾、减灾有关措施。更多还原

【Abstract】 With the rapid development of national economy, the demand for mineral resources increases sharply. Because of the lower grade ore, a lot of mine tailings generated during mineral processing. Used for tailings storage, the tailings reservoir is formed by building an artificial dam. There are three types in formulation, one through intersection the valley, one around the foot of the mountain slopes and the other enclose the flat terrain areas. While in recent years, the safety accidents of tailings storage happen frequently. Post tailings stacking dam which is built by using the tailings in the tailings reservoir is poor in stability especially in flooding season, due to the small size of tailing particles it used. Once the dam-burst occurs, tailings stockpiled in the tailings reservoir discharged together with floods, that may form artificial debris with a high velocity and a long impact extension, will bring disaster to the downstream region. Combined with toxic chemical composition and heavy metal ions in the flotation wastewater, directly discharge will pollute the farmland and villages and bring inestimable environmental damage. In view of its dangerous impact, tailings dam-break accident is ranking 18th in the world’s most dangerous disasters.Through theoretical and numerical analysis of dam-break, the process of dam-break and debris mixed with flotation wastewater after the tailings-dam-break was simulated. The distribution hydrology on each time point of the regional area was obtained. These provide means and basis for the disaster early warning and control. The main research contents include:(1) Established a digital terrain model (DTM) of the study district. First the automatic vectorization tool of MapGIS was used to change the scanned-map into electronic contour lines. Then the break line and error were dealt with 3D-Mine. At last the fine contour lines were assigned elevation;(2) Calculated the rainfall of each whole time-point during 24 hours. According to "Differential Operators Manual of rainstorm and flood in Hunan Province" the design rainfall of the standard duration (1Omin, 60min,6h,24h) was found. The rainfall HD of any time-point D between the standard duration can be calculated by the index equation of design rainfall Hs and HL of the two adjacent standard durations (short as S, long as L).(3) The two-dimensional debris flow simulation software FLO-2D was introduced to simulate, the disaster development during 24 hours after the tailings dam collapse in the area in condition of correctly settling an amount of parameters such as regional rainfall, dam failure, inflow, outflow, infiltration, breach and others on the basis of survey and analysis. Simulation dynamically shows the process of depth and flow velocity change with time in the study region, which provides a ration method for safety estimation.(4) As there was a planned Xiamen Chengdu Expressway located at the foot of the tailings dam about 500 meters away, the depth change process of flooded embankment was simulated, providing a basis for the location of tailings storage, the plan of the highway route and the disaster warning of the downstream break-dam.(5) Disaster prevention and mitigation measures of tailings dam break accident were proposed.更多还原