尾矿库溃坝机理及在线监测预警方法研究

发布时间：2018-02-01 03:30

本文关键词： 尾矿库溃坝机理路径及成因指标体系预警方法　出处：《北京科技大学》2015年博士论文　论文类型：学位论文

【摘要】：辨识并获取尾矿库溃坝前兆信息,实现对险情早期预警,是确保尾矿库安全运行的关键,也是当前溃坝灾害研究领域的前沿课题。本文通过现场工程试验和实验室试验,从溃坝的流变机理入手,在分析了国内外160起事故案例的基础上,系统分析了溃坝路径及成因,获得了溃坝在线监测指标,建立了溃坝预警指标体系,提出了溃坝预警的综合预警方法,开发了具备实时监测、分析、评价和预警功能的在线监测预警系统,并进行了工程应用。首先,对尾砂的物理力学性质和力学特性进行了试验研究,结果表明：自坝前至水面方向,密实度由大到小,颗粒由粗到细；随深度增加,密实度由小到大,粒径呈现间歇特征,但总体上是由粗到细。尾砂在外荷载作用下表现出明显的压硬性和剪胀特性,并呈现出一定的流变特性；破坏类型是剪切破坏,破坏后是不可恢复的塑性变形。其次,对尾砂的流变特性进行分析和试验研究,发现了尾砂随时间不断变形的蠕变特性,以及抗剪强度随时间逐渐降低的性质,基于流变学理论,提出了尾矿库流变溃坝机理,阐明了尾矿坝的变形破坏先后经历了衰减变形、稳定变形和加速变形三个阶段,并以此为基础建立了变形分级预警准则。随后,对国内外溃坝事故进行统计分析,明确了溃坝类型为六类,即渗流破坏、洪水漫顶、浸润线过高、坝坡过陡、坝体上升速度过快和地震液化；采用鱼刺图成因分析法,获得了六类溃坝的路径及成因,并利用相关性分析法对指标进行分析,建立了反映溃坝风险的6大类、18个指标体系；结合现有仪器技术发展水平,逐一分析了风险指标实现在线监测的可行性,确定了尾矿库溃坝在线监测的8个指标。再者,对溃坝风险预警指标体系和预警方法进行研究,明确了溃坝预警由明确警义、寻找警源、分析警兆、预报警度和发布警情等五部分组成,并建立了5类警情、11个警素、3类警源和警兆的四级指标体系,提出了指标预警、统计预警、模型预警和综合预警的溃坝风险预警方法。最后,利用C#语言,开发了具备信息管理、预警分析和警情发布功能的尾矿库溃坝在线监测预警系统,实现了在线监测、分析、评价和预警的自动化,并在福建龙岩某尾矿库进行了工程应用,取得很好的工程效果。
[Abstract]:It is the key to ensure the safe operation of tailing reservoir to identify and obtain the precursor information of tailing dam break and to realize the early warning of dangerous situation. It is also a frontier subject in the field of dam-break disaster research at present. Based on the analysis of 160 accident cases at home and abroad, this paper starts with the rheological mechanism of dam break through field engineering experiments and laboratory tests. The path and cause of dam break are analyzed systematically, the on-line monitoring index of dam break is obtained, the early warning index system of dam break is established, the comprehensive early warning method of dam break warning is put forward, and the real-time monitoring and analysis are developed. The online monitoring and warning system of evaluation and early warning function is applied in engineering. Firstly, the physical and mechanical properties of the tailings are studied. The results show that from the front of the dam to the surface of the water, the compactness is from large to small, and the particle size is from coarse to fine. With the increase of depth, the compactness changes from small to large, the particle size is intermittent, but generally from coarse to fine. The tailings show obvious compressive hardening and shear-expansion characteristics under external load, and show certain rheological characteristics. The failure type is shear failure, and the plastic deformation is irrecoverable after failure. Secondly, the rheological properties of tailings are analyzed and tested. The creep properties of tailings are found to deform with time, and the shear strength decreases with time, based on rheological theory. The rheological dam-break mechanism of tailings dam is put forward. The deformation and failure of tailing dam have undergone three stages: attenuation deformation, steady deformation and accelerated deformation. Based on these three stages, the early warning criterion of deformation classification has been established. Then, through statistical analysis of dam-break accidents at home and abroad, six types of dam-break are determined, that is, seepage failure, flood overtopping, too high line of infiltration, steep slope of dam, too fast rise speed of dam body and earthquake liquefaction. In this paper, the path and cause of dam break of six types are obtained by using the method of fish-burr analysis, and the indexes are analyzed by the method of correlation analysis, and 18 index systems are established to reflect the risk of dam break. Combined with the development level of existing instruments, the feasibility of on-line monitoring of risk index is analyzed one by one, and the 8 indexes of on-line monitoring of dam break in tailings reservoir are determined. Furthermore, the early warning index system and early warning method of dam break risk are studied. It is clear that dam break early warning consists of five parts: clear warning meaning, searching for warning source, analyzing warning signs, warning degree and issuing warning information. A four-level index system of 5 kinds of police information, 11 types of warning elements and 3 types of warning sources and warning signs is established. The methods of early warning of dam break risk are put forward, which are index early warning, statistical early warning, model early warning and comprehensive early warning. Finally, the online monitoring and early warning system of tailings dam break is developed with C # language, which has the functions of information management, early warning analysis and warning release, and realizes the automation of on-line monitoring, analysis, evaluation and early warning. It has been applied to a tailings reservoir in Longyan, Fujian Province, and achieved good engineering results.
【学位授予单位】：北京科技大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TD926.4

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