基于模袋法堆坝的尾矿坝稳定性研究

发布时间：2018-05-27 20:28

本文选题：尾矿坝 + 模袋法　；参考：《北京科技大学》2017年博士论文

【摘要】：作为解决细粒尾矿堆坝问题的新技术,模袋法堆坝将细粒尾矿充灌在设定的土工模袋内,利用模袋材料透水固砂、加速固结等优点,实现细粒尾矿的快速安全堆坝,受到了细粒尾矿堆坝研究领域的普遍关注。模袋法技术最初发源于水利护坡领域,并形成了一系列的研究成果。本文将该技术成果成功引入到尾矿库筑坝领域,研究发展了适合于尾矿库筑坝的关键技术,结合尾矿筑坝的特点和要求,本文重点研究了对于模袋法堆坝中特别关注的稳定性作用机理及如何验算的问题,形成的成果总结如下:(1)通过细粒尾矿模袋充灌试验,探索了细粒尾砂模袋法堆坝的粒径适用范围。试验结果表明:粒度+0.074mm在10%～20%,-0.045mm约70%的尾矿可直接实现模袋法堆砌子坝的筑坝方式,突破了该粒径范围内不能采用尾矿直接筑坝的限制。(2)揭示了模袋坝的强度增强作用机理。结合模袋体强度增强机理分析和模袋体的多项力学特性试验,对模袋体及模袋体间的力学特性进行了深入研究。由于土工袋张力的约束作用,模袋材料与尾砂共同发挥作用,使得模袋体较松散尾砂的抗剪强度明显提高,增强了其整体性,使尾砂由"散体材料"变成具有"一定连续性的材料",坝体稳定安全系数提高25%以上。(3)建立了模袋法尾矿坝的数值模拟和分析方法。本文通过水平条块划分并建立平衡方程的方法论证了模袋法尾矿坝的边坡稳定性。依据模袋坝体的破坏模式主要为袋与袋之间滑动的特性,采用接触面单元模拟模袋体的层间接触,结合抗剪强度折减法和接触面有限单元法,计算分析了模袋坝的层间滑移破坏特征,得到了模袋体层间滑移变形与破坏过程。将上述研究结果应用于两个模袋法堆坝的工程实践中,得到有效验证。
[Abstract]:As a new technology to solve the dam problem of fine-grained tailings, the mold bag method fills the fine tailings into the set geo-mold bag, and makes use of the advantages of the mold bag material to permeate the sand and accelerate the consolidation, so as to realize the rapid and safe dam of the fine-grained tailings. It has received widespread attention in the field of fine tailing dam research. The technology of mould bag method originated in the field of water conservancy slope protection and formed a series of research results. In this paper, the technical achievements are successfully introduced into the field of tailings dam construction, and the key technologies suitable for the dam construction of the tailings reservoir are studied and developed, combining with the characteristics and requirements of the tailings dam construction. In this paper, the mechanism of stability and how to check calculation are studied, and the results are summarized as follows: 1) through the filling test of fine tailing mold bag, The application range of fine tailing sand bag method for dam diameter is explored. The test results show that the dam construction mode can be realized directly in the tailings of 10 ~ 20 ~ 0.045 mm tailings with grain size of 10 ~ 20% and 0.045 mm, which breaks through the limit of direct dam construction by tailings within the range of particle size, and reveals the mechanism of strengthening the strength of the dam. Based on the analysis of strength enhancement mechanism of mold bag and the experiment of several mechanical properties of mould bag, the mechanical properties of mould bag and mold bag are studied in depth. Because of the restraint of the soil bag tension, the mould bag material and the tailings act together, which makes the shearing strength of the loose tailings of the mold bag body increase obviously, and the integrity of the mold bag body is enhanced. The method of numerical simulation and analysis of tailings dam by mold bag method is established by changing tailing sand from "bulk material" to "material with certain continuity", and the safety coefficient of dam body stability is increased by more than 25%. In this paper, the slope stability of the tailings dam is proved by the method of dividing the horizontal strip and establishing the equilibrium equation. According to the failure mode of the dam, the contact surface element is used to simulate the interlayer contact of the bag body, combined with the shear strength reduction method and the contact surface finite element method. The interlayer slip failure characteristics of formwork bag dam are calculated and analyzed, and the slip deformation and failure process are obtained. The above research results are applied to the engineering practice of two formwork bag method, and the results are verified effectively.
【学位授予单位】：北京科技大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TD926.4

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