School of Energy and Mining, China University of Mining and Technology-Beijing, Beijing, China.
School of Civil Engineering, North China University of Technology, Beijing, China.
PLoS One. 2024 Aug 7;19(8):e0305425. doi: 10.1371/journal.pone.0305425. eCollection 2024.
The presence of lenses such as tailings slurry, frozen soil, and saturated zones disrupts the continuity of tailings dams and their normal seepage patterns, elevating the seepage line of the dam body and significantly impacting local stability. This study, to investigate how lenses affect the stability and failure mechanisms of tailings dams, employs numerical simulation and physical models and constructs a model of the tailings dam, incorporating tailings clay lens and void lens, to investigate variations in hydraulic gradients, seepage velocities, seepage flow, pore water pressure, and the patterns of seepage failure. This research reveals that the tailings clay lens within the dam body increases the hydraulic gradient in its vicinity due to its low permeability and raises the phreatic line. As the tailings clay lens approaches the dam body, the phreatic line tends to escape along the upper part of the lens towards the dam surface. In addition, the void lens could lead to a more pronounced seepage gradient along its path on the dam surface, with a liquefaction beneath it. As the void lens nears the toe of the slope, the dam failure mode transitions from a step-like progressive failure to an arch-shaped settlement failure along the void lens.
透镜的存在，如尾矿浆、冻土和饱和带，破坏了尾矿坝的连续性及其正常渗流模式，抬高了坝体的渗流线，并对局部稳定性产生重大影响。本研究旨在探讨透镜如何影响尾矿坝的稳定性和破坏机制，采用数值模拟和物理模型，构建了一个包含尾矿粘土透镜体和空洞透镜体的尾矿坝模型，以研究水力梯度、渗流速度、渗流流动、孔隙水压力和渗流破坏模式的变化。研究表明，由于尾矿粘土透镜体的低渗透性，它会增加坝体附近的水力梯度，并抬升地下水位。随着尾矿粘土透镜体接近坝体，地下水位往往会沿着透镜体的上部向坝面逸出。此外，空洞透镜体可能会导致在其路径上沿坝面出现更明显的渗流梯度，其下方会发生液化。随着空洞透镜体接近边坡趾部，坝的破坏模式从阶梯状渐进破坏转变为沿空洞透镜体的拱形沉降破坏。
