Seepage field characteristic and stability analysis of tailings dam under action of chemical solution

Abstract

As one of the important influencing factors of tailings dam stability, seepage field distribution within the dam is often affected by the tailings mineral characteristics. While the alkalinity or acidity of reservoir water and long term immersion will partially change the physical and mechanical properties of tailings. This study carried out permeability tests of tailings under the action of chemical solution. On this basis, a three dimensional (3D) model was constructed to analyze the velocity field and effective saturation within the tailings dam. Moreover, the dam section along the valley bottom was selected as the basic section in calculation, so as to analyze the changes in infiltration point and buried depth of the phreatic line under different permeability coefficient ratios. The results suggest that, under the action of acid-alkaline solution, the permeability coefficients of tailings reduced, and the stronger solution acidity-alkalinity resulted in the longer action time and more obvious change; under the action of chemical solution, the fluid flow velocity in the dam gradually decreased, and the drat beach length in the reservoir gradually shortened. Besides, when the upper layer permeability coefficients of tailings was lower than that of the lower layer, the dam phreatic line had a shallow buried depth and a high infiltration point.

Seepage and Deformation Analysis of Tailing Dam regarding the Upper Reservoir of Tiantai Pumped Storage Station

“…Yang et al ( 2022) presented that the tailing dam was stable and safe under normal water level and rainfall conditions, but the stability and safety of the dam decreased significantly under high water level and rainfall conditions, and the risk of seepage failure increased. [6] Zhang et al ( 2021) concluded that the permeability coefficient ratio is an important parameter for the seepage stability analysis of tailings dam, which should be determined by the field test and adjusted according to the actual situation. [7] Fetisov et al ( 2020) believed that seepage evaluation should be carried out when designing of dams' height increase in a framework of water balance prediction.…”

The influence of normal distribution dispersion of fracture size on blockiness and REV of fractured rock masses

“…The study of blockiness level is of great significance to avoid geological disasters such as rockfalls and tailings pond failures (Wang et al, 2019;Wang et al, 2021;Wang et al, 2022a;Lin et al, 2022;Ma and Liu, 2022). Blockiness is defined as the percentage of the volume of isolated blocks formed by fractures to the total volume of the rock (Xia et al, 2016).…”

Non-linear mechanical characteristics of tailings in large-scale high tailings dams

“…The statistical analysis of many tailings pond accidents reveals many reasons for tailings pond accidents, including rainstorms, overtopping, earthquake liquefaction, seepage failure, dam foundation instability, dam structure failure, and load increase. The final cause of dam instability, which mainly refers to changes in the stress fields and seepage fields of tailings dams caused by the aforementioned factors (Wang et al, 2021), is discussed. It is worth noting that the instability characteristics of tailings ponds are completely different at high stress and low stress, so it is necessary to study them.…”