Stability of inner dump slope under coal pillar support: case study in an open-pit coal mine

Abstract

The stability of an inner dump slope was investigated under the effect of coal pillar support considering the development position of dumping. Based on the instability mechanism and load distribution characteristics of the supporting coal pillar, the three-dimensional mechanical effects of the supporting coal pillar are characterized. Using the two-dimensional equivalent principle and the residual thrust method, the stability of the inner dump slope was analyzed under the effect of pillar support at different dump development positions. The quantitative effects of various factors on the inner dump slope stability were revealed, and the coal pillar shape parameters were optimized through numerical simulations. The results indicate that the slope stability coefficient is linearly related to the top width and height of the coal pillar, slope angle, and base inclination angle, and has an exponential relation with the coal pillar strike length and slope height increment. There are quadratic and absolute value relations with the coal pillar outer and the inner bottom angle, respectively. The top width of the coal pillar in the inner dump of Shengli East No.2 open-pit coal mine should be at a level of + 824 m, and the optimal top width and height are 15 and 36.7 m, respectively. The instability mechanism of the supporting and retaining coal pillar obtained by numerical simulations and the stability of the inner dump are in good agreement with the theoretical analysis. Our results provide a theoretical basis for the design, treatment, and safe implementation of similar open-pit mine slope engineering.

Spatial Distribution and Migration Characteristics of Heavy Metals in Grassland Open-Pit Coal Mine Dump Soil Interface

“…The soil parameters were entered according to actual conditions. Assuming that the slope is a bare natural land with vegetation coverage of 0 and the surrounding area is grassland, the erosion results after 15 years were simulated [39].…”

Remote Sensing Identification and Hazard Assessment Methods for Spoil Sites

“…Second, limit equilibrium approaches (Li et al, 2022;) have been combined with numerical simulations for engineering mechanics analysis, which aims to examine the stability of individual spoil sites. For instance, methods such as the nite element strength reduction technique (Lu et al, 2021), the nite difference method (Li, 2021), and the discrete element method (He et al, 2021), in conjunction with the rigid limit equilibrium analysis, have been adopted to evaluate the slope stability in spoil sites in the presence of rainfall conditions (Cui et al, 2021), in high and cold regions (Li, 2021), or under general circumstances. Thirdly, preliminary qualitative analyses of spoil sites were conducted through geological eld surveys combined with expert evaluations.…”

Application of Treatment for Deep Hole Drilling Debris in Gas-Rich Soft Coal Seams

“…In addition, insufficient recognition of in situ drilling slurry depth leads to a certain blindness in the extension of drilling depth. Thus, the study of drill hole debris disposal will be highly valued in particular engineering applications [5][6][7][8][9].…”