This poster presents a seepage and slope stability analysis of a reclamation design of a coarse coal refuse pile in the Appalachian region. The reclamation utilized on site material and short paper fiber to amend grass to grow. Finite element method was utilized to evaluate the reclamation performance to a 100 year rainstorm event.
Restoration of abandoned mine lands is on-going in Appalachia and across the United States. One potential technique to reclaim these areas is through the use of geomorphic landforming combined with paper mill residuals used as a soil amendment. The geomorphic approach attempts to approximate the long-term, steady state landform condition, leading to reduced erosional adjustment compared to standard engineered fill designs. This study analyzed regraded mine refuse slopes for safety and erosion sustainability under a 100-year storm event for the Royal Scot refuse pile located near Rupert, WV.
The project involved the design and evaluation of a cap and cover system composed of two layers. The first layer is a 60 cm compacted barrier layer (hydraulic barrier) and second is a 30cm vegetative growth layer. The focus of the analysis was the effectiveness of the hydraulic barrier layer and the final slope stability of the system.
A 3D finite element modeling was performed to assess ground surface terrain profiles considering weather and material strength. Results from the modeling indicate that for a 100-year storm event, the slope remains stable with a factor of safety of 2.3. After the 100-year storm event, the growth layer retained most of the precipitation infiltration (~80%), proving the effectiveness of the low permeability layer. The model shows the water within the pile returning to the initial volume after 56 days.