Design of Slope Stabilization Methods Associated With a Coal Outcrop Fire
Key Features
- 40,000 ft2 area with an average slope of about 100%
- Multiple rotational failures from subsurface burning of coal in an underlying abandoned coal mine
- Designed a gabion cover system
- Provided an outlet to vent hot gases
- Revegetated the area
- Provided construction management services
EarthFax designed methods to stabilize a steep-slope area of approximately 40,000 square feet that had been affected by a coal outcrop fire. The fire had originated in an adjacent abandoned underground coal mine and had resulted in denuding of the area and mass failure of several portions of the slope, including multiple rotational failure cracks with depths in excess of 25 feet and top widths in excess of 10 feet. The purpose of the remedial-action was to stabilize the slope (with a gradient of approximately 100 percent) and to smother as many of the hot spots as possible.
The design consisted of creating a uniform slope in areas that had been subject to mass failure, installing gabions and anchoring the gabions to the slope using rock bolts, filling the gabions with road-base material and topsoil, and revegetating the area. Due to previous unsuccessful attempts to extinguish the fire, we also designed a chimney to permit venting of hot gases from a single location and control the future spread of the fire. EarthFax provided construction oversight and survey control during implementation of the project.
