Technical Papers

Numerical Evaluation of Effectiveness of Drainwells in Dewatering Overburden at Surface Coal Mines

Abstract:

Typical sedimentary sequences overlying coal seams consist of interbedded sandstones, siltstones, shales, and rider coal seams. In many surface coal mine settings, these sediments are saturated; and prior dewatering of them is necessary for effective and economic mining, including the stacking of saturated spoils. Such sedimentary sections usually have a very low vertical hydraulic conductivity that does not allow them to drain in a timely manner prior to their being stripped. One potential solution is installation of drainwells. Drainwells are small diameter wells that can collect water laterally from the various more permeable layers in the overburden and then gravity drain it to a lower layer – often the coal seam being mined – where it can be removed by pumping wells or sumps located in the bottom of the pit. A ground-water flow model utilizing the 3-dimensional finite element code MINEDW has been used to evaluate the effectiveness of using drainwells in a hydrogeologic setting that is typical of the Powder River Basin. A series of numerical simulations were completed using various combinations and spacings of drainwells and pumping wells to dewater the overburden and coal seams. The numerical simulations suggest that drainwells can be a very effective method of overburden dewatering.

Citation:

Howell, R.L., L.C. Atkinson, and H. Liu. 2000. Numerical evaluation of effectiveness of drainwells in dewatering overburden at surface coal mines. Society for Mining, Metallurgy, and Exploration Annual Meeting, Salt Lake City, Utah, 28 February-1 March.

Authors:

Houmao Liu

Link to Full Text:

Dewatering a Coal Mine.pdf

Latest News
  • Griddle 2.0 Pre-release Now Available Griddle offers automatic, interactive, and easy-to-use surface meshing and volume grid generation capabilities for FLAC3D,...
    Read More
  • Paper Awarded Silver Medal by SAIMM The paper "A risk-based methodology to improve the definition of geotechnical sectors in slope design"...
    Read More
  • Learning FLAC3D 7.0 New FLAC3D introductory tutorials are now available on our website. See how easy it is...
    Read More

Upcoming Events
16 Aug
RockEng 2020 - CANCELED
The theme of RockEng2020 is Canadian Strengths and Future Directions in Rock Mechanics. This will be a two-day, single-stream symposium... Read More
21 Sep
AFTES 2020 - Underground, a space for innovation
The central theme of this edition is “the underground, a space of innovation”.... Read More
21 Sep
71st Highway Geology Symposium
Better highways through applied geology... Read More