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
  • A Big Hand of Applause for Our 2023 Summer Interns ITASCA Minneapolis would like to extend our sincerest thanks to our 2023 summer interns for...
    Read More
  • Itasca has announced the release of FLAC2D v9 Itasca has announced the release of FLAC2D v9, revolutionizing the way we analyze and predict...
    Read More
  • RockMass and ITASCA Release New Integration to Enable Safer Excavation Through Efficient Design RockMass and ITASCA are pleased to announce a new integration that will enable users to...
    Read More

Upcoming Events
20 Dec
Getting Started with FLAC2D/FLAC3D
Live Online Introductory Training Course. December 20-21, 2023.... Read More
2 Jun
6th Itasca Symposium on Applied Numerical Modeling
Itasca is pleased to announce that the 6th Itasca Symposium on Applied Numerical Modeling will take place June 3 - 6, 2024, in Toronto,... Read More