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
  • Introducing Our New IMASS Constitutive Model The Itasca Constitutive Model for Advanced Strain Softening (IMASS) has been developed to represent the...
    Read More
  • Itasca Symposium 2020 - Registration Now Open! Registration is now open for the Fifth International Itasca Symposium....
    Read More
  • 2019 Sloan Outstanding Paper Award Dr. Mojtaba Bahaaddini (Shahid Bahonar University of Kerman), along with Associate Professor Glenn Sharrock (Itasca/UQ),...
    Read More

Upcoming Events
19 Jan
Evaluation of impacts of lahars on structures using DEM numerical modelling
Lahars represent natural phenomena that can generate severe damage in densely populated urban areas. The evaluation of pressures genera... Read More
21 Jan
Griddle Version 2.0 has been Released | Learn What's New
Griddle 2.0 Has Been Released! Join us for a webinar on "What's New in Griddle 2.0?"... Read More
8 Mar
FLAC3D 2021 Online, Live Introductory Training
... Read More