Technical Papers

Use of a Finite Element Code to Model Complex Mine Water Problems

Abstract:

Numerical models are now used routinely to predict ground-water inflows to both surface and underground mines and to help design dewatering systems. Two of the more complex problems encountered in mine dewatering are 1) predicting the configuration of the phreatic surface and height of the seepage face in pit highwalls for slope stability analysis and 2) predicting inflow to underground mines, particularly from discrete geologic structures and under non-Darcian flow. Frustrated by the limitations of the most common ground-water flow codes in dealing with these problems, we have developed a 3-dimensional, finite element code, designated MINEDW, that has been specially designed to address the relatively unique hydrologic complexities of mining.

MINEDW includes subroutines to calculate the height of the seepage face in a pit wall, to simulate faults without adding more discretization, and to simulate non-Darcian flow and the transition to Darcian flow as heads and gradients decrease. Examples of MINDEW solutions to relatively idealized problems are given and compared to those from physical models, analytical solutions, and another numerical code (MODFLOW).

MINEDW has been applied to a large mining operation in Indonesia involving dewatering of both a large pit and underground drifts. This case has been made even more challenging by karstic features and very high, but variable (particularly as demonstrated by a recent El Niño-induced drought) precipitation. How the hydrogeology was conceptualized and incorporated into the numerical model, how the mine plans and variable precipitation were simulated, and the results of the calibration and predictive simulations are described.

Citation:

Azrag, E., V.I. Ugorets, and L.C. Atkinson. 1998. Use of a finite element code to model complex mine water problems. Proceedings of Symposium on Mine Water and Environmental Impacts, International Mine Water Association, Johannesburg, South Africa, 1 September: pp. 31-41.

Authors:

Houmao Liu

Jianwei Xiang

Link to Full Text:

Addressing Complex Mine-Water Problems.pdf

Latest News
  • 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
  • 6th Itasca Symposium on Applied Numerical Modeling The next Itasca Symposium will take place June 3 - 6, 2024, in Toronto, Canada....
    Read More
  • Itasca International Inc. announces the Selection of its New CEO Itasca International Inc. announces the Selection of its New CEO ...
    Read More

Upcoming Events
29 May
Getting Started with FLAC2D/FLAC3D
Objectives of the training: •Understand the FLAC2D/ FLAC3D numerical approach and the types ofproblems it can solve•Know how to manipul... Read More
5 Jun
IMAT Workshop
ITASCA is launching IMAT (Itasca's Mining Analysis Toolbox) our groundbreaking software tailored exclusively for underground and open p... Read More
26 Aug
FLAC3D V9.1 and Griddle V2.0 2024
... Read More