Three-dimensional modeling of large arrays of pillars for coal mine design.
Esterhuizen GS; Mark C
Proceedings of the International Workshop on Numerical Modeling for Underground Mine Excavation Design. Esterhuizen GS, Mark C, Klemetti TM, Tuchman RJ, eds., Pittsburgh, PA: National Institute for Occupational Safety and Health, IC 9512, 2009 Jun; :37-46
The stability of the pillar line during retreat pillar mining is affected by the mining sequence, the mining geometry and the properties of the pillars, the gob, and the surrounding strata. Numerical models can assist in quantifying the complex interaction between these components as pillars are extracted and the roof caves to form the gob. However, modeling the details of the pillar geometry, as well as the large-scale surrounding strata, in a single three-dimensional model can pose significant challenges in terms of computer memory and solution run times. This paper describes a modeling technique that allows large arrays of pillars to be modeled by making use of equivalent elements that capture the stress-strain response of the pillars and the immediate roof and floor rocks. The stress-strain response is obtained from numerical models that have been calibrated against instrumented case studies. The pillar response is programmed into relatively large equivalent elements in a large-scale three-dimensional model, negating the need to model the details of the pillars and surrounding excavations. An example is presented in which this method is used to assess retreat mining in two different geological settings. This modeling technique significantly improves the capabilities for evaluating retreat mining pillar stability in a variety of geotechnical conditions.
Mining-industry; Underground-mining; Models; Mathematical-models; Computer-models; Computer-software; Room-and-pillar-mining; Retreat-mining; Coal-mining
Esterhuizen GS; Mark C; Klemetti TM; Tuchman RJ
Proceedings of the International Workshop on Numerical Modeling for Underground Mine Excavation Design