Experiment Study on the Relationship between the Height of Capping Layer and the Porosity of Broken Rocks

Abstract:

The gas seepage characteristics of four kinds of broken rocks of different gradations and the relationship between the capping height and the porosity were studied by means of the simulation experiment and the theoretical analysis. The results show that the air flow in the capping layer composed of broken rocks is in the non-Darcy state which can be described as Forchheimer equation and Ergun equation. Moreover, on the basis of the experimental data, the relational expressions between the permeability, the non-Darcy β factor and the porosity were determined. Through the numerical fitting, the equation of the minimum capping height and the porosity was ultimately derived, which provided the basis and the reference for the determination of capping height and the air leakage control of mine.

• Periodical: Advanced Materials Research (Volumes 594-597)
• Pages: 2323-2330
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.594-597.2323
• Online since: November 2012
• Authors: Cui Feng Du, Bin Li
• Keywords: Capping Layer, Critical Height, Mine Air Leakage, Porosity, Seepage Characteristics

References

[1] Zhang J F, Jiao J J. Influence of grain shape on characteristics of pores and seepage in porous media (in Chinese). Journal of Yangtze River Scientific Research Institute, Vol. 28, No. 3 (2011), p.39

[2] Huang X W, Tang P, Miao X X, et al. Testing study on seepage properties of broken sandstone (in Chinese). Rock and Soil Mechanics, Vol. 26, No. 9 (2005), p.1385

[3] Du C F, Wang B, Liu Z J, et al. Experiment study on the air leakage characteristics of the capping in underground mining turned from open-pit mining (in Chinese). Metal Mine, Vol. 8 (2009), p.122

[4] Gan D Q, Zhu L Q, Chen C, et al. Experimental study on the air leakage during joint mining of open-pit and underground mining (in Chinese). Metal Mine, Vol. 2 (2011), p.1

[5] Yuan R, Albert S Kim. Study on fluid flow passing through a porous media. Acta Analysis Functionalis Applicata, Vol. 13, No. 4 (2011), p.357

[6] Li S C, Chen Z Q, Miao X X, et al. Nonlinear dynamic study on gas flow in broken rock mass (in Chinese). Chinese Journal of Rock Mechanics and Engineering, Vol. 26, No. 7 (2007), p.1372

[7] Yu W, Li Q, Huang W, et al. Study on the laws of gas flow in over-broken rock mass (in Chinese). Journal of Yanshan University, Vol. 31, No. 4 (2007), p.317

[8] Deng C H, Tong L, Chen B F, et al. Direct numerical simulation for fluid flow in porous media (in Chinese). Journal of Wuhan University of Technology (Transportation Science ＆ Engineering), Vol. 35, No. 6 (2011), p.1257

[9] Tian S J, Wang Y M. Experimental Research on the Characteristics of the Seeping Wind of the Caved ore Rock (in Chinese). Metal Mine, Vol. 9 (1994), p.28

[10] Wang Q, Ren F Y: Mining Science (in Chinese).2nd Ed. (Metallurgical Industry Press, Beijing 2011).

[11] Jacob Bear: Dynamics of Fluids in Porous Media. (American Elsevier Publishing Company, Inc., New York 1972).

DOI: 10.1016/0160-9327(73)90013-6

[12] Forchheimer P. Wasserbew egung durch Boden. Z Ver Deutsch Ing, Vol. 45 (1901), p.1736

[13] Ergun S. Fluid flow through packed columns. Chem. Eng. Prog, Vol. 48 (1952), p.89