Prediction Method of Coal Fracture Based on Failure Approach Index and Hoek-Brown Criterion

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According to Mohr-Coulomb criterion, the yield approach index (YAI) of Hoek-Brown criterion is derived. The rock-mass intact coefficient KV is introduced, and coal failure approach index is defined by combining failure degree. On the basis of logging data and stratified in-site stress model, the failure approach index and yield approach index are calculated in wellbore direction. Based on FAI values, coal fracture degree is divided four grades of A, B, C, D, and coal fracture classification method is proposed. Taking ZP-1 Well in QinShui basin as an example, the distribution regularity of coal fracture degree is predicted by the method. The results indicate that failure approach index of ZP-01 well is between 0.8-1.2; the section of 551-552.7m of coal seam is fractured (grade A), and the rest section of coal seam is regarded as grade B. Through electron microscope to scan coal sample structure, the results agree well with the prediction results, therefore the classification method is reliable. Depending on theory results, computer program is corresponding developed.

Info:

Periodical:

Advanced Materials Research (Volumes 383-390)

Edited by:

Wu Fan

Pages:

4994-4999

DOI:

10.4028/www.scientific.net/AMR.383-390.4994

Citation:

X. Wang et al., "Prediction Method of Coal Fracture Based on Failure Approach Index and Hoek-Brown Criterion", Advanced Materials Research, Vols. 383-390, pp. 4994-4999, 2012

Online since:

November 2011

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$35.00

[1] QU Ping, SHEN Rui-chen and YANG Heng-lin, Evaluation model of wellbore stability in coal seam, ACTA PETROLEI SINICA, vol. 30, pp.455-459, March (2009).

[2] ZANG Xiu-ping, RUAN Han-ting and LI Ping, Status quo and trends analysis of factors considered in rock mass classification methods, Rock and Soil Mechanics, vol. 28, pp.2245-2248, October (2007).

[3] WEN Chang-ping, Bayes discriminant analysis method of rock-mass quality classification, JOURNAL OF CHINA COAL SOCIETY, vol. 33, pp.395-399, April (2008).

[4] XU Hong-fa, ZHOU Jian-min and Wu Hua-Jie, Simplified method for national standard for engineering classification of rock mass, Rock and Soil Mechanics, vol. 26, pp.88-90, December (2005).

[5] ZHANG Chuan-qing, ZHOU Hui and FENG Xia-ting, Stability assessment of rockmass engineering based on failure approach index, Rock and Soil Mechanics, vol. 28, pp.888-893, May (2007).

[6] ZHOU Hui, ZHANG Chuan-qing and FENG Xia-ting, Analysis of rock mass stability in tunnel and underground engineering based on yield approach index, Chinese Journal of Rock Mechanics and Engineering, vol. 24, pp.3083-3087, August (2005).

[7] DU Li-hui and HUANG Li-qing, The nonlinear axisymmetric finite element method for analysis of surrounding rock inconsideration of creeping, Journal of Hydraulic Engineering, vol. 16, pp.85-89, January (2001).

[8] Hoek E and Brown E T, Practical estimates of rock mass strength, Int. J. Rock Mech. Min. Sci, vol. 34, pp.1165-1186, August (1998).

[9] WANG Qing-yu, Problem to Determine The Integrity Coefficient of Rock Mass, Site Investigation Science and Technology, vol. 11, pp.63-65, August (1994).

[10] ZHANG Yi, YAN Xiang-zhen and YAN Qing-zhi, 3D Model for the Stratified Calculation of Ground Stress and Fracture Criterion of Wellhole Rock, " Journal of Xi, an Petroleum Institute (Natural Science Edition), vol. 15, pp.42-43, April (2000).

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