Geomechanics and Engineering

Techno-Press (테크노프레스)
권호 표지
DOI QR코드

DOI QR Code

Analytical solutions for crack initiation on floor-strata interface during mining

  • Zhao, Chongbin (Computational Geosciences Research Centre, Central South University)
  • Received : 2014.06.25
  • Accepted : 2014.11.15
  • Published : 2015.02.25
⟨ Previous Next ⟩

Abstract

From the related engineering principles, analytical solutions for horizontal crack initiation and propagation on a coal panel floor-underlying strata interface due to coal panel excavation are derived in this paper. Two important concepts, namely the critical panel width of horizontal crack initiation on the panel floor-underlying strata interface and the critical panel width of vertical fracture (crack) initiation in the panel floor, have been presented. The resulting analytical solution indicates that: (1) the first criterion can be used to express the condition under which horizontal plane cracks (on the panel floor-underlying strata interface or in the panel floor because of delamination) due to the mining induced vertical stress will initiate and propagate; (2) the second criterion can be used to express the condition under which vertical plane cracks (in the panel floor) due to the mining induced horizontal stress will initiate and propagate; (3) this orthogonal set of horizontal and vertical plane cracks, once formed, will provide the necessary weak network for the flow of gas to inrush into the panel. Two characteristic equations are given to quantitatively estimate both the critical panel width of vertical fracture initiation in the panel floor and the critical panel width of horizontal crack initiation on the interface between the panel floor and its underlying strata. The significance of this study is to provide not only some theoretical bases for understanding the fundamental mechanism of a longwall floor gas inrush problem but also a benchmark solution for verifying any numerical methods that are used to deal with this kind of gas inrush problem.

Keywords

Acknowledgement

Supported by : Natural Science Foundation of China

References

  1. Ali, A.Y. and Bradshaw, S.M. (2010), "Bonded-particle modelling of microwave-induced damage in ore particles", Min. Eng., 23(10), 780-790. https://doi.org/10.1016/j.mineng.2010.05.019
  2. Bunger, A.P., Menand, T., Cruden, A., Zhang, X. and Halls, H. (2013), "Analytical predictions for a natural spacing within dyke swarms", Earth Planet. Sci. Lett., 375, 270-279. https://doi.org/10.1016/j.epsl.2013.05.044
  3. Exadaktylos, G. (2012), "A study of the transient fluid flow around a semi-infinite crack", Int. J. Solid. Struct., 49(23-24), 3323-3334. https://doi.org/10.1016/j.ijsolstr.2012.07.012
  4. Faccanoni, G. and Mangeney, A. (2013), "Exact solution for granular flows", Int. J. Numer. Anal. Method. Geomech., 37(10), 1408-1433. https://doi.org/10.1002/nag.2124
  5. Hudson, J.A., Brown, E.T., Fairhurst, C. and Hoek, E. (1993), Comprehensive Rock Engineering: Principles, Practice and Projects, Volume 1-5, Pergamon Press, New York, NY, USA.
  6. Karim, M.R., Krabbenhoft, K. and Lyamin, A.V. (2013), "Permeability determination of porous media using large-scale finite elements and iterative solver", Int. J. Numer. Anal. Method. Geomech., 38(10), 991-1012. https://doi.org/10.1002/nag.2245
  7. Noack, K. (1995), "Control of high gas emissions in underground coal mines", Int. J. Coal Geol., 35(1-4), 57-82. https://doi.org/10.1016/S0166-5162(97)00008-6
  8. Stark, R.F. and Booker, J.R. (1997), "Surface displacements of a non-homogeneous elastic half-space subjected to uniform surface tractions. Part I: Loading on arbitrarily shaped areas", Int. J. Numer. Anal. Method. Geomech., 21(6), 361-378. https://doi.org/10.1002/(SICI)1096-9853(199706)21:6<361::AID-NAG875>3.0.CO;2-U
  9. Wang, J.G., Kabir A., Liu, J.S. and Chen, Z.W. (2012), "Effects of non-Darcy flow on the performance of coal seam gas wells", Int. J. Coal Geol., 93, 62-74. https://doi.org/10.1016/j.coal.2012.01.013
  10. Wang, J.G., Liu, J.S. and Kabir, A. (2013), "Combined effects of directional compaction, non-Darcy flow and anisotropic swelling on coal seam gas extraction", Int. J. Coal Geol., 109-110, 1-14. https://doi.org/10.1016/j.coal.2013.01.009
  11. Xia, M. and Zhou, K.P. (2010), "Particle simulation of failure process of brittle rock under triaxial compression", Int. J. Min. Metal. Mater., 17(5), 507-513. https://doi.org/10.1007/s12613-010-0350-4
  12. Ye, Z., Chen, D. and Wang, J.G. (2014), "Evaluation of non-Darcy effect in coalbed methane production", Fuel, 121, 1-10. https://doi.org/10.1016/j.fuel.2013.12.019
  13. Zhao, C. and Valliappan, S. (1995), "Finite element modelling of methane gas migration in coal seams", Comput. Struct., 55(4), 625-629. https://doi.org/10.1016/0045-7949(94)00495-O
  14. Zhao, C., Hebblewhite, B.K. and Galvin, J.M. (2000), "Analytical solutions for mining induced horizontal stress in floors of coal mining panels", Comput. Method. Appl. Mech. Eng., 184(1), 125-142. https://doi.org/10.1016/S0045-7825(99)00097-3
  15. Zhao, C., Hobbs, B.E. and Ord, A. (2008), Convective and Advective Heat Transfer in Geological Systems, Springer, Berlin, Germany.
  16. Zhang, X., Jeffrey, R.G., Bunger, A.P. and Thiercelin, M. (2011), "Initiation and growth of a hydraulic fracture from a circular wellbore", Int. J. Rock Mech. Min. Sci., 48(6), 984-995. https://doi.org/10.1016/j.ijrmms.2011.06.005

Cited by

  1. Micro-seismic monitoring in mines based on cross wavelet transform vol.11, pp.6, 2016, https://doi.org/10.12989/eas.2016.11.6.1143
  2. Analytical solution of the asymmetric transient wave in a transversely isotropic half-space due to both buried and surface impulses vol.81, 2016, https://doi.org/10.1016/j.soildyn.2015.11.003
  3. Three dimensional transient Green's functions in a thermoelastic transversely isotropic half-space vol.97, pp.12, 2017, https://doi.org/10.1002/zamm.201600106
  4. Propagation of Rayleigh waves in fluid-saturated non-homogeneous soils with the graded solid skeleton distribution vol.40, pp.11, 2016, https://doi.org/10.1002/nag.2491
  5. Study of the Crack Propagation Model Under Seepage–Stress Coupling Based on XFEM vol.35, pp.5, 2017, https://doi.org/10.1007/s10706-017-0257-1
  6. Bi-material transversely isotropic half-space containing penny-shaped crack under time-harmonic horizontal loads vol.172, 2017, https://doi.org/10.1016/j.engfracmech.2016.12.025
  7. In situ investigations into mining-induced overburden failures in close multiple-seam longwall mining: A case study vol.12, pp.4, 2015, https://doi.org/10.12989/gae.2017.12.4.657
  8. Influence of undercut and surface crack on the stability of a vertical escarpment vol.12, pp.6, 2015, https://doi.org/10.12989/gae.2017.12.6.965
  9. Experimental and numerical study of shear crack propagation in concrete specimens vol.20, pp.1, 2015, https://doi.org/10.12989/cac.2017.20.1.057
  10. Optimization study on roof break direction of gob-side entry retaining by roof break and filling in thick-layer soft rock layer vol.13, pp.2, 2017, https://doi.org/10.12989/gae.2017.13.2.195
  11. A review paper about experimental investigations on failure behaviour of non-persistent joint vol.13, pp.4, 2017, https://doi.org/10.12989/gae.2017.13.4.535
  12. A fracture mechanics simulation of the pre-holed concrete Brazilian discs vol.66, pp.3, 2015, https://doi.org/10.12989/sem.2018.66.3.343
  13. Direct shear testing of brittle material samples with non-persistent cracks vol.15, pp.4, 2015, https://doi.org/10.12989/gae.2018.15.4.927