Stress characterization and support measures estimation around a coalmine tunnel passing through jointed rock masses: constraints from BEM simulation

  • Authors

    • Md. Kamrul Islam
    • Md. Rafiqul Islam Shahjalal University of Science and Technology
    2016-06-16
    https://doi.org/10.14419/ijag.v4i2.6196
  • Barapukuria Coalmine, Tunnel, Jointed Rock Mass, Strength Factor, BEM Simulation.

  • Abstract

    In the present research, the stress characterization around an unsupported coalmine tunnel passing through jointed rock masses was ana-lyzed and effective support system was calculated by BEM numerical simulations. The distribution and magnitudes of major and minor principal stress contours, mean stress, differential stress, total displacement, maximum shear strain, maximum shear stress contours around the tunnel are simulated by using the examine2D software. It is reasonable to mention that examine2D is a plane strain boundary element program for calculation of stresses and displacements around underground and surface excavation in rock. Modeling results reveal that the major principal stress (σ1) was about 13 MPa at the immediate roof of the tunnel that ultimately increased to 20 MPa toward the left side and right side. Mean stress contour value was 12 MPa at the immediate roof and 15 MPa toward the both rib sides. The distribution contour value of differential stress at the roof and rib sides were 16 MPa and 23 MPa, respectively. The contour values of the strength factor around the tunnel ranged from 0.51 to 1.02, which specify that the loosening zone would be extended up to 1.53 m towards the roof and 1.25 m at the sidewalls. The thickness (1.53 m) of loosening zone can be classified as soft or poor rock mass. In the immediate roof, floor and the both rib sides of the tunnel, the Spalling Criterion values ranged from 2.7 to 8.0 MPa, which indicate no potential for rock-burst around the tunnel. However, flexible support would be required to accommodate the dilatancy deformation during development period. Finally, the stiff support would be required to provide a strong supporting reaction and to maintain the long-term stability of the tunnel.

  • References

    1. [1] Banerjee PK (1994), the Boundary Element Methods in Engineering, McGraw-Hill, New York.

      [2] Beskos (1987), Boundary element methods in dynamic analysis. Appl. Mech. Rev., ASME, 40:1–23.

      [3] Boon CW, Houlsby GT, Utili S 2(015), Designing Tunnel Support in Jointed Rock Masses Via the DEM. Rock Mech Rock Eng48, 603–632. http://dx.doi.org/10.1007/s00603-014-0579-8.

      [4] Brown ET (1981), Putting the NATM into perspective. Tunnels and Tunnelling, 13–17.

      [5] Brown ET (1999), Rock mechanics and the Snowy Mountain Scheme. In: The Spirit of the Snowy.ATSE Symposium, November 1999. Australian Academy of Technological Sciences and Engineering (Available for downloading at www.atse.org.au).

      [6] Carranza TC (2009), Analytical and Numerical Study of the Mechanics of Rockbolt Reinforcement around Tunnels in Rock Masses.Rock Mechanics and Rock Engineering, 42(2), 175-228.http://dx.doi.org/10.1007/s00603-009-0178-2.

      [7] Castro LAM, McCreath D, Kaiser PK (1995), Rock Mass Strength Determination from Breakouts in Tunnels and Boreholes. Proc. of 8th ISRM Congress, Tokyo, September, 1995, pp. 531-536.

      [8] Castro LAM, Grabinsky MW, McCreath DR (1997), Damage Initiation through Extension Fracturing in a Moderately Jointed Brittle Rock Mass. Int. J. Rock Mech. Min. Sci. &Geomech. Abstr. Vol. 34, No. 3/4, p.557, paper no. 110 and in Proc. of 36th U.S. Rock Mechanics Symposium - NYRocks’97, New York, USA.http://dx.doi.org/10.1016/s1365-1609(97)00053-1.

      [9] Chen SG, Zhao J (1998), Use of monitoring records and management system in Ertan cavern construction. Rock Mech. Rock Eng., 31 (2), 125–131.http://dx.doi.org/10.1007/s006030050013.

      [10] Cruse TA (1988), Boundary Element Analysis in Computational FractureMechanics, Kluwer, Dordrecht, the Netherlands.http://dx.doi.org/10.1007/978-94-009-1385-1.

      [11] Cruse TA (1996), BIE Fracture Mechanics Analysis: 25 Years of Developments, Computational Mech., 18, pp. 1–11.http://dx.doi.org/10.1007/BF00384172.

      [12] Dong F, Song HW, Guo ZH, Liang S (1994), The surrounding rock supporting theory based on the loosening zone. J. China Coal Soc., 19 (1), 21–32.

      [13] Dong F, Song HW, Jing HW, Zhou RZ (1996), Surrounding Rock State of Underground Projects and Bolt Performance Mechanism, Wanguo Academy Publishing House, Beijing (1996), pp. 283–286.

      [14] Hamdan N (2013), Two-Dimensional Numerical Modelling of Wave Propagation in Soil Media. PhD thesis. Department of Geotechnical Engineering, Institute for Infrastructure & Environment, Heriot-Watt University, September 2013.

      [15] Hoek E, Kaiser PK, Bawden WF (1995). Support of underground excavations in hard rock. Taylor & Francis Group, p 215.

      [16] Islam MR,Faruque MO,Shinjo R (2015),Damage zone propagation and support pressure estimationaround two access tunnels of the Barapukuria coalmine in Bangladesh: a two-dimensional numerical modeling approach. International Journal of Advanced Geosciences, 3 (2) (2015) 14-24. http://dx.doi.org/10.14419/ijag.v3i2.4865.

      [17] Islam MR, and Faruque, M.O., 2012. Numerical modeling of slope stability consideration of an open-pit coalmine in the Phulbari coal basin, NW Bangladesh. Electronic Journal of Geotechnical Engineering (EJGE) 17(y): 3717-3729.

      [18] Islam MR, Hayashi D, Kamruzzaman ABM (2009), Finite element modeling of stress distributions and problems for multi-slice longwall mining in Bangladesh, with special reference to the Barapukuria coal mine. International Journal of Coal Geology 78(2), 91–109. http://dx.doi.org/10.1016/j.coal.2008.10.006.

      [19] Islam MR, and Shinjo R (2009a), Mining-induced fault reactivation associated with the main conveyor belt roadway and safety of the Barapukuria Coal Mine in Bangladesh: Constraints from BEM simulations. International Journal of Coal Geology 79(4), 115-130. http://dx.doi.org/10.1016/j.coal.2009.06.007.

      [20] Islam MR,Shinjo R (2009b), Numerical simulation of stress distributions and displacements around an entry roadway with igneous intrusion and potential sources of seam gas emission of the Barapukuria coalmine, NW Bangladesh. International Journal of Coal Geology 78(4),249–262. http://dx.doi.org/10.1016/j.coal.2009.03.001.

      [21] Islam MR and Hayashi D (2008), Geology and coal bed methane resource potential of the Gondwana Barapukuria Coal Basin, Dinajpur, Bangladesh. International Journal of Coal Geology 75, 127–143.http://dx.doi.org/10.1016/j.coal.2008.05.008.

      [22] Islam MR, Islam, M.S., 2005. Water inrush Hazard in Barapukuria Coal Mine, Dinajpur District, Bangladesh. Bangladesh Journal of Geology 24, 1–17.

      [23] Jiang Y, Yoneda H, Tanabashi Y (2000), Theoretical estimation of loosening pressure on tunnels in soft rocks. Tunnelling Underground Space Technol., 16 (2), 99–105.http://dx.doi.org/10.1016/S0886-7798(01)00034-7.

      [24] Lang TA (1961), Theory and practice of rock bolting. Trans Soc Min Engrs Am Inst Min MetallPetrolmEngrs 220: 333–348.

      [25] Lu, S., Song. H., 1991. The surrounding rock classification method based on the loosening zone. Proceedings of the 2nd International Mining Symposium, China University of Mining and Technology.

      [26] Manolis GD. Davies TG, (1993), Boundary Element Techniques in Geomechanics. Computational Mechanics Publications, Elsevier Applied Science, London New York, 1993.

      [27] MikkolaR,Viitala (2000), Cave-ins in the Paijanne tunnel and their repair. Tunnelling Underground Space Technol., 15(2), 129-138.http://dx.doi.org/10.1016/S0886-7798(00)00040-7.

      [28] Mukherjee S (1982), Boundary Element Methods in Creep and Fracture, Applied Science Publishers, New York.

      [29] MuyaMS, He B, Wang J, Li G (2006), Effects of Rock Bolting on Stress Distribution around Tunnel Using the Elastoplastic Model. Journal of China University of Geosciences, 17, 337–341.http://dx.doi.org/10.1016/S1002-0705(07)60008-9.

      [30] Pacher F (1964), Deformationsmessungen in versuchsstollenalsmittelzurerforschung des gebirgsverhaltens und zurbemessung des ausbaues. Felsmechanik und Ingenieurs-geologieSupplementum (4): 149–161.http://dx.doi.org/10.1007/978-3-662-25703-6_12.

      [31] Rabcewicz LV (1964). The new Austrian tunnelling method. Water Power 16: 453–515

      [32] Song HW, Lu SM (2001), Repair of a Deep Mine Permanent Access Tunnel Using Bolt, Mesh and Shotcrete. Tunnelling and Underground Space Technology16, 235-240.http://dx.doi.org/10.1016/S0886-7798(01)00045-1.

      [33] Utili S, Crosta GB (2011a), Modelling the evolution of natural slopes subject to weathering: part I. Limit analysis approach. J Geophys Res Earth Surf 116:F01016.

      [34] Utili S, Crosta GB (2011b), Modelling the evolution of natural slopes subject to weathering: part II. Discrete element approach. J Geophys Res Earth Surf 116:F01017.

      [35] Windsor CR, Thompson AG (1993), Rock reinforcement – technology, testing, design and evaluation. In: Hudson JA (ed) Comprehensive Rock Engineering, v. 4, PergamonPress,Oxford, pp 451–484.http://dx.doi.org/10.1016/b978-0-08-042067-7.50023-4.

  • Downloads

  • How to Cite

    Islam, M. K., & Islam, M. R. (2016). Stress characterization and support measures estimation around a coalmine tunnel passing through jointed rock masses: constraints from BEM simulation. International Journal of Advanced Geosciences, 4(2), 21-27. https://doi.org/10.14419/ijag.v4i2.6196

    Received date: 2016-05-05

    Accepted date: 2016-05-30

    Published date: 2016-06-16