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Creep Failure of Roof Stratum Above Mined-Out Area

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Abstract

By taking into account the rheological behavior of the rock mass, the creep failure of a roof stratum seated on pillars in mined-out area is analyzed through a newly developed visco-elastic model. The time-dependent deflection of the roof stratum is obtained by numerical inversion of Laplace transform. The study shows that when creep properties of both the pillars and roof stratum are considered, the expected deflection in the roof stratum increases with time. Consequently, the roof would fail when the critical tensile stress is reached as the result of the increased deflection. To demonstrate the present analytical procedure, the failure time of roof stratum of the Xingtai Gypsum Mine in China was estimated, and the results obtained agreed with the observation. The case study indicates that the analytic approach provides a new way to assess the potential impact of the time-dependence of the roof stratum deformation and is useful in predicting its stability above a mined-out area.

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Abbreviations

a, b, h :

Half of length, half of width, and thickness of the roof stratum

α, β:

Coefficients of regression

A, H, D :

Area of the

δ:

Plastic constraint

Ep, Er :

Young’s modulus of the pillar and the roof

η1, η2, k1, k2 :

Coefficients viscosity and elasticity modulus for Burgers model

P, Q, P1, Q1, P2, Q2 :

Linear operators with respect to time

Pr1(s), Qr1(s), Pr2(s), Qr2(s):

Linear operators with respect to Laplace variable for associated with the roof

p 0, p 1, p 2, q 0, q 1, q 2,:

Material constants

s :

Transform variable

σ p :

Critical strength of the pillar

σ:

Average strength of the pillar

w 0, w 0 :

Deflection at the center of the plate in terms of time and transform variable respectively

ζ:

Ratio of the accumulated cross area of pillars to total mined out area

\(\hat{\sigma },\hat{\varepsilon }\) :

Transformed stress and strain

σ ii , ε ii , s ij, d ij :

Spherical stress, spherical strain, deviatoric stress, and deviatoric strain respectively

t], σc :

Tensile strength and uniaxial compressive strength of the rock mass

σ xmax :

Maximum stress in x-direction

References

  • Auvray C et al (2008) The influence of relative humidity on the rate of convergence in an underground gypsum mine. Int J Rock Mech Min Sci 45:1454–1468

    Article  Google Scholar 

  • Bieniawski ZT, van Heerden WL (1975) The significance of in situ tests on large rock specimens. Int J Rock Mech Min Sci 12:101–113

    Google Scholar 

  • Castellanza R et al (2008) An attempt to predict the failure time of abandoned mine pillar. Rock Mech Rock Eng 41(3):377–401

    Article  Google Scholar 

  • Claire S et al (2009) Discrete modeling of time-dependent rockfill behavior. Int J Numer Anal Methods Geomech 33:665–685

    Article  Google Scholar 

  • Cohen AM (2006) Numerical methods for Laplace transform inversion [M]. Springer, New York

    Google Scholar 

  • Crump KS (1976) Numerical inversion of Laplace transformations using a Fourier series approximation. J Assoc Comput Mach 23(1):89–96

    Article  Google Scholar 

  • Dubner H, Abate J (1968) Numerical inversion of Laplace transforms by relating them to the Finite Fourier cosine transforms. J Assoc Comput Mach 15(1):115–123

    Article  Google Scholar 

  • Durbin F (1974) Numerical inversion of Laplace transforms: an efficient improvement to Dubner & Abate’s method. Comput J 17(4):371–376

    Google Scholar 

  • Fan P et al (2008) Numerical inversion of Laplace transforms in viscoelastic problems by Fourier series expansion. Chin J Theor Appl Mech 40(2):215–221 (in Chinese)

    Google Scholar 

  • Findley WN, Lai JS, Onaran K (1976) Creep and relaxation of nonlinear viscoelastic materials—with an introduction to linear viscoelasticity. North-Holland Company, New York

    Google Scholar 

  • He X et al (2004) Identification of permeability coefficient of rock mass in dam foundation based on genetic neutral network. Chin J Rock Mech Eng 23(5):751–757

    Google Scholar 

  • Jin ZM, Xu LS (1994) Control of strong roof strata in coal mine [M]. Press of Coal Mining Industry, Beijing (in Chinese)

    Google Scholar 

  • Kousick B (1999) A unique approach to determine the time-dependent in situ strength of coal pillars. In: Proceedings of Second International Workshop on Coal Pillar Mechanics and Design, Vail, pp 5–8

  • Lai XP, Zhang LJ et al (2003) Application of neural network in statistics and perdition of damage evolution of large-scale mined-out area [J]. J Univ Sci Technol 25(4):301–304 (in Chinese)

    Google Scholar 

  • Malan DF (2002) Simulating the time-dependent behaviour of excavations of hard rock. Rock Mech Rock Eng 34(4):225–254

    Article  Google Scholar 

  • Martin CD, Maybee WG (2000) The strength of hard-rock pillars. Int J Rock Mech Min Sci 37:1239–1246

    Article  Google Scholar 

  • Mohammad N, Reddish DJ, Stace LR (1997) The relation between in situ and laboratory rock properties used in numerical modelling. Int J Rock Mech Min Sci 34(2):289–297

    Article  Google Scholar 

  • Napier JL (1997) A viscoplastic discontinuum model of time-dependent fracture and seismicity effect in brittle rock. Int J Rock Mech Min Sci 34(7):1075–1089

    Article  Google Scholar 

  • Qian MG, Miao XX (2003) The key strata theory and strata control [M]. Press of China University of Science and Technology, Jiangsu (in Chinese)

  • Salamon MDG, Munro AH (1967) A study of the strength of coal pillars. J S Afr Inst Min Metall 68:55267

    Google Scholar 

  • Sandrine LG (1999) Experimental design optimization and thermophysical parameter estimation of composite materials using genetic algorithms (PhD thesis). Virginia Polytechnic Institute and State University, Blacksburg

  • Shen NQ, Yang JW et al (2001) Neural network based collapse prediction of mined out area [J]. Coal Geol Explor 20(3):42–43 (in Chinese)

    Google Scholar 

  • Song Y (2005) Water injection, compressive fracturing and softening—the control techniques for strong and hard collapse roof strata of coal seam [M]. Press of Coal Mining Industry, Beijing (in Chinese)

  • Sterpi D, Gioda G (2009) Visco-plastic behavior around advancing tunnels in squeezing rock. Rock Mech Rock Eng 42:319–339

    Article  Google Scholar 

  • Wang XP, Cao LM (2002) Theory of genetic algorithm, application and software realization [M]. Press of Xi’an Jiaotong University, Xi’an

  • Wang J-A, Shang XC, Ma HT (2008a) Investigation of catastrophic ground collapse in Xingtai gypsum mines in China. Int J Rock Mech Min Sci 45:1480–1499

    Article  Google Scholar 

  • Wang J-A, Shang XC, Liu H (2008b) Study on fracture mechanism and catastrophic collapse of strong roof strata above the mined area [J]. J China Coal Soc 33(8):850–855

    Google Scholar 

  • Wei PJ, Zhang SY, Wu YL (1999) Correspondence principle and numerical methods of inverse integral transformation in viscoelastic mechanics. Adv Mech 29(3):317–330 (in Chinese)

    Google Scholar 

  • Wu LX, Wang JZ et al (1994) Strip mining theory and practice under buildings [M]. Press of China University of Science and Technology, Jiangsu (in Chinese)

    Google Scholar 

Download references

Acknowledgments

The presented work has been financially supported by the State Key Foundation Research (973 Project) granted by the Ministry of China Science and Technology (No. 2010CB731500). Prof. M. Kwaśniewski from the Silesian Technical University, Poland, and Prof. Lin Jeen-Shan from the University of Pittsburgh, USA, have provided their kind help in modification of the manuscript, which are gratefully acknowledged.

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Correspondence to J. -A. Wang.

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Wang, J.A., Li, D.Z. & Shang, X.C. Creep Failure of Roof Stratum Above Mined-Out Area. Rock Mech Rock Eng 45, 533–546 (2012). https://doi.org/10.1007/s00603-011-0216-8

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