Numerical simulation of mechanisms of deformation, failure and energy dissipation in porous rock media subjected to wave stresses

The pore characteristics, mineral compositions, physical and mechanical properties of the subarkose sandstones were acquired by means of CT scan, X-ray diffraction and physical tests. A few physical models possessing the same pore characteristics and matrix properties but different porosities compared to the natural sandstones were developed. The 3D finite element models of the rock media with varied porosities were established based on the CT image processing of the physical models and the MIMICS software platform. The failure processes of the porous rock media loaded by the split Hopkinson pressure bar (SHPB) were simulated by satisfying the elastic wave propagation theory. The dynamic responses, stress transition, deformation and failure mechanisms of the porous rock media subjected to the wave stresses were analyzed. It is shown that an explicit and quantitative analysis of the stress, strain and deformation and failure mechanisms of porous rocks under the wave stresses can be achieved by using the developed 3D finite element models. With applied wave stresses of certain amplitude and velocity, no evident pore deformation was observed for the rock media with a porosity less than 15%. The deformation is dominantly the combination of microplasticity (shear strain), cracking (tensile strain) of matrix and coalescence of the cracked regions around pores. Shear stresses lead to microplasticity, while tensile stresses result in cracking of the matrix. Cracking and coalescence of the matrix elements in the neighborhood of pores resulted from the high transverse tensile stress or tensile strain which exceeded the threshold values. The simulation results of stress wave propagation, deformation and failure mechanisms and energy dissipation in porous rock media were in good agreement with the physical tests. The present study provides a reference for analyzing the intrinsic mechanisms of the complex dynamic response, stress transit mode, deformation and failure mechanisms and the disaster mechanisms of rock media.

[1]  M. D. Sharma,et al.  Three-dimensional wave propagation in a general anisotropic poroelastic medium: phase velocity, group velocity and polarization , 2004 .

[2]  I. Vardoulakis,et al.  Local rock surface instabilities , 1986 .

[3]  J. G. Williams,et al.  Stress wave propagation effects in split Hopkinson pressure bar tests , 1995, Proceedings of the Royal Society of London. Series A: Mathematical and Physical Sciences.

[4]  E. Mashinskii.  Experimental study of the amplitude effect on wave velocity and attenuation in consolidated rocks under confining pressure , 2005 .

[5]  Y. Ju,et al.  Laboratory investigation on mechanisms of stress wave propagations in porous media , 2009 .

[6]  Børge Arntsen,et al.  Numerical simulation of the Biot slow wave in water‐saturated Nivelsteiner Sandstone , 2001 .

[7]  M. Sharma.  Surface waves in a general anisotropic poroelastic solid half-space , 2004 .

[8]  M. Bouchon,et al.  Numerical simulation of the propagation of P waves in fractured media , 1999 .

[9]  R. Zipf,et al.  Seismological and energy balance constraints on the mechanism of a catastrophic bump in the Book Cliffs coal mining district, Utah, U.S.A. , 1997 .

[10]  Yang Ju,et al.  A statistical model for porous structure of rocks , 2008 .

[11]  Boris Gurevich,et al.  Attenuation and dispersion of P-waves in porous rocks with planar fractures: Comparison of theory and numerical simulations , 2006 .

[12]  D. A. Gorham,et al.  An improved method for compressive stress-strain measurements at very high strain rates , 1992, Proceedings of the Royal Society of London. Series A: Mathematical and Physical Sciences.

[13]  C. A. Tang,et al.  Numerical simulation of damage accumulation and seismic energy release during brittle rock failure-Part II: Rib pillar collapse , 1998 .

[14]  José M. Carcione,et al.  Wave propagation in anisotropic, saturated porous media: Plane‐wave theory and numerical simulation , 1996 .

[15]  F.E. Heuze,et al.  Insights into ground shock in jointed rocks and the response of structures there-in , 2006 .

[16]  E. A. Kraut,et al.  Advances in the theory of anisotropic elastic wave propagation , 1963 .

[17]  R. P. Young,et al.  Dynamic modelling of induced seismicity , 2004 .

[18]  P. Johnson,et al.  Laboratory study of linear and nonlinear elastic pulse propagation in sandstone , 1996 .

[19]  Basil Beamish,et al.  Instantaneous outbursts in underground coal mines: An overview and association with coal type , 1998 .

[20]  J. Carcione,et al.  A constitutive equation and generalized Gassmann modulus for multimineral porous media , 2005 .

[21]  A. L. Florence,et al.  Experimental and analytical study of the dynamic response of low‐porosity brittle rocks , 1993 .

[22]  Heping Xie,et al.  Fractals in Rock Mechanics , 2020 .

[23]  Yoshiaki Fujii,et al.  Prediction of coal face rockbursts and microseismicity in deep longwall coal mining , 1997 .

[24]  J. Santamarina,et al.  Shear wave propagation in jointed rock: state of stress , 2002 .

[25]  S. Lasocki,et al.  Seismic hazard assessment under complex source size distribution of mining-induced seismicity , 2008 .

[26]  S. C. Hunter,et al.  The Dynamic Compression Testing of Solids by the Method of the Split Hopkinson Pressure Bar , 1963 .

[27]  M. Biot.  Theory of Propagation of Elastic Waves in a Fluid‐Saturated Porous Solid. I. Low‐Frequency Range , 1956 .

[28]  U. S. Lindholm.  Some experiments with the split hopkinson pressure bar , 1964 .

[29]  Stuart Crampin,et al.  The fracture criticality of crustal rocks , 1994 .

[30]  M. J. Forrestal,et al.  A split Hopkinson pressure bar technique to determine compressive stress-strain data for rock materials , 2001 .

[31]  C. A. Tang,et al.  Instability leading to coal bumps and nonlinear evolutionary mechanisms for a coal-pillar-and-roof system , 2006 .

[32]  Measurements of wave processes in isotropic and transversely isotropic elastic rocks , 1974 .

[33]  Y. Xuan,et al.  Investigation of one-dimensional Si/SiO2 hotonic crystals for thermophotovoltaic filter , 2008 .