Stress-drop effect on brittleness evaluation of rock materials

Abstract

Uniaxial or triaxial compression test of cylindrical rock specimens using rock mechanics testing machine is a basic experimental method to study the strength and deformation characteristics of rock and the development process of rock fracture. Extensive literature review has been conducted on this issue; meanwhile, experimental and numerical studies have been conducted on the stress-drop effect on the brittleness of rock materials. A plastic flow factor of λ is proposed to describe the stress-drop effect. Evaluation methods of the factor λ corresponding to the four yield criteria of rock mass are proposed. Those four yield criteria are Tresca criterion, von-Mises criterion, Mohr-Coulomb criterion and Drucker-Prager criterion. For simplicity purposes, an engineering approximation approach has been proposed to evaluate the stress-drop with a non-zero strain increment. Numerical simulation results validated the effectiveness of the plastic flow factors λ as well as the engineering approximation approach. Based on the results in this study, finite element code can be programmed for brittle materials with stress-drop, which has the potential to be readily incorporated in finite element codes.

Keywords

rock material / stress-drop effect / plastic flow factor / strength criteria

References

[1] TarasovB, PotvinY. Universal criteria for rock brittleness estimation under triaxial compression [J]. International Journal of Rock Mechanics and Mining Sciences, 2013, 59(4): 57-69

[2] LabuzJ F, BiolziL. Experiments with rock: Remarks on strength and stability issues [J]. International Journal of Rock Mechanics & Mining Sciences, 2007, 44(4): 525-537

[3] YangS-Q, JingH-W, WangS-Y. Experimental investigation on the strength, deformability, failure behavior and acoustic emission locations of red sandstone under triaxial compression [J]. Rock Mechanics and Rock Engineering, 2012, 45(4): 583-606

[4] WongT-F, BaudP. The brittle-ductile transition in porous rock: A review [J]. Journal of Structural Geology, 2012, 44(11): 25-53

[5] WuQ-H, LiX-B, TaoM, DongL-J. Conventional triaxial compression on hollow cylinders of sandstone with various fillings: Relationship of surrounding rock with support [J]. Journal of Central South University, 2018, 25(8): 1976-1986

[6] ZengW, YangS-Q, TianW-L, KaiW. Numerical investigation on permeability evolution behavior of rock by an improved flow-coupling algorithm in particle flow code [J]. Journal of Central South University, 2018, 25(6): 1367-1385

[7] XuX-L, KarakusM, GaoF, ZhangZ-W. Thermal damage constitutive model for rock considering damage threshold and residual strength [J]. Journal of Central South University, 2018, 25(10): 2523-2536

[8] KahramanS. Correlation of TBM and drilling machine performances with rock brittleness [J]. Engineering Geology, 2002, 65(4): 269-283

[9] AltindagR. The evaluation of rock brittleness concept on rotary blast hole drills [J]. Journal of the Southern African Institute of Mining and Metallurgy, 2002, 102: 61-66

[10] GongQ-M, ZhaoJ. Influence of rock brittleness on TBM penetration rate in Singapore granite [J]. Tunnelling and Underground Space Technology, 2007, 22: 317-324

[11] ALTINDAG R. The role of rock brittleness on analysis of percussive drilling performance [C]// Proceedings of 5th National Rock Mechanics. Turkish, 2000: 105–112.

[12] HajiabdolmajidV, KaiserP. Brittleness of rock and stability assessment in hard rock [J]. Tunneling and Underground Space Technology, 2003, 18(1): 35-48

[13] CopurH, BilginN, TuncdemirH, BalciC. A set of indices based on indentation tests for assessment of rock cutting performance and rock properties [J]. Journal of the Southern African Institute of Mining and Metallurgy, 2003, 103(9): 589-599

[14] JarvieD M, HillR J, RubleT E P R M. Unconventional shale-gas systems: The Mississippian Barnett Shale of north-central Texas as one model for thermo genic shale-gas assessment [J]. AAPG Bull, 2007, 91(4): 475-499

[15] MiskiminsJ L. The impact of mechanical stratigraphy on hydraulic fracture growth and design considerations for horizontal wells [J]. Bulletin, 2012, 91: 475-499

[16] RICKMAN R, MULLEN M, PETRE J, GRIESER W V, KUNDERT D. A practical use of shale petro-physics for stimulation design optimization: all shale plays are not clones of the barnett shale [C]// Presented at the SPE Anuual Technical Conference and Exhibition. Denver, Colorado, 2008, September. SPE-115258.

[17] SuorineniF T, ChinnasaneD R, KaiserP K. A procedure for determining rock-type specific Hoek-Brown brittle parameters [J]. Rock Mechanics Rock Engineering, 2009, 42(6): 849-881

[18] WangF P, GaleJ F W. Screening criteria for shale-gas systems [J]. Gulf Coast Association of Geological Societies Transactions, 2009, 59: 779-793

[19] YagizS. Assessment of brittleness using rock strength and density with punch penetration test [J]. Tunneling and Underground Space Technology, 2009, 24(1): 66-74

[20] AltindagR. Assessment of some brittleness indexes in rock drilling efficiency [J]. Rock Mechanics Rock Engineering, 2010, 43(3): 361-370

[21] TarasovB G, PotvinY. Absolute, relative and intrinsic rock brittleness at compression [J]. Mining Technology, 2012, 121(4): 218-225

[22] TarasovB G, PotvinY. Universal criteria for rock brittleness estimation under triaxial compression [J]. International Journal of Rock Mechanics and Mining Science, 2013, 59(4): 57-69

[23] MengF-Z, ZhouH, ZhangC-Q, XuR-C, LuJ-J. Evaluation methodology of brittleness of rock based on post-peak stress-strain curves [J]. Rock Mechanics Rock Engineering, 2015, 48(5): 1787-1805

[24] JinX-C, ShahS N, RoegiersJ C, ZhangB. An Integrated petrophysics and geomechanics approach for fracability evaluation in shale reservoirs [J]. SPE Journal, 2015, 20(3): 518-526

[25] RybackiE, MeierT, DresenG. What controls the mechanical properties of shale rocks? -Part II: Brittleness [J]. Journal of Petroleum Science and Engineering, 2016, 144(8): 39-58