Characteristics of stress thresholds of granite after triaxial dynamic impact treatment

Abstract

The geostress and rock blasting in underground engineering may greatly affect the stress thresholds of surrounding rock. In this study, pre-damage impact tests were first conducted on granite under varying confining pressures (5, 10 and 15 MPa) and numbers of impacts (1, 5, 10 and 15 impacts). Then, uniaxial compression tests were undertaken on the pre-damaged granite to study the evolution of stress thresholds using the crack volume strain method and acoustic emission method. The crack damage stre0sses determined by the two methods were compared. Additionally, based on the rise time amplitude and average frequency, the evolution law of microcracks inside rock specimens was revealed, and an improved acoustic emission method was proposed. The results indicated that as the number of impacts increased, the crack closure stress, crack damage stress, and peak stress of granite specimens initially rose and then declined, while they continuously increased with the confining pressure. The proportion of shear cracks first declined and then rose with greater number of impacts and decreased with higher confining pressure, and that of tensile cracks showed the opposite trend. The improved acoustic emission method was more accurate in identifying the crack damage stress.

Keywords

stress threshold / crack volume strain / crack damage stress / rock damage / acoustic emission

References

[1] LiS, ZhuW-c, NiuL-l, et al.. Experimental study on creep of double-rock samples disturbed by dynamic impact [J]. International Journal of Rock Mechanics and Mining Sciences, 2021, 146104895

[2] DiederichsM S, KaiserP K, EberhardtE. Damage initiation and propagation in hard rock during tunnelling and the influence of near-face stress rotation [J]. International Journal of Rock Mechanics and Mining Sciences, 2004, 41(5): 785-812

[3] MartinC D, ChandlerN A. The progressive fracture of Lac du Bonnet granite [J]. International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 1994, 31(6): 643-659

[4] MartinC D. Seventeenth cohesion loss and stress Canadian geotechnical colloquium: The effect of path on brittle rock strong [J]. Can Geotech J, 1997, 34(5): 698-725

[5] LiX F, LiH B, LiuL W, et al.. Investigating the crack initiation and propagation mechanism in brittle rocks using grain-based finite-discrete element method [J]. International Journal of Rock Mechanics and Mining Sciences, 2020, 127104219

[6] LajtaiE Z. Microscopic fracture processes in a granite [J]. Rock Mechanics and Rock Engineering, 1998, 31(4): 237-250

[7] LajtaiE Z, Scott DuncanE J, CarterB J. The effect of strain rate on rock strength [J]. Rock Mechanics and Rock Engineering, 1991, 24(2): 99-109

[8] BraceW F, PauldingB W, ScholzC. Dilatancy in the fracture of crystalline rocks [J]. Journal of Geophysical Research, 1966, 71(16): 3939-3953

[9] EberhardtE, SteadD, StimpsonB, et al.. Identifying crack initiation and propagation thresholds in brittle rock [J]. Canadian Geotechnical Journal, 1998, 35(2): 222-233

[10] EberhardtE, SteadD, StimpsonB, et al.. Changes in acoustic event properties with progressive fracture damage [J]. International Journal of Rock Mechanics and Mining Sciences, 1997, 34(34): 71.e1-71.e12

[11] CaiX, ChengC-q, ZhouZ-l, et al.. Rock mass watering for rock-burst prevention: Some thoughts on the mechanisms deduced from laboratory results [J]. Bulletin of Engineering Geology and the Environment, 2021, 80(11): 8725-8743

[12] LiH, ZhongR-z, PelL, et al.. A new volumetric strain-based method for determining the crack initiation threshold of rocks under compression [J]. Rock Mechanics and Rock Engineering, 2024, 57(2): 1329-1351

[13] GongF-q, WuC. Identifying crack compaction and crack damage stress thresholds of rock using load - unload response ratio (LURR) theory [J]. Rock Mechanics and Rock Engineering, 2020, 53(2): 943-954

[14] KimJ S, LeeK S, ChoW J, et al.. A comparative evaluation of stress-strain and acoustic emission methods for quantitative damage assessments of brittle rock [J]. Rock Mechanics and Rock Engineering, 2015, 48(2): 495-508

[15] WangC-l, DuG-y, HanY, et al.. Evolution characteristics of acoustic emission and strain energy for deep granite under different damage stages [J]. Geomechanics and Geophysics for Geo-Energy and Geo-Resources, 2023, 9114

[16] NingJ-g, WangJ, JiangJ-q, et al.. Estimation of crack initiation and propagation thresholds of confined brittle coal specimens based on energy dissipation theory [J]. Rock Mechanics and Rock Engineering, 2018, 51(1): 119-134

[17] PengJ, CaiM, WuZ-j, et al.. Crack initiation stress of thermally damaged rock under uniaxial compression [J]. Engineering Geology, 2023, 326107317

[18] SunX, HardyH R, RaoM. Acoustic emission monitoring and analysis procedures utilized during deformation studies on geologic materials [M]. Acoustic Emission: Current Practice and Future Directions. ASTM International100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, 1991365380

[19] ZhaoX G, CaiM, WangJ, et al.. Damage stress and acoustic emission characteristics of the Beishan granite [J]. International Journal of Rock Mechanics and Mining Sciences, 2013, 64: 258-269

[20] LeiX L, NishizawaO, KusunoseK, et al.. Compressive failure of mudstone samples containing quartz veins using rapid AE monitoring: The role of asperities [J]. Tectonophysics, 2000, 328(34): 329-340

[21] IshidaT, LabuzJ F, MantheiG, et al.. ISRM suggested method for laboratory acoustic emission monitoring [J]. Rock Mechanics and Rock Engineering, 2017, 50(3): 665-674

[22] RückM, RahnerR, SoneH, et al.. Initiation and propagation of mixed mode fractures in granite and sandstone [J]. Tectonophysics, 2017, 717: 270-283

[23] MoradianZ, EinsteinH H, BallivyG. Detection of cracking levels in brittle rocks by parametric analysis of the acoustic emission signals [J]. Rock Mechanics and Rock Engineering, 2016, 49(3): 785-800

[24] ZhouZ-l, WangP-y, CaiX, et al.. Estimating crack closure and damage stress thresholds of rock during uniaxial compression based on axial plastic strain [J]. Journal of Central South University, 2023, 30(10): 3335-3348

[25] GongF-q, SiX-f, LiX-b, et al.. Dynamic triaxial compression tests on sandstone at high strain rates and low confining pressures with split Hopkinson pressure bar [J]. International Journal of Rock Mechanics and Mining Sciences, 2019, 113: 211-219

[26] PengK, ZhangY, WangY-m, et al.. Static compression behavior and strength weakening mechanism of dynamically damaged granite after water soaking [J]. Engineering Failure Analysis, 2024, 156107760

[27] WangY, LiX, ZhengB. Stress - strain behavior of soil-rock mixture at medium strain rates—Response to seismic dynamic loading [J]. Soil Dynamics and Earthquake Engineering, 2017, 93: 7-17

[28] ZhouY X, XiaK, LiX B, et al.. Suggested methods for determining the dynamic strength parameters and mode-I fracture toughness of rock materials [M]. The ISRM Suggested Methods for Rock Characterization, Testing and Monitoring: 2007–2014, 2011, Cham. Springer International Publishing. 3544

[29] LuoK, WangY-m, LuoS, et al.. Dynamic compressive behavior of impact-damaged and water-soaked sandstone with different length-to-diameter ratios [J]. Archives of Civil and Mechanical Engineering, 2023, 24121

[30] ZhuC, XuY-z, HeM-c, et al.. Identification of failure behaviors of underground structures under dynamic loading using machine learning [J]. Journal of Rock Mechanics and Geotechnical Engineering, 2025, 17(1): 414-431

[31] GaoM-z, XieJ, GaoY-n, et al.. Mechanical behavior of coal under different mining rates: A case study from laboratory experiments to field testing [J]. International Journal of Mining Science and Technology, 2021, 31(5): 825-841

[32] ZhangZ-h, LiangZ-z, TangC-a, et al.. A comparative study of current methods for determining stress thresholds of rock subjected to compression [J]. Rock Mechanics and Rock Engineering, 2023, 56(11): 7795-7818

[33] ZhouZ-q, WangJ-g, JiangX-w, et al.. Confining pressure effect of dynamic failure of limestone under cyclic impact [J]. Modern Tunnelling Technology, 2023, 60(6): 228-236

[34] XuJ-h, KangY, LiuF, et al.. Mechanical properties and fracture behavior of flawed granite under dynamic loading [J]. Soil Dynamics and Earthquake Engineering, 2021, 142106569

[35] PengK, RenJ, WangY-m, et al.. Mechanical and damage evolution characteristics of granite after heating-cooling cycles [J]. Journal of Central South University, 2023, 30(12): 4082-4096

[36] CaiM, KaiserP K, TasakaY, et al.. Generalized crack initiation and crack damage stress thresholds of brittle rock masses near underground excavations [J]. International Journal of Rock Mechanics and Mining Sciences, 2004, 41(5): 833-847

[37] RenF-q, ZhuC, KarakusM, et al.. Rockburst mitigation mechanisms of pressure relief borehole and rock bolt support: Insights from granite true triaxial unloading rockburst tests [J]. Engineering Geology, 2024, 336107571

[38] WuC, GongF-q, LuoY. A new quantitative method to identify the crack damage stress of rock using AE detection parameters [J]. Bulletin of Engineering Geology and the Environment, 2021, 80(1): 519-531

[39] PengK, RenJ, WuT, et al.. Influences of arch height and stress sate on tunnel failure: Insights from orthogonal true-triaxial experiment [J]. Theoretical and Applied Fracture Mechanics, 2025, 136104824

[40] ZhaoY-l, WangY-x, TangL-ming. The compressive-shear fracture strength of rock containing water based on Druker-Prager failure criterion [J]. Arabian Journal of Geosciences, 2019, 1215452

[41] AggelisD G, SouliotiD V, SapouridisN, et al.. Acoustic emission characterization of the fracture process in fibre reinforced concrete [J]. Construction and Building Materials, 2011, 25(11): 4126-4131

[42] ZhangZ-h, DengJ-hui. A new method for determining the crack classification criterion in acoustic emission parameter analysis [J]. International Journal of Rock Mechanics and Mining Sciences, 2020, 130104323

[43] FengP, WeiM-d, DaiF, et al.. DEM investigation on the mechanical behaviors of flawed specimens subjected to coupled static-dynamic loads [J]. Soil Dynamics and Earthquake Engineering, 2020, 135106220

[44] LiH-b, XiaX, LiJ-c, et al.. Rock damage control in bedrock blasting excavation for a nuclear power plant [J]. International Journal of Rock Mechanics and Mining Sciences, 2011, 48(2): 210-218

RIGHTS & PERMISSIONS

Central South University