Characteristics of microseismic b-value associated with rock mass large deformation in underground powerhouse caverns at different stress levels

Abstract

Rock mass large deformation in underground powerhouse caverns has been a severe hazard in hydropower engineering in Southwest China. During the development of rock mass large deformation, a sequence of fractures was generated that can be monitored using microseismic (MS) monitoring techniques. Two MS monitoring systems were established in two typical underground powerhouse caverns featuring distinct geostress levels. The MS b-values associated with rock mass large deformation and their temporal variation are analysed. The results showed that the MS b-value in course of rock mass deformation was less than 1.0 in the underground powerhouse caverns at a high stress level while larger than 1.5 at a low stress level. Prior to the rock mass deformation, the MS b-values derived from both the high-stress and low-stress underground powerhouse caverns show an incremental decrease over 10% within 10 d. The results contribute to understanding the fracturing characteristics of MS sources associated with rock mass large deformation and provide a reference for early warning of rock mass large deformation in underground powerhouse caverns.

Keywords

underground powerhouse caverns / rock mass large deformation / stress level / microseismic monitoring / b-value

References

[1] LaiX P, CaiM F, XieM W. In situ monitoring and analysis of rock mass behavior prior to collapse of the main transport roadway in Linglong Gold Mine, China [J]. International Journal of Rock Mechanics and Mining Sciences, 2006, 43(4): 640-646

[2] LiZ-L, DouL-M, WangG-F, et al.. Risk evaluation of rock burst through theory of static and dynamic stresses superposition [J]. Journal of Central South University, 2015, 22(2): 676-683

[3] TangL-Z, XiaK W. Seismological method for prediction of areal rockbursts in deep mine with seismic source mechanism and unstable failure theory [J]. Journal of Central South University of Technology, 2010, 17(5): 947-953

[4] MaK, TangC A, WangL X, et al.. Stability analysis of underground oil storage Caverns by an integrated numerical and microseismic monitoring approach [J]. Tunnelling and Underground Space Technology, 2016, 54: 81-91

[5] StorkA L, VerdonJ P, KendallJ M. The microseismic response at the in Salah Carbon Capture and Storage (CCS) site [J]. International Journal of Greenhouse Gas Control, 2015, 32: 159-171

[6] CaiM, KaiserP K, MartinC D. Quantification of rock mass damage in underground excavations from microseismic event monitoring [J]. International Journal of Rock Mechanics and Mining Sciences, 2001, 38(8): 1135-1145

[7] CaiM, KaiserP K. Assessment of excavation damaged zone using a micromechanics model [J]. Tunnelling and Underground Space Technology, 2005, 20(4): 301

[8] DaiF, LiB, XuN-W, et al.. Deformation forecasting and stability analysis of large-scale underground powerhouse Caverns from microseismic monitoring [J]. International Journal of Rock Mechanics and Mining Sciences, 2016, 86: 269-281

[9] LiB, XuN-W, DaiF, et al.. Dynamic analysis of rock mass deformation in large underground Caverns considering microseismic data [J]. International Journal of Rock Mechanics and Mining Sciences, 2019, 122104078

[10] MaK, TangC-A, XuN-W, et al.. Failure precursor of surrounding rock mass around cross tunnel in high-steep rock slope [J]. Journal of Central South University, 2013, 20(1): 207-217

[11] FengG-L, FengX-T, ChenB-R, et al.. Effects of structural planes on the microseismicity associated with rockburst development processes in deep tunnels of the Jinping-II Hydropower Station, China [J]. Tunnelling and Underground Space Technology, 2019, 84273-280

[12] XuN-W, TangC-N, LiH, et al.. Excavation-induced microseismicity: Microseismic monitoring and numerical simulation [J]. Journal of Zhejiang University: Science A, 2012, 13(6): 445-460

[13] HudymaM, PotvinY H. An engineering approach to seismic risk management in hardrock mines [J]. Rock Mechanics and Rock Engineering, 2010, 43(6): 891-906

[14] GutenbergB, RichterC F. Frequency of earthquakes in California [J]. Bulletin of the Seismological Society of America, 1944, 34(4): 185-188

[15] BormannP. Are new data suggesting a revision of the current M_w and M_e scaling formulas? [J]. Journal of Seismology, 2015, 19(4): 989-1002

[16] AkiK. Seismic displacements near a fault [J]. Journal of Geophysical Research, 1968, 73(16): 5359-5376

[17] ZhangP-H, YangT-H, YuQ-L, et al.. Microseismicity induced by fault activation during the fracture process of a crown pillar [J]. Rock Mechanics and Rock Engineering, 2015, 48(4): 1673-1682

[18] WyssM, ShimazakiK, WiemerS. Mapping active magma Chambers by b values beneath the off-Ito volcano, Japan [J]. Journal of Geophysical Research: Solid Earth, 1997, 102(B9): 20413-20422

[19] AmelungF, KingG. Earthquake scaling laws for creeping and non-creeping faults [J]. Geophysical Research Letters, 1997, 24(5): 507-510

[20] WiemerS, McnuttS R, WyssM. Temporal and three-dimensional spatial analyses of the frequency-magnitude distribution near Long Valley Caldera, California [J]. Geophysical Journal International, 1998, 134(2): 409-421

[21] SchorlemmerD, WiemerS, WyssM. Variations in earthquake-size distribution across different stress regimes [J]. Nature, 2005, 437(7058): 539-542

[22] WiemerS, WyssM. Mapping the frequency-magnitude distribution in asperities: An improved technique to calculate recurrence times? [J]. Journal of Geophysical Research: Solid Earth, 1997, 102(B7): 15115-15128

[23] KhanP K, ChakrabortyP P. The seismic b-value and its correlation with Bouguer gravity anomaly over the Shillong Plateau area: Tectonic implications [J]. Journal of Asian Earth Sciences, 2007, 29(1): 136-147

[24] MousaviS M. Mapping seismic moment and b-value within the continental-collision orogenic-belt region of the Iranian Plateau [J]. Journal of Geodynamics, 2017, 103: 26-41

[25] BoraD K, BorahK, MahantaR, et al.. Seismic b-values and its correlation with seismic moment and Bouguer gravity anomaly over Indo-Burma ranges of northeast India: Tectonic implications [J]. Tectonophysics, 2018, 728–729: 130-141

[26] KulhanekO, PerssonL, NuanninP. Variations of b-values preceding large earthquakes in the shallow subduction zones of Cocos and Nazca plates [J]. Journal of South American Earth Sciences, 2018, 82: 207-214

[27] LEGGE N, SPOTTISWOODE S. Fracturing and microseismicity ahead of a deep gold mine stope in the pre-remnant and remnant stages of mining [C]// 6th ISRM Congress, Montreal, Canada, 1987: 2071 -1048.

[28] LiuJ-P, FengX-T, LiY-H, et al.. Studies on temporal and spatial variation of microseismic activities in a deep metal mine [J]. International Journal of Rock Mechanics and Mining Sciences, 2013, 60: 171-179

[29] LuC-P, LiuG-J, LiuY, et al.. Microseismic multi-parameter characteristics of rockburst hazard induced by hard roof fall and high stress concentration [J]. International Journal of Rock Mechanics and Mining Sciences, 2015, 76: 18-32

[30] MaX, WestmanE, SlakerB, et al.. The b-value evolution of mining-induced seismicity and mainshock occurrences at hard-rock mines [J]. International Journal of Rock Mechanics and Mining Sciences, 2018, 104: 64-70

[31] Ministry of Water Resources of the People’s Republic of China. GB50287-99. Code for water resource and hydropower engineering geological investigation [S]. 1999, 82p. (in Chinese)

[32] SjöbergJ, ChristianssonR, HudsonJ A. ISRM suggested methods for rock stress estimation—Part 2: Overcoring methods [J]. International Journal of Rock Mechanics and Mining Sciences, 2003, 40(78): 999

[33] SugawaraK, ObaraY. Draft ISRM suggested method for in situ stress measurement using the compact conical-ended borehole overcoring (CCBO) technique [J]. International Journal of Rock Mechanics and Mining Sciences, 1999, 363307-322

[34] ChengL-J, LiZ-G, WangJ-S, WangD, XiaXDesign report on reinforcement measures for surrounding rock mass in underground group caverns of the Houziyan Hydropower Station along Dadu River [R], 2014, Chengdu, China, HydroChina Chengdu Engineering Corporation, 1163(in Chinese)

[35] StockwellR G, MansinhaL, LoweR P. Localization of the complex spectrum: The S transform [J]. IEEE Transactions on Signal Processing, 1996, 44(4): 998-1001

[36] HaimsonB C, CornetF H. ISRM Suggested Methods for rock stress estimation—Part 3: Hydraulic fracturing (HF) and/or hydraulic testing of pre-existing fractures (HTPF) [J]. International Journal of Rock Mechanics and Mining Sciences, 2003, 40(78): 1011-1020

[37] ZhangC-H, LiuH-B, ZhangL-LStability evaluation and supports design optimization for surrounding rock mass in underground powerhouse caverns at the Wudongde Hydropower Station along Jinsha River [R], 2015, Wuhan, China, Changjiang Institute of Survey, Planning, Design and Research, 5761(in Chinese)

[38] LiA, XuN-W, DaiF, et al.. Stability analysis and failure mechanism of the steeply inclined bedded rock masses surrounding a large underground opening [J]. Tunnelling and Underground Space Technology, 2018, 77: 45-58

[39] LiA, LiuY, DaiF, et al.. Continuum analysis of the structurally controlled displacements for large-scale underground Caverns in bedded rock masses [J]. Tunnelling and Underground Space Technology, 2020, 97: 103288

[40] WoessnerJ. Assessing the quality of earthquake catalogues: Estimating the magnitude of completeness and its uncertainty [J]. Bulletin of the Seismological Society of America, 2005, 95(2): 684-698

[41] GreenhoughJ, MainI G. A Poisson model for earthquake frequency uncertainties in seismic hazard analysis [J]. Geophysical Research Letters, 2008, 35(19): L19313

[42] LiuX-L, HanM-S, HeW, et al.. A new b value estimation method in rock acoustic emission testing [J]. Journal of Geophysical Research: Solid Earth, 2020, 12512e2020JB019658

[43] XuY, DaiF. Dynamic response and failure mechanism of brittle rocks under combined compression-shear loading experiments [J]. Rock Mechanics and Rock Engineering, 2018, 513747-764

[44] LiuY, DaiF, DongL, et al.. Experimental investigation on the fatigue mechanical properties of intermittently jointed rock models under cyclic uniaxial compression with different loading parameters [J]. Rock Mechanics and Rock Engineering, 2018, 51(1): 47-68

[45] FengG-L, FengX-T, ChenB-R, et al.. Characteristics of microseismicity during breakthrough in deep tunnels: Case study of Jinping-II hydropower station in China [J]. International Journal of Geomechanics, 2020, 20(2): 04019163

[46] XuY, DaiF, XuN W, et al.. Numerical investigation of dynamic rock fracture toughness determination using a semicircular bend specimen in split Hopkinson pressure bar testing [J]. Rock Mechanics and Rock Engineering, 2016, 493731-745

[47] DongL-J, WesselooJ, PotvinY, et al.. Discrimination of mine seismic events and blasts using the fisher classifier, naive Bayesian classifier and logistic regression [J]. Rock Mechanics and Rock Engineering, 2016, 49(1): 183-211

[48] DongL-J, ZouW, LiX-B, et al.. Collaborative localization method using analytical and iterative solutions for microseismic/acoustic emission sources in the rockmass structure for underground mining [J]. Engineering Fracture Mechanics, 2019, 21095-112