Stability analysis of underground surrounding rock mass based on block theory

Abstract

Evaluation of the performance of existing support in underground tunnels is of great importance for production and interests. Based on field investigation, the shape and number of joints and fractures were investigated in the mining area. Then, the stability of each structural blocks is analyzed by 3D wedge stability analysis software (Unwedge). Moreover, a new analysis method based on critical block theory is applied to analyze the stability of excavated laneways in continuous and discontinuous rock and monitor the stress changes in a fractured tunnel rock mass. The test results indicate that the 3D wedge stability analysis software for underground excavation can evaluate deep tunnel support. Besides, there is no direct relation between the size of the block and the instability of the tunnel. The support method, on large and thick key blocks, needs to be improved. In a broken tunnel section, U-shaped steel support can effectively promote the stress state of the surrounding rock. By monitoring the surrounding rock, it is proven that the vibrating string anchor stress monitoring system is an efficient and real-time method for tunnel stability evaluation.

Keywords

key block theory / Unwedge analysis software / stress monitoring system / support evaluation

References

[1] MengX-R, PengR, ZhaoG-M, LiY-M. Roadway engineering mechanical properties and roadway structural instability mechanisms in deep wells [J]. KSCE Journal of Civil Engineering, 2018, 22(5): 1954-1966

[2] JiangL-S, MitrH S, MaN-J, ZhaoX-D. Effect of foundation rigidity on stratified roadway roof stability in underground coal mines [J]. Arabian Journal of Geosciences, 2016, 9(1): 32-44

[3] PengR, MengX-R, ZhaoG-M, LiY-M, ZhuJ-M. Experimental research on the structural instability mechanism and the effect of multi-echelon support of deep roadways in a kilometer-deep well [J]. Plos One, 2018, 13(2): 1-24

[4] WangQ, PanR, JiangB, LiS C, HeM C, SunH B, WangL, QinQ, YuH C, LuanY C. Study on failure mechanism of roadway with soft rock in deep coal mine and confined concrete support system [J]. Engineering Failure Analysis, 2017, 81: 155-177

[5] MengQ-B, HanL-J, XiaoY, LiH, WenS-Y, ZhangJ. Numerical simulation study of the failure evolution process and failure mode of surrounding rock in deep soft rock roadways [J]. International Journal of Mining Science and Technology, 2016, 26(2): 209-221

[6] KangH P, LinJ, FanM J. Investigation on support pattern of a coal mine roadway within soft rocks-a case study [J]. International Journal of Coal Geology, 2015, 140: 31-40

[7] XueY, GaoF, LiuX-G, LiangX. Permeability and pressure distribution characteristics of the roadway surrounding rock in the damaged zone of an excavation [J]. International Journal of Mining Science and Technology, 2017, 27(2): 211-219

[8] ZUO Y J, WANG J, DONG L J, SHU W W, YU M L, SUN W J B, WU Z H. Optimization for U-shaped steel support in deep tunnels under coupled static-dynamic loading [J]. Advances in Civil Engineering, 2019, Article 4172103. DOI: https://doi.org/10.1155/2019/4172103.

[9] LiX B, GongF Q, WangS F, LiD Y, TaoM, ZhouJ, HungL Q, MaC D, DuK, FengF. Coupled static-dynamic loading mechanical mechanism and dynamic criterion of rockburst in deep hard rock mines [J]. Chinese Journal of Rock Mechanics and Engineering, 2019, 38(4): 708-723(in Chinese)

[10] LiX B, PengD X, FengF, LiX S. Stability analysis of horizontal insulating pillar in deep mining from caving to filling method on the basis of refined plate theory [J]. Journal of China University of Mining & Technology, 2019, 48(3): 484-494(in Chinese)

[11] LiX-B, FengF, LiD-Y. Numerical simulation of rock failure under static and dynamic loading by splitting test of circular ring [J]. Engineering Fracture Mechanics, 2017, 188: 184-201

[12] LiX B, GongF Q, TaoM, DongL J, DuK, MaC D, ZhouZ L, YinT B. Failure mechanism and coupled static-dynamic loading theory in deep hard rock mining: A review [J]. Journal of Rock Mechanics and Geotechnical Engineering, 2017, 9(4): 767-782

[13] ChengG W, LiL C, ZhuW C, YangT H, TangC A, ZhengY, WangY. Microseismic investigation of mining-induced brittle fault activation in a Chinese coal mine [J]. International Journal of Rock Mechanics and Mining Sciences, 2019, 123: 104096

[14] LIU X G, ZHU W C, GUAN K, ZHANG H X. Effect of shaft pillar extraction on stability of main shaft: A case study at Xincheng gold mine, China [J]. Mathematical Problems in Engineering, 2018, Article 1652312. DOI: https://doi.org/10.1155/2018/1652312.

[15] LiuC, LiuX L, PengX C, WangE Z, WangS J. Application of 3D-DDA integrated with unmanned aerial vehicle-laser scanner (UAV-LS) photogrammetry for stability analysis of a blocky rock mass slope [J]. Landslides, 2019, 16(9): 1645-1661

[16] González-PalacioC, Menéndez-DíazA, Álvarez-VigilA E, González-NiciezaC. Identification of non-pyramidal key blocks in jointed rock masses for tunnel excavation [J]. Computers and Geotechnics, 2005, 32(3): 179-200

[17] LiuX G, ZhuW C, YuQ L, ChenS J, GuanK. Estimating the joint roughness coefficient of rock joints from translational overlapping statistical parameters [J]. Rock Mechanics and Rock Engineering, 2019, 52(3): 753-769

[18] WangS H, HuangR Q, NiP P, JeonS. Advanced discretization of rock slope using block theory within the framework of discontinuous deformation analysis [J]. Geomechanics and Engineering, 2017, 12(4): 723-738

[19] JiaC, LiY, LianM-Y, ZhouX-Y. Jointed surrounding rock mass stability analysis on an underground cavern in a hydropower station based on the extended key block theory [J]. Energies, 2017, 10(4): 563-580

[20] HuJ-H, YangC, ZhouK-P, LiJ-L, GaoF. Stability of undercut space in fragment orebody based on key block theory [J]. Transactions of Nonferrous Metals Society of China, 2016, 26(7): 1946-1954

[21] GoodmanR E. Block theory and its application to rock engineering [J]. Prentice-Hall, 1985, 26103-105

[22] KocharyanG G, KulyukinA M. Construction of a three-dimensional block structure on the basis of jointed rock parameters estimating the stability of underground workings [J]. Soil Mechanics and Foundation Engineering, 1994, 31: 62-66

[23] KocharyanG G, KulyukinA M. Study of caving features for underground workings in a rock mass of block structure with dynamic action. Part II. Mechanical properties of interblock gaps [J]. Journal of Mining Science, 1994, 30: 437-446

[24] KocharyanG G. Study of caving features for underground workings in a rock mass of block structure with dynamic action. Part III. Analysis of the stability of an individual rock block in the roof of a working [J]. Journal of Mining Science, 1994, 30: 525-532

[25] KocharyanG G, BrigadinI V, KaryakinA G, KulyukinA M, IvanovE A. Study of caving features for underground workings in a rock mass of block structure with dynamic action. Part IV. effect of rock mass structure on the stability of mine workings [J]. Journal of Mining Science, 1995, 31: 1-7

[26] WangS-H, NiP-P. Application of block theory modeling on spatial block topological identification to rock slope stability analysis [J]. International Journal of Computational Methods, 2013, 11: 1350044

[27] GreifV, VlckoJ. Key block theory application for rock slope stability analysis in the foundations of medieval castles in Slovakia [J]. Journal of Cultural Heritage, 2013, 14(4): 359-364

[28] DongL-J, SunD-Y, LiX-B, ZhouZ-L. Interval non-probabilistic reliability of a surrounding jointed rockmass in underground engineering: A case study [J]. IEEE Access, 2017, 518804-18817

[29] KrasnovskyA A, MirenkovV E. Identification of weakenings in a rock block [J]. Journal of Mining Science, 2010, 46(2): 113-119

[30] HatzorY. The block failure likelihood: A contribution to rock engineering in blocky rock masses [J]. International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 1993, 30(7): 1591-1597

[31] ChenG. Probabilistic key block analysis of a mine ventilation shaft stability-a case study [J]. Geomechanics & Geoengineering, 2012, 7(4): 255-262

[32] WuW-X, GongF-Q, YangW-M. Experimental simulation study of spalling in deep rectangular tunnel with plastic fine grain marble [J]. Tunnelling and Underground Space Technology, 2020, 98: 103319

[33] GongF-Q, WuW-X, LiT-B, SiX-F. Experimental simulation and investigation of spalling failure of rectangular tunnel under different three-dimensional stress states [J]. International Journal of Rock Mechanics and Mining Sciences, 2019, 122104081

[34] XiaM, GongF-Q. Effects of loading waveforms on rock damage using particle simulation method [J]. Journal of Central South University, 2018, 25(7): 1755-1765

[35] LuoY, GongF-Q, LiX-B, WangS-Y. Experimental simulation investigation of influence of depth on spalling characteristics in circular hard rock tunnel [J]. Journal of Central South University, 2020, 27(3): 891-910

[36] UrbancicT I, TrifuC I. Recent advances in seismic monitoring technology at Canadian mines [J]. Journal of Applied Geophysics, 2000, 45(4): 225-237

[37] DongL-J, ShuW-W, LiX-B, HanG-J, ZouW. Three dimensional comprehensive analytical solutions for locating sources of sensor networks in unknown velocity mining system [J]. IEEE Access, 2017, 511337-11351

[38] DongL-J, SunD-Y, LiX-B, DuK. Theoretical and experimental studies of localization methodology for ae and microseismic sources without pre-measured wave velocity in mines [J]. IEEE Access, 2017, 5: 16818-16828

[39] DongL J, WesselooJ, PotvinY, LiX B. 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

[40] DongL J, WesselooJ, PotvinY, LiX B. Discriminant models of blasts and seismic events in mine seismology [J]. International Journal of Rock Mechanics and Mining Sciences, 2016, 86: 282-291

[41] KemenyJ, PostR. Estimating three-dimensional rock discontinuity orientation from digital images of fracture traces [J]. Computers & Geosciences, 2003, 29: 65-77

[42] SunG H, ZhengH, HuangY Y. Stability analysis of statically indeterminate blocks in key block theory and application to rock slope in Jinping-I Hydropower Station [J]. Engineering Geology, 2015, 186(SI): 57-67

[43] FeketeS, DiederichsM. Integration of three-dimensional laser scanning with discontinuum modelling for stability analysis of tunnels in blocky rockmasses [J]. International Journal of Rock Mechanics And Mining Sciences, 2013, 57: 11-23

[44] GreifV, VlckoJ. Stability of undercut space in fragment orebody based on key block theory [J]. Transactions of Nonferrous Metals Society of China, 2016, 26(7): 1946-1954