Experimental Study on Mechanical Properties and Anchorage Performances of Rock Mass in the Fault Fracture Zone
Publication: International Journal of Geomechanics
Volume 18, Issue 7
Abstract
The mechanical properties and anchorage performances of rock masses are important to the success of underground engineering in fault fracture zones, but the impact of the rock block size and cementing strength on these properties and performances is unclear. A set of laboratory methods was developed to simulate the development of rock masses in fault fracture zones. Next, model specimens were prepared from natural rock blocks of different sizes and cementing materials of various strengths, and an aluminum alloy bar was installed as a model bolt to fabricate anchored model specimens. Compared with natural rock samples, the fault fracture rock mass exhibited a clear degradation in its strength and deformation parameters, and the degradation coefficients ranged from 19.20 to 86.51%. Under an applied axial load, as the rock block size or cementing strength increased, the mechanical parameters, including peak strength and elastic modulus, for both anchored and nonanchored model specimens increased from 16.90 to 69.05%. Because of the anchorage performance of the bolt, the anchored model specimens presented larger mechanical parameters than those of the nonanchored models. The effective anchorage strength of the bolt was found to be generally stable as the rock block size increased, but it decreased with the cementing strength. The ultimate failure modes of the anchored models with smaller aggregate sizes or lower cementing strengths were found to be characterized by cracks propagating along the cementing surface. For models with a larger rock block size or higher cementing strength, crack development throughout the intact rock blocks was also observed.
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Acknowledgments
The financial support from the National Key Basic Research and Development Program of China (No. 2017YFC0603001) and National Natural Science Foundation of China (No. 51734009, 51704279) are gratefully acknowledged.
References
Bauer, J. F., Meier, S., and Philipp, S. L. (2015). “Architecture, fracture system, mechanical properties and permeability structure of a fault zone in lower Triassic sandstone, Upper Rhine Graben.” Tectonophys., 647–648, 132–145.
Bobet, A., and Einstein, H. H. (2011). “Tunnel reinforcement with rockbolts.” Tunnelling Underground Space Technol., 26(1), 100–123.
Cai, Y., Esaki, T., and Jiang, Y. (2004). “An analytical model to predict axial load in grouted rock bolt for soft rock tunnelling.” Tunnelling Underground Space Technol., 19(6), 607–618.
Carranza-Torres, C. (2009). “Analytical and numerical study of the mechanics of rockbolt reinforcement around tunnels in rock masses.” Rock Mech. Rock Eng., 42(2), 175–228.
Chen, Y. (2014). “Experimental study and stress analysis of rock bolt anchorage performance.” J. Rock Mech. Geotech. Eng., 6(5), 428–437.
Fu, H. Y., Jiang, Z. M., and Li, H. Y. (2011). “Physical modeling of compressive behaviors of anchored rock masses.” Int. J. Geomech., 186–194.
Gao, F. Q., and Kang, H. P. (2008). “Effect of pre-tensioned rock bolts on stress redistribution around a roadway—Insight from numerical modeling.” J. China. Univ. Min. Tech., 18(4), 509–515.
Huang, Z., Broch, E., and Lu, M. (2002). “Cavern roof stability-mechanism of arching and stabilization by rockbolting.” Tunnelling Underground Space Technol., 17(3), 249–261.
Jeon, S., Kim, J., Seo, Y., and Hong, C. (2004). “Effect of a fault and weak plane on the stability of a tunnel in rock—A scaled model test and numerical analysis.” Int. J. Rock Mech. Min. Sci., 41(1), 658–663.
Jing, H. W., Yang, S. Q., Zhang, M. L., Xu, G. A., and Chen, K. F. (2014). “An experimental study on anchorage strength and deformation behavior of large-scale jointed rock mass.” Tunnelling Underground Space Technol., 43, 184–197.
Kang, H., et al. (2016). “Mechanical performances and stress states of rock bolts under varying loading conditions.” Tunnelling Underground Space Technol., 52, 138–146.
Li, C. C., Stjern, G., and Myrvang, A. (2014). “A review on the performance of conventional and energy-absorbing rockbolts.” J. Rock Mech. Geotech. Eng., 6(4), 315–327.
Li, Y., Li, C., Zhang, L., Zhu, W., Li, S., and Liu, J. (2017). “An experimental investigation on mechanical property and anchorage effect of bolted jointed rock mass.” Geosci. J., 21(2), 253–265.
Lin, H., Liu, T., Xiong, Z., Cao, R., and Cao, P. (2014). “Numerical simulations of the effect of bolt inclination on the shear strength of rock joints.” Int. J. Rock Mech. Min. Sci., 66, 49–56.
Liu, Q., Lei, G., and Peng, X. (2016). “Advance and review on the anchoring mechanism in deep fractured rock mass.” Chin. J. Rock Mech. Eng., 35(2), 312–332 (in Chinese).
Liu, Q., Lu, C., Lu, F., and Liu, X. (2013). “Application and analysis of ground surface pre-grouting strengthening deep fault fracture zone.” Chin. J. Rock Mech. Eng., 32, 3688–3695 (in Chinese).
Malmgren, L., and Nordlund, E. (2008). “Interaction of shotcrete with rock and rock bolts—A numerical study.” Int. J. Rock Mech. Min. Sci., 45(4), 538–553.
Spang, K., and Egger, P. (1990). “Action of fully-grouted bolts in jointed rock and factors of influence.” Rock Mech. Rock Eng., 23(3), 201–229.
Stille, H., Holmberg, M., and Nord, G. (1989). “Support of weak rock with grouted bolts and shotcrete.” Int. J. Rock Mech. Min. Sci. Geomech. Abstr., 26(1), 99–113.
Su, H., Jing, H., Zhao, H., Yu, L., and Wang, Y. (2017). “Strength degradation and anchoring behavior of rock mass in the fault fracture zone.” Environ. Earth Sci., 76(4), 179.
Yi, W. X., and Wang, E. Y. (2016). “Experimental research on measurement of permeability coefficient on the fault zone under coal mine in situ.” Arab. J. Geosci., 9(4), 253.
Yin, S., Zhang, J., and Liu, D. (2015). “A study of mine water inrushes by measurements of in situ stress and rock failures.” Nat. Hazards, 79(3), 1961–1979.
Zhu, H., Xu, Q. W., Ding, W., and Huang, F. (2011). “Experimental study on the progressive failure and its anchoring effect of weak-broken rock vertical slope.” Front. Arch. Civ. Eng. China, 5(2), 208–224.
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Published In
International Journal of Geomechanics
Volume 18 • Issue 7 • July 2018
Copyright
© 2018 American Society of Civil Engineers.
History
Received: Jun 7, 2017
Accepted: Jan 17, 2018
Published online: Apr 24, 2018
Published in print: Jul 1, 2018
Discussion open until: Sep 24, 2018
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