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The Effect of Tunnel Depth on the Variations of Rock Bolt’s Axial Forces in Seismic Mode

Journal Name:

  • International Journal of Science and Engineering Investigations

Publication Year:

  • 2016

Key Words:

Author NameUniversity of Author
Abstract (2. Language): 
In this study, through Pseudo-static analysis with the help of finite element modeling software phase2, effect the tunnel depth and the direction of seismic coefficients on the axial force of rock bolts mounted in circular tunnels and it variations in different conditions evaluated. The circular tunnels are modeled with a diameter of 4 meters and in depths of 5, 10, 25 and 35 meters in the Shale rocks. The tunnels are supported by end anchored rock bolts with length of 3 meters and spacing of 2 meters. Also the ground surface modeled with the dip of 5 degrees and the earthquake magnitudes of 6.5, 7, 7.5 and 8 on the Richter scale considered. The results of the evaluations show that with increasing the tunnel depth, the variations of axial forces have decreased because of reduction in displacements around tunnel. Furthermore, in greater earthquake magnitudes, the variations of rock bolts' axial forces have increased because, they forces the tunnel to have more movements and in this condition, the rock bolts are under higher tensile stresses. Moreover, in steep surfaces for tunnels with small sections (tunnel diameter less than or equal to 4 meters), the alignment of horizontal acceleration of seismic coefficient with steep direction and the opposite direction of vertical seismic coefficient with gravitational force had resulted in the highest variance of rock bolts’ axial force.
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REFERENCES

References: 

[1] W.J. Gale, C. Mark, D.C. Oyler, and J. Chen, “Computer Simulation of Ground Behavior and Rock Bolt Interaction at Emerald Mine 2004”.
Proc. 23rd Intl. Conf. on Ground Control in Mining, Morgantown, WV, Morgantown, WV: West Virginia University, 27-34, 2004.
[2] A.C. Kliche, “Rock slope stability. Society for Mining Metallurgy”. USA, 1999.
[3] D.C. Wyllie, and C.W. Mah, “Rock slope engineering”, Fourth edition. London, Spon Press, 2004.
[4] T. Ramamurthy, “Engineering in rocks for slopes, foundation and tunnels”, Prentice Hall of India Private Limited, New Delhi, India, 2007.
[5] E. Hoek, and D.F. Wood, “Rock Support”, Mining Magazine, 159, 4, 282-287, 1988.
[6] J. Sulem, M. Panet, and A. Guenot, “An analytical solution for time-dependent displacements in a circular tunnel”, Int. J. Rock Mech. Mining Sci. Geomech, 24, 155-164, 1987.
[7] E. Hoek, “Practical Rock Engineering” , 2007.
[8] T. Solak, “Ground behavior evaluation for tunnels in blocky rock masses”, Tunneling and Underground Space Technology, 24, 323-330, 2009.
[9] K. Kovári, “Tunneling in Squeezing Rock”, Tunnel, 5, 98, 12-31, 1998.
[10] E. Hoek, C. Carranza-Torres, and B. Corkum, “Hoek–Brown Failure Criterion-2002 Edition”. Rocscience, 2002.
[11] Rocscience, “A 2D finite element program for calculating stresses and estimating support around the underground excavations”. Geomechanics Software and Research. Rocscience Inc., Toronto, Ontario, Canada, 1999.
[12] A., Kaynia, “Personal communication”, 2011.

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