Effect of buttress on reduction of rock slope sliding along geological boundary

Authors

  • Ryota Moriya
  • Daisuke Fukuda
  • Jun-ichi Kodama
  • Yoshiaki Fujii

Abstract

In open−cut limestone mines in Japan, huge rock slopes with geological boundary between limestone and bedrock have been formed by mining activities. In addition, latent sliding plane near the toe of slope may be formed through the development of damaged zone with increase in size of rock slope. It has been reported that inelastic time−dependent sliding deformation of rock slope along both the geological boundary and latent sliding plane can occur. In this case, one of the countermeasures to suppress sliding deformation is an application of rock buttress to the slope surface where the sliding is taking place. However, effect of rock buttress on reduction of the rock slope sliding has not been clarified yet. In this paper, the effect of rock buttress on reduction of the rock slope sliding was discussed based on 2−dimensional finite element analysis using non−linear visco−elastic model. The results indicate that (i)degree of deterioration of sliding plane at the timing of the application of rock buttress significantly affects the expected life of rock slope, (ii)optimum height of rock buttress can exist, (iii)larger Young's modulus of rock buttress results in the longer expected life of rock slope and (iv)the balance of increase and decrease of normal and shear stresses on sliding plane by buttress is important and the obtained results can be changed by the difference of friction angle and the geometry of sliding plane.

References

Nakamura, N., Tsukayama, Y., Hirata, A. and Kaneko, K., (2003), Displacement Measurement of Rock Slope with Cover Rock and its Interpretation, J. MMIJ, Vol. 119, pp. 547-552 (in Japanese with English abstract)

Obara, Y., Nakamura, N., Kang, S. S. and Kaneko, K. (2000), Measurement of local stress and estimation of regional stress associated with stability assessment of an open-pit rock slope, Int. J. Rock. Mech. Min. Sci., 37, pp. 1211-1221

Okubo, S. (1992), Analytical Consideration of Constitutive Equation of Variable Compliance Type, J. MMIJ, Vol. 108, pp. 601-606 (in Japanese with English abstract)

Pande, G. N. and Sharma, K. G. (1979), On joint/interface elements and associated problems of numerical ill−conditioning Int. J. Numer. Anal. Meth. Geomech, Vol. 3, pp. 293-300

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Published

2016-11-28

Issue

Section

Part 1 Hardrock