Topping Failure Analysis of Anti-Dip Bedding Rock Slopes Subjected to Crest Loads
Authors: Chaoyi Sun, Congxin Chen, Yun Zheng, Kaizong Xia, Wei Zhang
Abstract:
Crest loads are often encountered in hydropower, highway, open-pit and other engineering rock slopes. Toppling failure is one of the most common deformation failure types of anti-dip bedding rock slopes. Analysis on such failure of anti-dip bedding rock slopes subjected to crest loads has an important influence on engineering practice. Based on the step-by-step analysis approach proposed by Goodman and Bray, a geo-mechanical model was developed, and the related analysis approach was proposed for the toppling failure of anti-dip bedding rock slopes subjected to crest loads. Using the transfer coefficient method, a formulation was derived for calculating the residual thrust of slope toe and the support force required to meet the requirements of the slope stability under crest loads, which provided a scientific reference to design and support for such slopes. Through slope examples, the influence of crest loads on the residual thrust and sliding ratio coefficient was investigated for cases of different block widths and slope cut angles. The results show that there exists a critical block width for such slope. The influence of crest loads on the residual thrust is non-negligible when the block thickness is smaller than the critical value. Moreover, the influence of crest loads on the slope stability increases with the slope cut angle and the sliding ratio coefficient of anti-dip bedding rock slopes increases with the crest loads. Finally, the theoretical solutions and numerical simulations using Universal Distinct Element Code (UDEC) were compared, in which the consistent results show the applicability of both approaches.
Keywords: Anti-dip slopes, crest loads, stability analysis, toppling failure.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.2021783
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 906References:
[1] F. Lanaro, L. ing, O. Stephansson, G. Barla. “DEM modelling of laboratory tests of block toppling”. International Journal of Rock Mechanics and Mining Sciences, 1997, 34, pp. 209-218.
[2] C. Sagaseta, J. M. Sanchez, J. Canizal. “A general analytical solution for the required anchor force in rock slopes with toppling failure”. International Journal of Rock Mechanics and Mining Sciences, 2001, 38, pp. 421–435.
[3] L. Muler. “New consideration of the Vajont slide”. Felsmechnik und Ingenieurgeologie, 1968, 6, pp. 29-91.
[4] O. Aydan, T. Kawamoto. “The stability of slopes and underground openings against flexural toppling and their stabilization”. Rock Mechanics and Rock Engineering, 1992, 25(3), pp. 143-165.
[5] R. E. Goodman, J. W. Bray. “Toppling of rock slopes//Proceedings of ASCE Specialty Conference”, Rock Engineering for Foundations and Slopes, Vol.2. Colorado: Boulder, 1976, pp. 201-234.
[6] A. Bobet. “Analytical solutions for toppling failure”. International Journal of Rock Mechanics and Mining Sciences, 1999, 36(7), pp. 971–980.
[7] C. H. Liu, M. B. Jaksa, A. G. Meyers. “A transfer coefficient method for rock slope toppling”. Canadian Geotechnical Journal, 2009, 46(1), pp. 1–9.
[8] C. H. Liu, M. B. Jaksa, A. G. Meyers. “Toppling mechanisms of rock slopes considering stabilization from the underlying rock mass”. International Journal of Rock Mechanics and Mining Sciences, 2008, 45(8), pp. 348-354.
[9] C. H. Liu, M. B. Jaksa, A. G. Meyers. “Improved analytical solution for toppling stability analysis of rock slopes”. International Journal of Rock Mechanics and Mining Sciences, 2008, 45(8), pp. 1361-1372.
[10] Y. Zheng, C. X. Chen, X. X. Zhu, Z. Ou, X. M. Xiu, T. T. Liu. “Analysis of toppling failure of rock slopes subjected to seismic loads”. Rock and Soil Mechanics, 2014, 35(4), pp. 1025-1032.
[11] D. Y. Sun, Y. J. Peng, X. Z. Wang. “Application of DDA in the analysis of rock slope toppling failure”. Chinese Journal of Rock Mechanics and Engineering, 2002, 21(1), pp. 39-42.
[12] M. H. Freitas, R. J. Watters. “Some field examples of toppling failure”. Geotechnique, 1973, 23(4), pp. 495-514.
[13] M. Bukovansky, M. A. Rodriguez, G. Cedrun. “Three rock slides in stratified and jointed rocks”. Advances in rock mechanics. In: Proceedings of the Third Congress of the ISRM, 1974, pp. 854-862.
[14] C. H. Liu, C. X. Chen. “Analysis of toppling failure of rock slopes due to earthquakes”. Chinese Journal of Rock Mechanics and Engineering, 2010, 29(Supp1), pp. 3193-3198.