ABSTRACT
The aim of this study was to evaluate the performance of less accurate analysis methods of slope stability, in order to reduce the number of operations used by the most accurate methods available in the literature. The study evaluated four methods for calculating slope stability. Fellenius (FELLENIUS, 1936FELLENIUS, W. Calculation of stability of earth dams. In: TRANS. 2nd CONGRESSO ON LARGE DAMS, 4; 1936, Washington, v.4, 445p.), Bishop (BISHOP, 1955BISHOP, A. W. “The Use of the Slip Circle in the Stability Analysis of Slopes” Géotechnique, London, v.5, n.1, p.7-17, 1955.), Simplified Bishop (BISHOP & MORGENSTERN, 1960BISHOP, A. W.; MORGENSTERN, N. Stability coefficients for Earth Slopes. Géotechnique, London, v.10, n. 4, p.164-169, 1960.) and Simplified Janbu (JANBU, 1973JANBU, N. Slope stability computations. Embankment dam - engineering. In: HIRSCH FIELD, E.; POULOS, S. (Ed.) Casa grande memorial, New York: Wiley, 1973. v.E, p.47– 86.) were compared with the Spencer method (SPENCER, 1967SPENCER, E. E. A method of the analysis of the stability of em-bankments assuming parallel inter-slice forces. Géotechnique, London, v.17, p.11–26, 1967.), which is considered an accurate method for calculating the factor of safety (FS). The procedure was performed in scenarios with different soil groups according to the Unified Soil Classification System (USCS) (ASTM 2011ASTM D-2487-11 Standard practice classification of soils for engineering purposes (Unified Soil Classification System) West Conshohocken: ASTM, 2011. doi:10.1520/D2487-11
https://doi.org/10.1520/D2487-11...
), heights and slope inclinations, and under conditions of reservoir subject to fast and slow emptying. Thus, comparative analyses were made using the correlation index “r”, the accuracy index “d” (WILLMOTT et al, 1985WILLMOTT, C. J.; CKLESON, S. G.; DAVIS, R. E. Statistics for evaluation and comparisons of models. Journal of Geophysical Research, Ottawa, v.90, n.C5. p.8995-9005, 1985.) and the performance index “c” (CAMARGO & SENTELHAS, 1997CAMARGO, A. P.; SENTELHAS, P. C. Avaliação do desempenho de diferentes métodos de estimativa da evapotrasnpiração potencial no estado de São Paulo. Revista Brasileira de Agrometeorologia, Santa Maria, v. 5, n.1, p. 89-97, 1997.). The methods that had optimal performance for the analyzed conditions were the Simplified Bishop, the Simplified Janbu and the Bishop methods; the Simplified Bishop method obtained a correlation coefficient of 99%. Thus, they can be used as alternative methods to replace the Spencer method in the analysis of slope stability on earth dams.
KEYWORDS:
Fellenius; Bishop; Simplified Bishop; Simplified Janbu; Spencer
