Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 30075
Comparison between Deterministic and Probabilistic Stability Analysis, Featuring Consequent Risk Assessment

Authors: Isabela Moreira Queiroz

Abstract:

Slope stability analyses are largely carried out by deterministic methods and evaluated through a single security factor. Although it is known that the geotechnical parameters can present great dispersal, such analyses are considered fixed and known. The probabilistic methods, in turn, incorporate the variability of input key parameters (random variables), resulting in a range of values of safety factors, thus enabling the determination of the probability of failure, which is an essential parameter in the calculation of the risk (probability multiplied by the consequence of the event). Among the probabilistic methods, there are three frequently used methods in geotechnical society: FOSM (First-Order, Second-Moment), Rosenblueth (Point Estimates) and Monte Carlo. This paper presents a comparison between the results from deterministic and probabilistic analyses (FOSM method, Monte Carlo and Rosenblueth) applied to a hypothetical slope. The end was held to evaluate the behavior of the slope and consequent risk analysis, which is used to calculate the risk and analyze their mitigation and control solutions. It can be observed that the results obtained by the three probabilistic methods were quite close. It should be noticed that the calculation of the risk makes it possible to list the priority to the implementation of mitigation measures. Therefore, it is recommended to do a good assessment of the geological-geotechnical model incorporating the uncertainty in viability, design, construction, operation and closure by means of risk management. 

Keywords: Probabilistic methods, risk assessment, risk management, slope stability.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1124587

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1264

References:


[1] Hammersley, J.M. & Handscomb, D.C. (1964). Monte Carlo Methods John Wiley & Sons, New York, USA.
[2] Baecher, G. B. & Christian, J. T. (2003). Reliability and Statistics in Geotechnical Engineering. John Wiley and Sons, England.
[3] Tobutt D.C. & Richards E.A. (1979). The reability of earth slopes. International Journal for Numerical and Analytical Methods in Geomechanics, 3:323-354.
[4] Rosenblueth, E. (1975). Point Estimates for Probability Moments. Proceedings of the National Academy of Sciences of the United States of America, USA, 72(10): 3812–3814.
[5] Melo, A. V. (2014). Análise de Risco Aplicadas a Baragens de Terra e Enrocamento: Estudo de caso de Barragens da CEMIG GT. Dissertação de Mestrado, Publicação, Engenharia de Transporte e Geotecnia – Escola de Engenharia, Universidade Federal de Minas Gerais, Belo Horizonte, MG.
[6] Assis, A.P., Espósito, T.J., Gardoni, M.G. & Silva, P.D.E.A. (2001). Métodos Estatísticos Aplicados a Geotecnia. Publicação G.AP–002/01, Departamento de Engenharia Civil e Ambiental, Universidade de Brasília, Brasília, DF, 177 p.
[7] Wesseloo, J. & Read, J. Guidelines for Open Pit Slope Design. Editors: John Read & Peter Stacey.Acceptance Criteria, 221 – 236.
[8] Maia, J.A.C. (2003). Métodos Probabilísticos Aplicados à Estabilidade de Taludes e Cavidades em Rocha. Dissertação de Mestrado, Publicação G.DM–099/03, Departamento de Engenharia Civil e Ambiental, Universidade de Brasília, Brasília, DF, 192 p.
[9] Wyllie, D. C. and Mah, C. W.: Rock Slope Engineering, Civil and Mining, 4th Edition, Taylor & Francis, London and New-York, 2004.
[10] Maia, J.A.C. (2007). Modelagem Probabilística da Zona Plástica de Obras Subterrâneas em Meios Rochosos. Tese de Doutorado, Publicação G.TD-040/07, Departamento de Engenharia Civil e Ambiental, Universidade de Brasília, Brasília, DF, 161 p.
[11] Rocscience (2013). Tutoriais do Slide 6.0.
[12] Pinto, A. V. (2008). Gestão de Risco e Segurança de Barragem. Apresentação no 3º Simpósio de Segurança de Barragens e Riscos Associados –G.DM–180/09, Departamento de Engenharia Civil e Ambiental, Universidade de Brasília, Brasília, DF, 128 p.
[13] Perini, D. S. (2009). Estudo dos Processos Envolvidos na Análise de Riscos de Barragens de Terra. Dissertação de Mestrado, Publicação G.DM–180/09, Departamento de Engenharia Civil e Ambiental, Universidade de Brasília, Brasília, DF, 128 p.