522
Proceedings of the 18
th
International Conference on Soil Mechanics and Geotechnical Engineering, Paris 2013
CRR/CSR is lower than unity. It is widely accepted that
estimating the cyclic resistance ratio (CRR) can be estimated on
the basis of dynamic and static penetration tests (Robertson and
Wride 1998, Boulanger 2004 and Idriss, etc.).
a)
b)
Figure 5. a) The breakdown into layers and density index (ID%). b) The
distribution of Density Index (ID%). Test No. 1. Tailings dam No. 1.
Figure 6. Example of the factor of safety (F.S) profile. Test No. 1.
Tailings dam No. 1.
3 CONCLUSIONS
To predict the behaviour of mine tailings dams in view to
managing the risks inherent to them, it appears necessary to
carry out a probabilistic approach However, in practice
implementing this type of approach is limited by the difficulty
of managing the data to be used in reliability calculations for the
limit conditions concerned. This article proposed a method for
estimating in situ the density index (ID%) and the effective
friction angle (
’) and its variability, making it possible to carry
out a probabilistic study of these structures. A single model was
proposed for all the mine tailings dams in Chile, in view to
linking a probability law to ID% and the
’.
A method was proposed that takes into account the spatial
variability of data for performing a reliability calculation of
liquefaction potential, which is the main cause for the failure of
this type of structure. On the basis of the results obtained, we
showed that the method proposed for estimating liquefaction
potential permits evaluating the probability of triggering this
phenomenon. Estimating the reliability of a dam in relation to
the limit states of static and dynamic stability demonstrates the
advantages and applicability of the approach, by using the
variability of the geotechnical characteristics of mine tailings
and resistance to penetration (qd
N1
) in particular.
4 ACKNOWLEDGEMENTS
Fundings for the work described in this paper was provided by
the research department of the Pontifical Catholic University of
Valparaiso Chile. This article was developed with the important
collaboration from the Professor, Mr Pierre Foray, Laboratory
3S-R, Institut National Polytechnique de Grenoble, France.
2
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