ANALYSIS OF BENCH SLOPES STABILITY OF THE COAL OPEN PIT ,SIBOC W-S’ USING FOSM METHOD

References: 12th International Multidisciplinary Scientific GeoConference, www.sgem.org, SGEM2012 Conference Proceedings/ ISSN 1314-2704, June 17-23, 2012, Vol. 1, 9 - 16 pp

ABSTRACT:

The objective of this paper is to develop a numerical procedure for the approximate
calculation of the first to statistical moments (mean or expected value and the standard
deviation or its square, the variance) of the factor of safety, F. The performance function
is formulated using simplified Bishop’s limit equilibrium method to calculate the basic
statistical parameters, the reliability index and the probability of the failure. The
reliability index defined by Hasofer and Lind is used as an index of safety measure.
Searching the critical probabilistic surface that is associated with the lowest reliability
index will be formulated as an optimization problem. In this paper, First-Order –
Second-Moment (FOSM) method based on Taylor series expansion about mean is
applied to calculate the minimum Hasofer –Lind reliability index and critical
probabilistic failure surface .To illustrate the applicability and to investigate the
effectiveness of FOSM method of stability analyses carried out for a bench slope at the
open coal mine in Sibovc field will be used as numerical example.Results shown that
the proposed method is capable to achieve better solution for reliability analysis of
bench slope if compared with those obtained in limit equilibrium analyses.

Keywords: Slope stability, Reliability, FOSM Method, Probability of failure.