Rock Mechanics and Rock Engineering (2022) 55:7675–7693
A General Solution forEstimating theSafety Factor ofBimslopes
EmadKhorasani1 · MehdiAmini2· EdmundMedley3· SadeghTarighAzali4· MohammadFarouqHossaini5
Received: 20 May 2022 / Accepted: 24 August 2022 / Published online: 13 September 2022
© The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature 2022
Bimslopes are slopes underlain by block-in-matrix rocks/soils (bimrocks/bimsoils), which are heterogeneous geomateri-
als with complex behavior. Abundant uncertainties in the mechanical, spatial, and geological nature of bimslopes make
it diﬃcult to estimate stability conditions of bimslopes. In this paper, some factors aﬀecting the stability of bimslopes are
investigated using the ﬁnite-element method. The main contributory factors include Volumetric Block Proportion (VBP),
the inclination of blocks, and the strength of matrix/block interfaces. By performance of sensitivity analysis on these factors,
a statistically signiﬁcant equation was obtained to estimate the safety factor of bimslopes using the multivariate regression
method. The inﬂuence of block conﬁgurations and groundwater levels on the stability of bimslopes was then investigated
to more conﬁdently use the multivariate equation. Finally, to check the validity of procedures presented in this paper, a real
failed bimslope in the Sungun mine (Iran) was investigated. The acceptable results from the Sungun analysis demonstrated
the safety factor of bimslopes can be estimated using the practical solution presented in this paper.
• Development of more than 1300 numerical models to analyze the key factors aﬀecting the stability of block-in-matrix
• Investigation of the inﬂuence of volumetric block proportion, the inclination of blocks, and strength of matrix/block
interface on the safety factor of bimslopes.
• Consideration of the substantial uncertainties aﬀecting the analysis of bimslopes.
• Presentation of the results of research in the form of applied schemes and tables.
• Provision of a practical procedure and equation for estimating the safety factor of bimslopes.
Keywords Bimrocks· Bimslopes· Slope stability· Numerical modeling· Sensitivity analysis
* Emad Khorasani
Sadegh Tarigh Azali
Mohammad Farouq Hossaini
1 School ofMining Engineering, College ofEngineering,
University ofTehran, Northern Kargar Street, Tehran, Iran
2 Thurber Engineering Ltd., Vancouver, Canada
3 Terraphase Engineering, Oakland, CA94612, USA
4 RahsazTarh Consulting Engineers, Tehran, Iran
5 School ofMinerals andEnergy Resources Engineering,
UNSW, Sydney, Australia