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| Titel |
Strength Mobilisation of Rock Masses in Relation to Deep Seated Landslide |
| VerfasserIn |
Ferdaus Ahmad, William Murphy, James Lawrence, Steve Hencher |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250108398
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| Publikation (Nr.) |
 EGU/EGU2015-8151.pdf |
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| Zusammenfassung |
| Almost any form of analysis used in the design of slopes, foundations and underground
excavations in rock requires reliable estimation of the strength and deformation
characteristics of rock masses. The Hoek-Brown Failure Criterion, which was developed in
the late 1970s, suggests that rock mass strength is dependent primarily on lithological type,
fracture spacing and intact rock strength relative to the in-situ stress level.
This criterion is applicable to fractured rock masses where the potential for simple
kinematical failure along individual discontinuities is not possible. In other words, it should
not be applied to the analysis of structurally controlled failures. A fundamental
assumption of the Hoek-Brown criterion is that the rock mass to which it is applied is
homogeneous and isotropic. Thus, the simple hypothesis to be tested is: Does the
Hoek-Brown (HB) Failure Criterion adequately characterise the strength of slopes in rock
masses?
The rock mass strength of material from failures in rock slopes was examined. Standard
rock mass classification, GSI, was employed during fieldwork and intact samples were tested
for strength. Back analysis was employed using limit equilibrium and finite element
methods to conduct slope stability analyses and determine the likely rock mass
strength and the HB characteristics. The research revealed that the HB criterion
overestimated the cohesion but is accurate in estimating the friction angle. It was also
noted that the GSI value obtained from back analysis is not representative of the
rocks’ properties in the field. The GSI criterion needs adjustment in order to increase
its applicability and to characterise materials with discontinuities that control the
strength.
The results of this research will assist engineers and engineering geologists
to have a better understanding in selecting reliable estimates of the strength and
deformation characteristics of rock masses in the analysis of the design of slopes. |
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