SSR (Slope Stability Rating) classification system is a new rating system which has been proposed in Iran to study the stability of fractured rock slopes of non-structurally controlled failures. In this system, the stability can be evaluated by means of slope design charts. In this study the system is reviewed using 46 slope cases from Iran and Australia. Using the above mentioned design charts, the recommended stable angle for each slope was compared with the current slope conditions. This comparison showed that, in the design charts, increasing of stable excavation angle by slope height reduction is partly large in the cases that the height of slope is less than 100 meters. In addition the design curves overestimate stable design angle especially for flatter slopes. As a result of this work, the modified SSR system rock slope design charts for maximum excavation angle (FS=1.0) and also for some conservative excavation angles (FS=1.2, 1.3, 1.5) are presented.


Estimates of rock slope stability are required by the civil and mining engineering industry for a wide variety of projects. . In these projects, it is necessary to make use of classification systems to estimate the stable angle of a required or existing slope. Many rock mass classification systems have been developed over 100 years since first attempt were made to formalize an empirical approach to tunnel design. Some of classification systems like RMR (Bieniawski 1973) and Q (Barton & Lunde 1974) have gained broad acceptance in the civil and mining industry, while others, such as those suggested by Terzaghi (1946) and Palmstrom (1996) are specific to underground openings. All of these rock mass classification systems have been applied successfully in tunneling and underground mining, but most of them have limitations and shortcomings, when it comes to rock slope problems.

This content is only available via PDF.
You can access this article if you purchase or spend a download.