The rock slope engineer is faced with two types of design problem:
(a) General stability analyses which apply to the overall design of highway or opencast mine slopes and where the quality of the geological data available does not justify a detailed stability calculation.
(b) Particular stability analyses which are required for critical slopes identified by the general analysis or for slopes which act as foundations for arch dams, large buildings and similar projects in which a high financial investment is concentrated on a relatively small volume of rock.
These two types of design problem are linked in the flow chart presented in Fig. 1 which shows that any slope design study should proceed from a general to a particular form of analysis.
Details of the methods which may be used for the stability analysis of critical slopes (step 8 in Fig. 1) have been published by Hoek, Bray & Boyd (1973). The present paper will deal with the general methods of slope analysis which may be used for step 2 in Fig. 1.
2. Recognition of failure mechanism
Good rock slope engineering starts with good geological data collection and any attempt to carry out a stability analysis without first having defined the geology of the slope is a total waste of time. Rock slope failure is generally controlled by structural discontinuities such as faults, bedding planes and joints in the rock mass and hence the definition of these features is the most important part of the preliminary