Slope stability investigations generally consist of three major aspects: site characterization, stability analyses, and remedial measures (if required). If the geotechnical conditions at a site can be adequately defined, then the stability of a site can be evaluated using one of many slope stability analysis methods. Measures can be taken to mitigate any significant slope stability hazards indicated by the stability analysis. However, developing a realistic yet appropriately conservative model of a site can be most challenging where the geology is complex and site conditions make data acquisition difficult. Furthermore, on more critical projects, the engineer may ask himself if a three-dimensional stability analysis would be more appropriate than conventional twodimensional methods.
This paper describes the investigative approach developed to evaluate the stability of a section of sea cliff for a proposed resort hotel site. The investigation included continuous diamond-core borings with geophysical logging. The strict hotel footprint requirements also prompted a comparison between two and three-dimensional stability analyses for determining the factors of safety at the site and for defining a construction setback line to mitigate the potential instabilities of the sea cliff.