In routine geotechnical design of foundations, slopes and retaining walls a factor of safety is applied to ultimate collapse loads. But very different factors of safety are used for different structures. Also soil has several different strengths; peak, constant volume (or critical state) and residual. Moreover, it is not always clear what constitutes failure of geotechnical structures, or who decides when failure has occurred.
The talk will consider the bases of conventional geotechnical design, the relationship between soil strength and stiffness, and choices of soil strength and factor of safety for routine design. This will lead to some simple methods for determining characteristic values for soil strength parameters for routine design of foundations and slopes.
Engineers Australia members participating in AGS technical sessions can record attendance on their personal CPD logs. Members should refer to Engineers Australia CPD policy for details on CPD types, requirements and auditing guidelines.