ABSTRACT
The advantages and limitations of using back analysis to evaluate soil shear strengths are discussed. A reliability approach is used to estimate the probability of failure for a given design factor of safety and combination of the back-calculated Mohr-Coulomb shear strength parameters c’ and ϕ’ Analysis of 39 landslides in the Orinda formation are used to illustrate the theoretical procedure. The required design factor of safety to achieve a given level of reliability against slope failure can be determined reflecting the amount of slope performance data.
