A Study on Interface Shear Strength Variability and Probability of failure of Land Filled Stability Analysis

Now a day’s failure of modern landfills by slippage of lining materials is common. The majority of failures are controlled by slippage at interfaces between lining components. Information and variability of interface shear strength is required to carry out both limit equilibrium stability analysis using characteristic shear strengths and probability of failure analysis. Current practice is to carry out a limited number of site specific tests and this provides insufficient information on the variability of interface strength for design. The implications of variable shear strength are examined though probability of failure analysis of two common design cases: veneer and waste body slippage. The reliability analyses show that relatively high probabilities of failure are obtained when using variability values from the literature and an internal database even when factors of safety ? 1.5. The use of repeatability data produces lower probabilities for typically used factors of safety, although they are still higher than recommended target of probability failure (Pf) values.