Reliability-Based Stability Analysis of Fiber-Reinforced Infinite Slopes: Fid-Bau Portal

Reliability-Based Stability Analysis of Fiber-Reinforced Infinite Slopes

Diab, Assile Abou / Najjar, Shadi / Sadek, Salah

Fiber-reinforcement has been proven to be an effective technique for stabilizing new or existing slopes against shallow failures. For sandy soil, the main benefit of fiber reinforcement is the increase in the friction angle. Such an increase will theoretically allow for designing slopes that are steeper or higher for any given design factor of safety. The friction angle of fiber-reinforced sand can be predicted from the properties of the unreinforced sand and the properties of the individual fibers using available discrete or energy-based empirical models. It has been proven that these model predictions suffer from a given level of model uncertainty. As a result, the predicted friction angle of fiber-reinforced sand may be more uncertain than that of unreinforced sand. In this study, the uncertainty in the friction angle of fiber-reinforced sand is quantified by combining traditional spatial variability with model uncertainty. The combined uncertainty is then incorporated in a reliability-based design methodology that is tailored for assessing the risk of failure of fiber-reinforced infinite slopes. The results indicate that the design factor of safety against slope stability failure may have to be increased in fiber-reinforced infinite slopes to maintain the same level of reliability as traditional non-reinforced slopes. The required factor of safety is affected by the choice of the model used to predict the fiber-reinforced friction angle and by the anticipated degree of spatial variability in the friction angle of the unreinforced soil.