Impact of Spatial Variability on the Design of Drilled Shafts in Weak Carbonate Rocks

摘要

This paper provides a framework for studying the combined effect of model uncertainties and uncertainties due to spatial variability on the side friction and end bearing of drilled shafts in weak carbonate rocks. Reliability assessments using Monte Carlo simulations indicated that the tip resistance could play a role in increasing the reliability index of a shaft if incorporated in design. The effect of the tip resistance is higher when for shafts with larger diameters and shorter lengths. For designs where the end bearing is ignored, model uncertainties and uncertainties due to spatial variability result in reliability indices between 2.0 and 2.4. These reliability indices increase to 2.5 and 3.5 when end bearing is included in the analysis.