Study on spatial variability of soils and load-bearing capacity of drilled shafts in lateritic ground

The natural variability of soil, influenced by weathering, human activity, and geological formation processes, is a critical factor in geotechnical engineering. This variability introduces significant uncertainty, particularly in the design of deep foundations, where the complex interaction between soil and structures, combined with varying geological conditions, complicates the prediction of structural behavior. However, focusing on deep foundations, this study examines soil property variability in southern Brazil. Standard penetration tests and slow static load tests were conducted to estimate pile load-bearing capacities. A reliability assessment method was employed to evaluate the accuracy of different prediction techniques, with results compared against load-settlement test data. Findings reveal significant discrepancies between prediction methods, with longer piles satisfying safety requirements, while shorter piles showed higher variability and did not meet the same safety standards. This research highlights the importance of incorporating soil variability and probabilistic analysis into foundation design to enhance reliability and safety.