Data-driven approach to enhance deep foundation safety: reliable methods for predicting bored pile capacity

The interpretation methods used to predict ultimate pile capacity from load-settlement curves yield varied results due to their unique assumptions and limitations. Misinterpreting ultimate pile capacity can negatively impact the safety and economy of deep foundations, which often consist of numerous piles. This study examines a database of 93 static pile load tests on axially loaded bored concrete piles to identify suitable methods for predicting ultimate pile capacity. Specifically, 43 static pile load tests from Pile Database A were analyzed to compare ultimate capacities derived from theoretical methods, twelve pile load test interpretation techniques, and numerical analysis using PLAXIS 3D. For the numerical analysis, all bored piles in Database A were loaded until a pile head settlement equal to 8% of the pile diameter, which is the average failure settlement percentage derived from 50 full-scale static pile load tests (Database-B). The results indicate that the interpretation methods of DeBeer and Mazurkiewicz provide results closest to the maximum test load in static pile load tests, with an average deviation of 4.16% from the maximum applied test load. Therefore, these methods are reliable for predicting the ultimate capacity of bored piles. The findings of this study are expected to help design professionals adopt suitable and reliable methods for accurately assessing the ultimate capacity of bored piles.