Predicting displacement of augered cast-in-place piles based on load test database

Performance-based design for piles requires the prediction of displacements of piles during loading. In general, such prediction is challenging, given the complexity of load mechanisms, soil profiles and construction effects. This study makes use of the normalized load–displacement behavior of axially loaded piles and develops a probabilistic model for the load–displacement curves based on a load test database. It is shown that displacements of piles can be effectively predicted by using the probabilistic model, and such prediction can be made for a pile design where a load test is not performed. For a pile where a load test is already performed but only loaded to a lower load level, the compression capacity and the displacement at higher load levels can be predicted. The prediction is demonstrated for augered cast-in-place piles in compression, although the analysis method may be applicable to other pile types.