Evaluation of Piles' Ultimate Capacity utilizing Direct CPT Methods Considering Consolidation and Aging Setup-Video

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The study evaluated the long-term capacity of piles in existing Louisiana bridges, motivated by severe scour after the 2015 floods. Because piles may gain capacity over decades, the analysis considered both consolidation setup—the increase as excess pore pressure dissipates—and aging setup, which continues afterward.<br /><br />Researchers combined eight leading direct CPT pile-capacity methods with setup parameters derived from instrumented Louisiana pile tests and published case studies. For clay, the estimated consolidation parameter was 0.53; aging parameters were 0.23 for clay and 0.16 for sand. The methods were applied layer by layer, then summed to estimate total pile capacity.<br /><br />For ten instrumented piles, CPT methods combined with consolidation setup generally underestimated shaft resistance and overestimated end bearing. Incorporating aging improved predictions substantially. The Philip-Burnett and UF methods gave the most accurate estimates of total resistance. Overall, the findings show that long-term aging should be included when assessing existing piles, especially those in service for decades.

Keywords

pile capacity

CPT methods

consolidation setup

aging setup

bridge foundations