Evaluation of pile set-up using iCAP dynamic restrike software analysis in the state of Alabama

The purpose of this thesis is to study the time-dependent changes in driven pile axial resistance, particularly set-up, in Alabama soils. After piles are driven into the soil, significant variations of pile axial resistance typically occur with time. When a pile's axial resistance increases with time after installation, the increased amount of resistance is referred to as set-up. Incorporating the amount of set-up into the overall design of driven pile foundations can potentially reduce sizes of elements, ultimately reducing cost. For years, the Alabama Department of Transportation (ALDOT) has been collecting pile installation and restrike data during the impact of a pile-driving hammer with Pile Driving Analyzers (PDARTM) to estimate the pile axial resistance of driven piles at the end-of-initial-driving (EOID) process as well as at various time periods after EOID. The ALDOT provided acquired PDARTM data for 23 test piles installed in Alabama. The PDARTM data were analyzed using a software called iCAPRTM. The iCAPRTM results indicate that the set-up effect was prevalent in most soils with an average increase in total pile axial resistance of 70% over a large range of time intervals after EOID. Where the piles were driven into dense sand, firm silty sand, or clay fill the pile resistance usually decreased over time by an average of 11% over a large range of time intervals after EOID.