Side Shear Setup. I: Test Piles Driven in Florida

The available literature indicates that pile side shear increases almost linearly with the logarithm of time elapsed after driving, sometimes described using a dimensionless setup factor. A test pile program conducted by the University of Florida measured side shear setup (SSS) for up to 4.7 years on five, 457-mm  (18-in), square, prestressed, concrete piles driven into coastal plain soils at different sites. Dynamic tests performed during initial driving and two restrikes measured short-term SSS. Osterberg cells, the first installed in driven concrete piles, measured long-term SSS starting within 24  h of driving and continuing with two to five additional, staged tests. Extensive instrumentation, including vibrating wire strain gauges, Marchetti total stress cells, and vibrating wire piezometers, divided the five piles into 28 segments by soil type with horizontal effective stress measurements for 18 of the segments. This paper describes the University of Florida test pile program and its results. A companion paper analyzes the test results and recommends procedures for implementing SSS in design.