Side Shear Setup. II: Results From Florida Test Piles

• Published in: Journal of geotechnical and geoenvironmental engineering Vol. 131; no. 3; pp. 301 - 310
• Main Authors: Bullock, Paul J, Schmertmann, John H, McVay, Michael C, Townsend, Frank C
• Format: Journal Article
• Language: English
• Published: New York, NY American Society of Civil Engineers 01-03-2005
• Subjects: Applied sciences; Buildings. Public works; Earthwork. Foundations. Retaining walls; Exact sciences and technology; Geotechnics; TECHNICAL PAPERS; Florida; United States; North America; America; Skin friction; Ageing; CE Database subject headings: Driven piles; Pile load tests; Shear strength; Penetration test; Experimental study; Recommendation; Penetration tests; Time dependence; Experimental result; Effective stress; Time studies; Aging; Application; Loading test(mechanics); Driven pile
• DOI: 10.1061/(ASCE)1090-0241(2005)131:3(301)
• EISSN: 1943-5606
• ISSN: 1090-0241

This paper analyzes the results of a driven pile side shear setup (SSS) test program performed at the University of Florida and described in a companion paper. All pile segments showed SSS, with similar magnitudes in both cohesionless and cohesive soils, and irrespective of depth. Horizontal effective stresses increased after driving, but then stabilized as induced pore pressures dissipated. SSS continued long after pore pressure dissipation due to other aging effects. Pile load tests in all soil types, and standard penetration tests with torque measurement (SPT-T) in cohesive soils, confirmed the approximate semilog-linear time versus SSS behavior and the usefulness of the setup factor
A
. Staged (repeated) tests significantly increased SPT-T measurements, suggesting a reduction factor of 0.4 for SSS results measured by staged testing. We believe that engineers can now include SSS in routine design, using a minimum setup factor
A=0.1
for soils similar to those tested, or higher if supported by dynamic or static pile tests, or by SPT-T predictor tests. Examples demonstrate a proposed SSS design method.