ACIP Piles Installation and Monitoring Program in North America-Paper

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The 2016 DFI ACIP Pile Committee program, conducted with the Florida Department of Transportation, evaluated installation monitoring and the performance of augered cast-in-place piles for potential use in bridge specifications.<br /><br />Seven 18- and 24-inch-diameter piles, installed to depths of 40 or 60 feet, were tested in compression, tension, and lateral loading. The program combined manual and automated installation monitoring, Thermal Integrity Profiling (TIP), embedded strain gauges in compression piles, and extraction of one pile for visual inspection. Cone penetration testing identified very loose soils at an initial test location, prompting relocation of the test layout.<br /><br />Load tests followed applicable ASTM procedures. Compression and tension piles were loaded to geotechnical failure; lateral piles were loaded until head deflection reached at least one inch. Strain measurements in a compression pile were used to estimate load transfer and shaft resistance. Measured unit shaft resistance was broadly consistent with predictions, and similar resistance was reported for the 24-inch compression pile. The paper notes that tension-test head movement included an estimated contribution from stretching of the un-sleeved steel center bar, rather than pile movement alone.<br /><br />The extracted 18-inch pile had an average measured diameter of 19.2 inches. Its generally uniform TIP temperature indicated a relatively uniform pile, and TIP-based diameter estimates—adjusted for grout volume observed during installation—agreed well with measurements from the extracted pile.<br /><br />Overall, the program demonstrated a comprehensive approach to monitoring ACIP pile installation and assessing pile integrity and load performance, providing data to inform their consideration in bridge specifications.

Keywords

augered cast-in-place piles

DFI ACIP Pile Committee

Florida Department of Transportation

bridge specifications

installation monitoring

Thermal Integrity Profiling

load testing

compression piles

tension piles

lateral loading