SYMPOSIA PAPER Published: 29 July 2019
STP161120170183

Understanding the Energy Transfer Mechanism in the Near Field of Impact Driven Piles

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Pile installation by applying an impact to the top of a pile appears to be a simple construction process, but analyzing that process is complicated because it involves a source of energy, the structural member (pile), and the ground into which the pile is driven. Codes and regulatory standards suggest some basic guidance for analyses but much is still unknown. Pile driving creates vibrations in the surrounding ground that can cause direct damage to nearby structures, cracking in underground utilities, or dynamic settlement of loose sands with attendant potential damage. It is customary to monitor surface ground motions starting as close as 1.5 m from the pile and to use the surface vibration data to interpret energy propagation. The work described herein, however, presents ground motion measurements from impact pile driving not only along the surface but also in the body of the ground at different radial distances and depths. Ground motion data during impact pile driving were obtained by installing motion sensors starting very close to the pile, 0.2 m, and moving away to approximately 0.8 and 2 m at the same depth as well as along the ground surface at greater distances. An extensive analysis of the ground motion amplitude and dominant frequencies was performed. Shear wave velocity degradation in the near field of an impact-driven pile was evaluated by studying ground motion signatures from the sensor arrays. From the measured ground motion, the hypothesis of three different soil behavior zones (plastic, nonlinear, and near-linear) surrounding a driven pile was generally confirmed. In addition, high-frequency vibration near the pile was observed to modify to lower frequencies at a greater distance from the pile. All measurements were made at sites where production piles were being driven, so coordination with the pile-driving contractors was an additional challenge.

Author Information

Grizi, Athina
University of Nottingham, Dept. of Civil Engineering, Nottingham, GB
Athanasopoulos-Zekkos, Adda
University of Michigan, Dept. of Civil and Environmental Engineering, Ann Arbor, MI, US
Woods, Richard, D.
University of Michigan, Dept. of Civil and Environmental Engineering, Ann Arbor, MI, US
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Developed by Committee: D18
Pages: 376–393
DOI: 10.1520/STP161120170183
ISBN-EB: 978-0-8031-7668-3
ISBN-13: 978-0-8031-7667-6