Gentle Driving of Piles (GDP) at a sandy site combining axial and torsional vibrations: Part II - cyclic/dynamic lateral loading tests. (15th February 2023)

• Record Type: Journal Article
• Authors: Kementzetzidis, Evangelos; Pisanò, Federico; Elkadi, Ahmed S.K.; Tsouvalas, Apostolos; Metrikine, Andrei V.
• Is Part Of: Ocean engineering. Volume 270(2023)
• Publication Date: 2023-02-15
• Subjects: Piles & piling -- Soil/structure interaction -- Cyclic loading -- Dynamics -- Pile–soil gapping -- Sands; Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2022.113452
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: Gentle Driving of Piles (GDP) is a new technology for the vibratory installation of tubular (mono)piles. Its founding principle is that both efficient installation and low noise emission can be achieved by applying to the pile a combination of axial and torsional vibrations. Preliminary development and demonstration of the proposed technology are the main objectives of the GDP research programme. To this end, onshore medium-scale tests in sand have been performed on piles installed using both impact and vibratory driving methods (including GDP). While the results of the installation tests are presented by Tsetas et al. (2023), this work focuses on the post-installation performance of GDP-driven piles under a sequence of slow/large-amplitude (cyclic) and faster/low-amplitude (dynamic) load parcels. The field data point out the influence of onshore unsaturated soil conditions, which result in complex cyclic pile stiffness trends due to the interplay of pile–soil gapping and soil's fabric changes. The pile stiffness under small-amplitude vibrations is strongly correlated with the previous response to large load cycles, and noticeably frequency-dependent for load cycles with a period lower than 1 s. Overall, the post-installation performance of GDP-driven piles appears to be satisfactory, which encourages further development and demonstration at full scale. Highlights: Cyclic lateral behaviour of piles was investigated through field tests in sandy soil. 10 m long piles were driven with impact pilling, vibro hammering and the GDP method. GDP-installed piles were overall stiffer and accumulated less lateral deflection.