Model Tests on Horizontal Impedance Functions of Fixed-Head Inclined Pile Groups under Soil Nonlinearity
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 140, Issue 6
Abstract
The effects of soil nonlinearity on the dynamic behavior of fixed-head floating inclined pile groups are investigated experimentally in the form of horizontal impedance functions (IFs) and internal forces in piles. A model of inclined pile groups embedded in dry cohesionless soil and subjected to a broad range of lateral harmonic loadings at the pile-cap level are examined. Piles with a spacing-to-the-diameter ratio () of 5 with practical pile inclinations of 0, 5, and 10° along the direction of loading are reported. Results show a profound impact of local nonlinearity and resonance of soil on the horizontal impedance functions. The inclined pile groups show higher values of horizontal IFs than the vertical pile group, in accordance with the general understanding. Influence of pile inclinations on the horizontal IFs is further examined through the variation of soil reactions along the depth of the piles. Semiempirical expressions for estimating the soil reactions, as a function of pile inclinations, are proposed. As for the internal forces in piles, bending strains for the inclined piles are smaller than the vertical pile; the axial strains show an opposite behavior.
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Acknowledgments
The work presented in this paper has been conducted with financial assistance from Maeda Engineering Foundation, Japan. Any opinions, findings, conclusions, or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the sponsors.
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Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 140 • Issue 6 • June 2014
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© 2014 American Society of Civil Engineers.
History
Received: Feb 15, 2013
Accepted: Feb 25, 2014
Published online: Mar 18, 2014
Published in print: Jun 1, 2014
Discussion open until: Aug 18, 2014
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