Model tests and numerical analyses on horizontal impedance functions of inclined single piles embedded in cohesionless soil
- 375 Downloads
Horizontal impedance functions of inclined single piles are measured experimentally for model soil-pile systems with both the effects of local soil nonlinearity and resonant characteristics. Two practical pile inclinations of 5° and 10° in addition to a vertical pile embedded in cohesionless soil and subjected to lateral harmonic pile head loadings for a wide range of frequencies are considered. Results obtained with low-to-high amplitude of lateral loadings on model soil-pile systems encased in a laminar shear box show that the local nonlinearities have a profound impact on the horizontal impedance functions of piles. Horizontal impedance functions of inclined piles are found to be smaller than the vertical pile and the values decrease as the angle of pile inclination increases. Distinct values of horizontal impedance functions are obtained for the ‘positive’ and ‘negative’ cycles of harmonic loadings, leading to asymmetric force-displacement relationships for the inclined piles. Validation of these experimental results is carried out through three-dimensional nonlinear finite element analyses, and the results from the numerical models are in good agreement with the experimental data. Sensitivity analyses conducted on the numerical models suggest that the consideration of local nonlinearity at the vicinity of the soil-pile interface influence the response of the soil-pile systems.
Keywordsinclined single piles harmonic loads horizontal impedance functions local nonlinearity finite element model
Unable to display preview. Download preview PDF.
- Association Francaise de Genie Paraismique (AFSP) (1990), Recommendations AFPS 90. Presses des Ponts et Chaussees, France.Google Scholar
- Deng N, Kulesza R and Ostadan F (2007), “Seismic Soil-pile Group Interaction Analysis of a Battered Pile Group,” 4th International Conference on Earthquake Geotechnical Engineering, Thessaloniki, June 25–28, Paper No. 1733.Google Scholar
- Eurocode (2000), “Structures in Seismic Regions, Part 5: Foundations, Retaining Structures and Geotechnical Aspects,” Seismic Eurocode EC8, European Committee for Standardization, Belgium.Google Scholar
- Gazetas G and Mylonakis G (1998), “Seismic Soilstructure Interaction: New Evidence and Emerging Issues,” Geotechnical Earthquake Engineering and Soil Dynamics III, ASCE, Geotechnical Special Publication, Vol. 2, pp. 1119–1174.Google Scholar
- Kagawa T (1978), “On the Similitude in Model Vibration Tests of Earth-structures,” Proceedings of Japan Society of Civil Engineers (275), 69–77. (in Japanese)Google Scholar
- Kokusho T and Iwatate T (1979), “Scaled Model Tests and Numerical Analyses on Nonlinear Dynamic Response of Soft Grounds,” Proceedings of Japanese Society of Civil Engineers (285), 57–67. (in Japanese)Google Scholar
- Okawa K, Kamei H, Zhang F and Kimura M (2005), “Seismic Performace of Group-pile Foundation with Inclined Piles,” Proceedings of 1st Greece-Japan Workshop, Athens, October 11–12.Google Scholar
- Padron LA, Aznarez JJ, Maeso O and Santana A (2010), “Dynamic Stiffness of Deep Foundations with Inclined Piles,” Earthquake Engineering and Structural Dynamics, 39: 1343–1367.Google Scholar
- Poulos HG (1980), “An Approach for the Analysis of Offshore Pile Groups,” Numerical Methods in Offshore Piling, Institution of Civil Engineers, London, 119–126.Google Scholar
- Poulos HG and Davis EH (1980), Pile Foundation Analysis and Design, John Wiley & Sons, New York.Google Scholar
- Rocha M (1957), “The Possibility of Solving soil Mechanics Problems by the Use of Models,” Proceedings of 4th International Conference on Soil Mechanics, London, pp. 183–188.Google Scholar