Lateral Resistance of Steel Pipe Pile with Wings by Static Cyclic Loading Tests
- 295 Downloads
Steel pipe piles subjected to lateral loads exhibit toughness even after yielding of the steel, and thus possess a high earthquake resistance. A steel pipe pile with wings attached to its tip can be driven into the ground by rotation. However, because the wings are larger than the pile diameter, the soil around the pile shaft is loosened, resulting in an alteration of the lateral subgrade reaction of the pile. In the present study, static lateral loading tests were conducted to ascertain how the lateral resistance of a pile was affected by the attachment of wings and the wing diameter, and to examine the occurrence of secular change after one year.
The soil deposit at the test site was a weak volcanic ash. Four types of piles of diameter (Dp) 267.4 mm and length 5000 mm were tested, namely, piles without wing, piles with wing diameters 2.3Dp and 3.0Dp, respectively (used to investigate the effect of the wing diameter), and a pile with wing diameter 2.3Dp after one year of its insertion into the ground (used to evaluate the recovery of the loosened soil). The cyclic load applied to a pile was gradually increased by displacement control at the pile head, and the lateral displacement of the pile head and the bending moment along the pile were measured. The test results showed that (1) the lateral resistances of the winged piles were smaller than that of the piles without wing, owing to the loosening of the surrounding soil by the wings; (2) the maximum bending moments of the winged piles tended to be smaller than that of the piles without wing for a given pile head displacement; (3) the pile wing diameter had little effect on the lateral resistance; and (4) there was no aging in the lateral resistance of the loosened soil around a winged pile, even one year after insertion of the pile.
KeywordsSteel Pipe Piles Lateral Resistance Pile Head Load Wing Diameter Bending Moment Distribution
The authors would like to express their special gratitude to Dr. Eng. Kashiwa and Dr. Eng. Nakano for their useful suggestions for this study. The study was supported by JSPS KAKENHI (Grant No. JP17H03342).
- 1.Tsuchiya, T.: The trend of a screwed steel pile and the problems in the future. Found. Eng. Equip. Mon. 34(11), 2–6 (2006). [in Japanese]Google Scholar
- 2.Inoue, N.: Recent trend of small-diameter rotating intrusive steel pipe pile construction method. Found. Eng. Equip. Mon. 41(2), 36–39 (2013). [in Japanese]Google Scholar
- 3.Jun, A.M., Mamoru, F., Makoto, N., Gorou, K., Emi, K.: Effect of penetration velocity on turbulence of soil around the screw pile. In: Summaries of Technical Papers of Annual Meeting Hokkaido Chapter, Architectural Institute of Japan, pp. 685–686, August 2004. [in Japanese]Google Scholar
- 4.Naoya, K., Shoichi, N., Nmihiko, I., Tadashi, M., Yoshiaki, T., Chihiro, A.: Maintenance of technical standard about building site, soil and foundation (Part 6: Study on Lateral Loading Behaviour of a Steel Pipe Pile with Wings). In: Summaries of Technical Papers of Annual Meeting Kanto Chapter, Architectural Institute of Japan, pp. 407–408, August 2011. [in Japanese]Google Scholar
- 6.Mori, G., Hayashi, M., Shinohara, T.: Lateral loading behavior of screw steel pipe pile. In: Japan National Conference on Geotechnical Engineering, vol. 35, No. 727, pp. 1755–1756, June 2000. [in Japanese]Google Scholar
- 7.Method and Commentaries for Lateral Load Test of Piles [in Japanese]. The Japanese Geotechnical Society, May 2010Google Scholar