Proceedings-DFI/EFFC 11th International Conference on Piling and Deep Foundations, 2014, Stockholm, Sweden, (DFI)
Analysis of Plugging Effect for Open-Ended Piles in Sandy Soil
Junyoung Ko and Sangseom Jeong, Yonsei University, Korea; Moonkyung Chung, Korea Institute of Construction Technology, Korea
The plugging effect of open-ended piles in sandy soil is analyzed by full-scale field test and plugging measurement. PLR (plug length ratio) measurement data from 144 field cases are analyzed with pile diameter. Based on the plugging measurements, PLR of open-ended piles which have above 1000mm diameter is predicted to be above 0.9. Through plugging measurements, a new empirical method is suggested for quantifying the plugging effect of open-ended piles. The proposed PLR equation is possible to predict the behavior of soil plug in the preliminary design stage. In addition, in order to investigate the behavior of the soil plug of open-ended pile, field load tests are performed on instrumented three piles driven into sand. It is obtained that the resistance components of open-ended pile are separated by double-walled pile system. It is found that inner shaft capacity is developed nearby pile tip. However, upper soil plug did not influence the inner shaft capacity. Also, it is found that all test piles are floating piles and unplugged condition because the sum of inner shaft capacity and outer shaft capacity is calculated about 58 to 76% of the ultimate bearing capacity.
|article #1890; publication #100 (IC-2014)|