Proceedings of DFI-India 2019: 9th Conference on Deep Foundation Technologies for Infrastructure Development in India, (DFI)
Effect of Under-Ream Angle and Bulb Spacing on Capacity of Under-Reamed Piles in Marine Clay
Minu J. and Benny Mathews Abraham, Ph.D.
Even though many model studies have been conducted to understand the behavior of under-reamed piles, most of them have been in sand. While in practice, under-reamed piles are provided in clayey soil. Hence, this study was undertaken to understand the behavior of these piles in a scenario closer to the one in practice. It aims at understanding the variation in capacity of single under-ream piles with under-ream angle and the variation of capacity of double under-reamed piles with bulb spacing tested in marine clay. A total of 9 model piles (timber) were tested, out of which four were single underreamed with under-ream angles of 15°, 30°, 45° and 60°. There were four double under-reamed piles with bulb spacings of 1.0Du, 1.25Du, 1.5Du and 1.75Du, where Du is the diameter of the bulb. Also, one normal pile with a diameter same as that of the stem diameter of under-reamed was tested to compare the results. The results of tests on under-reamed piles in marine clay are more or less in agreement with the relevant Indian Standard. It is hoped that the results of this study would be of help to geotechnical engineers.
|article #3287; publication #1059 (India2019)|