Improved Behavior of Bell-Bottomed Poles

Model studies are conducted on poles with and without a bellbottom. The bellbottom has a base diameter of twice the pole diameter and has a slope 1 horizontal to 2 vertical. Improved behavior of bellbottomed poles subjected to horizontal loads has been studied in terms of the diameter of the poles, density of the soil, and the eccentricity ratio. Tests have been carried out on 2.5, 3 and 3.5 in (63.5, 76.2, and 88.9 mm) poles, respectively, in dry loose, dry dense, and submerged dense sands with different eccentricity ratios from 0.0 to 2.0. The present studies show that by bellbottoming the poles the lateral resistance can be increased by as much as 1.25 times that of the pole without bellbottom.