Bearing capacity of tapered piles

This thesis summarizes the findings of load tests conducted on model tapered, partially tapered, and straight piles. All piles were 50.8 mm in diameter with the tapered piles reduced to 25.4 mm diameter at the toe. The piles were driven into a medium-dense pluviated sand bed under 3 different pressure regimes: no additional pressure, surcharged, and surcharged with confining pressure.; Test results showed that bearing capacity increased with increasing volumetric displacement, taper angle, percentage of pile tapered, confining pressure, and depth of driving. Tapered piles provided equal or greater bearing capacity under no additional pressure condition and significantly greater capacity under the surcharged with confining pressure condition. The surcharged condition yielded unreliable results.; End bearing in all conditions was reliably estimated by a double passive pressure method. The bearing capacity could be reliably determined using pile driving formulae.