Tapered driven piles have been used worldwide for over 7000 years.
Despite this long, successful history, foundation designers and contractors still do not fully appreciate what is called 'taper benefit', i.
the fact that in friction- or floating-pile applications that tapered piles are generally much more cost effective than constant-perimeter piles on a load-bearing basis.
This is because the unique physical mechanism of wedging by which tapered driven piles develop resistance to both axi.
John S. Horvath Consulting Engineer Small angles, large benefits...the unique behavior of tapered piles, paperback/john s. horvath
