Load Transfer Behaviour of Bored Piles

In this paper is reported the result of test on two prototype bored piles instrumented with re-bar gauge and telltales, for determining the axial load Capacity, and also for load transfer behaviour studies.It has been shown that （1） within a distance of five diameters above pile end, mobilization of skin friction is related to the magnitude of end resistance in such way that increase in end resistance is accompanied by decrease in skin friction; （2） vertical displacement required for full developmeat of skin friction of a clay layer is related to the depth of embedment of the layer, this being smaller for deep layers; and （3） setllement of pile end for attaining full end resistance is about 0.03d for sand and 0.015d for stiff clay, where d is diameter of pile, which values are much smaller than those reported by Vesic （1970） for driven piles.