The Scale Effect in the Transposition of the Results of Deep-sounding Tests on the Ultimate Bearing Capacity of Piles and Caisson Foundations

Synopsis Static penetration tests are often used in a number of countries to determine the length and the bearing capacity of piles. In recent times more attention has been given to the scale effect, i.e. the influence of the ratio of the transversal dimensions of the pile to the diameter of the base of the cone utilized in the test. In the extreme cases the penetration of the cone on to the soil is caused either by expulsion of an instantaneously incompressible material or by the volume decrease with structural modification of a very compressible soil. In reality the penetration will be caused generally by a combination of these two phenomena. In so far as the transversal dimensions of the piles are sufficiently small as not to alter the boundary-conditions, i.e. to obtain that the ratios of the distances of the pile-base to the different boundaries of the bearing stratum may be considered equal to the corresponding ratios of these distances to the diameter of the cone-base, the penetration resistance of...