Deformations as the fundamental basis for selection or fundations

Abstract

Reflection on the trend towards increased size and quality-finish of buildings logically justifies the fact that the controlling criterion in foundation design has ceased to be dictated by the accepted factor of safety against failure, having become, instead, determined with respect to tolerable settlements and deformations.  Complete indications are given for the quantitative estimation of settlements of all types of foundations, in accordance with experience developed by the author in Brazil, duly adjusted to the most up-to-date and coherent inlernational theorizalion. For firsl degree approximation the Standard Penetration Test SPT is employed, but special emphasis is given to indispensable corrections (for deplh, etc.), local correlations being supplied. The geotechnical testing and calculations corresponding to more refined estimation of settlements are indicated for the cases that may require it. Finally the acceptance levels of differential settlements are discussed aiming at the exercise of conscious decisions in this controlling problem.