Probability Distribution in the Variability of the Ny Factor of Shallow Foundations

Abstract

Due to the existing variability in the calculation of the bearing capacity factors, specifically when obtaining the N value of the bearing capacity, which is estimated by a large number of equations that have been obtained by approaches of limit equilibrium, method of characteristics, empirical, semi-empirical, among others; thus existing a great uncertainty, therefore, this article took a total of 55 equations that compute this value to carry out a probabilistic study where N values were obtained for friction angles of 5º, 10º, 15º, 20º, 25º, 30º and 35º, being the variability obtained being directly proportional to friction angle. Also, it was found that the data have a good correlation with the Lognormal distribution, according to the Kolgomorov-Smirnov and Anderson-Darling tests, in this context, Lognormal cumulative probability distribution curves of the data under study were elaborated, thus allowing not to opt for a single or deterministic value but a probable or acceptable value according to the size of a project with a conservative range.