Reliability-based design in sandy soils by CPT measurements

Field tests, as static cone penetration tests (CPT), are widely used in granular soil characterization because they are largely correlated by empirical charts and graphics to the main physical and mechanical soil properties (i.e. DR, , lithology etc.) but seldom the uncertainties concerned with such estimations are taken into account. In this paper results from analyses on spatial variability distribution of measured parameters from CPTs performed at Scanzano Jonico site are employed for assessing pile bearing capacity by means of direct and indirect methods. Although those formulations are widely accepted by literature and used in practice, they are not discussed in terms of resulting reliability level of the pile bearing capacity. In this paper, Bustamante and Gianeselli’s formulation have been adopted as direct method, for estimating pile bearing capacity from qc profile at Scanzano Jonico site. As far as the reliability-based design of limit pile resistance is concerned, the statistical properties of design variables are based on the variability study carried out on such sands in the companion paper. Finally results are discussed in terms of reliability level and advantages in usage of direct instead of indirect methods for pile design in sands.