ABSTRACT
National Cooperative Highway Research Program, project, NCHRP 24-17, “LRFD Deep Foundations Design” was initiated to: (i) Provide recommended revisions to the driven pile and drilled shaft portions o f section 10 o f AASHTO Specifications and (ii) Provide a detailed procedure for calibrating deep foundation resistance factors. The current AASHTO specifications as well as other existing codes based on Load and Resistance Factor Design (LRFD) prin ciples were developed using insufficient data, hence they utilized mostly back-calculated factors. The main challenges of the project are therefore: (a) Compilation of large, high quality databases and (b) Framework for a procedure and data manage ment to enable: (i) LRFD parameter evaluation and (ii) Future updates. These challenges include two re quirements: (i) Organization o f the factors following the design - construction - quality control sequence (i.e. independence in resistance factors according to the chronological stage and the evaluation proce
dure) and (ii) Overcome the generic difficulties of applying the LRFD methodology to geotechnical applications, i.e. incorporation o f indirect variability, (e.g. site or parameters interpretation), judgment (e.g. previous experience), and other similar factors.
