PREDICTABILITY OF THE INTERNATIONAL GEOTECHNICAL CODE FOR THE ESTIMATING ULTIMATE BEARING CAPACITY OF LARGE-DIAMETER BORED PILES

Abstract

 This technical report presents a comparative study of the predictability of estimating the ultimate pile capacity between widely accepted international design codes of pile foundations, including the: Japan Road Association code (JPA, 2002), DIN 4014 (1990), Egyptian geotechnical design code-Part 4 (2001), and AASHTO (2007). The ultimate pile capacities inferred from the results of load-settlement test using the Chin extrapolation method (1970) were compared with the predicted values obtained from international codes of design. The study covers a wide range of Egyptian soil formations by utilizing 58 case studies of bored piles (loading tests) constructed and tested in numerous regions inside Egypt. The average error percentage obtained from each code of design has been calculated, and the predictability of these design codes has been evaluated based on four independent statistical criteria. JRA code (2002) and DIN 4014 (1990) have revealed well predictability and accuracy of estimating ultimate pile capacity against the other international codes of design.