Reliability analysis of shallow foundations in reference to design codes development

In this study, FORM analysis is carried out for shallow foundation of a typ ical building in order to evaluate relative magnitude of uncertainties invo lved in the force and the resistance sides. The distinguished feature of th is study is to take into account the uncertainty of the earthquake force as much as possible. Tthis is because, the seismic design dominates major par t of structural design in Japan, and without referring to this problem, no useful information of practical Value is gained. The results of the FORM an alysis exhibited the reliability index values between 2.0 to 3.5, which is considered to be in a reasonable range. Since the 50 year maximum earthquak e force is considered in the reliability calculation, calculated reliabilit y index values are for the period of 50 years. The sensitivity factor obtai ned in a case more realistic ground variability is taken into account exhib ited values not very different from those obtained in the upper structures. (C) 2000 Elsevier Science Ltd. All rights reserved.