Resistance factors for ultimate limit state design of large-diameter bored piles

In the LRFD methodology for ultimate limit state design, resistance factors can be applied to both resistances and loads. Resistance factors at a target reliability level can be derived based on statistical data on resistances and load effects using reliability theory. In this paper, resistance factors for limit state design of large-diameter bored piles are developed using a design point method, based on the statistics of prediction model performance obtained from Hong Kong load test cases. A design method for large-diameter bored piles in soils and a design method for large-diameter bored piles socketed in rocks are considered. The resistance factors for the shaft and toe resistance components are calculated separately. Copyright ASCE 2009