Discussion of "Safety Factor Evaluation for Single Piles in Sand"

The discusser of this paper describes an analysis of 35 piles driven into a thick cohesionless stratum not underlain by a weak deposit. When an allowance is made for the embedment ratio of the pile point in the bearing stratum, this analysis gives a mean ratio of measured to predicted ultimate point resistance, m sub 4 = 1.15, and a corresponding standard deviation, s sub r = 0.35, while for the ultimate skin friction these values are m sub r = 1.9 and s sub r = 0.75. It is also pointed out that a guide to suitable safety factors in foundation engineering must include many additional factors, such as the variability and uncertainity of the loading and soil resistance and the seriousness of a failure.