Abstract
Driven-pile setup is referred to a phenomenon in which the bearing capacity of driven piles increases with time after the end of driving (EOD). The setup effect can significantly improve the bearing capacity (ultimate resistance) of driven piles after initial installation, especially the ultimate shaft resistance. Based on the reliability theory and considering the setup effects of driven piles, this article presents an increase factor (Msetup) for the ultimate resistance of driven piles to modify the reliability index calculation formula. At the same time, the correlation between R0 and Rsetup is comprehensively considered in the reliability index calculation. Next, the uncertainty analysis of load and resistance is conducted to determine the ranges of relevant parameters. Meanwhile, the influence of four critical parameters (factor of safety FOS, the ratio of dead load to live load ρ = QD/QL, Msetup, the correlation coefficient between R0 and Rsetup, and ρR0,Rsetup) on reliability index are analyzed. This parametric study indicates that ρ has a slight influence on the reliability index. However, the reliability index is significantly influenced by FOS, Msetup, and ρR0,Rsetup. Finally, by comparisons with the existing results, it is concluded that the formula proposed in this study is reasonable, and more uncertainties are considered to make the calculated reliability index closer to a practical engineering application. The presented formula clearly expresses the incorporation of the pile setup effect into reliability index calculation, and it is conducive to improving the prediction accuracy of the design capacity of driven piles. Therefore, the reliability analysis of driven piles considering setup effects will present a theoretical basis for the application of driven piles in engineering practice.
Highlights
Piles that are driven into the soil usually show an increase in bearing capacity over time after end of driving (EOD), which is often referred to as the setup effect of driven piles
This paper presented an increase factor for the ultimate resistance for driven piles to modify the reliability index calculation formula
It is concluded that FOS has a significant influence on the reliability index of driven piles considering setup effects
Summary
Piles that are driven into the soil usually show an increase in bearing capacity (ultimate resistance) over time after EOD, which is often referred to as the setup effect of driven piles. This phenomenon is reported by many geotechnical engineers. Due to different uncertainties associated with EOD resistance and setup resistance, Komurka et al [19] proposed an approach to split factors of safety into EOD and setup parts in terms of pile capacity, and this method was especially suitable for load and resistance factor design (LRFD). Through a validation example analysis, it is verified that the method proposed in this study is reasonable, and it is concluded that the method proposed in this study is more accurate in calculating the reliability index and considers more uncertainties
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
