Load and Resistance Factor Design Calibration to Determine a Resistance Factor for the Modification of the Kansas Department of Transportation-Engineering News Record Formula.

摘要

This report contains the results of a study describing the development of resistance factors for use with the Kansas Department of Transportation (KDOT) Engineering News Record (ENR) formula for driven piles. KDOT has verified driven pile resistance for many years using a version of the ENR formula. This formula yields estimates of nominal resistance values that are much lower than the actual resistance, based on department experience and comparisons with other resistance measurement methods. For this study actual ENR resistance estimates were compared with estimates obtained using a pile driving analyzer (PDA) system. The PDA values were taken as the true capacity. There were 175 end-of-drive data points and 189 restrike data points available for statistical analysis. A set of correction (resistance) factors to be used with the ENR formula was developed, with individual factors based on given probabilities of pile failure (capacity being exceeded).