There is a paucity of methods available in design codes for estimating the ultimate toe resistance of small displacement steel piles driven to rock. This paper attempts to address this lack of guidance by inspecting various design techniques for determining ultimate toe capacity of these types of piles and comparing them to field-measured values. Methods of determining pile toe capacity for both small displacement driven steel piles and drilled sockets were researched and combined with collected field records of previous pile driving sites. A process to determine quality data for use in this work was developed by including information from geotechnical site investigations, pile driving records and pile driving analysis (PDA) records. By plotting unconfined compressive strength of rock versus measured ultimate pile unit toe capacity of these piles, a regression line to predict the ultimate unit toe capacity of the pile was established as 7.5 times the unconfined compressive strength of the rock. Comparing this empirical relationship to previously published design methods for calculating ultimate pile unit toe capacity, it was found that most of the toe capacity methods developed for drilled sockets were overly conservative when applied to small displacement driven steel piles. An author reinterpretation of the method developed by Ladanyi and Roy (1971) adjusted the difference in influence of rock discontinuity on pile toe capacity and showed good agreement with the measured field data. The most effective existing method was determined to be that of Rehnman and Broms (1971 ), as it was the only method developed for small displacement driven steel piles.
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