Bored Piles in Rock: Recent Design Lessons Learned-PPT Presentation

PPT Presentation

Pdf Summary

The presentation shares design lessons from decades of bidirectional testing of large bridge foundations in bedrock, emphasizing that reliable design depends on adequate site characterization.

Three lessons stand out:

1. <strong>Rock-socket side and base resistance usually mobilize together at small, compatible displacements.</strong> Unless there is a rational, documented reason to do otherwise, designers should generally account for both sources of resistance. Exceptions exist but are considered uncommon.

2. <strong>Bedrock classified as poor or very poor may still provide substantial axial resistance.</strong> In some cases, the combined side and base resistance of a rock socket can exceed the structural axial capacity of the reinforced-concrete pile.

3. <strong>Construction quality strongly governs bored-pile performance.</strong> Attention to construction practices, inspection, and verification is essential, making design and construction inseparable.

Ignoring these findings can lead to uneconomical designs, larger carbon footprints, greater construction and performance risks, and fewer opportunities to identify post-construction anomalies.

Keywords

bidirectional testing

bridge foundations

bedrock characterization

rock socket resistance

axial resistance

bored piles

construction quality

site investigation

foundation design

reinforced-concrete pile