A Review of Residual Load Development In Driven Cast-In-Situ Piles-Video

Video Transcription

Video Summary

Megan Packer presents a case study of residual load development in four instrumented driven cast-in-situ (DCIS) end-bearing piles near Bristol, monitored from installation through approximately two weeks of curing before static load testing. DCIS piles can develop residual loads during both driving and concrete curing. Temperature and strain measurements showed that hydration initially heated and compressed the piles, followed by cooling, contraction and continued strain development. Temperature correction substantially changed the interpretation of early strains, while residual strains had not stabilized by testing.<br /><br />Three interpretation methods produced different load distributions. The Siegel and McGill-Frey method most closely matched theoretical drag loads from consolidation of the soft clay. The neutral plane was at or near the pile toe, suggesting negative skin friction was mobilized along nearly the full pile length.<br /><br />The findings highlight the influence of soil consolidation and concrete curing on DCIS pile behavior. Curing strains may particularly affect serviceability assessments, and further instrumented studies are needed.

Keywords

residual load development

DCIS piles

concrete curing strains

negative skin friction

soil consolidation