Quality Assessment of Drilled Shaft Foundations at the Jane Byrne Interchange-PPT Presentation

PPT Presentation

Pdf Summary

The Jane Byrne Interchange reconstruction in Chicago involved more than 400 drilled shafts installed by six contractors, primarily under slurry. GRL assessed 92 shafts using Cross-Hole Sonic Logging (CSL) and 49 using Thermal Integrity Profiling (TIP).<br /><br />CSL evaluates concrete quality by measuring sonic-wave transmission between access tubes. TIP uses heat released during concrete curing to identify variations in shaft dimensions, concrete condition, and reinforcing-cage position. CSL testing found anomalies in 50 shafts—54% of those tested. Of these, 9 were rated Class B and 41 Class C; 78% of anomalies occurred within the lower three shaft diameters. Coring was recommended for 10 shafts, and dynamic load tests were conducted on two to verify capacity.<br /><br />The two load-tested shafts exceeded their required capacities. Shaft A had a required capacity of 1,504 kips and a CAPWAP-indicated capacity of 2,640 kips. Shaft B required 2,853 kips and showed 3,620 kips. TIP identified some minor reductions in effective radius near shaft bottoms, generally without requiring further investigation.<br /><br />The assessment concluded that TIP and CSL can provide broadly comparable results, while TIP offers additional information about cage alignment and concrete cover, can be performed sooner after placement, and was more effective at quantifying conditions at shaft toes.

Keywords

Jane Byrne Interchange

Chicago

drilled shafts

Cross-Hole Sonic Logging

CSL

Thermal Integrity Profiling

TIP

concrete quality

shaft integrity

load testing