DRILLED SHAFT BASE QUALITY REDUCTIONS IDENTIFIED WITH THERMAL INTEGRITY PROFILING-PPT Presentation

PPT Presentation

Pdf Summary

The presentation explains how Thermal Integrity Profiling (TIP) can be used to identify quality reductions at drilled-shaft bases. TIP measures heat generated as concrete or grout cures and relates temperature to the volume of placed material. Results are expressed as an “effective radius”—the radius of intact concrete that would produce the measured temperature—reflecting both shaft geometry and concrete-quality variations.<br /><br />Temperature-to-volume interpretation is relatively straightforward along the shaft’s middle section, but temperature losses near the top and bottom require adjustment. The presentation focuses on bottom-of-shaft corrections using a hyperbolic tangent approximation. Key inputs include the average temperature above the roll-off, soil temperature, the roll-off’s position relative to the shaft base, and the curve’s slope. These assumptions can change the calculated effective radius and the conservatism of the assessment.<br /><br />Examples describe shafts with different casing, rock-socket, reinforcing-cage, and concrete-placement conditions, but the text does not report specific test outcomes.<br /><br />The main conclusion is that TIP can effectively identify shaft-base conditions, provided the analysis accounts for the bottom node’s location, the shaft base, placed concrete volume, foundation details, and field and boundary conditions. Misapplying these variables can produce incorrect effective-radius estimates at the base.

Keywords

Thermal Integrity Profiling

TIP

drilled-shaft bases

effective radius

concrete quality

temperature interpretation

bottom-of-shaft correction

hyperbolic tangent approximation

foundation inspection

shaft integrity