DRILLED SHAFT BASE QUALITY REDUCTIONS IDENTIFIED WITH THERMAL INTEGRITY PROFILING-Video

Video Transcription

Video Summary

The presentation examined using thermal integrity profiling (TIP) to assess the bases of drilled shafts. TIP measures concrete curing heat along the shaft and uses temperature-to-volume relationships to estimate effective radius, which reflects both shaft geometry and concrete quality. The speaker emphasized that interpreting base conditions requires careful correction for temperature losses near the shaft bottom. Key inputs include average shaft temperature, soil temperature, the position of the lowest sensor relative to the shaft base, and the correction-curve slope. Incorrectly positioning the correction curve can produce misleading radius estimates; accurate installation details and concrete-volume records are essential.<br /><br />Project examples showed TIP identifying a severely deficient base, later confirmed by coring, and a subtler anomaly supported by crosshole sonic logging. The speaker concluded that TIP can effectively detect base defects when boundary conditions are understood. In discussion, participants highlighted the value of reviewing temperature over time, the need for industry standards, and possible CSL signal losses caused by loose material around tubes. Remediation may involve coring, cleaning, and pressure grouting.

Keywords

thermal integrity profiling

drilled shaft bases

effective radius

temperature correction

crosshole sonic logging

concrete defects