Evaluating Thermal Integrity Profiling Defects and Rating Criteria-PPT Presentation

PPT Presentation

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The presentation evaluates Thermal Integrity Profiling (TIP) for detecting defects in drilled shafts and proposes temperature-based rating criteria.

Three 4-foot-diameter, 30-foot-long shafts were constructed using a standard 5,000-psi concrete mix. Two had permanent casing and one temporary casing. The researchers introduced planned defects using materials such as plywood, sandbags, and drilling spoil, then assessed the shafts with TIP and cross-hole sonic logging. Thermaly software was used to model defect effects and plan defect dimensions and locations.

The existing TIP rating approach classifies shafts using effective average radius reduction and local cover. The presenters note that it assumes defects are at the shaft edge and depends on accurate reported concrete volumes—conditions that may not reflect actual construction. Their analysis found that defects reducing cross-sectional area by 8% or more generally produced average temperature reductions of at least 4°F. For larger defects, TIP-reported apparent radius reductions tended to underestimate the actual equivalent reductions.

The proposed supplemental criteria classify defects by temperature reduction:
- <strong>Acceptable:</strong> cross-sectional area reduction up to 6%; average temperature reduction no more than 2°F and local reduction no more than 5°F.
- <strong>Marginally acceptable:</strong> 7–12% area reduction; average reduction of 2–5°F and local reduction of 5–9°F.
- <strong>Unacceptable:</strong> area reduction of 12% or more, with average reductions of at least 5°F across most or all wires/tubes, or a local reduction greater than 9°F.

The temperature-based criteria agreed with the area-based classifications for all but one defect, illustrating both the approach’s potential and the need for further validation.

Keywords

Thermal Integrity Profiling

TIP

drilled shafts

defect detection

temperature-based rating criteria

cross-hole sonic logging

concrete shaft defects

effective average radius reduction

local cover reduction

construction defect validation