DFI Journal - The Journal of the Deep Foundations Institute

Volume 10, Issue 1, January 2016
DOI: 10.1080/19375247.2016.1184490

Papers are only available to members. If you are a member, please click on the "Login" link at the top of the site. You may use your DFI login.

If you are not a member, click here join.

Please click here to complete purchase by clicking on the PDF $25 icon and completing the payment form. The paper will be emailed to you within 48 hours.

Analyzing thermal integrity profiling data for drilled shaft evaluation

K. R. Johnson

Abstract


Thermal integrity profiling (TIP) is the most recent non-destructive test method to gain widespread popularity in post-construction evaluation of drilled shafts. The allure lies in its ability to detect anomalies across the entire cross-section of a shaft as well as provide a measure of lateral cage alignment. Similarly remarkable, early developments showed that the shape of a temperature profile (with depth) matched closely with the shape of the shaft, thus allowing for a fairly straightforward interpretation of data. Immediately apparent however, was that the relationship between shape and temperature was with two major exceptions: (1) near the ends of the shaft where heat can escape both radially and longitudinally and (2) where drastic changes in the surroundings are encountered (e.g. soil to water, soil to air). Today, methods for analyzing these portions of data exist, but can often involve tedious levels of parameter iterations and trial-and-error thermal modeling. This is particularly true when the effects of time are not well understood. A comparison of model and field results is presented to provide further insight into these types of temperature distributions and to address the difficulties associated with their analysis. This paper shows how thermal modeling can be used to track the effects of time on analysis, and concludes with case studies that demonstrate the findings.

Keywords:
thermal integrity profiling, non-destructive test, drilled shafts, TIP analysis, hyperbolic corrections, effective radius