Thermal Integrity Profiling of Deep Foundations

Confirmation of pile integrity including diameter, length, shape, reinforcement, and concrete quality are integral to acceptability of deep foundations.  Historically, validation of such topics has included visual observation of construction as well as testing such as by sonic methods.  Thermal integrity profiling (TIP) is one of the more recent methods that provides advantages over others.  In this paper, the TIP methodology is reviewed and case histories of its application for cast-in-place concrete foundations are presented. Results from several TIP tests are compared with pile integrity testing (PIT) results. The applications include 1.5m (5ft) diameter and approximately 10m (33ft) long caissons, 36cm (14in.) diameter and approximately 25m (80ft) long augered cast-in-place (ACIP) piles, and and 0.9m (3ft) diameter and 12m (40ft) long caissons. Detailed information is presented on the foundations tested, test set up, and test data. Results show both variations and similarities in findings from the two test methods. Results suggest that overall TIP is a more superior method for the assessment of foundation integrity, particularly for ACIP piles; for it is not limited by the piling length to diameter condition, and it can offer additional useful quality information that other methods such as sonic or PIT cannot provide.