A New Data Interpretation Approach for Pile Thermal Integrity Testing-Paper

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The paper presents a staged approach to interpreting thermal integrity profiling (TIP), a pile-testing method that uses heat generated during concrete curing to identify possible defects. Because conventional TIP interpretation relies largely on experience and temperature anomalies can have multiple causes, the authors combine measured temperature data with finite-element (FE) modelling.<br /><br />The approach was tested on a 20 m continuous-flight-auger pile containing three deliberately placed inclusions. In Stage 1, one-dimensional FE models accounted for concrete and soil thermal properties to relate peak temperature to concrete cover. This relationship was used to estimate effective pile radius along the shaft and reconstruct its three-dimensional shape, highlighting regions of potential necking or expansion. The estimated pile volume was close to the recorded concrete consumption.<br /><br />In Stage 2, two-dimensional FE models examined selected cross-sections. Simulated temperatures for different assumed defect locations and sizes were compared with field measurements, and the best-fitting configuration was selected. The method accurately estimated the size and location of two inclusions, each occupying about 9% of the cross-section, but did not detect the smallest inclusion, which occupied 3%.<br /><br />The staged process progressively provides information about anomaly location, size and shape, allowing engineers to decide whether further investigation is warranted based on risk. The results suggest that combining TIP data with FE analysis can improve defect assessment soon after construction, potentially enabling timely and lower-cost remedial work. Further development, including three-dimensional modelling and optimisation algorithms, is proposed.

Keywords

thermal integrity profiling

pile testing

finite element modelling

concrete defects

temperature anomaly

continuous flight auger pile

defect detection

pile integrity assessment

concrete curing heat

thermal profiling interpretation