Use of Thermal Integrity Profiling (TIP) in Drilled Shaft Evaluation

US Transportation Collection2022PDFTech ReportBoeckmann, AndrewYeskoo, R AndrewAxtell, PaulDan Brown and AssociatesMissouri. Department of Transportation. Construction and Materials DivisionUnited States. Department of Transportation. Federal Highway AdministrationMissouri. Department of Transportation. Construction and Materials DivisionUnited StatesMissouriConcrete structuresCrossheadingsDrillingEvaluation and assessmentShaft sinkingTemperature measurementConcreteThermal stabilityFiber opticsDrilled shaftDeep foundationConcrete integrityThermal integrity profilingCrosshole sonicloggingcmr 22-002MoDOT project # TR202015Final Report (April 2020-December2021)Thermal Integrity Profiling (TIP) methods have emerged as a viable concrete integrity test method alternative to crosshole sonic logging (CSL). The objective of this study was to evaluate TIP methods for potential implementation on MoDOT drilled shaft projects. The study included a review of experience from previous research and project applications as well as collection of new data from a MoDOT project application. Together, the previous studies and the new research indicate TIP and CSL are generally complementary, with TIP more effective for identifying defects outside the reinforcing cage and weak concrete defects and CSL more effective for identifying defects within the reinforcing cage and soft bottom conditions. However, the results of this study indicate soft bottom conditions may be detectable with TIP methods, especially if temperature versus time records at the bottom of the shaft are evaluated.This research also included implementation of fiber optic methods for collecting TIP data. Laboratory and field results indicate fiber optic methods result in similarly accurate temperature results compared with conventional TIP, although practical limitations generally mean the fiber optic methods do not produce as complete of a time record. Cost data was also analyzed, indicating conventional TIP may result in cost savings compared to CSL, which is primarily a result of savings associated with remote data collection for many TIP projects. Finally, recommended specifications for MoDOT implementation of TIP methods were developed. The proposed specifications are included as an appendix.126