Abstract:
Drilled foundations are commonplace on heavy construction projects, from large diameter drilled shafts extending deep into bedrock, to small micro-piles installed beneath an existing building. The quality of the drilled foundation is critical due to heavy foundation loads and often limited redundancy. Installation equipment, processes, and techniques vary widely as well, this is one reason QA/QC of drilled foundations is critical.
There have been many technological advancements in drilled foundation testing over the last decade. Newer testing methods include the SHAPE device (SHape Area Profile Evaluator) which can determine the radii, shape, verticality, and volume of the drilled shaft excavation, Thermal Integrity Profiling (TIP) which uses thermal wires or a thermal probe to measure concrete temperature during hydration to evaluate shaft integrity, as well as traditional tests for integrity evaluation with Cross-hole Sonic Logging (CSL) and Gamma-Gamma Logging (GGL).
This presentation will provide a brief review of these QA/QC testing methods and results from several interesting projects where some or all these test types were performed on the same shaft. These case studies show cases where good correlations/conclusions resulted from the different tests performed on the same shaft as well as an example where the conclusions differed between some of these tests. Limitations of these methods will be discussed in addition to recommendations on the integrity evaluation process.   Â