Use and Comparison of New QA/QC Technologies in a Test Shaft

Abstract

Drilled shafts are increasingly being used for foundation support. The quality of the constructed foundation is critical due the heavy foundation loads and limited redundancy of many drilled shaft foundations. On a recent project in the United States, several traditional and newer methods of quality control and quality assurance were used to assess the drilled shaft excavation, base condition, concrete quality, and capacity. The radii, shape, verticality, and volume of the drilled shaft excavation was evaluated with a SHaft Area Profile Evaluator (SHAPE), and the cleanliness of the shaft base prior to concrete placement was assessed with a Shaft Quantitative Inspection Device (SQUID). The placed concrete quality was evaluated with Cross-hole Sonic Logging (CSL) as well as Thermal Integrity Profiling (TIP). Finally, a bi-directional static load test (BDSLT) was conducted on the test shaft to determine the shaft capacity. This paper will provide a brief review of the QA/QC tests and their results. In addition, the constructed shaft quality information available from similar methods will be compared and discussed including advantages and disadvantages of the respective methods.