Transmission Pier Foundation QC/QA

摘要

Transmission line foundations often consist of concrete piers. Examples of construction situations that may result in problematic piers are presented to motivate the use of deep foundation non-destructive testing methods. Advantages and shortcomings of established testing methods are briefly reviewed. A newer technology, Thermal Integrity Profiling (TIP), is then discussed and compared with established ones. TIP is based on the premise that heat energy released during cement hydration depends on cement content and on total concrete volume. Temperature measurements obtained inside a curing foundation correlate with the effective radius of the foundation and with concrete quality. The theoretical background of thermal integrity profiling is summarized; descriptions of alternate ways of obtaining internal temperature measurements follow. Measurement interpretation is discussed, including relating data measured at the reinforcement cage during curing to concrete quality, shaft diameters, local concrete cover, and reinforcement cage alignment. Case studies of electrical transmission line construction where this technology was employed are presented.