Experimental investigation of the UPV wavelength in compacted soil.

• There was no great variation in wavelength sizes between sandy and clayey soil. • For the frequency of 45 kHz, specimens of at least 200 mm are required. • Between 5 and 7 waves are required to have flat waves. • The smallest discontinuity detected by the ultrasound was between 8 and 19 mm. Considering this parameter, the minimum length of a soil test specimen to be compacted, to enable its characterization, was determined using ultrasonic testing. The experimental stage involved the production of specimens in different lengths for two types of soils (clayey and sandy) and three compaction energies (normal, intermediate, and modified). Ultrasound tests were performed after molding (0 days) and 28 days of compaction, using 45 kHz frequency longitudinal transducers and compression wave. The results indicated that the minimum length of the specimen should be 200 mm when the velocity stabilization occurred for the Clayey and Sandy soils. However, the factors considered (transducer frequency, compaction energy and apparent specific mass) may infer significant changes in wavelength. [ABSTRACT FROM AUTHOR]