Postprint version. Published in Proceedings of the ASCE Geo-Institute Soft Ground Technology Conference, May 28, 2001, pages 170-181. Copyright © 2001 American Society of Civil Engineers. The definitive version is available online at: http://dx.doi.org/10.1061/40552(301)14.
NOTE: At the time of publication, the author James L. Hanson was not yet affiliated with Cal Poly.
The feasibility of using ultrasonic testing, in particular P-wave velocities, to evaluate stabilized soils was investigated. A high-plasticity clay soil that was stabilized with lime, cement, and lime - fly ash mixtures was used in the study. The testing program consisted of determination of P-wave velocities and compression characteristics of the stabilized soils immediately after compaction and subsequent to 7 days and 28 days of curing. Variation of velocity with stabilizing agent, curing time, and also with the compression characteristics of the soils was investigated. It was observed that P-wave velocities were higher for samples stabilized with cement compared with samples stabilized with lime and fly ash. In addition, velocities increased with curing time for all the stabilized mixes. In general, the velocities of the samples increased as the unconfined compressive strength of the samples increased. However, there was a substantial amount of scatter in the data. The trends observed in the modulus data were better and the P-wave velocities of the stabilized soils increased as the modulus of the soils increased. Also the variation of modulus with time was similar to the variation of velocity with time. In addition, the P-wave velocities increased as the densities of the samples increased.
Civil and Environmental Engineering