Effect of ultrasonic energy on self-weight consolidation of clay minerals

Consolidation is the densification of soft saturated soils occurring when water is extruded from the soil. Because water flows slowly through porous media, consolidation is time intensive. We investigated the effect of ultrasonic energy on the self-weight consolidation of clay minerals, with a series of laboratory tests in which a sonic bath directly generated ultrasonic waves at the clay slurry. The test conditions included the power and duration of the sonic energy, the initial water content, and the soil type. The results showed a significant reduction in consolidation time when ultrasound is applied. The time required for the same amount of settlement is shorter for the sonicated specimens, and the sonicated clay slurry had a much-increased final settlement. The degree of enhancement varied with the test conditions. A scanning electron microscope was used to monitor possible changes in the soil structure during the tests. The ultrasound did not significantly affect the soil structure, but density the layers of particles. Using the test results, we discuss the potential development of a new method that can reduce the construction period.