Volume 20, Issue 4 (December 1997)
Grain-Size Analysis by Buoyancy Method
A new routine experiment referred to as buoyancy analysis is proposed to determine the grain-size distribution of fine-grained soils. The buoyancy analysis is based on the sedimentation principles of the hydrometer and pipette analyses. It determines the percent by weight finer than a given grain size by measuring the buoyant weight of a 2.5-cm-diameter sphere immersed in the soil suspension. The buoyancy analysis is slightly more accurate than the hydrometer analysis, has a shorter duration, and its readings can be fed directly into a computer. It yields results identical to those of the hydrometer analysis when the sphere is immersed within the depth range of the hydrometer bulb.